*2.2.4 Objective 4: propagating and assessing the growth performance of the regenerated BAT species under the different ecosystems and conservation management approaches*

The growth performance of the regenerated and potted plantlets was assessed in terms of the quantity and quality of their morphological traits, re-established/ grown under the completely randomized design (CRD) experiments. The three main in-situ conservation practices for BAT recovery management namely: active management, habitat restoration and habitat preservation. The conservation practices were classified based on their management intensity for the endangered species as high, medium, and low intensity for the active, habitat preservation and restoration management practices; respectively [4, 7].

#### *2.2.4.1 Active management: Greenhouse production at Makerere University*

About 100 BAT plantlets were transferred into a specially designed greenhouse, constructed at Makerere University, where they were monitored to full maturity. The plantlets, while still in pots, were regularly watered during the first 3–4 weeks (twice a day in the morning and evening), so as to get acclimatized to the harsh greenhouse weather conditions. Afterwards, the plantlets were transplanted from their conditioning pots, and re-planted about 5–10 cm in depth into previously fumigated soils, so as to grow under normal greenhouse soils and weather to maturity. Active management assumes that the species in question is critically endangered, and requires delicate management beyond its natural ecosystems to ensure rescue and full recovery [13].

#### *2.2.4.2 Habitat preservation: BAT production in Mabira forest (Site 2)*

At least a 1-acre area on one of the 4-gently sloping hills in Mabira forest, study site 2 (**Figure 1**) was randomly selected and isolated for BAT species growth trails. The plantlets were established in the preserved habitat of site 2, which are relatively identical soil and weather conditions of the BAT native ecosystem in site 1 using the same procedures in active management. The species under habitat preservation management were to grow under natural environment conditions: soil, temperature, humidity and rainfall to support species recovery. The habitat preservation management assumes that, if it is successful in supporting full species re-establishment, any other unoccupied ecological habitat with relatively similar environmental conditions will facilitate full species recovery by natural dispersal mechanism [11].

#### *2.2.4.3 Habitat restoration: BAT production in Mt. Elgon slopes (Site 1)*

About 1 acre of the experimental land in site 2 will also be isolated and BAT plantlets were planted in its native ecosystem using the same procedures described above in habitat preservation practices. The plantlets were monitored in their native environment until their full recovery and maturity. The habitat restoration management assumes that the endangered species is capable of full establishment once the native habitat is restored [11].

#### **2.3 Data collection and analyses**

Under each conservation management practice experiment, the 100 BAT plantlets were sowed at a standard spacing of 15 × 20cm, in a completely randomized design (CRD) experiment and were replicated three times [16]. Soil samples were collected and taken to Makerere University Soil Science Laboratory, for analysis of biophysical and chemical parameters such as pH, humus, electric conductivity, and nutrient (N, P, K and micronutrients), using the calorimetry method [17]. The daily ambient weather conditions, including the area temperature, rainfall and humidity were collected using digital thermometers, rain gauges and hydrometers; respectively.

Likewise, data on the morphological traits of the regenerated BAT plants such as leaf number and size, plant height, number of branches per plant and number of mature plants, as well as reproductive aspects of the mature plants (number of flowering stems, flowers, fruits and seeds per plant) were collected. The morphological

*Integrated Conservation Approaches for Rescuing, Regeneration and Adaptive Management… DOI: http://dx.doi.org/10.5772/intechopen.106893*

and reproductive data were used for a detailed study of the species' recovery, regeneration and adaptation under the different in-situ conservation management practices and ecosystems.

The species' performance under the different in-situ conservation management practices was assessed by establishing the correlation relationships between the species' morphological and reproductive traits, and the management aspects or environment data: management practice, soil and weather parameters. Besides correlation relationships, Analysis of Variance (ANOVA) between the BAT species performance, morphological and reproductive traits under different conservation management against the soil and weather parameters were analyzed using Genstat statistical package [18]. The statistical significance for the data analyses was set at a 95% (*p* = 0.05) confidence interval. The most feasible management practice(s) for BAT species rescue, recovery and establishment was recommended not only for adaptive management and conservation of BAT species but also for conservation of other critically endangered plant species in Uganda.

#### **2.4 Justification of the methodology and approach taken**

*Bothriocline auriculata* (BAT) species is endemic in Uganda and is exclusively sited along Elgon slopes (Site 1), where field surveys were conducted. But because the species is near extinction, we envisage collecting a few species samples which were regenerated into mass seedlings to support full species recovery. The critically-endangered species have not been studied until now, and hence no scientific data: mainly on the species reproductive modes, germination and seed regeneration capacity, species plant physiology, growth performance and adaptive capacity to abiotic stress etc., exist to guide the species conservation actions. Faced with this uncertainty, natural germination and tissue culture methods were employed to regenerate the species samples into mass seedlings [15]. The tissue culture method was used as a backup against natural germination which takes an extended time and its success is not 100% guaranteed.

While on the contrarily, the tissue culture method is capable of exponentially multiplying a few plant tissues into mass seedlings under aseptic conditions in a short time and produces disease-free seedlings [15]. However, artificial crossings between the plantlets produced by tissue culture and a few produced by the germination process were made to address the challenge of genetically identical seedlings produced via tissue culture and simultaneously increase of genetic diversity of the species' offspring over successive generations during conservation.

The BAT taxon is expected to have varying adaptive capacities to abiotic stress and growth rates when subjected to varying weather and soil conditions during its in-situ conservation, as well as under different ecosystems and conservation management practices. Therefore, the BAT species' growth performance was monitored from sowing to maturity, under CRD field experiments [16]. The CRD trials were set up in the species' native habitat and Mabira tropical rainforest, as the 2 sites coincidently have nearly identical weather patterns, vegetation types, soil conditions, and hydrological regimes, − which are likely to favor BAT species' successful growth. For instance, both sites receive bimodal rainfall patterns with a mean annual rainfall of 1300 mm, which is evenly distributed within the two distinct long and short wet seasons from September to December, and March to May, respectively. The mean annual temperatures of both sites range from 21 to 25°C, with both the minimum and maximum mean annual temperature ranges of 16–17°C, and 28–29°C, respectively [19].

Data on BAT species morphological traits: leaf number/size, vigor, seedling rate, plant number/height, branches per plant as well as reproductive traits; flowering stems, flowers, fruits, and seeds per plant were recorded on a bi-weekly basis for growth performance analysis. Soil samples were collected and analyzed for pH, EC, and nutrient composition using the calorimetry method [16], and the weather variables: temperature, rainfall and humidity etc., were collected from site weather stations. The soil and weather parameters will depict local soil health and weather conditions that are suitable for the successful in-situ conservation of the BAT species in the study sites.

Using GenStat software [18], Spearman's correlation was employed to assess the relationship between species growth performance, soil parameters, and weather variables under different conservation management practices and the environment. Analysis of Variance (ANOVA) was employed to determine statistical significances (*p* = 0.05), and model relationships between different conservation practices (as the independent variables), and soil and weather parameters, − as the dependent variables. The ANOVA test will identify the most responsive conservation management practice(s) that support the BAT species rescue, recovery and regeneration in the natural environment.

## **3. Results and discussion**

#### **3.1 Description of the suitability of the ecosystems**

Study site: although study site 1 is located along the slopes of Mount Elgon at higher altitudes from 2745 to 3150 m while study site 2 is within Mabira Forest is located at a significantly lower altitude from 1000 to 1340 meters Above Sea Level, both sites coincidently have nearly identical weather patterns, vegetation types, soil and hydrological regimes. Thus the environmental conditions of the 2 sites are most likely to favor the successful regeneration and conservation of the target species: *Bothriocline auriculata* (BAT) species, and hence their choice.

For instance, both sites receive bimodal rainfall patterns with a mean annual rainfall of 1900 mm and 1300 mm for sites 1 and 2 respectively, where the long and short rainy seasons range from September to December, and March to May, respectively [19]. The mean annual temperatures for the two sites also range from 21 to 25°C, with minimum and maximum mean annual temperature ranges of 16–17°C, and 28–29°C, respectively [19]. Like climate along Mt. Elgon slopes (Site 1), MWE [10] independently observed that the general climate of the Mabira forest area (site 2) displays comparably small inter-seasonal variations in wind, rainfall, humidity, and temperatures throughout the year. This is because the forest is in close proximity to Lake Victoria and at an elevation of up to 1340 m, which moderates the area's microclimatic conditions including the warming effect despite being within the equatorial region [10]. It is against this background, that the two sites were selected for the study and conservation of the BAT species.

## **3.2 Conservation status of the** *Bothriocline auriculata* **species in terms of the spatial distribution, species richness and abundance of the individual plants**

Like many endangered species, BAT species is susceptible to many environmental threats within its natural ecosystems. Thus, the ecological threats to the species'

*Integrated Conservation Approaches for Rescuing, Regeneration and Adaptive Management… DOI: http://dx.doi.org/10.5772/intechopen.106893*

survival within its native ecosystem (site 1), were identified and classified under three major categories namely human-use threat, livestock threat and habitat destruction threat, using the frequency and density method [12].

Conservation status, distribution and species richness of *Bothriocline auriculata* species were studied in its native ecosystem on the slopes of Mt. Elgon (Site 1) following an eco-geographical field survey [11, 20]. The survey method was successfully used by Choudhury and Khan [20] used the survey method to assess the population structure, species richness and conservation status of endemic and critically endangered plant species of *Aquilaria malaccensis, Gleditsia assamica*, and *Gymnocladus assamicus,* in India.

In this study, the type of host vegetation and flora at the landscape level are very important ecosystem components in the study of the conservation status of the inhabiting species, including species diversity, spatial distribution and ecological patterns in spatial variability. *Bothriocline auriculata* species host native ecosystems along the slopes of Mount Elgon differ considerably from the rest of the mountainous zones across Uganda due to the unique climatic conditions and physiography. The type of vegetation and flora diversity also vary with the elevation along the slopes of Mount Elgon. There are seven main classes of vegetation namely; mixed montane forest, bamboo, shrubs and thickets, low canopy montane forest, high canopy montane forest, and low, mid and high moorland ecosystems [3].

**Table 1** presents the current *Bothriocline auriculata* (BAT) species conservation status in terms of relative abundance and spatial distribution of the individual plants within the host native ecosystems and vegetation types along the slopes of Mount Elgon, Uganda.

The number of *Bothriocline auriculata* plants was more abundant in the midland altitude and ecosystems having bamboo, shrubs and tickets followed by the high mixed montane forest vegetation (**Table 1**). The *Bothriocline auriculata* exhibited a very low species richness and limited ecological range along the slopes of Mount Elgon because the remaining plant populations were on the verge of extinction from their native ecosystems. The results are consistent with the findings by the International Union for Conservation of Nature [3, 7] who reported that the *Bothriocline auriculata* species are critically endangered and are on the verge of existing. The IUCN [7] also reported that *Bothriocline auriculata* species was also endemic


*Values are arithmetic means with standard deviation (±SD) computed for values taken from every sampling area or zone along the line transect. Comparisons were made between the sampling zones, and n = number of plants collected per zone. Means in the same row bearing different superscript alphabetic letters are significantly different at a 5% (p = 0.05) confidence level.*

#### **Table 1.**

*Spatial distribution of the Bothriocline auriculata plants in the species' native ecosystems.*

#### **Figure 3.** *Distribution of plant species in different altitudes of Mt. Elgon.*

in Uganda whose ecological range was restricted to a few sites along the slopes of Mount Elgon between 2745 and 3150 meters Above Sea Level (A.S.L).

**Figure 3** shows variations in the spatial distribution of *Bothriocline* plants with the altitude along the Mount Elgon slopes. The *Bothriocline* species richness and abundance increase with altitude along the gradient transect, and are the highest mid-altitude zones between 1500 and 2500 m above sea level. The mid-altitudes are composed of the mixed montane forest, bamboo, shrubs and thickets, as well as low canopy montane forest with a more favorable protective vegetative cover and microclimate as opposed to the highland altitudes (**Figure 3**).

On the other hand, the *Bothriocline* species richness and abundance begin to decline at higher altitudes from 2501 m and above. The vegetation type at higher altitudes is dominated by low and high canopy montane forest and moorland coupled with mild to cool temperatures; that is not favorable for the protection and proliferation of the *Bothriocline* species (**Figure 3**).

Overall, the richness of *Bothriocline auriculata* species is low with the narrow ecological range within the species' native ecosystems along the slopes of Mount Elgon (**Figure 3**). The species' spatial distribution and plant populations are restricted to mid-altitudes having mixed montane forest, bamboo, shrubs and thickets. Previous studies also confirm that the *Bothriocline auriculata* species thrive well under tropical ecosystems with dense vegetative cover, and the species' plant populations are abundant in the montane forest, mountainous areas and bamboo thickets [3, 7].

The low species richness and narrow ecological range suggest the high vulnerability of the *Bothriocline auriculata* species which could be primarily driven by environmental and human-induced threats to the species' survival, existing population and protective ecosystem. The possible environmental or natural factors could be soil biotic and abiotic factors (fertility, pH, microbiota, moisture etc.), extreme weather episodes like heat waves or high temperatures, erratic rainfall and humidity.

Similarly, the likely human-induced threats to the *Bothriocline* species' survival and population could include among others, anthropogenic climate change episodes such as dry spells, flooding coupled with mismanagement of the fragile ecosystems

#### *Integrated Conservation Approaches for Rescuing, Regeneration and Adaptive Management… DOI: http://dx.doi.org/10.5772/intechopen.106893*

namely, over-harvest/grazing, arable farming and deforestation for timber and fuel wood; that often destroy the species protective ecosystems.

In this context, future studies should focus on profiling the environmental and human-induced threats that compromise the survival of the *Bothriocline auriculata* species, as well as species richness, spatial distribution and ecological range across its native protective ecosystems. If so, the data will inform future species conservation options and adaptive management practices within the same ecosystems or find better alternative host environments.

## **3.3 Rescue the critically-endangered** *Bothriocline auriculata* **species from its native ecosystem**

Intensive eco-geographical surveys and scouting were performed along the slopes of Mount Elgon, the species' native ecosystem as well as on nearby farmlands, bushes and thickets to find, locate and rescue any remaining species specimens. Despite several repetitive surveys, 114 species specimens were found and positively identified within its native ecosystem along the slopes of Mount Elgon.

Regrettably, the species plants did not have seeds and seedlings in the wild so seed germination or artificial propagation of seedlings could be carried out for conservation purposes. Failure to produce seeds suggests that the *Bothriocline auriculata* species does not attain a complete growth cycle where the species enter flowering phases to produce seeds after attaining full maturity but rather remains in the vegetative phase. Besides being a survival mechanism in a fragile ecosystem, unfavorable weather mainly dry spells and humidity put additional stress on the plants, suppressing hormones for flowering and seed production thereby remaining in vegetative phases ([7] and IUCN, 2020).

Failure to enter into the flowering phase and complete the growth cycle could partially explain the low species richness and limited ecological, as well as the fast declining *Bothriocline auriculata* plant population within its endemic and native ecosystems; where the species is classified by the IUCN as critically endangered ([7] and 2020). In response, future studies should identify both human-induced and ecological factors that affect the growth performance of *Bothriocline auriculata,* and propel the species not to enter into flowering phases but rather remain in vegetative phases. Ecological biotic and abiotic factors limit the species' dispersal and geographical range.

Due to the small populations of the *Bothriocline auriculata* species and the absence of the seeds, only a few vegetative portions of the species plants were collected from the species. For this study, 15 vegetative portions (leaves and branches) of the specimens were collected, and the donor parent plants were left living in the wild. As such, the 15 specimen portions were rescued and regenerated into mass seedlings using the lab tissue culture and micropropagation protocols at Makerere University.
