*Characteristics of the studied forest ecosystems: geographical location or range in which each forest was sampled (latitude and longitude), size of sampling plots, number of plots used, climatic region (M: Mediterranean; T: temperate), foliage periodicity of dominant species (E: evergreen; D: deciduous) and percentages of herb, shrub and tree species in the exotic flora in each forest.*

**67**

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

the temperate region. The lowland deciduous forest [39] is dominated by the decidu

*Geographical distribution (only referential location) of forest types included in the study. Different studies* 

of the temperate region of Chile occupying mainly riverine habitats.

*covered different surfaces. Nomenclature of forest types is indicated in* **Table 1**

10.5°C in the lowland evergreen forest [41].

**2.3 Data analysis**

**Figure 1.**

ous species *Nothofagus obliqua* and is distributed in the central valley of the temperate region. Finally, the swamp evergreen forest [40] is dominated by the evergreen species *Myrceugenia exsucca* and *Blepharocalyx cruckshanksii* and is distributed on the lowlands

*.*

Climate of forests included in this study varied from approximately 350 mm of annual precipitation and an annual mean temperature of 14°C in the sclerophyllous forest, to near 2500 mm of annual precipitation and an annual mean temperature of

We performed two types of analyses: first, we analysed together all data from all forest types, in order to examine the contribution of every variable to the variation in exotic species richness. Thus, in the same model, we evaluated the independent effects of the climatic region (Mediterranean vs. temperate), foliage periodicity of forests (deciduous vs. evergreen), native species richness and native species cover, as well as the statistical interactions between the climatic region and each native vegetation variable. Although the areas of plots were in general quite similar between forests (**Table 1**), the size of plots differed between some of them (**Table 1**), and preliminary log(10) area-log (N° species) correlations were significant for all forest types. Hence, to compare exotic and native species richness at a plot scale among all forest types, we controlled the size of plots by dividing values of exotic species richness as well as native species richness by the log(10) of the area of each plot. On


*DOI: http://dx.doi.org/10.5772/intechopen.82233*

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

#### **Figure 1.**

*Diversity and Ecology of Invasive Plants*

**66**

**Forest type** Sclerophyllous forest (Sc)

Mediterranean montane

deciduous forest (Mm)

Mediterranean Subantarctic

35°35′

71°02′

100

26

M

D

83.3

16.7

0.0

Andean forest (Sa)

Temperate montane deciduous

38°26′

71°31′

100

20

T

E

95.0

5.0

0.0

forest (Tm)

Lowland deciduous forest (Ld)

Swamp evergreen forest (Se)

Swamp deciduous forest (Sd)

Lowland evergreen forest (Le)

**Table 1.**

41°00′

73°00′

200

10

*Characteristics of the studied forest ecosystems: geographical location or range in which each forest was sampled (latitude and longitude), size of sampling plots, number of plots used, climatic region* 

*(M: Mediterranean; T: temperate), foliage periodicity of dominant species (E: evergreen; D: deciduous) and percentages of herb, shrub and tree species in the exotic flora in each forest.*

T

E

90.5

9.5

0.0

40°30′

72°30′

200

10

T

D

90.0

10.0

0.0

39–41°

72–73°

100

27

T

E

85.7

7.1

7.1

39–40°

72–73°

140

35

T

D

88.0

12.0

0.0

**Lat.** 32°17′ 35–36°

71–72°

100

21

M

D

28.6

42.9

28.6

71°11′

100

18

M

E

100

0.0

0.0

**Long.**

**Plot (m2**

**)**

**N° plots**

**Region**

**Foliage**

**% herbs**

**% shrubs**

**% trees**

*Geographical distribution (only referential location) of forest types included in the study. Different studies covered different surfaces. Nomenclature of forest types is indicated in* **Table 1***.*

the temperate region. The lowland deciduous forest [39] is dominated by the deciduous species *Nothofagus obliqua* and is distributed in the central valley of the temperate region. Finally, the swamp evergreen forest [40] is dominated by the evergreen species *Myrceugenia exsucca* and *Blepharocalyx cruckshanksii* and is distributed on the lowlands of the temperate region of Chile occupying mainly riverine habitats.

Climate of forests included in this study varied from approximately 350 mm of annual precipitation and an annual mean temperature of 14°C in the sclerophyllous forest, to near 2500 mm of annual precipitation and an annual mean temperature of 10.5°C in the lowland evergreen forest [41].

#### **2.3 Data analysis**

We performed two types of analyses: first, we analysed together all data from all forest types, in order to examine the contribution of every variable to the variation in exotic species richness. Thus, in the same model, we evaluated the independent effects of the climatic region (Mediterranean vs. temperate), foliage periodicity of forests (deciduous vs. evergreen), native species richness and native species cover, as well as the statistical interactions between the climatic region and each native vegetation variable. Although the areas of plots were in general quite similar between forests (**Table 1**), the size of plots differed between some of them (**Table 1**), and preliminary log(10) area-log (N° species) correlations were significant for all forest types. Hence, to compare exotic and native species richness at a plot scale among all forest types, we controlled the size of plots by dividing values of exotic species richness as well as native species richness by the log(10) of the area of each plot. On

the other hand, cover values of native species per plot were quantified by the sum of cover among all native species per plot. However, due to larger plots that may have more species and therefore more components for this sum, to use native species cover in the analyses, we controlled the differences in the species number by dividing the sum of cover by the number of native species per plot. Thus, we obtained a variable representing a mean cover of native species per plot.

Finally, we assessed the relationships between exotic species richness and native species richness and cover separately for each forest type with the aim to evaluate if these intra-forest relationships are generalised among different forest types in central-south Chile. In these cases, because within each forest type the size of plots was equal among plots, we did not control the area of them and used the absolute number of exotic and native species as well as the sum of native species cover directly.

All statistical analyses were carried out using SPSS 15.0 by generalised linear models (GLMs).

#### **3. Results**

#### **3.1 Exotic flora**

Among the eight forest types, we recorded 56 exotic species corresponding to three trees (5.4%), four shrubs (7.1%) and 49 herbs (87.5%). The most common species were *Rumex acetosella* and *Rosa rubiginosa* present in six forest types; *Hypochaeris radicata*, *Prunella vulgaris* and *Veronica serpyllifolia* present in five forest types; and *Anthoxanthum odoratum*, *Holcus lanatus*, *Leontodon taraxacoides*, *Lotus uliginosus*, *Plantago lanceolata*, *Trifolium repens* and *Rubus constrictus* present in four forest types. In general, exotic species were mostly herbs in all forests with percentages greater than 80%, except in the Mediterranean deciduous forest (**Table 1**). Species composition per forest-type is shown in **Table 2**.

#### **3.2 Relationship between native vegetation and exotic species richness**

Regarding all forests, exotic species richness varied between 0 and 20 species per plot. After controlling the area of plots, exotic species richness was significantly greater in temperate forests than in Mediterranean forests along all gradients of cover and richness of native species and for each type of forest canopy (deciduous or evergreen) (**Table 3** and **Figures 2–4**). Exotic species richness was negatively and significantly related to the native species cover (**Table 3** and **Figure 2**). This pattern seems to occur in both Mediterranean and temperate forests as we found no significant interaction between the climatic region and native species cover (**Table 3**). However, the slope of this relationship in plots from the temperate region was greater than in plots from the Mediterranean-type climate region (**Figure 2**). In contrast, exotic species richness was not significantly related to the native species richness when all plots were analysed together or in each climatic region separately (**Table 3** and **Figure 3**). On the other hand, exotic species richness was significantly greater in deciduous forests than evergreen forests (**Table 3** and **Figure 4**). Yet, the interaction between region and foliage periodicity was significant (**Table 3**), indicating that higher exotic species richness in deciduous forests than evergreen forests occurred only in temperate forests (**Figure 4**).

When analysing data separately for each forest type, they showed different relationships between native vegetation variables and exotic species richness. A significant negative relationship between native species cover and exotic species

**69**

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

*Agrostis capillaris* 1 1 1

*Anthoxanthum odoratum* 1 1 1 1

*Cynosurus echinatus* 1 1

*Dactylis glomerata* 1 1 1 *Digitalis purpurea* 1 1 1

*Holcus lanatus* 1 1 1 1 *Hypochoeris radicata* 1 1 1 1 1

*Leontodon taraxacoides* 1 1 1 1 *Leucanthemum vulgare* 1 1 *Lolium multiflorum* 1 *Lolium perenne* 1 1 *Lotus uliginosus* 1 1 1 1 *Medicago polymorpha* 1 *Mentha pulegium* 1 *Panicum capillare* 1

*Plantago lanceolata* 1 1 1 1

*Rosa rubiginosa* 1 1 1 1 1 1 *Rubus constrictus* 1 1 1 1

*Sonchus asper* 1

*Taraxacum officinale* 1 1 1

*Stellaria media* 1 1

*Ranunculus repens* 1 1

*Prunella vulgaris* 1 1 1 1 1

*Rumex acetosella* 1 1 1 1 1 1 *Salix viminalis* 1

*Agrostis castellana* 1 1

*Bellardia trixago* 1 1

*Anagallis arvensis* 1

*Aster vahlii* 1

**Exotic species Sc Mm Sa Tm Sd Le Ld Se**

*Agrostis tenuis* 1

*Cirsium vulgare* 1 1

*DOI: http://dx.doi.org/10.5772/intechopen.82233*

*Achillea millefolium* 1

*Bromus hordeaceus* 1

*Chrysanthemum* sp. 1

*Gastridium ventricosum* 1

*Lapsana communis* 1

*Phleum pratense* 1

*Poa pratensis* 1 *Poa trivialis* 1

*Pinus radiata* 1

*Rubus ulmifolius* 1

*Crepis capillaris* 1

*Capsella bursa-pastoris* 1

*Erodium cicutarium* 1 *Fumaria officinalis* 1 *Galium aparine* 1

*Crataegus monogyna* 1

*Cytisus striatus* 1

**Exotic species Sc Mm Sa Tm Sd Le Ld Se** *Achillea millefolium* 1 *Agrostis capillaris* 1 1 1 *Agrostis castellana* 1 1 *Agrostis tenuis* 1 *Anagallis arvensis* 1 *Anthoxanthum odoratum* 1 1 1 1 *Aster vahlii* 1 *Bellardia trixago* 1 1 *Bromus hordeaceus* 1 *Capsella bursa-pastoris* 1 *Cirsium vulgare* 1 1 *Crataegus monogyna* 1 *Crepis capillaris* 1 *Cynosurus echinatus* 1 1 *Cytisus striatus* 1 *Chrysanthemum* sp. 1 *Dactylis glomerata* 1 1 1 *Digitalis purpurea* 1 1 1 *Erodium cicutarium* 1 *Fumaria officinalis* 1 *Galium aparine* 1 *Gastridium ventricosum* 1 *Holcus lanatus* 1 1 1 1 *Hypochoeris radicata* 1 1 1 1 1 *Lapsana communis* 1 *Leontodon taraxacoides* 1 1 1 1 *Leucanthemum vulgare* 1 1 *Lolium multiflorum* 1 *Lolium perenne* 1 1 *Lotus uliginosus* 1 1 1 1 *Medicago polymorpha* 1 *Mentha pulegium* 1 *Panicum capillare* 1 *Phleum pratense* 1 *Pinus radiata* 1 *Plantago lanceolata* 1 1 1 1 *Poa pratensis* 1 *Poa trivialis* 1 *Prunella vulgaris* 1 1 1 1 1 *Ranunculus repens* 1 1 *Rosa rubiginosa* 1 1 1 1 1 1 *Rubus constrictus* 1 1 1 1 *Rubus ulmifolius* 1 *Rumex acetosella* 1 1 1 1 1 1 *Salix viminalis* 1 *Sonchus asper* 1 *Stellaria media* 1 1

*Taraxacum officinale* 1 1 1

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

*Diversity and Ecology of Invasive Plants*

directly.

**3. Results**

models (GLMs).

**3.1 Exotic flora**

the other hand, cover values of native species per plot were quantified by the sum of cover among all native species per plot. However, due to larger plots that may have more species and therefore more components for this sum, to use native species cover in the analyses, we controlled the differences in the species number by dividing the sum of cover by the number of native species per plot. Thus, we obtained a

Finally, we assessed the relationships between exotic species richness and native species richness and cover separately for each forest type with the aim to evaluate if these intra-forest relationships are generalised among different forest types in central-south Chile. In these cases, because within each forest type the size of plots was equal among plots, we did not control the area of them and used the absolute number of exotic and native species as well as the sum of native species cover

All statistical analyses were carried out using SPSS 15.0 by generalised linear

Among the eight forest types, we recorded 56 exotic species corresponding to three trees (5.4%), four shrubs (7.1%) and 49 herbs (87.5%). The most common species were *Rumex acetosella* and *Rosa rubiginosa* present in six forest types; *Hypochaeris radicata*, *Prunella vulgaris* and *Veronica serpyllifolia* present in five forest types; and *Anthoxanthum odoratum*, *Holcus lanatus*, *Leontodon taraxacoides*, *Lotus uliginosus*, *Plantago lanceolata*, *Trifolium repens* and *Rubus constrictus* present in four forest types. In general, exotic species were mostly herbs in all forests with percentages greater than 80%, except in the Mediterranean deciduous forest (**Table 1**).

**3.2 Relationship between native vegetation and exotic species richness**

Regarding all forests, exotic species richness varied between 0 and 20 species per plot. After controlling the area of plots, exotic species richness was significantly greater in temperate forests than in Mediterranean forests along all gradients of cover and richness of native species and for each type of forest canopy (deciduous or evergreen) (**Table 3** and **Figures 2–4**). Exotic species richness was negatively and significantly related to the native species cover (**Table 3** and **Figure 2**). This pattern seems to occur in both Mediterranean and temperate forests as we found no significant interaction between the climatic region and native species cover (**Table 3**). However, the slope of this relationship in plots from the temperate region was greater than in plots from the Mediterranean-type climate region (**Figure 2**). In contrast, exotic species richness was not significantly related to the native species richness when all plots were analysed together or in each climatic region separately (**Table 3** and **Figure 3**). On the other hand, exotic species richness was significantly greater in deciduous forests than evergreen forests (**Table 3** and **Figure 4**). Yet, the interaction between region and foliage periodicity was significant (**Table 3**), indicating that higher exotic species richness in deciduous forests than evergreen forests occurred only in temperate forests (**Figure 4**). When analysing data separately for each forest type, they showed different relationships between native vegetation variables and exotic species richness. A significant negative relationship between native species cover and exotic species

variable representing a mean cover of native species per plot.

Species composition per forest-type is shown in **Table 2**.

**68**


#### **Table 2.**

*Exotic species recorded in each forest type. Nomenclature of forests is in* **Table 1.**


#### **Table 3.**

*Statistical results (generalised lineal models) for the effect of climatic region (Mediterranean vs. Temperate), foliage periodicity (evergreen vs. deciduous), native species cover and native species richness on exotic species richness (N = 167 plots).*

#### **Figure 2.**

*Relationship between exotic species richness and native species cover per climatic region. Exotic species richness per plot was divided by the logarithm (10) of the area of plots to control the differences of area between plots. Native species cover per plot was divided by the number of native species in the plot to control the differences of richness between plots.*

**71**

**Figure 4.**

*periodicity (P < 0.05).*

**Figure 3.**

*differences of area between plots.*

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

*Relationship between exotic species richness and native species richness per climatic region. Exotic species richness and native species richness per plot were divided by the logarithm (10) of the area of plots to control the* 

richness was observed in four forest types, representing 50% of studied forest types, two forests from the Mediterranean-type climate region and two from the temperate region (**Table 4** and **Figure 5**). There was no positive relationship between native species cover and exotic species richness. In turn, a significant relationship between native species richness and exotic species richness was observed only in three forest types, representing 38% of forests included in this study, all of them corresponding

*Exotic species richness per climatic region and foliage periodicity type (mean ± 1 S.E.) (N = 167 plots). Different letters indicate significant statistical differences between each combination of region and foliage* 

*DOI: http://dx.doi.org/10.5772/intechopen.82233*

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

#### **Figure 3.**

*Diversity and Ecology of Invasive Plants*

**Source of variation Chi2 P** Climatic region 54.999 <0.001 Foliage periodicity 8.377 0.004 Native cover 5.201 0.023 Native richness 2.241 0.134 Climatic region × foliage 17.278 <0.001 Climatic region × native cover 0.029 0.864 Climatic region × native richness 0.066 0.798

**Exotic species Sc Mm Sa Tm Sd Le Ld Se**

*Trifolium repens* 1 1 1 1

*Veronica serpyllifolia* 1 1 1 1 1

*Teline monspessulana* 1 1 *Trifolium dubium* 1 1 *Trifolium pratense* 1 1 1

*Urtica dioica* 1

*Verbascum thapsus* 1

*Exotic species recorded in each forest type. Nomenclature of forests is in* **Table 1.**

*Veronica scutellata* 1

*Statistical results (generalised lineal models) for the effect of climatic region (Mediterranean vs. Temperate), foliage periodicity (evergreen vs. deciduous), native species cover and native species richness on exotic species* 

*Relationship between exotic species richness and native species cover per climatic region. Exotic species richness per plot was divided by the logarithm (10) of the area of plots to control the differences of area between plots. Native species cover per plot was divided by the number of native species in the plot to control the differences of* 

**70**

**Figure 2.**

*richness between plots.*

**Table 3.**

**Table 2.**

*richness (N = 167 plots).*

*Relationship between exotic species richness and native species richness per climatic region. Exotic species richness and native species richness per plot were divided by the logarithm (10) of the area of plots to control the differences of area between plots.*

**Figure 4.**

*Exotic species richness per climatic region and foliage periodicity type (mean ± 1 S.E.) (N = 167 plots). Different letters indicate significant statistical differences between each combination of region and foliage periodicity (P < 0.05).*

richness was observed in four forest types, representing 50% of studied forest types, two forests from the Mediterranean-type climate region and two from the temperate region (**Table 4** and **Figure 5**). There was no positive relationship between native species cover and exotic species richness. In turn, a significant relationship between native species richness and exotic species richness was observed only in three forest types, representing 38% of forests included in this study, all of them corresponding


#### **Table 4.**

*Statistical results (generalised linear models, ordinal multinomial distribution of data and logit function link) of analyses per forest type for the effect of native species richness and native species cover on exotic species richness. Significant relationships in bold.*

**Figure 5.**

*Relationships between exotic species richness and native species cover in every forest type. Curves are shown only for significant relationships.*

**73**

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

to temperate forests (**Table 4** and **Figure 6**). However, in this case, in two forests the relationship was negative while in one forest type (Swamp deciduous forest) the

*Relationships between exotic species richness and native species richness in every forest type. Curves are shown* 

In this study, we document that exotic species richness is related to variation in native species cover, foliage periodicity and, at a less extent, native species richness. Additionally, these relationships depend on climate and/or forest type in forest

The significant negative relationships between exotic species richness and native species cover pooling all forests as well as within some forest types suggest competitive effects of native vegetation on invasion of exotic plants [27]. Variability of native cover within forests may be produced by natural causes (including natural disturbances) as well as anthropogenic disturbances. Regardless of the cause determining this variability, lower native cover entails more resources for invasive species [13, 14, 27]. Therefore, our results suggest a high importance of competition

relationship was positive (**Figure 6**).

*only for significant relationships.*

**4. Discussion**

**Figure 6.**

communities of Chile.

*DOI: http://dx.doi.org/10.5772/intechopen.82233*

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

**Figure 6.**

*Diversity and Ecology of Invasive Plants*

**Table 4.**

*Significant relationships in bold.*

**Forest type Native species** 

**richness**

Sclerophyllous forest (Sc) 1.901 0.168 0.626 0.429 Mediterranean Subantarctic Andean forest (Sa) 1.217 0.270 7.337 **0.007** Mediterranean montane deciduous forest (Mm) 1.043 0.307 8.109 **0.004** Lowland deciduous forest (Ld) 11.351 **0.001** 0.012 0.913 Swamp deciduous forest (Sd) 7.781 **0.005** 0.550 0.458 Lowland evergreen forest (Le) 0.074 0.786 0.058 0.810 Temperate montane deciduous forest (Tm) 4.526 **0.033** 11.450 **0.001** Swamp evergreen forest (Se) 0.004 0.951 6.160 **0.013**

*Statistical results (generalised linear models, ordinal multinomial distribution of data and logit function link) of analyses per forest type for the effect of native species richness and native species cover on exotic species richness.* 

*Relationships between exotic species richness and native species cover in every forest type. Curves are shown only* 

**Total native cover**

**Chi2 P Chi2 P**

**72**

**Figure 5.**

*for significant relationships.*

*Relationships between exotic species richness and native species richness in every forest type. Curves are shown only for significant relationships.*

to temperate forests (**Table 4** and **Figure 6**). However, in this case, in two forests the relationship was negative while in one forest type (Swamp deciduous forest) the relationship was positive (**Figure 6**).

#### **4. Discussion**

In this study, we document that exotic species richness is related to variation in native species cover, foliage periodicity and, at a less extent, native species richness. Additionally, these relationships depend on climate and/or forest type in forest communities of Chile.

The significant negative relationships between exotic species richness and native species cover pooling all forests as well as within some forest types suggest competitive effects of native vegetation on invasion of exotic plants [27]. Variability of native cover within forests may be produced by natural causes (including natural disturbances) as well as anthropogenic disturbances. Regardless of the cause determining this variability, lower native cover entails more resources for invasive species [13, 14, 27]. Therefore, our results suggest a high importance of competition in invasion processes of exotic species in these forest communities. Similarly, other observational studies performed within forest ecosystems [19, 28, 31, 42] as well as an increasing number of experimental studies have demonstrated the importance of resource availability and competition liberation for plant invasion [8, 12, 21, 23, 43]. Therefore, although many exotic plant species may also invade closed-canopy forests, as documented by Martin et al. [32], our results suggest that more covered sites within or between native forests may better resist plant invasion.

Globally within the study area, we observed no significant relationship between exotic and native species richness. Instead, when every forest was separately analysed, two of them showed a significant negative relationship, which is consistent with the idea that negative relationships between exotic and native species richness would only occur when other factors are controlled (i.e. within each forest type) [3, 7, 15, 21]. This result suggests that, at least in these two forest types, exotic and native species may be competing by resources. However, our results did not agree to Shea and Chesson [7] and some empirical studies [6, 19, 22, 25, 44, 45], which proposed that in geographical comparisons (in our case in the analysis pooling data from all forests), positive relationships between exotic and native species richness should emerge. In particular, the absence of a positive correlation between native and exotic species richness when all forests were analysed together contrasts to Fuentes et al. [26], who found similar geographical tendencies between native and exotic species richness along Chile, although in this case, using much larger scales to measure species richness. Davies et al. [46] proposed that positive relationships between exotic and native species richness would mainly occur when richness is quantified at large spatial scales [26]. This would occur because greater environmental heterogeneity within large quadrants would favour both exotic and native species. Instead, this would not occur at small spatial scales such as a plotscale (this study), even though plots are compared at a geographical scale [46]. However, Souza et al. [47] found that native and exotic species richness may be positively correlated both at local and landscape scales. Consistent to Souza et al. [47], we observed a positive relationship between exotic and native species richness occurring within a forest type (at a local scale). This positive correlation could be produced by a similar response of native and exotic species to environmental factors [7, 47], or because native species are facilitating exotic species [16, 47]. In the forest type in which this positive relationship was observed (swamp deciduous forest), soil conditions are extreme, with soils permanently saturated with water and low soil oxygen [38]. Therefore, it is probable that within this community, only in microsites (at a scale of 100 m<sup>2</sup> or less) where soil conditions are a little more favourable, more species, exotics as well as natives, can coexist. Nevertheless, it is not possible to rule out facilitative effects of native on exotic species in this case either.

We observed that in the temperate region, deciduous forests presented greater exotic species richness than evergreen forests, which suggests that the seasonal increase in light conditions in deciduous forests may be a factor contributing to an increase of invasion probability in temperate forests. Higher light requirement of exotic species has been proposed as an important life history attribute favouring the invasion in low-cover sites [14, 43], for instance, ruderal habitats. In fact, most of the exotic species of central-south of Chile have been documented as shadeintolerant species [48]. Although the relationship between foliage periodicity and plant invasion has scarcely been evaluated, our results agree to Ibáñez et al. [33] who documented greater exotic species richness in deciduous forests than evergreen forests in eastern North America. Thus, this factor may be an important driver of plant invasion in forest ecosystems although more studies are needed to assess the generality of this relationship.

**75**

tions between native and exotic species.

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

although, in this case, using larger scales to measure exotic species richness.

If more xeric climates such as in the Mediterranean region of Chile entail more stressful conditions for exotic species (as suggested by the greater exotic species richness in the temperate climate), based on the stress-gradient hypothesis [34], in the Mediterranean region, facilitative interactions and positive relationships may be expected between native vegetation and exotic species richness, while competitive and negative relationships in temperate forests. Thus, the fact that the relationship between native cover and plant invasion was observed in both climatic regions only partially supports the stress-gradient hypothesis [34]. However, the slope of this relationship was steeper in the temperate region than in the Mediterraneantype climate region, suggesting that competitive effects of native vegetation on exotic species were stronger in the less stressful climatic region, which agrees to the stress-gradient hypothesis [11, 34]. Additionally, we did not find a significant negative relationship between native cover and exotic species richness in the most xeric forest included in this study (sclerophyllous forest), which again suggests that under more stressing conditions in terms of water availability, competition would be weaker, or that facilitative effects of native vegetation on exotic species counteracted any competitive interaction (e.g. [10, 12, 17]). Furthermore, two among five temperate forests presented negative relationships between native cover and exotic richness, and in the other temperate forest (lowland deciduous forest), a negative relationship between native and exotic species richness was observed. These results suggest that in temperate forests negative relationships between native vegetation and exotic species are more frequent than in Mediterranean forests, which agree with the stress-gradient hypothesis. On the other hand, the fact that deciduous forests presented greater exotic richness than evergreen forests only in the temperate region suggests that in more humid regions the light conditions may be a more important limiting factor for exotic species than in Mediterranean-type climates. This result may also be consistent with the stress-gradient hypothesis since competition by light would be stronger under less stressful abiotic conditions (temperate region). In consequence, our results suggest that the stress-gradient hypothesis may be useful to predict patterns of relationship between exotic species richness and native vegetation when species richness is analysed at small spatial scales. Other studies [11] have also found support for this hypothesis in the context of interac-

Finally, our results suggest that maintaining or increasing native species cover may help to control or reduce plant invasion, at least in terms of exotic species richness. This may be a successful management strategy for the control of invasion mainly in

On the other hand, our results show that under the same conditions of cover, richness and foliage periodicity of native species, forests from the temperate climate region were richer in exotic species than forests from the Mediterranean-type climate region. This suggests that the Mediterranean-type semiarid region of Chile represents a more stressful condition than the temperate region for exotic species invading forest ecosystems, which agrees to several studies documenting that greater exotic species richness seems to establish mainly in more productive climates [6, 20, 26, 33]. For instance, Lonsdale [6] found a lower number of exotic species in deserts and savannas than in forest habitats around the world, and Stohlgren et al. [20] found a positive relationship between productivity and exotic species richness within North America. Ibáñez et al. [33] documented higher exotic species richness in areas with warmer temperatures and higher summer precipitation in a region of eastern North America. Finally, in the same country, Chile, Fuentes et al. [26] observed greater exotic species richness at a regional scale (10 × 10 km) within Mediterranean and temperate regions than in deserts or colder areas. Nevertheless, in contrast to our results, Fuentes et al. [26] observed higher exotic species richness in the Mediterranean region than the temperate region

*DOI: http://dx.doi.org/10.5772/intechopen.82233*

#### *Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

On the other hand, our results show that under the same conditions of cover, richness and foliage periodicity of native species, forests from the temperate climate region were richer in exotic species than forests from the Mediterranean-type climate region. This suggests that the Mediterranean-type semiarid region of Chile represents a more stressful condition than the temperate region for exotic species invading forest ecosystems, which agrees to several studies documenting that greater exotic species richness seems to establish mainly in more productive climates [6, 20, 26, 33]. For instance, Lonsdale [6] found a lower number of exotic species in deserts and savannas than in forest habitats around the world, and Stohlgren et al. [20] found a positive relationship between productivity and exotic species richness within North America. Ibáñez et al. [33] documented higher exotic species richness in areas with warmer temperatures and higher summer precipitation in a region of eastern North America. Finally, in the same country, Chile, Fuentes et al. [26] observed greater exotic species richness at a regional scale (10 × 10 km) within Mediterranean and temperate regions than in deserts or colder areas. Nevertheless, in contrast to our results, Fuentes et al. [26] observed higher exotic species richness in the Mediterranean region than the temperate region although, in this case, using larger scales to measure exotic species richness.

If more xeric climates such as in the Mediterranean region of Chile entail more stressful conditions for exotic species (as suggested by the greater exotic species richness in the temperate climate), based on the stress-gradient hypothesis [34], in the Mediterranean region, facilitative interactions and positive relationships may be expected between native vegetation and exotic species richness, while competitive and negative relationships in temperate forests. Thus, the fact that the relationship between native cover and plant invasion was observed in both climatic regions only partially supports the stress-gradient hypothesis [34]. However, the slope of this relationship was steeper in the temperate region than in the Mediterraneantype climate region, suggesting that competitive effects of native vegetation on exotic species were stronger in the less stressful climatic region, which agrees to the stress-gradient hypothesis [11, 34]. Additionally, we did not find a significant negative relationship between native cover and exotic species richness in the most xeric forest included in this study (sclerophyllous forest), which again suggests that under more stressing conditions in terms of water availability, competition would be weaker, or that facilitative effects of native vegetation on exotic species counteracted any competitive interaction (e.g. [10, 12, 17]). Furthermore, two among five temperate forests presented negative relationships between native cover and exotic richness, and in the other temperate forest (lowland deciduous forest), a negative relationship between native and exotic species richness was observed. These results suggest that in temperate forests negative relationships between native vegetation and exotic species are more frequent than in Mediterranean forests, which agree with the stress-gradient hypothesis. On the other hand, the fact that deciduous forests presented greater exotic richness than evergreen forests only in the temperate region suggests that in more humid regions the light conditions may be a more important limiting factor for exotic species than in Mediterranean-type climates. This result may also be consistent with the stress-gradient hypothesis since competition by light would be stronger under less stressful abiotic conditions (temperate region). In consequence, our results suggest that the stress-gradient hypothesis may be useful to predict patterns of relationship between exotic species richness and native vegetation when species richness is analysed at small spatial scales. Other studies [11] have also found support for this hypothesis in the context of interactions between native and exotic species.

Finally, our results suggest that maintaining or increasing native species cover may help to control or reduce plant invasion, at least in terms of exotic species richness. This may be a successful management strategy for the control of invasion mainly in

*Diversity and Ecology of Invasive Plants*

only in microsites (at a scale of 100 m<sup>2</sup>

generality of this relationship.

in invasion processes of exotic species in these forest communities. Similarly, other observational studies performed within forest ecosystems [19, 28, 31, 42] as well as an increasing number of experimental studies have demonstrated the importance of resource availability and competition liberation for plant invasion [8, 12, 21, 23, 43]. Therefore, although many exotic plant species may also invade closed-canopy forests, as documented by Martin et al. [32], our results suggest that more covered

Globally within the study area, we observed no significant relationship between

or less) where soil conditions are a little

more favourable, more species, exotics as well as natives, can coexist. Nevertheless, it is not possible to rule out facilitative effects of native on exotic species in this

We observed that in the temperate region, deciduous forests presented greater exotic species richness than evergreen forests, which suggests that the seasonal increase in light conditions in deciduous forests may be a factor contributing to an increase of invasion probability in temperate forests. Higher light requirement of exotic species has been proposed as an important life history attribute favouring the invasion in low-cover sites [14, 43], for instance, ruderal habitats. In fact, most of the exotic species of central-south of Chile have been documented as shadeintolerant species [48]. Although the relationship between foliage periodicity and plant invasion has scarcely been evaluated, our results agree to Ibáñez et al. [33] who documented greater exotic species richness in deciduous forests than evergreen forests in eastern North America. Thus, this factor may be an important driver of plant invasion in forest ecosystems although more studies are needed to assess the

sites within or between native forests may better resist plant invasion.

exotic and native species richness. Instead, when every forest was separately analysed, two of them showed a significant negative relationship, which is consistent with the idea that negative relationships between exotic and native species richness would only occur when other factors are controlled (i.e. within each forest type) [3, 7, 15, 21]. This result suggests that, at least in these two forest types, exotic and native species may be competing by resources. However, our results did not agree to Shea and Chesson [7] and some empirical studies [6, 19, 22, 25, 44, 45], which proposed that in geographical comparisons (in our case in the analysis pooling data from all forests), positive relationships between exotic and native species richness should emerge. In particular, the absence of a positive correlation between native and exotic species richness when all forests were analysed together contrasts to Fuentes et al. [26], who found similar geographical tendencies between native and exotic species richness along Chile, although in this case, using much larger scales to measure species richness. Davies et al. [46] proposed that positive relationships between exotic and native species richness would mainly occur when richness is quantified at large spatial scales [26]. This would occur because greater environmental heterogeneity within large quadrants would favour both exotic and native species. Instead, this would not occur at small spatial scales such as a plotscale (this study), even though plots are compared at a geographical scale [46]. However, Souza et al. [47] found that native and exotic species richness may be positively correlated both at local and landscape scales. Consistent to Souza et al. [47], we observed a positive relationship between exotic and native species richness occurring within a forest type (at a local scale). This positive correlation could be produced by a similar response of native and exotic species to environmental factors [7, 47], or because native species are facilitating exotic species [16, 47]. In the forest type in which this positive relationship was observed (swamp deciduous forest), soil conditions are extreme, with soils permanently saturated with water and low soil oxygen [38]. Therefore, it is probable that within this community,

**74**

case either.

temperate forests as well as in some Mediterranean-type climate forests. Instead, in more xeric Mediterranean forests (e.g. sclerophyllous forest), an increase in cover of native species does not seem to be enough to reduce exotic species richness, and other actions are needed to control plant invasion.

## **Acknowledgements**

We thank the Chilean phytosociologists who have greatly contributed to knowledge of Chilean plant communities and have published original tables of species which allowed performing this study. This work was supported by a doctoral fellowship from CONICYT to PIB and by ICM-P05-002. PIB thanks FB 0002-2014.

#### **Author details**

Pablo I. Becerra1,2\* and Ramiro O. Bustamante3,4

1 Departamento de Ecosistemas y Medio Ambiente, Facultad de Agronomía e Ingeniería Forestal Pontificia Universidad Católica de Chile, Santiago, Chile

2 Center of Applied Ecology and Sustainability, CAPES, Santiago, Chile

3 Instituto de Ecología y Biodiversidad, Santiago, Chile

4 Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile

\*Address all correspondence to: pablobecerra@uc.cl

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**77**

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

Insights into Ecology, Evolution and Biogeography. USA: Sinauer Associates;

[10] Lenz TI, Facelli JM. Shade facilitates

chenopod shrubland in South Australia. Austral Ecology. 2003;**28**:480-490

[11] Von Holle B. Environmental stress alters native-nonnative relationships at the community scale. Biological Invasions. 2013;**15**:417-427. DOI: 10.1007/s10530-012-0297-7

[12] Becerra P, Bustamante R. Effect of a native tree on seedling establishment of two exotic species in a semiarid ecosystem. Biological Invasions.

[13] Hobbs R, Huenneke L. Disturbance, diversity, and invasions: Implications for conservation. Conservation Biology.

[15] Naeem S, Knops J, Tilman D, Howe K, Kennedy T, Gale S. Plant diversity increases resistance to invasion in the absence of covarying extrinsic factors.

[16] Bruno JF, Stachowicz JJ, Bertness MD. Inclusion of facilitation into ecological theory. Trends in Ecology &

[17] Von Holle B. Biotic resistance to invader establishment of a southern Appalachian plant community is determined by environmental conditions. Journal of Ecology.

[14] Bartomeus I, Sol D, Pino J, Vicente P, Font X. Deconstructing the native-exotic richness relationship in plants. Global Ecology and Biogeography. 2012;**21**:524-533. DOI: 10.1111/j.1466-8238.2011.00708.x

Oikos. 2000;**91**:97-108

Evolution. 2003;**18**:119-125

2005;**93**:16-26

an invasive stem succulent in a

2005. pp. 13-40

2011;**13**:2763-2773

1992;**6**:324-337

*DOI: http://dx.doi.org/10.5772/intechopen.82233*

[1] Groves R, Burdon J. Ecology of Biological Invasions. Cambridge, UK: Cambridge University Press; 1986. 180 p

[2] Drake J, Mooney H, di Castri F, Groves R, Kruger F, Rejmanek M, et al. Biological Invasions: A Global Perspective. Chichester, UK: Wiley;

[3] Huston MA. Management strategies for plant invasions: Manipulating productivity, disturbance, and competition. Diversity and Distributions. 2004;**10**:167-178

[4] Jauni M, Gripenberg S, Ramula S. Non-native plant species benefit from disturbance: A meta-analysis. Oikos. 2015;**124**:122-129. DOI: 10.1111/

[5] Catford J, Daehler C, Murphy H, Sheppard A, Hardesty B, Westcott D, et al. The intermediate disturbance hypothesis and plant invasions: Implications for species richness and management. Perspectives in Plant Ecology, Evolution and Systematics. 2012;**14**:231-241. DOI: 10.1016/j.

[6] Lonsdale W. Global patterns of plant invasions and the concept of invasibility. Ecology. 1999;**80**:1522-1536

[7] Shea K, Chesson P. Community ecology theory as a framework for biological invasions. Trends in Ecology

[8] Davis MA, Pelsor M. Experimental

[9] Bruno JF, Fridley JD, Bromberg KD, Bertness MD. Insights into biotic interactions from studies of species invasions. In: Sax DF, Stachowicz JJ, Gaines SD, editors. Species Invasions:

& Evolution. 2002;**17**:170-176

support for a resource-based mechanistic model of invasibility. Ecology Letters. 2001;**4**:421-428

**References**

1989. 550 p

oik.01416

ppees.2011.12.002

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

#### **References**

*Diversity and Ecology of Invasive Plants*

**Acknowledgements**

actions are needed to control plant invasion.

**76**

**Author details**

Santiago, Chile

provided the original work is properly cited.

Pablo I. Becerra1,2\* and Ramiro O. Bustamante3,4

3 Instituto de Ecología y Biodiversidad, Santiago, Chile

\*Address all correspondence to: pablobecerra@uc.cl

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

4 Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile,

1 Departamento de Ecosistemas y Medio Ambiente, Facultad de Agronomía e Ingeniería Forestal Pontificia Universidad Católica de Chile, Santiago, Chile

temperate forests as well as in some Mediterranean-type climate forests. Instead, in more xeric Mediterranean forests (e.g. sclerophyllous forest), an increase in cover of native species does not seem to be enough to reduce exotic species richness, and other

We thank the Chilean phytosociologists who have greatly contributed to knowledge of Chilean plant communities and have published original tables of species which allowed performing this study. This work was supported by a doctoral fellowship from CONICYT to PIB and by ICM-P05-002. PIB thanks FB 0002-2014.

2 Center of Applied Ecology and Sustainability, CAPES, Santiago, Chile

[1] Groves R, Burdon J. Ecology of Biological Invasions. Cambridge, UK: Cambridge University Press; 1986. 180 p

[2] Drake J, Mooney H, di Castri F, Groves R, Kruger F, Rejmanek M, et al. Biological Invasions: A Global Perspective. Chichester, UK: Wiley; 1989. 550 p

[3] Huston MA. Management strategies for plant invasions: Manipulating productivity, disturbance, and competition. Diversity and Distributions. 2004;**10**:167-178

[4] Jauni M, Gripenberg S, Ramula S. Non-native plant species benefit from disturbance: A meta-analysis. Oikos. 2015;**124**:122-129. DOI: 10.1111/ oik.01416

[5] Catford J, Daehler C, Murphy H, Sheppard A, Hardesty B, Westcott D, et al. The intermediate disturbance hypothesis and plant invasions: Implications for species richness and management. Perspectives in Plant Ecology, Evolution and Systematics. 2012;**14**:231-241. DOI: 10.1016/j. ppees.2011.12.002

[6] Lonsdale W. Global patterns of plant invasions and the concept of invasibility. Ecology. 1999;**80**:1522-1536

[7] Shea K, Chesson P. Community ecology theory as a framework for biological invasions. Trends in Ecology & Evolution. 2002;**17**:170-176

[8] Davis MA, Pelsor M. Experimental support for a resource-based mechanistic model of invasibility. Ecology Letters. 2001;**4**:421-428

[9] Bruno JF, Fridley JD, Bromberg KD, Bertness MD. Insights into biotic interactions from studies of species invasions. In: Sax DF, Stachowicz JJ, Gaines SD, editors. Species Invasions:

Insights into Ecology, Evolution and Biogeography. USA: Sinauer Associates; 2005. pp. 13-40

[10] Lenz TI, Facelli JM. Shade facilitates an invasive stem succulent in a chenopod shrubland in South Australia. Austral Ecology. 2003;**28**:480-490

[11] Von Holle B. Environmental stress alters native-nonnative relationships at the community scale. Biological Invasions. 2013;**15**:417-427. DOI: 10.1007/s10530-012-0297-7

[12] Becerra P, Bustamante R. Effect of a native tree on seedling establishment of two exotic species in a semiarid ecosystem. Biological Invasions. 2011;**13**:2763-2773

[13] Hobbs R, Huenneke L. Disturbance, diversity, and invasions: Implications for conservation. Conservation Biology. 1992;**6**:324-337

[14] Bartomeus I, Sol D, Pino J, Vicente P, Font X. Deconstructing the native-exotic richness relationship in plants. Global Ecology and Biogeography. 2012;**21**:524-533. DOI: 10.1111/j.1466-8238.2011.00708.x

[15] Naeem S, Knops J, Tilman D, Howe K, Kennedy T, Gale S. Plant diversity increases resistance to invasion in the absence of covarying extrinsic factors. Oikos. 2000;**91**:97-108

[16] Bruno JF, Stachowicz JJ, Bertness MD. Inclusion of facilitation into ecological theory. Trends in Ecology & Evolution. 2003;**18**:119-125

[17] Von Holle B. Biotic resistance to invader establishment of a southern Appalachian plant community is determined by environmental conditions. Journal of Ecology. 2005;**93**:16-26

[18] Planty-Tabacchi A, Tabacchi E, Naiman R, DeFerrari C, DéCamps H. Invasibility of species-rich communities in riparian zones. Conservation Biology. 1996;**10**:598-607

[19] Stohlgren TJ, Binkley D, Chong G, Kalkhan M, Schell L, Bull K, et al. Exotic plant species invade hot spots of native plant diversity. Ecological Monographs. 1999;**69**:25-46

[20] Stohlgren TJ, Barnett D, Flather C, Kartesz J, Peterjohn B. Plant species invasions along the latitudinal gradient in the United States. Ecology. 2005;**86**:2298-2309

[21] Levine J. Local interactions, dispersal, and native and exotic plant diversity along a California stream. Oikos. 2001;**95**:397-408

[22] Espinosa-García FJ, Villaseñor JL, Vibrans H. The rich generally get richer, but there are exceptions: Correlations between species richness of native plant species and exotic weeds in Mexico. Diversity and Distributions. 2004;**10**:399-407

[23] Bruno JF, Kennedy CW, Rand TA, Grant M. Landscape-scale patterns of biological invasions in shoreline plant communities. Oikos. 2004;**107**:531-540

[24] Howard TG, Gurevitch J, Hyatt L, Carreiro M, Lerdau M. Forest invasibility in communities in southeastern New York. Biological Invasions. 2004;**6**:393-410

[25] Perelman SB, Chaneton EJ, Batista WB, Burkart SE, León JC. Habitat stress, species pool size and biotic resistance influence exotic plant richness in the flooding Pampa grasslands. Journal of Ecology. 2007;**95**:662-673

[26] Fuentes N, Pauchard A, Sánchez P, Esquivel J, Marticorena A. A new comprehensive database of alien plant species in Chile based on herbarium

records. Biological Invasions. 2013;**15**:847-858. DOI: 10.1007/ s10530-012-0334-6

[27] Davis MA, Grime JP, Thompson K. Fluctuating resources in plant communities: A general theory of invasibility. Journal of Ecology. 2000;**88**:528-534

[28] Halpern C, Spies T. Plant species diversity in natural and managed forests of the pacific northwest. Ecological Applications. 1995;**5**:913-934

[29] Wiser S, Allen R, Clinton P, Platt K. Community structure and forest invasion by an exotic herb over 23 years. Ecology. 1998;**79**:2071-2081

[30] Simberloff D, Relva MA, Nuñez M. Gringos en el bosque: Introduced tree invasion in a native *Nothofagus/ Austrocedrus* forest. Biological Invasions. 2002;**4**:35-53

[31] Aragón R, Morales JM. Species composition and invasion in NW Argentinian secondary forests: Effects of land use history, environment and landscape. Journal of Vegetation Science. 2003;**14**:195-204

[32] Martin PH, Canham CD, Marks PL. Why forests appear resistant to exotic plant invasions: Intentional introductions, stand dynamics, and the role of shade tolerance. Frontiers in Ecology and the Environment. 2009;**7**:142-149

[33] Ibáñez I, Silander JA, Allen JM, Treanor SA, Wilson A. Identifying hotspots for plant invasions and forescating focal points of further spread. Journal of Applied Ecology. 2009;**46**:1219-1228

[34] Maestre FT, Callaway RM, Valladares F, Lortie CJ. Refining the stress-gradient hypothesis for competition and facilitation plant communities. Journal of Ecology. 2009;**97**:199-205

**79**

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest…*

heterogeneity and exotic invasions in temperate Pampa grasslands. Biological

[45] Sax DF. Native and naturalized plant diversity are positively correlated in scrub communities in California and Chile. Diversity and Distributions.

[46] Davies KF, Chesson P, Harrison S, Inouye BD, Melbourne BA, Rice KJ. Spatial heterogeneity explains the scale dependence of the native-exotic diversity relationship. Ecology.

[47] Souza L, Bunn W, Simberloff D, Lawton R, Sanders N. Biotic and abiotic influences on native and exotic richness relationship across spatial scales: Favourable environments for native species are highly invasible. Functional Ecology. 2011;**25**:1106-1112. DOI: 10.1111/j.1365-2435.2011.01857.x

[48] Ramírez C, Finot V, San Martin C, Ellies A. El valor indicador ecológico de las malezas del centro-sur de Chile.

Agrosur. 1991;**19**:94-116

Invasions. 2002;**4**:7-24

2002;**8**:193-210

2005;**86**:1602-1610

*DOI: http://dx.doi.org/10.5772/intechopen.82233*

[35] Amigo J, San Martin J, García L. Estudio fitosociológico de los bosques de *Nothofagus glauca* (Phil.) Krasser del centro-sur de Chile. Phytocoenologia.

[36] San Martín J, Troncoso A, Mesa A,

fitosociológico del bosque caducifolio magallánico en el límite norte de su área de distribución. Bosque. 1991;**12**:29-41

[37] Becerra P, Cruz G. Diversidad vegetacional de la Reserva Nacional Malalcahuello, IX región de Chile.

[38] Ferrada V. Estudio fitosociológico del Ñadi de Frutillar (Osorno, Chile) [thesis]. Facultad de Ciencias Forestales: Universidad Austral de Chile; 1987

[39] San Martín C, Ramírez C, Figueroa H, Ojeda N. Estudio sinecológico del bosque de roble-laurel-lingue del centro sur de Chile. Bosque. 1991;**12**:11-27

[40] Ramírez C, Ferriere F, Figueroa H. Estudio fitosociológico de los bosques pantanosos templados del sur de Chile. Revista Chilena de Historia Natural.

[41] Luebert F, Pliscoff P. Sinopsis bioclimática y vegetacional de Chile. Santiago, Chile: Editorial Universitaria.

[42] Teo D, Tan H, Corlett R, Min Wong C, Lum S. Continental rain forest fragments in Singapore resist invasion by exotic plants. Journal of Biogeography. 2003;**30**:305-310

[43] Grotkopp EM, Rejmánek M,

2002;**159**:396-419

Rost TL. Toward a causal explanation of plant invasiveness: Seedling growth and life-history strategies of 29 pine (*Pinus*) species. The American Naturalist.

[44] Chaneton E, Perelman S, Omacini M, León R. Grazing, environmental

Bravo T, Ramírez C. Estudio

Bosque. 2000;**21**:47-68

1983;**56**:11-26

316 p

2000;**30**:193-221

*Relationship between Exotic Plant Species Richness, Native Vegetation and Climate in Forest… DOI: http://dx.doi.org/10.5772/intechopen.82233*

[35] Amigo J, San Martin J, García L. Estudio fitosociológico de los bosques de *Nothofagus glauca* (Phil.) Krasser del centro-sur de Chile. Phytocoenologia. 2000;**30**:193-221

*Diversity and Ecology of Invasive Plants*

[18] Planty-Tabacchi A, Tabacchi E, Naiman R, DeFerrari C, DéCamps H. Invasibility of species-rich communities in riparian zones. Conservation Biology. records. Biological Invasions. 2013;**15**:847-858. DOI: 10.1007/

Fluctuating resources in plant communities: A general theory of invasibility. Journal of Ecology.

[27] Davis MA, Grime JP, Thompson K.

[28] Halpern C, Spies T. Plant species diversity in natural and managed forests of the pacific northwest. Ecological Applications. 1995;**5**:913-934

[29] Wiser S, Allen R, Clinton P, Platt K. Community structure and forest

invasion by an exotic herb over 23 years.

[30] Simberloff D, Relva MA, Nuñez M. Gringos en el bosque: Introduced tree invasion in a native *Nothofagus/ Austrocedrus* forest. Biological Invasions.

[31] Aragón R, Morales JM. Species composition and invasion in NW Argentinian secondary forests: Effects of land use history, environment and landscape. Journal of Vegetation

[32] Martin PH, Canham CD, Marks PL.

Science. 2003;**14**:195-204

2009;**7**:142-149

2009;**46**:1219-1228

2009;**97**:199-205

Why forests appear resistant to exotic plant invasions: Intentional introductions, stand dynamics, and the role of shade tolerance. Frontiers in Ecology and the Environment.

[33] Ibáñez I, Silander JA, Allen JM, Treanor SA, Wilson A. Identifying hotspots for plant invasions and forescating focal points of further spread. Journal of Applied Ecology.

[34] Maestre FT, Callaway RM, Valladares F, Lortie CJ. Refining the stress-gradient hypothesis for competition and facilitation plant communities. Journal of Ecology.

Ecology. 1998;**79**:2071-2081

s10530-012-0334-6

2000;**88**:528-534

2002;**4**:35-53

[19] Stohlgren TJ, Binkley D, Chong G, Kalkhan M, Schell L, Bull K, et al. Exotic plant species invade hot spots of native plant diversity. Ecological Monographs.

[20] Stohlgren TJ, Barnett D, Flather C, Kartesz J, Peterjohn B. Plant species invasions along the latitudinal

gradient in the United States. Ecology.

[22] Espinosa-García FJ, Villaseñor JL, Vibrans H. The rich generally get richer, but there are exceptions: Correlations between species richness of native plant species and exotic weeds in Mexico. Diversity and Distributions.

[23] Bruno JF, Kennedy CW, Rand TA, Grant M. Landscape-scale patterns of biological invasions in shoreline plant communities. Oikos. 2004;**107**:531-540

[24] Howard TG, Gurevitch J, Hyatt L,

[25] Perelman SB, Chaneton EJ, Batista WB, Burkart SE, León JC. Habitat stress, species pool size and biotic resistance influence exotic plant richness in the flooding Pampa grasslands. Journal of

[26] Fuentes N, Pauchard A, Sánchez P, Esquivel J, Marticorena A. A new comprehensive database of alien plant species in Chile based on herbarium

Carreiro M, Lerdau M. Forest invasibility in communities in southeastern New York. Biological

Invasions. 2004;**6**:393-410

Ecology. 2007;**95**:662-673

[21] Levine J. Local interactions, dispersal, and native and exotic plant diversity along a California stream.

1996;**10**:598-607

1999;**69**:25-46

2005;**86**:2298-2309

Oikos. 2001;**95**:397-408

2004;**10**:399-407

**78**

[36] San Martín J, Troncoso A, Mesa A, Bravo T, Ramírez C. Estudio fitosociológico del bosque caducifolio magallánico en el límite norte de su área de distribución. Bosque. 1991;**12**:29-41

[37] Becerra P, Cruz G. Diversidad vegetacional de la Reserva Nacional Malalcahuello, IX región de Chile. Bosque. 2000;**21**:47-68

[38] Ferrada V. Estudio fitosociológico del Ñadi de Frutillar (Osorno, Chile) [thesis]. Facultad de Ciencias Forestales: Universidad Austral de Chile; 1987

[39] San Martín C, Ramírez C, Figueroa H, Ojeda N. Estudio sinecológico del bosque de roble-laurel-lingue del centro sur de Chile. Bosque. 1991;**12**:11-27

[40] Ramírez C, Ferriere F, Figueroa H. Estudio fitosociológico de los bosques pantanosos templados del sur de Chile. Revista Chilena de Historia Natural. 1983;**56**:11-26

[41] Luebert F, Pliscoff P. Sinopsis bioclimática y vegetacional de Chile. Santiago, Chile: Editorial Universitaria. 316 p

[42] Teo D, Tan H, Corlett R, Min Wong C, Lum S. Continental rain forest fragments in Singapore resist invasion by exotic plants. Journal of Biogeography. 2003;**30**:305-310

[43] Grotkopp EM, Rejmánek M, Rost TL. Toward a causal explanation of plant invasiveness: Seedling growth and life-history strategies of 29 pine (*Pinus*) species. The American Naturalist. 2002;**159**:396-419

[44] Chaneton E, Perelman S, Omacini M, León R. Grazing, environmental

heterogeneity and exotic invasions in temperate Pampa grasslands. Biological Invasions. 2002;**4**:7-24

[45] Sax DF. Native and naturalized plant diversity are positively correlated in scrub communities in California and Chile. Diversity and Distributions. 2002;**8**:193-210

[46] Davies KF, Chesson P, Harrison S, Inouye BD, Melbourne BA, Rice KJ. Spatial heterogeneity explains the scale dependence of the native-exotic diversity relationship. Ecology. 2005;**86**:1602-1610

[47] Souza L, Bunn W, Simberloff D, Lawton R, Sanders N. Biotic and abiotic influences on native and exotic richness relationship across spatial scales: Favourable environments for native species are highly invasible. Functional Ecology. 2011;**25**:1106-1112. DOI: 10.1111/j.1365-2435.2011.01857.x

[48] Ramírez C, Finot V, San Martin C, Ellies A. El valor indicador ecológico de las malezas del centro-sur de Chile. Agrosur. 1991;**19**:94-116

**81**

**Chapter 5**

**Abstract**

*japonica*)

simulation, board game

**1. Introduction**

*and Michael Jungmeier*

a comprehensive review about Japanese knotweed.

Game of Clones: Students Model

*Anneliese Fuchs, Christina Pichler-Koban, Wilfried Elmenreich* 

*Fallopia japonica* as an invasive alien species in Europe and North America presents a significant problem to the existing flora as well as to infrastructures and agricultural land. That is why measures and attempts to control the plant are increasing rapidly. However, conservationists are not yet able to agree on the most suitable method. In the research project 'Game of Clones', a team of scientists together with the help of high school students is spatially modeling the spreading behavior of knotweed under different circumstances and is creating and providing a board game as well as a computer simulation as an experimental platform. To develop sustainable assumptions to be able to model the responses of knotweed to each control measure, a vast understanding of the plant is necessary. The chapter covers the results of research activities and experiments within the project and gives

**Keywords:** Japanese knotweed, invasive species, dispersal, modeling, computer

The spread of non-native species and their impact on the environment are a much-noticed topic in science and nature conservation. Recently, also a broader public is becoming increasingly interested, especially as the annual economic loss caused by alien species is estimated to be up to 5% of the world economic output [1]. Moreover, invasive alien species are an important factor in the loss of biodiversity. In fact, an analysis of the IUCN Red List shows that it is one of the most common threats associated with extinct species. Invasive alien species can also lead to changes in the structure and composition of ecosystems that have a significant negative impact on ecosystem services and affect the economy and well-being of humans [2–4]. Although the number of documented invasive species is underestimated in many countries, the introduction of invasive species has increased significantly. In Europe, for example, the number of invasive alien species increased by 76% between 1970 and 2007 (IUCN). Only a few of the thousands of species introduced into new areas actually become invasive, which is why their

the Dispersal and Fighting of

Japanese Knotweed (*Fallopia* 

#### **Chapter 5**

## Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed (*Fallopia japonica*)

*Anneliese Fuchs, Christina Pichler-Koban, Wilfried Elmenreich and Michael Jungmeier*

#### **Abstract**

*Fallopia japonica* as an invasive alien species in Europe and North America presents a significant problem to the existing flora as well as to infrastructures and agricultural land. That is why measures and attempts to control the plant are increasing rapidly. However, conservationists are not yet able to agree on the most suitable method. In the research project 'Game of Clones', a team of scientists together with the help of high school students is spatially modeling the spreading behavior of knotweed under different circumstances and is creating and providing a board game as well as a computer simulation as an experimental platform. To develop sustainable assumptions to be able to model the responses of knotweed to each control measure, a vast understanding of the plant is necessary. The chapter covers the results of research activities and experiments within the project and gives a comprehensive review about Japanese knotweed.

**Keywords:** Japanese knotweed, invasive species, dispersal, modeling, computer simulation, board game

#### **1. Introduction**

The spread of non-native species and their impact on the environment are a much-noticed topic in science and nature conservation. Recently, also a broader public is becoming increasingly interested, especially as the annual economic loss caused by alien species is estimated to be up to 5% of the world economic output [1]. Moreover, invasive alien species are an important factor in the loss of biodiversity. In fact, an analysis of the IUCN Red List shows that it is one of the most common threats associated with extinct species. Invasive alien species can also lead to changes in the structure and composition of ecosystems that have a significant negative impact on ecosystem services and affect the economy and well-being of humans [2–4]. Although the number of documented invasive species is underestimated in many countries, the introduction of invasive species has increased significantly. In Europe, for example, the number of invasive alien species increased by 76% between 1970 and 2007 (IUCN). Only a few of the thousands of species introduced into new areas actually become invasive, which is why their

identification is the main objective of invasion biology. In Austria, 1110 alien vascular plant species have been identified, which account for 27% of the total Austrian flora. Of these, 17 species are problematic for nature conservation as they invade near-natural habitats [5]. Japanese knotweed, *Fallopia japonica*, is one of them and is considered to cause large changes to the communities and ecosystems it invades. Its large size and its clonal, monocultural growth lead to the visual, structural, and chemical transformation of ecosystems. Wherever the plant takes root, the diversity of plant species decreases. The remaining competing species are mostly non-native [6–9] and show strong reductions in height, biomass, and specific leaf area (SLA) [10]. Once a *F. japonica* stand is established, the clonal connectivity increases its ability to grow further [6]. The vast spreading in riparian areas also results in the reduction of an overall abundance of invertebrates [3, 7]. Therefore, a large-scale invasion of *Fallopia* species is likely to seriously affect the biodiversity and quality of ecosystems and should be prevented [7].

Not only does Japanese knotweed have a negative effect on the environment, but it also causes damage to infrastructure and costs effort and money for removal work. Each year, a considerable sum is spent on vegetation management on railway and road networks [11]. *Fallopia japonica* prefers manmade locations where other plants do not have a chance; in railway structures these are graveled areas, platforms, and loading areas. Weed control is primarily carried out in the track area in order to avoid fine soil and humus accumulation and thus reduce increased water retention capacity. Also, for the treatment of the track-accompanying paths, security is the main reason [12]. The urgent need for action can also be seen in our current projects: the project "Vegetation control on roads and railways" aims for vegetation control of traffic infrastructure areas with a balanced consideration between conventional and effective eco-alternative methods. In another project we are taking over the scientific monitoring for railway embankment grazing on the Koralm railway in order to control Japanese knotweed [13].

In agriculture, in addition to knotweed competing with crops, contaminated goods such as humus landfills pose a real problem. Open soils and disturbed vegetation provide an opportunity for problematic plants to colonize. One centimeter of root is enough for Japanese knotweed to form a new population [14]. According to Section 21 of the Carinthian Nature Conservation Act, the release or sowing of wild plants […] into areas in which they are not native requires a permit. A permit may only be granted if neither the natural habitats nor the native wild animal and plant species are damaged. Large economic losses can therefore occur if humus landfills partly or fully overgrown with knotweed can no longer be used as such.

At present, there is no fully effective method to control knotweed. Still, in the literature, there is a long list of control methods ranging from mechanical methods such as pulling out and mowing [15] to grazing with sheep and goats [16], planting competitive native species [17, 18], covering the roots with tarpaulin, and using herbicides [18, 19] to biological control such as the use of Japanese knotweed psyllid [20].

In summary, characteristics, effects, and control measures of Japanese knotweed are subject to numerous research projects in Central Europe and North America; "Game of Clones" is one of them and approaches the topic in a somewhat different and playful way. A team of scientists together with the help of high school students aims to spatially model the spreading behavior of knotweed under different circumstances and to create and provide a computer simulation as an experimental platform as well as a board game. Considering that multiple components are required, first, a vast understanding of knotweed, especially regarding its ecological optima, its dispersal strategy, and its response to different control measures, is necessary. Therefrom, sustainable assumptions can be developed to be able to model the responses of knotweed to each control measure. For answering some of

**83**

**2. Methods**

**2.1 Literature research**

**2.2 Phenotypic and genotypic identification**

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

the questions, experiments will be used. The outcomes will lead to the creation of a board game and a computer simulation model based on a cellular automaton to be able to analyze and demonstrate the spreading behavior of knotweed in an interactive manner. Players will try out different measures to eradicate the clones and to keep particularly valuable areas clear from the weed. Doing this, they should go as easy on resources as possible. Depending on the individual starting points, different measures and combinations of measures will lead to success, in other words, reduce or stop the plant growth. The game takes place on actual existing land (satellite images), so the computer simulation can also be consulted for concrete action planning. The students in the research project will also play a part in the browserbased programming of the strategy game; in this way, they will simultaneously be an important reference group regarding its user-friendliness and functionality. The present chapter covers the results of the research activities and experiments within the project and gives a comprehensive review about Japanese knotweed. Section 2 starts with a description of all methods used, and Section 3 will be about the corresponding results. Section 4 finally discusses the question of the necessity of invasive species removal, summarizes the results, and concludes with a range of further recommendations for improving the existing evaluation and monitoring frameworks.

In "Game of Clones", a multitude of methods have been and are used. This is especially important because it is the only way to fully understand Japanese knotweed in all its parts and behaviors. The following chapter will describe each method with all its limitations and challenges in detail to be able to relate to the results.

As a start, the team of researchers has carried out an extensive literature search. The contributions and articles collected were reviewed and classified as more or less relevant to the research question of the project. With the support of the Regional Museum of Carinthia (Landesmuseum Kärnten), a bibliography of over 200 relevant papers on *Fallopia japonica* was compiled and divided into various topics: classification, taxonomy, identification, characteristics, history, growth, reproduction, spreading, usage, impacts, monitoring, control, management, invasions, and modeling.

For a serious discussion about the plant, the most urgent question that needs to be clarified and cannot be answered by the literature is what exact species we are dealing with in our project area. In Central Europe, there is evidence for two introduced species, *Fallopia japonica* and *Fallopia sachalinensis*; their hybrid *Fallopia × bohemica* has begun spreading as well [6, 21, 22]. The two original species are relatively easy to distinguish based on the shape and size of their leaves, but discriminating them from hybrids is challenging, even for experts. Hence, we will make use of DNA-barcoding, a taxonomic method for species identification using the DNA sequence of a marker gene [23]. The sequence of base pairs is used as a marker for a particular species, analogous to the barcode on food packaging. Since the DNA sequence changes by point mutations at a generally uniform rate, more closely related individuals (and species) have more similar sequences. As long as a species remains undivided, i.e., has a common gene pool, differences between different populations are compensated again and again by gene flow. So, if samples from two individuals have clearly different

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

the questions, experiments will be used. The outcomes will lead to the creation of a board game and a computer simulation model based on a cellular automaton to be able to analyze and demonstrate the spreading behavior of knotweed in an interactive manner. Players will try out different measures to eradicate the clones and to keep particularly valuable areas clear from the weed. Doing this, they should go as easy on resources as possible. Depending on the individual starting points, different measures and combinations of measures will lead to success, in other words, reduce or stop the plant growth. The game takes place on actual existing land (satellite images), so the computer simulation can also be consulted for concrete action planning. The students in the research project will also play a part in the browserbased programming of the strategy game; in this way, they will simultaneously be an important reference group regarding its user-friendliness and functionality. The present chapter covers the results of the research activities and experiments within the project and gives a comprehensive review about Japanese knotweed. Section 2 starts with a description of all methods used, and Section 3 will be about the corresponding results. Section 4 finally discusses the question of the necessity of invasive species removal, summarizes the results, and concludes with a range of further recommendations for improving the existing evaluation and monitoring frameworks.

#### **2. Methods**

*Diversity and Ecology of Invasive Plants*

of ecosystems and should be prevented [7].

Koralm railway in order to control Japanese knotweed [13].

identification is the main objective of invasion biology. In Austria, 1110 alien vascular plant species have been identified, which account for 27% of the total Austrian flora. Of these, 17 species are problematic for nature conservation as they invade near-natural habitats [5]. Japanese knotweed, *Fallopia japonica*, is one of them and is considered to cause large changes to the communities and ecosystems it invades. Its large size and its clonal, monocultural growth lead to the visual, structural, and chemical transformation of ecosystems. Wherever the plant takes root, the diversity of plant species decreases. The remaining competing species are mostly non-native [6–9] and show strong reductions in height, biomass, and specific leaf area (SLA) [10]. Once a *F. japonica* stand is established, the clonal connectivity increases its ability to grow further [6]. The vast spreading in riparian areas also results in the reduction of an overall abundance of invertebrates [3, 7]. Therefore, a large-scale invasion of *Fallopia* species is likely to seriously affect the biodiversity and quality

Not only does Japanese knotweed have a negative effect on the environment, but it also causes damage to infrastructure and costs effort and money for removal work. Each year, a considerable sum is spent on vegetation management on railway and road networks [11]. *Fallopia japonica* prefers manmade locations where other plants do not have a chance; in railway structures these are graveled areas, platforms, and loading areas. Weed control is primarily carried out in the track area in order to avoid fine soil and humus accumulation and thus reduce increased water retention capacity. Also, for the treatment of the track-accompanying paths, security is the main reason [12]. The urgent need for action can also be seen in our current projects: the project "Vegetation control on roads and railways" aims for vegetation control of traffic infrastructure areas with a balanced consideration between conventional and effective eco-alternative methods. In another project we are taking over the scientific monitoring for railway embankment grazing on the

In agriculture, in addition to knotweed competing with crops, contaminated goods such as humus landfills pose a real problem. Open soils and disturbed vegetation provide an opportunity for problematic plants to colonize. One centimeter of root is enough for Japanese knotweed to form a new population [14]. According to Section 21 of the Carinthian Nature Conservation Act, the release or sowing of wild plants […] into areas in which they are not native requires a permit. A permit may only be granted if neither the natural habitats nor the native wild animal and plant species are damaged. Large economic losses can therefore occur if humus landfills

At present, there is no fully effective method to control knotweed. Still, in the literature, there is a long list of control methods ranging from mechanical methods such as pulling out and mowing [15] to grazing with sheep and goats [16], planting competitive native species [17, 18], covering the roots with tarpaulin, and using herbicides [18, 19] to biological control such as the use of Japanese knotweed psyllid [20]. In summary, characteristics, effects, and control measures of Japanese knotweed are subject to numerous research projects in Central Europe and North America; "Game of Clones" is one of them and approaches the topic in a somewhat different and playful way. A team of scientists together with the help of high school students aims to spatially model the spreading behavior of knotweed under different circumstances and to create and provide a computer simulation as an experimental platform as well as a board game. Considering that multiple components are required, first, a vast understanding of knotweed, especially regarding its ecological optima, its dispersal strategy, and its response to different control measures, is necessary. Therefrom, sustainable assumptions can be developed to be able to model the responses of knotweed to each control measure. For answering some of

partly or fully overgrown with knotweed can no longer be used as such.

**82**

In "Game of Clones", a multitude of methods have been and are used. This is especially important because it is the only way to fully understand Japanese knotweed in all its parts and behaviors. The following chapter will describe each method with all its limitations and challenges in detail to be able to relate to the results.

#### **2.1 Literature research**

As a start, the team of researchers has carried out an extensive literature search. The contributions and articles collected were reviewed and classified as more or less relevant to the research question of the project. With the support of the Regional Museum of Carinthia (Landesmuseum Kärnten), a bibliography of over 200 relevant papers on *Fallopia japonica* was compiled and divided into various topics: classification, taxonomy, identification, characteristics, history, growth, reproduction, spreading, usage, impacts, monitoring, control, management, invasions, and modeling.

#### **2.2 Phenotypic and genotypic identification**

For a serious discussion about the plant, the most urgent question that needs to be clarified and cannot be answered by the literature is what exact species we are dealing with in our project area. In Central Europe, there is evidence for two introduced species, *Fallopia japonica* and *Fallopia sachalinensis*; their hybrid *Fallopia × bohemica* has begun spreading as well [6, 21, 22]. The two original species are relatively easy to distinguish based on the shape and size of their leaves, but discriminating them from hybrids is challenging, even for experts. Hence, we will make use of DNA-barcoding, a taxonomic method for species identification using the DNA sequence of a marker gene [23]. The sequence of base pairs is used as a marker for a particular species, analogous to the barcode on food packaging. Since the DNA sequence changes by point mutations at a generally uniform rate, more closely related individuals (and species) have more similar sequences. As long as a species remains undivided, i.e., has a common gene pool, differences between different populations are compensated again and again by gene flow. So, if samples from two individuals have clearly different

sequences, this is a sign that they come from different species [24]. The analysis of two marker genes (chloroplast marker and nuclear marker) should provide information on hybridization and distribution of the species in our project area of the Austrian federal states of Carinthia and Styria. The chloroplast marker is inherited from the maternal organism, so by using it we will see what species was maternal. The nuclear marker will indicate if the plant is homo- or heterozygote, therefore a hybrid.

In the months of July and August 2018, 95 leaf samples were collected and sent to the Canadian Centre for DNA Barcoding (CCDB) in Guelph for DNA sequencing. For 3 weeks, 72 of the leaf samples were taken from individuals in Carinthia and Styria. Care was taken to ensure that different locations and morphologically different stands were chosen. If a site was selected, a tissue piece with an area of 1 × 0.5 cm was sampled with clean forceps. Preference was always given to the youngest and greenest parts of the plant, rich in plastids and meristematic cells such as the tip of a leaf. The samples were then placed in airtight bags of silica gel and kept to dry. Before proceeding to the next sample, it was crucial to ensure that no residual tissue remained on the forceps by rinsing them in 95% ethanol and wiping them with a clean absorbent paper. For each sample, a herbarium voucher of several leaves and flowers was collected, dried, and archived in the Regional Museum of Carinthia. Additional metadata included the assumed species, age, and sex as well as a detailed description of the site consisting of GPS coordinates, address, and site conditions. A photo documentation comprising location, entire plant, leaf surface and underside, and flower complements the sample collection (**Figures 1** and **2**).

Each sample was assigned to a Museum ID, which links it to the voucher, the metadata, and the photo documentation. A total of 13 of the 95 samples were collected from reliably identified individuals of all three species from the herbarium in the Regional Museum of Carinthia to serve as a reference. Ten of the 95 samples were not taken from the field, but CCDB offered to organize reference samples from Eastern Asia to have some samples from Japanese knotweed's native range.

The analysis is still ongoing; in case the sequencing will be successful, the data will be fed into the global Barcode of Life Data System (BOLD).

**85**

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

Growth rates and propagation patterns are crucial parts of the basic data needed for the modeling of *Fallopia* populations. That is why we set up two transects on the campus of the Lakeside Science & Technology Park, a science and technology park in Klagenfurt. A transect is a straight line along which one counts and records occurrences of a species. The main advantage of transect mapping is its repeatability and standardization even under difficult terrain conditions. Both our transects (10 m each) were border on infiltration areas. The exact position of the transects was chosen in such a way that the shoots are rather in the middle of the observation area in order to be able to measure the propagation better. All methods were implemented according to the manual of vegetation-ecological monitoring by Andreas Traxler [25]. The transects were divided into 10 subplots (1 × 1 m each); the measured plants were each marked with a piece of yarn. In a weekly monitoring (April–July), the growth and propagation of *Fallopia japonica* was observed with two methods. On the one hand, three shoots were selected in both transects, in which the shoot width (at a height of 10 cm) and the height itself were measured with a caliper and meterstick. On the other hand, the number of shoots in each subplot was counted, and new shoots were marked and measured for their exact position. The data gain significance if they are interpreted in connection with the weather data for the period in question, as it is intended for the compilation of the logarithms of the computer simulation.

*Herbarium voucher of a sample of Fallopia sachalinensis (Herbarium collection code: KL—Kärntner* 

A good understanding of the underground processes in the *Fallopia* clone is of central importance for our research. To understand the connection between plant growth above- and underground and the knotweed's reaction to obstacles, we laid bare the entire root network of two stands in a large-scale field experiment. The method we used was already developed and successfully applied for the root

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

**2.3 Transect monitoring**

**Figure 2.**

*Landesherbar).*

**2.4 Rhizome uncovering**

exposure of forest trees in the past [26].

**Figure 1.** *Required tools for field sampling (E.C.O Institute of Ecology).*

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

#### **Figure 2.**

*Diversity and Ecology of Invasive Plants*

sequences, this is a sign that they come from different species [24]. The analysis of two marker genes (chloroplast marker and nuclear marker) should provide information on hybridization and distribution of the species in our project area of the Austrian federal states of Carinthia and Styria. The chloroplast marker is inherited from the maternal organism, so by using it we will see what species was maternal. The nuclear marker will indicate if the plant is homo- or heterozygote, therefore a hybrid. In the months of July and August 2018, 95 leaf samples were collected and sent to the Canadian Centre for DNA Barcoding (CCDB) in Guelph for DNA sequencing. For 3 weeks, 72 of the leaf samples were taken from individuals in Carinthia and Styria. Care was taken to ensure that different locations and morphologically different stands were chosen. If a site was selected, a tissue piece with an area of 1 × 0.5 cm was sampled with clean forceps. Preference was always given to the youngest and greenest parts of the plant, rich in plastids and meristematic cells such as the tip of a leaf. The samples were then placed in airtight bags of silica gel and kept to dry. Before proceeding to the next sample, it was crucial to ensure that no residual tissue remained on the forceps by rinsing them in 95% ethanol and wiping them with a clean absorbent paper. For each sample, a herbarium voucher of several leaves and flowers was collected, dried, and archived in the Regional Museum of Carinthia. Additional metadata included the assumed species, age, and sex as well as a detailed description of the site consisting of GPS coordinates, address, and site conditions. A photo documentation comprising location, entire plant, leaf surface and underside, and flower complements the sample collection (**Figures 1** and **2**). Each sample was assigned to a Museum ID, which links it to the voucher, the metadata, and the photo documentation. A total of 13 of the 95 samples were collected from reliably identified individuals of all three species from the herbarium in the Regional Museum of Carinthia to serve as a reference. Ten of the 95 samples were not taken from the field, but CCDB offered to organize reference samples from Eastern

Asia to have some samples from Japanese knotweed's native range.

will be fed into the global Barcode of Life Data System (BOLD).

The analysis is still ongoing; in case the sequencing will be successful, the data

**84**

**Figure 1.**

*Required tools for field sampling (E.C.O Institute of Ecology).*

*Herbarium voucher of a sample of Fallopia sachalinensis (Herbarium collection code: KL—Kärntner Landesherbar).*

#### **2.3 Transect monitoring**

Growth rates and propagation patterns are crucial parts of the basic data needed for the modeling of *Fallopia* populations. That is why we set up two transects on the campus of the Lakeside Science & Technology Park, a science and technology park in Klagenfurt. A transect is a straight line along which one counts and records occurrences of a species. The main advantage of transect mapping is its repeatability and standardization even under difficult terrain conditions. Both our transects (10 m each) were border on infiltration areas. The exact position of the transects was chosen in such a way that the shoots are rather in the middle of the observation area in order to be able to measure the propagation better. All methods were implemented according to the manual of vegetation-ecological monitoring by Andreas Traxler [25]. The transects were divided into 10 subplots (1 × 1 m each); the measured plants were each marked with a piece of yarn. In a weekly monitoring (April–July), the growth and propagation of *Fallopia japonica* was observed with two methods. On the one hand, three shoots were selected in both transects, in which the shoot width (at a height of 10 cm) and the height itself were measured with a caliper and meterstick. On the other hand, the number of shoots in each subplot was counted, and new shoots were marked and measured for their exact position. The data gain significance if they are interpreted in connection with the weather data for the period in question, as it is intended for the compilation of the logarithms of the computer simulation.

#### **2.4 Rhizome uncovering**

A good understanding of the underground processes in the *Fallopia* clone is of central importance for our research. To understand the connection between plant growth above- and underground and the knotweed's reaction to obstacles, we laid bare the entire root network of two stands in a large-scale field experiment. The method we used was already developed and successfully applied for the root exposure of forest trees in the past [26].

The stands are located on the campus of the Lakeside Science & Technology Park in Carinthia that borders directly on the Natura 2000 site Lendspitz-Maiernigg. During construction works 2 years ago, building rubble was piled up and populations of Japanese knotweed were able to colonize the area. The first location is a 4 m high hill with a 2-year-old stand; the second location borders on the parking lot, and its stands already exist for 4 years.

After the excavation work had been carried out and the site on the hill and next to the parking lot had been dug down by 2 m, the manual excavation work began. Together with the students, teachers, and soil experts of our two cooperating schools "BORG Spittal" based in Carinthia and "HBLFA Raumberg-Gumpenstein" based in Styria, the roots were then uncovered in a period of 2 days (**Figures 3** and **4**). The rough work was done with shovels, spades, and picks; the fine work was mainly done with screwdrivers. Bit by bit, the earth was dug away along the rhizomes and roots, thus exposing the roots. The results were documented in writing, in photographically, and in overview and detail drawings. The excavated shoot and rhizome parts were disposed of by the waste management department of the city of Klagenfurt so as not to contaminate further soil. After the two work days, the holes were dug up again by the excavator.

#### **2.5 Rhizoboxes**

Rhizoboxes are a non-invasive investigation method, which offers the possibility to survey the root system growth dynamics in time and space. Based on the root uncovering in Carinthia and the knowledge gained about length and width growth of the underground biomass, the experimental arrangements for the rhizoboxes were proposed. After a test experiment, adaptations took place; further experiments will follow. The method of using rhizoboxes aims to answer the following questions: how quickly do the rhizomes of knotweed grow (growth rates and depth and width growth) in vertical and horizontal rhizoboxes? What are the limiting factors (e.g., aboveground biomass, drought, cold, light, etc.)? For this purpose, 10 rhizoboxes in size of 30 × 100 cm were built, five in horizontal and five in vertical alignment (**Figures 5** and **6**).

**87**

**Figure 5.**

**Figure 4.**

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

*Measuring the length growth of the rhizome (HBLFA Raumberg-Gumpenstein).*

*The earth material must be sieved before the boxes are filled (HBLFA Raumberg-Gumpenstein).*

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

**Figure 3.** *Excavation work at location 1 (E.C.O. Institute of Ecology).* *Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

**Figure 4.** *Measuring the length growth of the rhizome (HBLFA Raumberg-Gumpenstein).*

**Figure 5.** *The earth material must be sieved before the boxes are filled (HBLFA Raumberg-Gumpenstein).*

*Diversity and Ecology of Invasive Plants*

again by the excavator.

five in vertical alignment (**Figures 5** and **6**).

*Excavation work at location 1 (E.C.O. Institute of Ecology).*

**2.5 Rhizoboxes**

The stands are located on the campus of the Lakeside Science & Technology

After the excavation work had been carried out and the site on the hill and next to the parking lot had been dug down by 2 m, the manual excavation work began. Together with the students, teachers, and soil experts of our two cooperating schools "BORG Spittal" based in Carinthia and "HBLFA Raumberg-Gumpenstein" based in Styria, the roots were then uncovered in a period of 2 days (**Figures 3** and **4**). The rough work was done with shovels, spades, and picks; the fine work was mainly done with screwdrivers. Bit by bit, the earth was dug away along the rhizomes and roots, thus exposing the roots. The results were documented in writing, in photographically, and in overview and detail drawings. The excavated shoot and rhizome parts were disposed of by the waste management department of the city of Klagenfurt so as not to contaminate further soil. After the two work days, the holes were dug up

Rhizoboxes are a non-invasive investigation method, which offers the possibility to survey the root system growth dynamics in time and space. Based on the root uncovering in Carinthia and the knowledge gained about length and width growth of the underground biomass, the experimental arrangements for the rhizoboxes were proposed. After a test experiment, adaptations took place; further experiments will follow. The method of using rhizoboxes aims to answer the following questions: how quickly do the rhizomes of knotweed grow (growth rates and depth and width growth) in vertical and horizontal rhizoboxes? What are the limiting factors (e.g., aboveground biomass, drought, cold, light, etc.)? For this purpose, 10 rhizoboxes in size of 30 × 100 cm were built, five in horizontal and

Park in Carinthia that borders directly on the Natura 2000 site Lendspitz-Maiernigg. During construction works 2 years ago, building rubble was piled up and populations of Japanese knotweed were able to colonize the area. The first location is a 4 m high hill with a 2-year-old stand; the second location borders on

the parking lot, and its stands already exist for 4 years.

**86**

**Figure 3.**

#### **Figure 6.** *The rhizome was traced to simplify the measuring (HBLFA Raumberg-Gumpenstein).*

**Attempt 1:** For the first experiment, fresh rhizome mass of Japanese knotweed was used to illustrate the growth in length, height, and width. On 13 July 2018, the first two boxes were filled with fresh earth material and the rhizome mass was planted (box 1 = 4 cm piece and box 2 = 7 cm piece). The first attempt was aborted because of glass jumps, mold formation, and too much soil and water.

**Attempt 2**: The second attempt started on July 27, 2018; four boxes were filled with fresh earth material. The length growth of the rhizome was measured approx. every 3–4 days, and the growth spurts were documented in an Excel file. The alignment of the boxes was optimized; the rhizome parts cast less intensively. After about 3 weeks, the growth directions and lengths were traced with a white marker. The boxes are still filled, and the rhizomes are moving inwards. Next steps will include:


**89**

**Figure 7.**

*University of Klagenfurt).*

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

precisely documenting length and width growth.

behavior of landslides during strong water accumulations [28].

• starting a new rhizobox experiment with fresh material in spring 2019 and

All experiences gained in our research will influence and have influenced the development of both the analog and the digital version of the strategy game 'Game of Clones'. The game is based on a spatial model using cellular automatons (**Figure 7**) to display dynamic vegetation patterns [27]. The basic approach of cellular automatons is a subdivision of the area into equally sized, mostly quadratic fields. The dynamics of the modeling results from an interaction between the neighboring cells, in which a "state" is set to overlap the neighboring field (discretely modeled temporal development). When defining neighborhoods for quadratic cells, the van Neumann neighborhood and the Moore neighborhood are being distinguished. Whereas in the van Neumann neighborhood only cells with common edges are considered neighbors (this results in 4 neighbors per cell), the Moore neighborhood also defines diagonally adjacent cells as neighbors (this results in 8 neighbors per cell). For "Game of Clones", we chose the approach of a model with hexagonal cells, in which there are always exactly six neighbors. An application of a hexagonal model can be found, for example, in the SCIDDICA model, which models the

The modeling of the game includes biological parameters such as nutrient uptake, growth, and propagation rates as well as system parameters such as the shape and size of the cells to be simulated. This intersection of disciplines requires a close cooperation between expert biologists and modelers. Starting from the literature and empirical findings (reference area and experiments), the model is

*Principle of the cellular automaton with hexagonal cells (Institute of Networked and Embedded Systems,* 

The rhizobox experiments were all conducted by the students Philipp Poier and Julian Heywood and their teachers Renate Mayer and Irene Sölkner from the HBLFA Raumberg-Gumpenstein. Next year, observations will be longer and more regular. The present studies served as first pilot experiments to get familiar with the method.

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

**2.6 Board game and computer simulation**

developed in an iterative process.

• starting a new rhizobox experiment with fresh material in spring 2019 and precisely documenting length and width growth.

The rhizobox experiments were all conducted by the students Philipp Poier and Julian Heywood and their teachers Renate Mayer and Irene Sölkner from the HBLFA Raumberg-Gumpenstein. Next year, observations will be longer and more regular. The present studies served as first pilot experiments to get familiar with the method.

#### **2.6 Board game and computer simulation**

*Diversity and Ecology of Invasive Plants*

**Attempt 1:** For the first experiment, fresh rhizome mass of Japanese knotweed was used to illustrate the growth in length, height, and width. On 13 July 2018, the first two boxes were filled with fresh earth material and the rhizome mass was planted (box 1 = 4 cm piece and box 2 = 7 cm piece). The first attempt was aborted because of glass jumps, mold formation, and too much soil and

*The rhizome was traced to simplify the measuring (HBLFA Raumberg-Gumpenstein).*

**Attempt 2**: The second attempt started on July 27, 2018; four boxes were filled with fresh earth material. The length growth of the rhizome was measured approx. every 3–4 days, and the growth spurts were documented in an Excel file. The alignment of the boxes was optimized; the rhizome parts cast less intensively. After about 3 weeks, the growth directions and lengths were traced with a white marker. The boxes are still filled, and the rhizomes are moving inwards. Next steps will

• leaving some earth and rhizome material in the boxes and storing it over the winter (covered with fleece) in order to test whether there will be further

• experimenting with two boxes being filled and sampled and simulating a longer growing period in the boarding school at a nearly constant tempera-

ture—the results are then evaluated in spring 2019, and

**88**

water.

**Figure 6.**

include:

growth next year,

All experiences gained in our research will influence and have influenced the development of both the analog and the digital version of the strategy game 'Game of Clones'. The game is based on a spatial model using cellular automatons (**Figure 7**) to display dynamic vegetation patterns [27]. The basic approach of cellular automatons is a subdivision of the area into equally sized, mostly quadratic fields. The dynamics of the modeling results from an interaction between the neighboring cells, in which a "state" is set to overlap the neighboring field (discretely modeled temporal development). When defining neighborhoods for quadratic cells, the van Neumann neighborhood and the Moore neighborhood are being distinguished. Whereas in the van Neumann neighborhood only cells with common edges are considered neighbors (this results in 4 neighbors per cell), the Moore neighborhood also defines diagonally adjacent cells as neighbors (this results in 8 neighbors per cell). For "Game of Clones", we chose the approach of a model with hexagonal cells, in which there are always exactly six neighbors. An application of a hexagonal model can be found, for example, in the SCIDDICA model, which models the behavior of landslides during strong water accumulations [28].

The modeling of the game includes biological parameters such as nutrient uptake, growth, and propagation rates as well as system parameters such as the shape and size of the cells to be simulated. This intersection of disciplines requires a close cooperation between expert biologists and modelers. Starting from the literature and empirical findings (reference area and experiments), the model is developed in an iterative process.

#### **Figure 7.**

*Principle of the cellular automaton with hexagonal cells (Institute of Networked and Embedded Systems, University of Klagenfurt).*

To be able to run the model with as many systems as possible, a browser-based implementation using html5 is provided to make the system compatible. Html5 supports the execution on operating systems and is—with certain restrictions with regard to screen size—also suitable for mobile devices. NetLogo, a multi-agent programming language with an integrated modeling environment, will be used for the simulation. The development process requires a repeated feedback of the results with biologists, whereby the model parameters and assumptions are repeatedly adjusted and compared with available findings (literature and experiments). This process is of particular scientific interest and value. The user interface is developed at the same time as the model is created. For this purpose, early user tests prototypes of the user interfaces to ensure ease of operation and an attractive design. The separation of model, view, and controller (Model-View-Controller Design Paradigm) allows a largely independent further development of program parts and supports a later independent use for other projects. The software is developed under an open source license and made available as a project result.

The board game "Game of Clones" is the analog version of the computer simulation and focuses on playability and fun instead of enforcing fully realistic scenarios. In the cooperative game, players work together in order to compete against Japanese knotweed, either winning or losing as a group. The board game was developed during biweekly meetings of the experts of the E.C.O. Institute of Ecology and the Institute of Networked and Embedded Systems from the University of Klagenfurt. A prototype of the board game is already available. During the development process, the students of BORG Spittal played through several test rounds and made a strong contribution to improving the game. The computer simulation will be completed by October 2019. In contrast to the board game, full attention will be paid to the closeness to reality whereby the program will be filled with all recorded data.

#### **3. Results**

#### **3.1 Literature research**

*Fallopia japonica* (Houtt.) from the knotweed family (Polygonaceae) has a number of synonyms, which makes literature research more difficult (frequently: *Polygonum cuspidatum* (Sieb. & Zucc.), *Reynoutria japonica* (Houtt.), and *Polygonum japonicum* (Meissn.)) as well as a number of phenotypically similar species and hybrids (in Austria in particular: *F. sachalinensis* and *F. × bohemica*) [29–31]. Until the definitive identification of the species in our study area, we use *Fallopia japonica* as the provisional collective name for these species.

Screening the literature, one of the main findings was that considering that it is only one single species, there is a huge amount of papers that revolve around Japanese knotweed. The articles cover various aspects of the plant, having a focus on morphology, systematics, spread, and control. Following a brief story-time about knotweed's introduction into Europe, this subchapter will be about the findings which proved to be relevant for the project.

*Fallopia japonica* was first introduced to Europe in 1825 by Philipp von Siebold, a Bavarian physician who worked for the Dutch government in Japan. Von Siebold had a strong interest in botany and natural history and sent a large shipment of live plants—over 500 different species—from Japan to the Netherlands, one of them being Japanese knotweed (under the name *Polygonum sieboldii*). It was intended to make a career as an ornamental and cattle feed plant and to be used in forestry as a feeding ground for red deer and as a covering plant for pheasants. The career as a useful plant did not start so well: it is of little use as a cover for pheasants, since it loses

**91**

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

Specialist Group (ISSG) of the IUCN Species Survival Commission.

its leaves in winter and red deer do not eat it, neither our grazing livestock. However, since in early autumn it is an excellent bee pasture when most of the European native plants have already flowered, the beekeepers have discovered Japanese knotweed for themselves [32]. Although the German Federal Nature Conservation Act and most of the Austrian Federal State Conservation Acts prohibit the planting of alien plants in the wild, beekeepers generously distributed the Japanese knotweed in the area—a first step on the way to a spread that currently places Japanese knotweed at No. 37 in the "Global Invasive Species Database", a database managed by the Invasive Species

When Japanese knotweed got introduced into Europe, they only introduced a female (male sterile) individuum, never the male indiviuum. A significant proportion of knotweed in Central Europe is not *F. japonica*, but the hybrid between it and *F. sachalinensis*—*F. bohemica*. This hybrid can reproduce with either parent and thus can replace the missing male specimens of *F. japonica*. In the same process, the hybrid produces the genetic diversity that *F. japonica* lacks

All *Fallopia* species have a strong clonal growth, which allows them to surpass the surrounding species as well as to colonize new areas quickly. The basic unit of the rhizome system is a shoot clump that varies in size in different *Fallopia* species. In general, the apex of a rhizome branch eventually becomes an aerial shoot. When the shoot clump no longer produces new aerial shoots and dies, some lateral buds break the dormancy and begin to grow horizontally as new rhizome branches sometimes extending over 1 m. While *F. japonica* has rather large shoot clumps connected by long thin rhizomes, *F. sachalinensis* produces smaller shoot clumps that are more closely connected and grow in rows. *F. × bohemica* combines the characteristics of both parents and has an intermediate patch structure with smaller shoot clumps than *F. japonica* and longer rhizome connections between individual shoot clumps than *F. sachalinensis.* The fragmentation and spread of rhizomes by flooding or human activity are the most important means of propagation, as rhizome fragments of 1 cm length and 0.7 g weight can regenerate. *Fallopia* species can also regenerate from stem parts, but with lower regeneration rates. *F. × bohemica* had the highest regeneration rate of all taxa (61%) and is the most successful in regenerating and establishing new shoots. *F. japonica* and *F.* 

*sachalinensis* show lower regeneration rates (39 and 21%, respectively) [35]*.*

will be less severe and restrictive [39].

The ability to regenerate in very poor soils with low nutrient requirements allows the plant to occur in a variety of habitats. It is not unusual for *F. japonica* to grow at the foot of buildings or on concrete surfaces [36]. The plant achieves it competitive superiority primarily by limiting access to light [37]. A factor, Japanese knotweed is very sensitive to, is frost. The plant is exposed to significant damages by late spring frosts when the shoots appear and by early frosts in autumn when the leaves senesce at the end of the growing season. This situation suggests that minimum spring temperatures may limit its range expansion [38]. However, climate change will open up habitats within threshold values, and frost conditions in these areas

All these circumstances and many more make it extremely hard to get control over the invasive species. In the literature, there are many control methods and attempts described, but there are none that are completely convincing, and it amounts to a combination of different methods. Mechanical regulations focus on mowing, and although mowing during the vegetation period reduces the height and the diameter growth of shoots, the total weight of the biomass more or less stays the same [15]. The combination of cutting or mowing and using glyphosate has shown to be the most efficient and least time-consuming strategy so far [19, 40]. It is important to replant the area immediately with competitive native species to fight against invasive recolonization. On average, a suppression of knotweed is necessary

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

so strikingly [33, 34].

#### *Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

its leaves in winter and red deer do not eat it, neither our grazing livestock. However, since in early autumn it is an excellent bee pasture when most of the European native plants have already flowered, the beekeepers have discovered Japanese knotweed for themselves [32]. Although the German Federal Nature Conservation Act and most of the Austrian Federal State Conservation Acts prohibit the planting of alien plants in the wild, beekeepers generously distributed the Japanese knotweed in the area—a first step on the way to a spread that currently places Japanese knotweed at No. 37 in the "Global Invasive Species Database", a database managed by the Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission.

When Japanese knotweed got introduced into Europe, they only introduced a female (male sterile) individuum, never the male indiviuum. A significant proportion of knotweed in Central Europe is not *F. japonica*, but the hybrid between it and *F. sachalinensis*—*F. bohemica*. This hybrid can reproduce with either parent and thus can replace the missing male specimens of *F. japonica*. In the same process, the hybrid produces the genetic diversity that *F. japonica* lacks so strikingly [33, 34].

All *Fallopia* species have a strong clonal growth, which allows them to surpass the surrounding species as well as to colonize new areas quickly. The basic unit of the rhizome system is a shoot clump that varies in size in different *Fallopia* species. In general, the apex of a rhizome branch eventually becomes an aerial shoot. When the shoot clump no longer produces new aerial shoots and dies, some lateral buds break the dormancy and begin to grow horizontally as new rhizome branches sometimes extending over 1 m. While *F. japonica* has rather large shoot clumps connected by long thin rhizomes, *F. sachalinensis* produces smaller shoot clumps that are more closely connected and grow in rows. *F. × bohemica* combines the characteristics of both parents and has an intermediate patch structure with smaller shoot clumps than *F. japonica* and longer rhizome connections between individual shoot clumps than *F. sachalinensis.* The fragmentation and spread of rhizomes by flooding or human activity are the most important means of propagation, as rhizome fragments of 1 cm length and 0.7 g weight can regenerate. *Fallopia* species can also regenerate from stem parts, but with lower regeneration rates. *F. × bohemica* had the highest regeneration rate of all taxa (61%) and is the most successful in regenerating and establishing new shoots. *F. japonica* and *F. sachalinensis* show lower regeneration rates (39 and 21%, respectively) [35]*.*

The ability to regenerate in very poor soils with low nutrient requirements allows the plant to occur in a variety of habitats. It is not unusual for *F. japonica* to grow at the foot of buildings or on concrete surfaces [36]. The plant achieves it competitive superiority primarily by limiting access to light [37]. A factor, Japanese knotweed is very sensitive to, is frost. The plant is exposed to significant damages by late spring frosts when the shoots appear and by early frosts in autumn when the leaves senesce at the end of the growing season. This situation suggests that minimum spring temperatures may limit its range expansion [38]. However, climate change will open up habitats within threshold values, and frost conditions in these areas will be less severe and restrictive [39].

All these circumstances and many more make it extremely hard to get control over the invasive species. In the literature, there are many control methods and attempts described, but there are none that are completely convincing, and it amounts to a combination of different methods. Mechanical regulations focus on mowing, and although mowing during the vegetation period reduces the height and the diameter growth of shoots, the total weight of the biomass more or less stays the same [15]. The combination of cutting or mowing and using glyphosate has shown to be the most efficient and least time-consuming strategy so far [19, 40]. It is important to replant the area immediately with competitive native species to fight against invasive recolonization. On average, a suppression of knotweed is necessary

*Diversity and Ecology of Invasive Plants*

To be able to run the model with as many systems as possible, a browser-based implementation using html5 is provided to make the system compatible. Html5 supports the execution on operating systems and is—with certain restrictions with regard to screen size—also suitable for mobile devices. NetLogo, a multi-agent programming language with an integrated modeling environment, will be used for the simulation. The development process requires a repeated feedback of the results with biologists, whereby the model parameters and assumptions are repeatedly adjusted and compared with available findings (literature and experiments). This process is of particular scientific interest and value. The user interface is developed at the same time as the model is created. For this purpose, early user tests prototypes of the user interfaces to ensure ease of operation and an attractive design. The separation of model, view, and controller (Model-View-Controller Design Paradigm) allows a largely independent further development of program parts and supports a later independent use for other projects. The software is developed under

The board game "Game of Clones" is the analog version of the computer simulation and focuses on playability and fun instead of enforcing fully realistic scenarios. In the cooperative game, players work together in order to compete against Japanese knotweed, either winning or losing as a group. The board game was developed during biweekly meetings of the experts of the E.C.O. Institute of Ecology and the Institute of Networked and Embedded Systems from the University of Klagenfurt. A prototype of the board game is already available. During the development process, the students of BORG Spittal played through several test rounds and made a strong contribution to improving the game. The computer simulation will be completed by October 2019. In contrast to the board game, full attention will be paid to the closeness to reality whereby the program will be filled with all recorded data.

*Fallopia japonica* (Houtt.) from the knotweed family (Polygonaceae) has a number of synonyms, which makes literature research more difficult (frequently: *Polygonum cuspidatum* (Sieb. & Zucc.), *Reynoutria japonica* (Houtt.), and *Polygonum japonicum* (Meissn.)) as well as a number of phenotypically similar species and hybrids (in Austria in particular: *F. sachalinensis* and *F. × bohemica*) [29–31]. Until the definitive identification of the species in our study area, we use *Fallopia japonica*

Screening the literature, one of the main findings was that considering that it is only one single species, there is a huge amount of papers that revolve around Japanese knotweed. The articles cover various aspects of the plant, having a focus on morphology, systematics, spread, and control. Following a brief story-time about knotweed's introduction into Europe, this subchapter will be about the find-

*Fallopia japonica* was first introduced to Europe in 1825 by Philipp von Siebold, a Bavarian physician who worked for the Dutch government in Japan. Von Siebold had a strong interest in botany and natural history and sent a large shipment of live plants—over 500 different species—from Japan to the Netherlands, one of them being Japanese knotweed (under the name *Polygonum sieboldii*). It was intended to make a career as an ornamental and cattle feed plant and to be used in forestry as a feeding ground for red deer and as a covering plant for pheasants. The career as a useful plant did not start so well: it is of little use as a cover for pheasants, since it loses

an open source license and made available as a project result.

as the provisional collective name for these species.

ings which proved to be relevant for the project.

**90**

**3. Results**

**3.1 Literature research**

for 2 years, before native species can be successfully established [18]. Another option is a long-term grazing of cows, sheep, or goats to keep the area knotweedfree [16]. A strategy which is becoming more popular is biological control, not least since Japanese knotweed was introduced without all its natural enemies. *Aphalara itadori* (*itadori* being the Japanese word for *Fallopia japonica*), a species of psyllid from Japan which feeds on Japanese knotweed, is the subject of an application for release into the wild in Great Britain. It has been licensed by the UK Government for the biological control of Japanese knotweed in England; this is the first time that biological control of a weed has been sanctioned in the European Union [41]. Other biological controls include a leaf beetle, *Gallerucida bifasciata* [42] or snails, *Succinea putris*, and *Urticicola umbrosus* [43].

#### **3.2 Phenotypic and genotypic identification**

So far, the leaf samples have been sent to the Canadian Centre for DNA Barcoding (CCDB), the analysis is not yet complete though. The expected results should clarify which *Fallopia* species occur in Carinthia and Styria and in what proportion. The phenotypic determination suggests that only sporadic samples of *F. sachalinensis* are expected. Due to insufficient morphological differences, the phenotypic discrimination between *F. japonica* and *F. x bohemica* was not possible.

#### **3.3 Transect monitoring**

The weekly monitoring of the two transects provided information on growth rates in height and diameter. The average height growth of the six plants studied decreased as the vegetation period progressed. While the growth of the shoots in April was averagely 21.7 cm per week, it dropped to an average of 14 cm in May and to an average of 1.2 cm in June. As a percentage, the plants grew by 40, 1, 15, and 0.9%, respectively. In **Figure 8**, the growth rate is visualized for each individual, and the initial length of the shoots is as follows: 117.6 cm (A.4.1.), 35 cm (A.5.1.), 77.5 cm (A.6.1.), 32 cm (B.6.1.), 26 cm (B.9.1.), and 36.7 cm (B.9.1.). The average diameter growth was between 1.2 and−0.5 mm per week. The negative values result

**93**

**Figure 9.**

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

shoot, which has shortened the shoot and weakened the plant.

water body, which is generally high in Klagenfurt.

**3.6 Board game and computer simulation**

*Overview drawing Site 1 (E.C.O. Institute of Ecology).*

from the fact that knotweed does not have woody shoots and the diameter size depends strongly on the water balance of the plant. Thus, it can happen that the diameter shrinks temporarily. While the growth of the diameter in April was averagely 0.3 mm (5%) per week, the growth rose to 1.8 mm (17%) in May. The plants lost biomass in the end of May/beginning of June resulting in negative values of −0.25 mm (−33%) and recovered in June with 1 mm (13%) growth rate. The initial diameters of the shoots as visualized in **Figure 8** are the following: 12 mm (A.4.1.), 2.1 mm (A.5.1.), 8.5 mm (A.6.1.), 3 mm (B.6.1.), 3 mm (B.9.1.), and 6 mm (B.9.1.). B.9.1. has low values starting in May; this results from a sudden wind break in the

The rhizome uncovering could not confirm the assumption that the largest biomass of Japanese knotweed is underground. At site 1, the 2-year-old stand grew at a height of 4 m—the longest rhizomes reached a depth of 80 cm and were mainly horizontal. The reason to assume is that the plant mainly invests in the above-ground mass in the first few years. Site 2, a 4-year-old stand, underlines this assumption. The rhizomes reach 2 m into the deep until they stand at the ground-

The initial length of the rhizome pieces put in the rhizoboxes ranges from 5 to 24 cm. The results show that there is no correlation between initial rhizome length and growth rate. The boxes have been positioned horizontally and vertically, which showed a slight advantage for the rhizomes put in the horizontal boxes. All rhizomes started growing at a slow pace and speeded up at the end. These preliminary results have been conducted by students; further experiments are planned (**Figures 9–11**)

All data and experiences gained in the project result in the development of a computer simulation. Along the way, we also created a board game for children and adults from the age of 10 years, which is currently on its way to a game publisher. The cooperation game allows players to work together as teammates against the opponent, Japanese knotweed. The game starts with a landscape full of differently

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

**3.4 Rhizome uncovering**

**3.5 Rhizoboxes**

and (**Table 1**).

**Figure 8.** *Height and diameter growth of shoots in two transects (A*&*B).*

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

from the fact that knotweed does not have woody shoots and the diameter size depends strongly on the water balance of the plant. Thus, it can happen that the diameter shrinks temporarily. While the growth of the diameter in April was averagely 0.3 mm (5%) per week, the growth rose to 1.8 mm (17%) in May. The plants lost biomass in the end of May/beginning of June resulting in negative values of −0.25 mm (−33%) and recovered in June with 1 mm (13%) growth rate. The initial diameters of the shoots as visualized in **Figure 8** are the following: 12 mm (A.4.1.), 2.1 mm (A.5.1.), 8.5 mm (A.6.1.), 3 mm (B.6.1.), 3 mm (B.9.1.), and 6 mm (B.9.1.). B.9.1. has low values starting in May; this results from a sudden wind break in the shoot, which has shortened the shoot and weakened the plant.

#### **3.4 Rhizome uncovering**

*Diversity and Ecology of Invasive Plants*

*Succinea putris*, and *Urticicola umbrosus* [43].

**3.2 Phenotypic and genotypic identification**

**3.3 Transect monitoring**

for 2 years, before native species can be successfully established [18]. Another option is a long-term grazing of cows, sheep, or goats to keep the area knotweedfree [16]. A strategy which is becoming more popular is biological control, not least since Japanese knotweed was introduced without all its natural enemies. *Aphalara itadori* (*itadori* being the Japanese word for *Fallopia japonica*), a species of psyllid from Japan which feeds on Japanese knotweed, is the subject of an application for release into the wild in Great Britain. It has been licensed by the UK Government for the biological control of Japanese knotweed in England; this is the first time that biological control of a weed has been sanctioned in the European Union [41]. Other biological controls include a leaf beetle, *Gallerucida bifasciata* [42] or snails,

So far, the leaf samples have been sent to the Canadian Centre for DNA Barcoding (CCDB), the analysis is not yet complete though. The expected results should clarify which *Fallopia* species occur in Carinthia and Styria and in what proportion. The phenotypic determination suggests that only sporadic samples of *F. sachalinensis* are expected. Due to insufficient morphological differences, the phenotypic discrimination between *F. japonica* and *F. x bohemica* was not possible.

The weekly monitoring of the two transects provided information on growth rates in height and diameter. The average height growth of the six plants studied decreased as the vegetation period progressed. While the growth of the shoots in April was averagely 21.7 cm per week, it dropped to an average of 14 cm in May and to an average of 1.2 cm in June. As a percentage, the plants grew by 40, 1, 15, and 0.9%, respectively. In **Figure 8**, the growth rate is visualized for each individual, and the initial length of the shoots is as follows: 117.6 cm (A.4.1.), 35 cm (A.5.1.), 77.5 cm (A.6.1.), 32 cm (B.6.1.), 26 cm (B.9.1.), and 36.7 cm (B.9.1.). The average diameter growth was between 1.2 and−0.5 mm per week. The negative values result

**92**

**Figure 8.**

*Height and diameter growth of shoots in two transects (A*&*B).*

The rhizome uncovering could not confirm the assumption that the largest biomass of Japanese knotweed is underground. At site 1, the 2-year-old stand grew at a height of 4 m—the longest rhizomes reached a depth of 80 cm and were mainly horizontal. The reason to assume is that the plant mainly invests in the above-ground mass in the first few years. Site 2, a 4-year-old stand, underlines this assumption. The rhizomes reach 2 m into the deep until they stand at the groundwater body, which is generally high in Klagenfurt.

#### **3.5 Rhizoboxes**

The initial length of the rhizome pieces put in the rhizoboxes ranges from 5 to 24 cm. The results show that there is no correlation between initial rhizome length and growth rate. The boxes have been positioned horizontally and vertically, which showed a slight advantage for the rhizomes put in the horizontal boxes. All rhizomes started growing at a slow pace and speeded up at the end. These preliminary results have been conducted by students; further experiments are planned (**Figures 9–11**) and (**Table 1**).

#### **3.6 Board game and computer simulation**

All data and experiences gained in the project result in the development of a computer simulation. Along the way, we also created a board game for children and adults from the age of 10 years, which is currently on its way to a game publisher. The cooperation game allows players to work together as teammates against the opponent, Japanese knotweed. The game starts with a landscape full of differently

**Figure 9.** *Overview drawing Site 1 (E.C.O. Institute of Ecology).*

**Figure 10.** *Detail drawing of a rhizome (E.C.O. Institute of Ecology).*

**95**

species [46].

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

**Date Rhizobox 1 Rhizobox 2 Rhizobox 3 Rhizobox 4** 27 July 2018 5 5 24 4 30 July 2018 6 7 27 5.5 2 August 2018 6 7.5 30.5 5.5 6 August 2018 6 7.5 31 5.5 10 August 2018 7 8.5 31.5 6.5 31 August 2018 13.5 15.5 42.5 9.5

suitable habitats for knotweed, occupied by randomly distributed *Fallopia* clones. The players will try out different measures to eradicate the clones and to keep particularly valuable areas clear from the weed. Doing this, they should go as easy on resources as possible. The player team wins if they manage to displace all plants from the game plan and loses if one of the nature conservation areas is overgrown or destroyed by clones of knotweed. The game is based on event and action cards. Each round starts with an event card, meaning Japanese knotweed moves in a specific speed and a specific spreading mechanism. Then, it is the players' turn and they can choose between action cards that portray control methods such as mowing, pulling out, sheep grazing, glyphosate, cover foil, or biological control (*Aphalara itadori*). Depending on the individual starting points, different measures and combinations of measures will lead to success, i.e., reduce or stop the plant growth. In several test rounds, we could see that the players started to realize how fast and determined Japanese knotweed can spread and how little can be done about it, if one does not take it seriously. The only way is to cooperate, to combine control measures and to act as soon as possible. Whenever the population is little, it is still quite easy to get rid of, and once the board is mostly overgrown by knotweed, it is extremely hard to push back the plant. The game is designed close to reality, and in terms of controlling knotweed, it shows that mechanical methods are time-consuming and inefficient, and that poison and cover foils are more efficient, but that they are not resource-saving and that one has to live with the consequences. Thus, Game of Clones creates awareness of invasive species in a playful way. The digital version is still in process, and the students in the research project will also play a part in the browser-based programming; in this way, they will simultaneously be an important

*Rhizome length growth in rhizoboxes (rhizome pieces in cm); rhizoboxes 1 and 2 are positioned horizontally,* 

*and rhizoboxes 3 and 4 are positioned vertically (HBLFA Raumberg-Gumpenstein).*

reference group regarding its user-friendliness and functionality.

the University of Klagenfurt)

(E.C.O. Institute of Ecology, Institute of Networked and Embedded Systems at

To our knowledge, the presented game is the only board game applying a cellular automata model to depict the spread of invasive plant species. While modeling plant growth with cellular automata is a well-established approach (a good overview can be found in [27]), there are only a few examples for usage of cellular automata simulations in board games: Franzel describes the usage of a board game to assess farmers' preferences among alternative agricultural technologies in [44]. Kang et al. [45] depict a computer simulation model addressing evolutionary game theory within a five-species jungle game, which is based on a Chinese board game. The work most related to our approach is the board game "Alien Invaders!" which teaches students how introduced species can affect native species with the example of native birds being affected by introduced

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

**Table 1.**

**Figure 11.** *Board game version of "Game of Clones".*


*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

#### **Table 1.**

*Diversity and Ecology of Invasive Plants*

**94**

**Figure 11.**

*Board game version of "Game of Clones".*

**Figure 10.**

*Detail drawing of a rhizome (E.C.O. Institute of Ecology).*

*Rhizome length growth in rhizoboxes (rhizome pieces in cm); rhizoboxes 1 and 2 are positioned horizontally, and rhizoboxes 3 and 4 are positioned vertically (HBLFA Raumberg-Gumpenstein).*

suitable habitats for knotweed, occupied by randomly distributed *Fallopia* clones. The players will try out different measures to eradicate the clones and to keep particularly valuable areas clear from the weed. Doing this, they should go as easy on resources as possible. The player team wins if they manage to displace all plants from the game plan and loses if one of the nature conservation areas is overgrown or destroyed by clones of knotweed. The game is based on event and action cards. Each round starts with an event card, meaning Japanese knotweed moves in a specific speed and a specific spreading mechanism. Then, it is the players' turn and they can choose between action cards that portray control methods such as mowing, pulling out, sheep grazing, glyphosate, cover foil, or biological control (*Aphalara itadori*). Depending on the individual starting points, different measures and combinations of measures will lead to success, i.e., reduce or stop the plant growth.

In several test rounds, we could see that the players started to realize how fast and determined Japanese knotweed can spread and how little can be done about it, if one does not take it seriously. The only way is to cooperate, to combine control measures and to act as soon as possible. Whenever the population is little, it is still quite easy to get rid of, and once the board is mostly overgrown by knotweed, it is extremely hard to push back the plant. The game is designed close to reality, and in terms of controlling knotweed, it shows that mechanical methods are time-consuming and inefficient, and that poison and cover foils are more efficient, but that they are not resource-saving and that one has to live with the consequences. Thus, Game of Clones creates awareness of invasive species in a playful way. The digital version is still in process, and the students in the research project will also play a part in the browser-based programming; in this way, they will simultaneously be an important reference group regarding its user-friendliness and functionality.

(E.C.O. Institute of Ecology, Institute of Networked and Embedded Systems at the University of Klagenfurt)

To our knowledge, the presented game is the only board game applying a cellular automata model to depict the spread of invasive plant species. While modeling plant growth with cellular automata is a well-established approach (a good overview can be found in [27]), there are only a few examples for usage of cellular automata simulations in board games: Franzel describes the usage of a board game to assess farmers' preferences among alternative agricultural technologies in [44]. Kang et al. [45] depict a computer simulation model addressing evolutionary game theory within a five-species jungle game, which is based on a Chinese board game. The work most related to our approach is the board game "Alien Invaders!" which teaches students how introduced species can affect native species with the example of native birds being affected by introduced species [46].

#### **4. Conclusion**

The project at the time of this publication still has a duration of 1 year, which means that many of the results are not yet complete and require further research.

The current results show that the issue of Japanese knotweed is very complex, and numerous studies and research projects have already been carried out and many are still ongoing. Due to the complexity and the costs of the control, the question arises whether the extensive control of knotweed is really necessary. But it turns out that even if one is of the opinion not to additionally intervene in the ecosystem and let nature take its course, *Fallopia japonica* also has significant economic effects, which cannot be ignored [1]. The need for further studies also arises from several disagreements in the literature such as the one regarding the gender of the species. Some say that the plant is clearly dioecious with distinct male and female individual organisms, and others speak of the plant being gynodioecious, which is the existence of male sterile and hermaphrodite individuals. There is not so much literature on the underground growth of Japanese knotweed. Hence the root uncovering was very informative, which is exactly why it would be advantageous to uncover the roots at another site, especially with older stands in order to present comparisons and observe the underground growth after the initial years.

The one method to fight knotweed does not exist. For every area, every situation, and every circumstance, a different strategy makes sense and mostly only the combination of different methods achieves an impact. When combating invasive species, however, one must always think in years. The computer simulation "Game of Clones" will be able to be underlaid with satellite images in order to establish a relationship to real areas. On the basis of the simulation, control strategies can be considered in advance of a measure concept. The project will also result in a practical guide and an explanatory video because the best way to combat an invasion is prevention and environmental education. During the collection of samples, there were numerous encounters with neighbors who were not aware of the problem and planted Japanese knotweed as a screen or threw plant remains into the compost. We hope that as many people as possible can be picked up by the game and sensitized to this topic. It would also be interesting to test whether the cooperative game method could be applied to other invasive plants in an adapted form.

#### **Acknowledgements**

This research project is part of Sparkling Science, a research program funded by the Austrian Federal Ministry of Education, Science and Research (BMWFW), a program that supports projects in which pupils **of all levels of education** are actively involved in the research process.

In the case of our project, students aged between 14 and 18 from BORG Spittal—a grammar school with special emphasis on music, art, sport, and science in Carinthia—supported us in the research project. Hence, special thanks to the students who helped with the sample collection for the DNA barcoding, with uncovering the root network, and with the transect monitoring and who also significantly contributed to improving the strategy game through test games and feedback rounds.

Special thanks also to our project partner DI Arthur Pitman from the Institute of Networked and Embedded Systems at the University of Klagenfurt. He was mainly responsible for co-developing the rules of the strategy game, processing the data gained in the project, and programming and modeling the computer simulation.

**97**

provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Institute of Networked and Embedded Systems (NES), University of Klagenfurt,

, Wilfried Elmenreich<sup>2</sup>

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

weed; within this framework, they carried out further experiments.

archiving the herbarium vouchers from the DNA Barcoding.

The Authors declare that there is no conflict of interest.

\*, Christina Pichler-Koban1

1 E.C.O. Institute of Ecology, Klagenfurt, Austria

\*Address all correspondence to: fuchs@e-c-o.at

We express our warm thanks to the students Philipp Poier and Julian Heywood

and the teachers and experts Dr. Andreas Bohner, DI Renate Mayer, and Irene Sölkner from the HBLFA Raumberg-Gumpenstein, a higher technical education and research institute in Styria that participated as a project partner. The school supported the rhizome uncovering and fully overtook the work of the rhizoboxes. Additionally, both students conducted their pre-scientific work on Japanese knot-

A big thank you also to Lisa Schmied, E.C.O. Institute of Ecology, who, during the rhizome uncovering, drew the rhizome of Japanese knotweed in all its

Eberwein from the Regional Museum of Carinthia (Kärntner Landesmuseum) who has been instrumental in researching the literature and who is responsible for

We would also like to show our gratitude to our final project partner, Dr. Roland

Finally, many thanks to the Lakeside Science & Technology Park for supporting us and letting us set up transects and carry out a large rhizome uncovering on their

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

perspectives.

property.

**Conflict of interest**

**Author details**

Anneliese Fuchs1

Austria

and Michael Jungmeier1

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

We express our warm thanks to the students Philipp Poier and Julian Heywood and the teachers and experts Dr. Andreas Bohner, DI Renate Mayer, and Irene Sölkner from the HBLFA Raumberg-Gumpenstein, a higher technical education and research institute in Styria that participated as a project partner. The school supported the rhizome uncovering and fully overtook the work of the rhizoboxes. Additionally, both students conducted their pre-scientific work on Japanese knotweed; within this framework, they carried out further experiments.

A big thank you also to Lisa Schmied, E.C.O. Institute of Ecology, who, during the rhizome uncovering, drew the rhizome of Japanese knotweed in all its perspectives.

We would also like to show our gratitude to our final project partner, Dr. Roland Eberwein from the Regional Museum of Carinthia (Kärntner Landesmuseum) who has been instrumental in researching the literature and who is responsible for archiving the herbarium vouchers from the DNA Barcoding.

Finally, many thanks to the Lakeside Science & Technology Park for supporting us and letting us set up transects and carry out a large rhizome uncovering on their property.

#### **Conflict of interest**

*Diversity and Ecology of Invasive Plants*

The project at the time of this publication still has a duration of 1 year, which means that many of the results are not yet complete and require further research. The current results show that the issue of Japanese knotweed is very complex, and numerous studies and research projects have already been carried out and many are still ongoing. Due to the complexity and the costs of the control, the question arises whether the extensive control of knotweed is really necessary. But it turns out that even if one is of the opinion not to additionally intervene in the ecosystem and let nature take its course, *Fallopia japonica* also has significant economic effects, which cannot be ignored [1]. The need for further studies also arises from several disagreements in the literature such as the one regarding the gender of the species. Some say that the plant is clearly dioecious with distinct male and female individual organisms, and others speak of the plant being gynodioecious, which is the existence of male sterile and hermaphrodite individuals. There is not so much literature on the underground growth of Japanese knotweed. Hence the root uncovering was very informative, which is exactly why it would be advantageous to uncover the roots at another site, especially with older stands in order to present comparisons and observe the underground growth after the

The one method to fight knotweed does not exist. For every area, every situation, and every circumstance, a different strategy makes sense and mostly only the combination of different methods achieves an impact. When combating invasive species, however, one must always think in years. The computer simulation "Game of Clones" will be able to be underlaid with satellite images in order to establish a relationship to real areas. On the basis of the simulation, control strategies can be considered in advance of a measure concept. The project will also result in a practical guide and an explanatory video because the best way to combat an invasion is prevention and environmental education. During the collection of samples, there were numerous encounters with neighbors who were not aware of the problem and planted Japanese knotweed as a screen or threw plant remains into the compost. We hope that as many people as possible can be picked up by the game and sensitized to this topic. It would also be interesting to test whether the cooperative game method

This research project is part of Sparkling Science, a research program funded by the Austrian Federal Ministry of Education, Science and Research (BMWFW), a program that supports projects in which pupils **of all levels of education** are

Special thanks also to our project partner DI Arthur Pitman from the Institute of Networked and Embedded Systems at the University of Klagenfurt. He was mainly responsible for co-developing the rules of the strategy game, processing the data gained in the project, and programming and modeling the computer simulation.

In the case of our project, students aged between 14 and 18 from BORG Spittal—a grammar school with special emphasis on music, art, sport, and science in Carinthia—supported us in the research project. Hence, special thanks to the students who helped with the sample collection for the DNA barcoding, with uncovering the root network, and with the transect monitoring and who also significantly contributed to improving the strategy game through test games and

could be applied to other invasive plants in an adapted form.

**4. Conclusion**

initial years.

**Acknowledgements**

feedback rounds.

actively involved in the research process.

**96**

The Authors declare that there is no conflict of interest.

#### **Author details**

Anneliese Fuchs1 \*, Christina Pichler-Koban1 , Wilfried Elmenreich<sup>2</sup> and Michael Jungmeier1

1 E.C.O. Institute of Ecology, Klagenfurt, Austria

2 Institute of Networked and Embedded Systems (NES), University of Klagenfurt, Austria

\*Address all correspondence to: fuchs@e-c-o.at

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

## **References**

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[2] van Kleunen M, Dawson W, Essl F, Pergl J. Global exchange and accumulation of non-native plants. Nature. 2015;**525**:100-107. DOI: 10.1038/ nature14910

[3] Horáčková J, Juřičková L, Šizling AL, Jarošík V, Pyšek P. Invasiveness does not predict impact: Response of native land snail communities to plant invasions in riparian habitats. PLoS One. 2014;**9**(9):10

[4] Gioria M, Dieterich B, Osborne B. Battle of the giants: Primary and secondary invasions by large herbaceous species. Biology & Environment Proceedings of the Royal Irish Academy. 2011;**111B**(3):1-17. DOI: 10.2307/23188047

[5] Essl F, Rabitsch W. Neobiota in Österreich. Wien: Umweltbundesamt; 2002. p. 432

[6] Aguilera AG, Alpert P, Dukes JS, Harrington R. Impacts of the invasive plant *Fallopia japonica* (Houtt.) on plant communities and ecosystem processes. Biological Invasions. 2010;**12**:1243-1252. DOI: 10.1007/s10530-009-9543-z

[7] Gerber E, Krebs C, Murrel C, Moretti M, Rocklin R, Schaffner U. Exotic invasive knotweeds (*Fallopia* ssp.) negatively affect native plant and invertebrate assemblages in European riparian habitats. Biological Conservation. 2008;**141**:614-654. DOI: DOI 10.1016/j.biocon.2007.12.009

[8] Künzi Y, Prati D, Fischer M, Boch S. Reduction of native diversity by invasive plants depends on habitat conditions. American Journal of Plant Sciences. 2016;**6**:2718-2733

[9] Skubala P. Invasive giant knotweed (*Fallopia sachalinensis*) alters the composition of oribatid mite communities. Biological Letters. 2012;**49**(2):143-155. DOI: 10.2478/ v10120-012-0016-1

[10] Mincheva T, Barni E, Siniscalco C. From plant traits to invasion success: Impacts of the alien *Fallopia japonica* (Houtt.) Ronse Decraene on two native grassland species. Plant Biosystems—An International Journal Dealing with all Aspects of Plant Biology. 2016;**10**:1348-1357. DOI: 10.1080/11263504.2015.1115437

[11] Williams F, Eschen R, Harris A, Djeddour D, Pratt C, Shaw RS, et al. The Economic cost of invasive non-native species on Great Britain. CABI Knowledge for Life. 2010;**CAB/001/09**:198

[12] Brandes D. Flora und vegetation der Bahnhöfe Mitteleuropas. Phytocoenologia. 1983;**11**(1):31-115

[13] OEBB. Nicht allein auf weiter Flur [Internet]. 2018. Available from: https:// konzern.oebb.at/de/nachhaltigkeit/ umwelt/nicht-allein-auf-weiter-flur [Accessed: 22-10-2018]

[14] Gelpke G. Problempflanzen [Internet]. ALN Amt für Landschaft und Natur Fachstelle Naturschutz. Zürich. 2012. Available from: http:// www.urtenen-schoenbuehl.ch/dl.php/ de/0ev23-wflz1s/Problempflanzen.pdf [Accessed: 23-10-2018]

[15] Končeková L, Šebová H, Pintér E. Evaluation of population regulation of invasive species *Fallopia x bohemica* by repeated mowing. Acta Horticulturae et Regiotecturae. 2014;**17**(1):13-15. DOI: 10.2478/ahr-2014-0004

**99**

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed…*

Molecular Research. 2013;**12**(3):4078- 4089. DOI: 10.4238/2013.September.27.9

[24] Hebert PDN, Cywinska A, Shelley LB, deWaard JR. Biological identifications through DNA barcodes. Proceedings of the Royal Society B. 2003;**270**(1512):313- 321. DOI: 10.1098/rspb.2002.2218

Vegetationsökologischen Monitorings. Wien: Umweltbundesamt; 1998. p. 158

[25] Traxler A. Handbuch des

[26] Kutschera L, Lichtenegger E. Wurzelatlas Mitteleuropäischer Waldbäume und Sträucher. Graz: Stocker Verlag; 2002. p. 604

[27] Balzter H, Braun PW, Köhler W. Cellular automata models for vegetation

[28] Avolio MV, Di Gregorio S, Lupiano V, Mazzanti P. SCIDDICA-SS3: A new version of cellular automata model for simulatin fast moving landslides. The Journal of Supercomputing. 2013;**65**(2):682-696. DOI: 10.1007/

dynamics. Ecological Modelling.

[29] Alberternst B, Boehmer HJ. 2011:15. Available from: Online Database of the European Network on Invasive Alien Species – NOBANIS.

[30] Tiebre M, Hardy O, Mahy G, Vanderhoeven S. Patterns of

[31] Tiebre M, Hardy O, Mahy G, Vanderhoeven S. Hybridization and morphogenetic variation in the invasive alien *Fallopia* (Polygonaceae) complex in Belgium. American Journal of Botany. 2007;**94**(11):1900-1910. DOI: 10.3732/

hybridization and hybrid survival in the invasive alien *Fallopia* complex (Polygonaceae). Plant Ecology and Evolution. 2011;**144**(11):12-18. DOI: DOI 10.5091/plecevo.2011.444

1998;**107, 9**:113-125

s11227-013-0948-1

www.nobanis.org

ajb.94.11.1900

*DOI: http://dx.doi.org/10.5772/intechopen.82873*

[16] Landesanstalt für Umweltschutz (LfU). Kontrolle des Japan-Knöterichs an Fließgewässern. In: Erprobung ausgewählter Methoden. Stuttgart: Handbuch Wasser; 1994. p. 63

[17] Koce J. The effects of leaf extracts of crack willow (*Salix fragilis*) on the growth of Japanese knotweed (*Fallopia japonica*). Acta Biologica Slovenica. 2016;**59**(1):13-21

[18] Skinner RH, van der Grinten M, Gover AE. Planting native species to control site reinfestation by Japanese Knotweed (*Fallopia japonica*) In. Ecological Restoration. 2012;**30**(2):192-

[19] Child L, Wade PM. The Japanese Knotweed Manual. Chichester: Packard Publishing Limited; 2000. p. 123 ISBN:

[20] Clements DR, Larsen T, Grenz J. Knotweed management strategies in North America with the advent of widespread hybrid bohemian knotweed regional differences, and the potential for biocontrol via the psyllid *Aphalara itadori* Shinji. Invasive Plant Science and Management. 2016;**9**:60-70. DOI:

10.1614/IPSM-D-15-00047.1

[21] Bzdega K, Agnieszka J, Książczyk T, Lewandowska A, Gancarek M, Sliwinska E, et al. A survey of genetic variation and genome evaluation within the invasive *Fallopia* complex. PLoS One. 2016;**11**(8). DOI: 10.1371/journal.pone.0161854

[22] Gaskin JF, Schwarzländer M, Grevstad FS, Haverhals MA, Bourchier RS, Miller TW. Extreme differences in population structure and genetic diversity for three invasive congeners: Knotweeds in western North America. Biological Invasions. 2014;**16**:2127-2136.

DOI: 10.1007/s10530-014-0652-y

[23] Sun XQ, Bai MM, Yao H, Guo JL, Li MM, Hang YY. DNA barcoding of populations of *Fallopia multiflora*, an indigenous herb in China. Genetics and

199. DOI: 10.3368/er.30.3.192

1085341-127

*Game of Clones: Students Model the Dispersal and Fighting of Japanese Knotweed… DOI: http://dx.doi.org/10.5772/intechopen.82873*

[16] Landesanstalt für Umweltschutz (LfU). Kontrolle des Japan-Knöterichs an Fließgewässern. In: Erprobung ausgewählter Methoden. Stuttgart: Handbuch Wasser; 1994. p. 63

[17] Koce J. The effects of leaf extracts of crack willow (*Salix fragilis*) on the growth of Japanese knotweed (*Fallopia japonica*). Acta Biologica Slovenica. 2016;**59**(1):13-21

[18] Skinner RH, van der Grinten M, Gover AE. Planting native species to control site reinfestation by Japanese Knotweed (*Fallopia japonica*) In. Ecological Restoration. 2012;**30**(2):192- 199. DOI: 10.3368/er.30.3.192

[19] Child L, Wade PM. The Japanese Knotweed Manual. Chichester: Packard Publishing Limited; 2000. p. 123 ISBN: 1085341-127

[20] Clements DR, Larsen T, Grenz J. Knotweed management strategies in North America with the advent of widespread hybrid bohemian knotweed regional differences, and the potential for biocontrol via the psyllid *Aphalara itadori* Shinji. Invasive Plant Science and Management. 2016;**9**:60-70. DOI: 10.1614/IPSM-D-15-00047.1

[21] Bzdega K, Agnieszka J, Książczyk T, Lewandowska A, Gancarek M, Sliwinska E, et al. A survey of genetic variation and genome evaluation within the invasive *Fallopia* complex. PLoS One. 2016;**11**(8). DOI: 10.1371/journal.pone.0161854

[22] Gaskin JF, Schwarzländer M, Grevstad FS, Haverhals MA, Bourchier RS, Miller TW. Extreme differences in population structure and genetic diversity for three invasive congeners: Knotweeds in western North America. Biological Invasions. 2014;**16**:2127-2136. DOI: 10.1007/s10530-014-0652-y

[23] Sun XQ, Bai MM, Yao H, Guo JL, Li MM, Hang YY. DNA barcoding of populations of *Fallopia multiflora*, an indigenous herb in China. Genetics and Molecular Research. 2013;**12**(3):4078- 4089. DOI: 10.4238/2013.September.27.9

[24] Hebert PDN, Cywinska A, Shelley LB, deWaard JR. Biological identifications through DNA barcodes. Proceedings of the Royal Society B. 2003;**270**(1512):313- 321. DOI: 10.1098/rspb.2002.2218

[25] Traxler A. Handbuch des Vegetationsökologischen Monitorings. Wien: Umweltbundesamt; 1998. p. 158

[26] Kutschera L, Lichtenegger E. Wurzelatlas Mitteleuropäischer Waldbäume und Sträucher. Graz: Stocker Verlag; 2002. p. 604

[27] Balzter H, Braun PW, Köhler W. Cellular automata models for vegetation dynamics. Ecological Modelling. 1998;**107, 9**:113-125

[28] Avolio MV, Di Gregorio S, Lupiano V, Mazzanti P. SCIDDICA-SS3: A new version of cellular automata model for simulatin fast moving landslides. The Journal of Supercomputing. 2013;**65**(2):682-696. DOI: 10.1007/ s11227-013-0948-1

[29] Alberternst B, Boehmer HJ. 2011:15. Available from: Online Database of the European Network on Invasive Alien Species – NOBANIS. www.nobanis.org

[30] Tiebre M, Hardy O, Mahy G, Vanderhoeven S. Patterns of hybridization and hybrid survival in the invasive alien *Fallopia* complex (Polygonaceae). Plant Ecology and Evolution. 2011;**144**(11):12-18. DOI: DOI 10.5091/plecevo.2011.444

[31] Tiebre M, Hardy O, Mahy G, Vanderhoeven S. Hybridization and morphogenetic variation in the invasive alien *Fallopia* (Polygonaceae) complex in Belgium. American Journal of Botany. 2007;**94**(11):1900-1910. DOI: 10.3732/ ajb.94.11.1900

**98**

*Diversity and Ecology of Invasive Plants*

[1] Pimentel D, McNair S, Janecka J, Wightman J, Simmonds C, O'Connel C, et al. Economic and environmental threats of alien plant, animal and microbe invasions. Agriculture, Ecosystems and Environment.

plants depends on habitat conditions. American Journal of Plant Sciences.

[9] Skubala P. Invasive giant knotweed (*Fallopia sachalinensis*) alters the composition of oribatid mite communities. Biological Letters. 2012;**49**(2):143-155. DOI: 10.2478/

[10] Mincheva T, Barni E, Siniscalco C. From plant traits to invasion success: Impacts of the alien *Fallopia japonica* (Houtt.) Ronse Decraene on two native grassland species. Plant

Biosystems—An International Journal Dealing with all Aspects of Plant Biology. 2016;**10**:1348-1357. DOI: 10.1080/11263504.2015.1115437

[11] Williams F, Eschen R, Harris A, Djeddour D, Pratt C, Shaw RS, et al. The Economic cost of invasive non-native species on Great Britain. CABI Knowledge

for Life. 2010;**CAB/001/09**:198

der Bahnhöfe Mitteleuropas. Phytocoenologia. 1983;**11**(1):31-115

[Accessed: 22-10-2018]

[Accessed: 23-10-2018]

10.2478/ahr-2014-0004

[14] Gelpke G. Problempflanzen [Internet]. ALN Amt für Landschaft und Natur Fachstelle Naturschutz. Zürich. 2012. Available from: http:// www.urtenen-schoenbuehl.ch/dl.php/ de/0ev23-wflz1s/Problempflanzen.pdf

[15] Končeková L, Šebová H, Pintér E. Evaluation of population regulation of invasive species *Fallopia x bohemica* by repeated mowing. Acta Horticulturae et Regiotecturae. 2014;**17**(1):13-15. DOI:

[12] Brandes D. Flora und vegetation

[13] OEBB. Nicht allein auf weiter Flur [Internet]. 2018. Available from: https:// konzern.oebb.at/de/nachhaltigkeit/ umwelt/nicht-allein-auf-weiter-flur

2016;**6**:2718-2733

v10120-012-0016-1

[2] van Kleunen M, Dawson W, Essl F, Pergl J. Global exchange and accumulation of non-native plants. Nature. 2015;**525**:100-107. DOI: 10.1038/

[3] Horáčková J, Juřičková L, Šizling AL, Jarošík V, Pyšek P. Invasiveness does not predict impact: Response of native land snail communities to plant invasions in riparian habitats. PLoS One.

[4] Gioria M, Dieterich B, Osborne B. Battle of the giants: Primary and

species. Biology & Environment Proceedings of the Royal Irish Academy. 2011;**111B**(3):1-17. DOI:

[5] Essl F, Rabitsch W. Neobiota in Österreich. Wien: Umweltbundesamt;

[6] Aguilera AG, Alpert P, Dukes JS, Harrington R. Impacts of the invasive plant *Fallopia japonica* (Houtt.) on plant communities and ecosystem processes. Biological Invasions. 2010;**12**:1243-1252.

DOI: 10.1007/s10530-009-9543-z

[7] Gerber E, Krebs C, Murrel C, Moretti M, Rocklin R, Schaffner U. Exotic invasive knotweeds (*Fallopia* ssp.) negatively affect native plant and invertebrate assemblages in European riparian habitats. Biological Conservation. 2008;**141**:614-654. DOI: DOI 10.1016/j.biocon.2007.12.009

[8] Künzi Y, Prati D, Fischer M, Boch S. Reduction of native diversity by invasive

secondary invasions by large herbaceous

**References**

2001;**84**:1-20

nature14910

2014;**9**(9):10

10.2307/23188047

2002. p. 432

[32] Bailey JP, Conolly AP. Prize-winners to pariahs—A history of Japanese Knotweed s. l. (Polygonaceae) in the British Isles. Watsonia. 2003;**23**:93-110

[33] Bailey JP, Bímová K, Mandák B. Asexual spread versus sexual reproduction and evolution in Japanese Knotweed s.l. sets the stage for the "Battle of the Clones". Biological Invasions. 2009;**11**:1189-1203. DOI: 10.1007/s10530-008-9381-4

[34] Grimsby JL, Tsirelson D, Gammon MA, Kesseli R. Genetic diversity and clonal vs sexual reproduction in *Fallopia spp*. (Polygonaceae). American Journal of Botany. 2007;**94**(6):957-964

[35] Adachi N, Terashima I, Takahashi M. Central die-back of monoclonal stands of *Reynoutria japonica* in an early stage of primary succesion on Mount Fuji. Annals of Botany. 1996;**77**:477-486

[36] Bímová K, Mandák B, Pyšek P. Experimental study of vegetative regeneration in four invasive Reynoutria taxa (Polygonaceae). Plant Ecology. 2003;**166**:1-11

[37] Siemens TJ, Blossey B. An evaluation of mechanisms preventing growth and survival of two native species in invasive bohemian knotweed (*Fallopia* × *bohemica*, Polygonaceae). American Journal of Botany. 2007;**94**:776-783

[38] Baxendale VJ, Tessier TJ. Duration of freezing necessary to damage the leaves of *Fallopia japonica* (Houtt.) Ronse Decraene. Plant Species Biology. 2015;**30**:279-284. DOI: 10.1111/1442-1984.12068

[39] Beerling DJ. The Impact of Temperature on the Northern distribution limits of the introduced species *Fallopia japonica* and *Impatiens glandulifera* in North-West Europe. Journal of Biogeography. 1993;**20**:45-53 [40] Bímová K, Mandák B, Pyšek P. Experimental control of Reynoutria congeners: A comparative study of a hybrid and its parents. In: Brundu G, Brock J, Camarda I, Child L, Wade M, editors. Plant Invasion: Species Ecology and Ecosystem Management. 2001. pp. 283-290

[41] Djeddour D, Shaw R. The biological control of *Fallopia japonica* in Great Britain: Review and current status. Outlooks on Pest Management. 2010;**21**:15-18. DOI: 10.1564/21feb04

[42] Wang Y, Ding J, Zhang G. *Gallerucida bifasciata* (Coleoptera: Chrysomelidae), a potential biological control agent for Japanese knotweed (*Fallopia japonica*). Biocontrol Science and Technology. 2008;**18**:59-74. DOI: 10.1080/09583150701742453

[43] Podroužková Š, Janovský Z, Horáčková J, Juřičková L. Do snails eat exotic plant species invading river floodplains. Journal of Molluscan Studies. 2014;**81**(1):1-8. DOI: 10.1093/ mollus/eyu073

[44] Franzel S. Use of an indigenous board game, 'Bao', for assessing farmers' preferences among alternative agriculture technologies. In: Tomorrow's Agriculture: Incentives, Institutions, Infrastructure and Innovations - Proceedings of the Twenty-fouth International Conference of Agricultural Economists. 2018. pp. 416-424

[45] Kang Y, Pan Q, Wang X, He M. A five-species jungle game. PLoS One. 2016;**11**(6). DOI: 10.1371/journal. pone.0157938

[46] Stracey C. Alien Invaders! A Board Game about the Threats Posed by Introduced Species. Science Scope. 2008;**31**(6)

*Diversity and Ecology of Invasive Plants*

[32] Bailey JP, Conolly AP. Prize-winners to pariahs—A history of Japanese Knotweed s. l. (Polygonaceae) in the British Isles. Watsonia. 2003;**23**:93-110

[40] Bímová K, Mandák B, Pyšek P. Experimental control of Reynoutria congeners: A comparative study of a hybrid and its parents. In: Brundu G, Brock J, Camarda I, Child L, Wade M, editors. Plant Invasion: Species Ecology and Ecosystem Management. 2001.

[41] Djeddour D, Shaw R. The biological control of *Fallopia japonica* in Great Britain: Review and current status. Outlooks on Pest Management. 2010;**21**:15-18. DOI: 10.1564/21feb04

[42] Wang Y, Ding J, Zhang G. *Gallerucida bifasciata* (Coleoptera: Chrysomelidae), a potential biological control agent for Japanese knotweed (*Fallopia japonica*). Biocontrol Science and Technology. 2008;**18**:59-74. DOI:

10.1080/09583150701742453

mollus/eyu073

pp. 416-424

pone.0157938

2008;**31**(6)

[43] Podroužková Š, Janovský Z, Horáčková J, Juřičková L. Do snails eat exotic plant species invading river floodplains. Journal of Molluscan Studies. 2014;**81**(1):1-8. DOI: 10.1093/

[44] Franzel S. Use of an indigenous board game, 'Bao', for assessing

Tomorrow's Agriculture: Incentives, Institutions, Infrastructure and Innovations - Proceedings of the Twenty-fouth International Conference of Agricultural Economists. 2018.

[45] Kang Y, Pan Q, Wang X, He M. A five-species jungle game. PLoS One. 2016;**11**(6). DOI: 10.1371/journal.

[46] Stracey C. Alien Invaders! A Board Game about the Threats Posed by Introduced Species. Science Scope.

agriculture technologies. In:

farmers' preferences among alternative

pp. 283-290

[33] Bailey JP, Bímová K, Mandák B. Asexual spread versus sexual

10.1007/s10530-008-9381-4

of Botany. 2007;**94**(6):957-964

reproduction and evolution in Japanese Knotweed s.l. sets the stage for the "Battle of the Clones". Biological Invasions. 2009;**11**:1189-1203. DOI:

[34] Grimsby JL, Tsirelson D, Gammon MA, Kesseli R. Genetic diversity and clonal vs sexual reproduction in *Fallopia spp*. (Polygonaceae). American Journal

[35] Adachi N, Terashima I, Takahashi M. Central die-back of monoclonal stands of *Reynoutria japonica* in an early stage of primary succesion on Mount Fuji. Annals of Botany. 1996;**77**:477-486

[36] Bímová K, Mandák B, Pyšek P. Experimental study of vegetative regeneration in four invasive Reynoutria taxa (Polygonaceae). Plant Ecology.

[37] Siemens TJ, Blossey B. An evaluation of mechanisms preventing growth and survival of two native species in invasive bohemian knotweed (*Fallopia* × *bohemica*, Polygonaceae). American Journal of Botany. 2007;**94**:776-783

[38] Baxendale VJ, Tessier TJ. Duration of freezing necessary to damage the leaves of *Fallopia japonica* (Houtt.) Ronse Decraene. Plant Species Biology. 2015;**30**:279-284. DOI: 10.1111/1442-1984.12068

[39] Beerling DJ. The Impact of Temperature on the Northern distribution limits of the introduced species *Fallopia japonica* and *Impatiens glandulifera* in North-West Europe. Journal of Biogeography. 1993;**20**:45-53

2003;**166**:1-11

**100**

## *Edited by Sudam Charan Sahu and Sanjeet Kumar*

This book, Diversity and Ecology of Invasive Plants, is a collection of reviewed and relevant research chapters, offering a comprehensive overview of recent developments in the field of invasive species biology. The book comprises chapters authored by various researchers and edited by experts active in the field of conservation of biodiversity. All chapters are complete in itself but united under a common topic. This publication aims at providing a thorough overview of the latest research efforts by international authors on diversity, distribution, and ecological consequences of invasive species and opens new possible research paths for further developments.

Published in London, UK © 2019 IntechOpen © TonyLMoorePhoto / iStock

Diversity and Ecology of Invasive Plants

Diversity and Ecology of

Invasive Plants

*Edited by Sudam Charan Sahu and Sanjeet Kumar*