**4. Results**

The analysis of the vegetation data resulted in the identification of two major plant communities namely the *Pennisetum sphacelatum-Andropogon appendiculatus* Peatland present on Platberg and the *Haplocarpa nervosa-Isolepis cernua* Peatland present on the Lesotho study sites. The phytosociological classification of the two major wetland communities is presented in Table 1.

## **4.1 Khalong-la-Lithunya**

The vegetation of this peatland is dominated by the grass *Pentachistis oreodoxa* and the forb *Haplocarpa nervosa* that covers up to 75% of the area (Plots 8-11, Species group B - Table 1). The forbs *Isolepis cernua, Ranunculus meyeri* and *Cotula radicalis* are prominent throughout this community. The canopy cover of the wetland ranged between 60% and 100%. A total of 21 different plant species comprising 14% grasses and 86% forbs were identified within this wetland with the average height of the plant species ranging between 2 and 6 cm. Small to medium sized erosion dongas were observed within this system.

In both exclosure plots the biomass was higher than that measured in the grazed plots (Figure 3). The biomass in exclosure plot 1 was 3 868.4 kg DM/ha compared to the 1 020 kg DM/ha in the grazed plot 1 while the biomass of exlosure plot 2 and grazed plot 2 was 2 002.7 kg DM/ha and 759.4 kg DM/ha respectively (Figure 4). The herbaceous layer of the exclosure plots had

the Mann-Whitney U Test (Welman et al., 2007) was used on the ranked data to determine

Fig. 3. All rooted herbaceous plants were harvested on a species basis in quadrats (0.5m2),

The analysis of the vegetation data resulted in the identification of two major plant communities namely the *Pennisetum sphacelatum-Andropogon appendiculatus* Peatland present on Platberg and the *Haplocarpa nervosa-Isolepis cernua* Peatland present on the Lesotho study sites. The phytosociological classification of the two major wetland communities is

The vegetation of this peatland is dominated by the grass *Pentachistis oreodoxa* and the forb *Haplocarpa nervosa* that covers up to 75% of the area (Plots 8-11, Species group B - Table 1). The forbs *Isolepis cernua, Ranunculus meyeri* and *Cotula radicalis* are prominent throughout this community. The canopy cover of the wetland ranged between 60% and 100%. A total of 21 different plant species comprising 14% grasses and 86% forbs were identified within this wetland with the average height of the plant species ranging between 2 and 6 cm. Small to

In both exclosure plots the biomass was higher than that measured in the grazed plots (Figure 3). The biomass in exclosure plot 1 was 3 868.4 kg DM/ha compared to the 1 020 kg DM/ha in the grazed plot 1 while the biomass of exlosure plot 2 and grazed plot 2 was 2 002.7 kg DM/ha and 759.4 kg DM/ha respectively (Figure 4). The herbaceous layer of the exclosure plots had

randomly placed in the grazed and exclosure plots in the peatlands.

medium sized erosion dongas were observed within this system.

where the pairwise differences lie.

**4. Results** 

presented in Table 1.

**4.1 Khalong-la-Lithunya** 

an average height of 4 cm while the grazed plots had an average height of 2 cm. No difference in species composition was found between the exclosure and grazed plots (Table 1).


Table 1. Phytosociological table of the major high-altitude wetlands of Lesotho and Platberg.

Impact of Domestic Animals on Ecosystem Integrity of Lesotho High Altitude Peatlands 257

number of 24 different species were identified comprising 13% grasses and 87% forbs. The canopy cover of the wetland ranged between 65% and 100% with medium sized erosion

Biomass for the exclosure plots was 555.4 kg DM/ha and 835.3 kg DM/ha respectively compared to the low 355.9 kg DM/ha and 190.6 kg DM/ha for grazed plots 3.2 and 4.2 (Figure 5). There was no difference in species composition between the exclosure and grazed plots (Table 1). The average height of the herbaceous layer was 3.8 cm compared to 1.8 cm in

The Kao peatland is characterized by the dominance of the forbs *Cotula radicalis, Isolepis cernua*, and *Haplocarpa nervosa* (Plots 16-18, Species group B - Table 1). A total number of 21 different species were identified comprising 14% grasses and 86% forbs. The canopy cover of the wetland ranged between 60% and 90% with medium to sized erosion dongas present. Biomass was low at 185.4 kg DM/ha and 145.5 kg DM/ha with the herbaceous layer only

The Platberg peatlands are characterised by the dominance of the grasses *Andropogon appendiculatus* and *Pennisetum sphacelata* while the grass *Pentaschistis* species and the sedge *Ficinia stolonifera* are prominent locally (Plots 1-7, Species group A - Table 1). A total of 19 different plant species comprising 42% grasses and 58% forbs were present. Canopy cover

These wetlands had an average biomass of 4302.5 kg DM/ha ranging between 2555.1 kg DM/ha and 5954.4 kg DM/ha (Figure 6). An average height of 51 cm was measured for the

ranged between 75% and 100% with no signs of erosion observed.

Fig. 6. Biomass of the Platberg peatlands in South Africa.

dongas present.

the grazed plots.

**4.3 Kao** 

1.5 cm high.

**4.4 Platberg peatlands** 

herbaceous layer.

Fig. 4. Biomass of the Khalong-la-Lithunya peatland in Lesotho.

#### **4.2 Koti-Sephola**

The grass *Pentachistis oreodoxa* and the forbs *Isolepis cernua, Haplocarpa nervosa* dominate the vegetation each covering between 25% and 65% of the area, while the forbs *Ranunculus meyeri* and *Cotula radicalis* are also prominent (Plots 12-15, Species group B - Table 1). A total

Fig. 5. Biomass of the Koti-Sephola peatland in Lesotho.

number of 24 different species were identified comprising 13% grasses and 87% forbs. The canopy cover of the wetland ranged between 65% and 100% with medium sized erosion dongas present.

Biomass for the exclosure plots was 555.4 kg DM/ha and 835.3 kg DM/ha respectively compared to the low 355.9 kg DM/ha and 190.6 kg DM/ha for grazed plots 3.2 and 4.2 (Figure 5). There was no difference in species composition between the exclosure and grazed plots (Table 1). The average height of the herbaceous layer was 3.8 cm compared to 1.8 cm in the grazed plots.

#### **4.3 Kao**

256 Ecosystems Biodiversity

The grass *Pentachistis oreodoxa* and the forbs *Isolepis cernua, Haplocarpa nervosa* dominate the vegetation each covering between 25% and 65% of the area, while the forbs *Ranunculus meyeri* and *Cotula radicalis* are also prominent (Plots 12-15, Species group B - Table 1). A total

Fig. 4. Biomass of the Khalong-la-Lithunya peatland in Lesotho.

Fig. 5. Biomass of the Koti-Sephola peatland in Lesotho.

**4.2 Koti-Sephola** 

The Kao peatland is characterized by the dominance of the forbs *Cotula radicalis, Isolepis cernua*, and *Haplocarpa nervosa* (Plots 16-18, Species group B - Table 1). A total number of 21 different species were identified comprising 14% grasses and 86% forbs. The canopy cover of the wetland ranged between 60% and 90% with medium to sized erosion dongas present. Biomass was low at 185.4 kg DM/ha and 145.5 kg DM/ha with the herbaceous layer only 1.5 cm high.

## **4.4 Platberg peatlands**

The Platberg peatlands are characterised by the dominance of the grasses *Andropogon appendiculatus* and *Pennisetum sphacelata* while the grass *Pentaschistis* species and the sedge *Ficinia stolonifera* are prominent locally (Plots 1-7, Species group A - Table 1). A total of 19 different plant species comprising 42% grasses and 58% forbs were present. Canopy cover ranged between 75% and 100% with no signs of erosion observed.

These wetlands had an average biomass of 4302.5 kg DM/ha ranging between 2555.1 kg DM/ha and 5954.4 kg DM/ha (Figure 6). An average height of 51 cm was measured for the herbaceous layer.

Fig. 6. Biomass of the Platberg peatlands in South Africa.

Impact of Domestic Animals on Ecosystem Integrity of Lesotho High Altitude Peatlands 259

between exclosure and non-grazed plots (p<0.05). The Platberg peatlands with no grazing present therefore significantly differs in terms of production from both the grazed and

**Exclosure plots** 101 4 33 **Grazed plots** 102 6 24 **Non- grazed plots** 103 7 96 Table 2. Kruskal-Wallis ANOVA by Ranks; Biomass Independent (grouping) variable:

Two distinctive vegetation communities resulted from the data classification namely the Platberg and Lesotho peatlands respectively (Table 1). Each unit reflects the homogeneity of the communities in terms of plant species composition and dominance. In all wetlands the forbs (including geophytes, succulents and sedges) comprised the largest percentage of species with grasses the lowest. The uniqueness of each unit can be ascribed to various

Studies done by Sieben et al. (2010) revealed that typical wetland plants cannot cope well with the cold conditions during winter months. This opens several niches for forbs, especially species that are not dominant in lowland wetlands to become dominant in high altitude wetlands. The forb *Ranunculus meyeri* (Species group B - Table 1) is such a species, which occur across all altitudes but are dominant in high-altitude wetlands (Sieben et al.,

The peat deposits vary in depth from shallow 10 cm to over 2 m deep (Kuenene, 2008). The peatlands are covered by short mat-like peat forming plants. Dominant species in the Lesotho peatlands include the grass *Pentaschistis oreodoxa*, the sedge *Isolepis cernua*, the geophyte *Rhodohypoxis deflexa*, and the forbs *Haplocarpa nervosa, Cotuls radicalis* and *Ranunculus meyeri* (Table 1). Unlike the Lesotho peatlands, the platberg peatlands are mainly grassland dominated with the grasses *Andropogon appendiculautus* and *Pennisetum sphacelatum* prominent. The sedge *Ficinia stolonifera* and the grass *Helictotrichon longifolium*

Waterlogged conditions are a requirement for peat formation. Peat formation is a very slow process and is mainly formed from the root decay of vascular plants that grow on the peatlands. This process takes place in the absence of oxygen. Anoxia or reduction conditions between and below the roots, decomposes the dead material to form amorphous peat. According to the species composition of the wetlands at Khalong-la-Lithunya, Koti-Sepola, and Kao, sedges such as *Isolepis cernua* are together with forbs such as *Haplocarpha nervosa*, and *Ranunculus meyeri* the main contributors to peat formation. In contrast at Platberg the grasses *Andropogon appendiculatus, Pennisetum sphacelatum* and *Helictotrichon longifolium* are

physical factors such as altitude, pH, moisture regime of the peat, and biotic impact.

2010). This species was found to be prominent in the Lesotho peatlands.

**Code Valid -** 

**N** 

**Sum of - Ranks** 

exclosure plots with a much higher biomass as a result of the absence of grazers.

Grazing Kruskal-Wallis test: H ( 2, N= 17)

**5.1 Species composition and richness** 

are locally dominant (Table 1).

the main contributors to peat formation.

**5. Discussion** 

#### **4.5 Biomass per grazing type**

The following boxplot uses the medians and quartiles to compare the distributions of biomass (kg DM/ha) of the plots by grazing type (non-grazed; exclosure plots; grazed) (Figure 7).

As expected there is some overlap in the values of the grazed and exclosure plots, the latter only being fenced off for the past 12 months, while the non-grazed plots have some overlap with the exclosure plots. Thus although there appear to be differences between the grazed and exclosure plots the overlap results in there being a non-significant difference between them.

Although overlaps exist, differences between the different treatments are observed indicating that the non-grazed Platberg peatlands have the highest production followed by the exclosure plots that show variable increases within the short time (12 months) since being fenced off, compared to the open grazed plots.

Fig. 7. Boxplots of the medians and quartiles comparing the biomass of the different grazing types.

The Kruskal-Wallis ANOVA by Ranks test was used to compare the Biomass (kg DM/ha) of the plots by grazing type. From the Kruskal-Wallis test [H ( 2, N=17)=12.071 p =.0024] it shows that there is a significant difference in the ranks of the plots categorised by grazing type (Table 2). Significant differences were found between the grazed, non-grazed and exclosure plots. By using the the Mann-Whitney U Test on the ranked data the significant differences were found to be between the grazed and non-grazed plots (p<0.01) and between exclosure and non-grazed plots (p<0.05). The Platberg peatlands with no grazing present therefore significantly differs in terms of production from both the grazed and exclosure plots with a much higher biomass as a result of the absence of grazers.


Table 2. Kruskal-Wallis ANOVA by Ranks; Biomass Independent (grouping) variable: Grazing Kruskal-Wallis test: H ( 2, N= 17)
