**2.5 Locations of study sites**

*Khalong la Lithunya* (KHL) wetland is a palustrine wetland and it is situated in the Mountain AEZ (**Figure 1**). It is located at an altitude/elevation of between 3181 and 3202 m above sea level (asl) and at points latitude 28° 53.821/longitude 28° 47.993 E. The geology of this land is Lesotho formation [5, 34]. There is a very sparse population in this area, as it is used only by those people who live in the animal posts and on work camps; however, there is remarkable damage done to the wetland area by soil erosion resulting from previous overgrazing of the land. Thus, with current protection from the Millennium Challenge Account (MCA), Lesotho wetland Restoration project, this piece of land is currently classified as low impact because currently there are no agricultural activities taking place. The mean annual rainfall often recorded for this area is 1000 mm deep.

*Ha Matela* (HM) wetland is a Riverine wetland situated in the Foothills AEZ at an elevation of 1820 m above sea level, at points; Latitude: �290 38.3333 /Longitude: 27<sup>0</sup> 76.6667 (**Figure 2**). The geology of this land is Lesotho formation [5, 34] with sedimentary and volcanic clastics. The land use types (LUTs) found in this area are pasture and cropping and it has been highly impacted. The mean annual rainfall often recorded for this area is 65 mm deep.

#### **2.6 Soil sampling and analysis**

A Garmin GPS (Geko 301) was used to determine the elevations of the study sites and to track the position of the points at which samples were collected. At KHL catchments, three transects, of approximately 1000 m each, were chosen and minipits (0.5 m) were dug at intervals of 70 m. At HM catchments, two transects were chosen on one side of the stream and one transect on the other side and the minipits (0.5 m) were dug at the upper, the middle and the lower slope of each transect and at 150 m interval along the stream.

At both sites, soil samples were collected from every exposed horizon in the mini-pits. The soil samples were put into polythene bags and taken to the laboratory where they were air-dried at room temperature for 72 h and then crushed to pass through a 2 mm sieve. The soil samples were then analyzed for total nitrogen [35]; available Phosphorus [36]; Base cations (Mg, Ca, Na and K) extracted using the Ammonium acetate at pH 7 and determined using the Atomic Absorption Spectrometer (Spectro AA 300). The soils were also analyzed for micronutrients (i.e. Cu, Fe, Zn, and Mn).

At both sites, water samples were collected from December 2010 to March 2011 across from installed plastic water bottles (DWB) which have been pre-rinsed with de-ionized water at a depth of 0.50 m in duplicates. Five DWB were installed in each of the three transects at KHL catchments. However, at HM catchments, the DWB were installed at the upper, middle and toe-slopes and the land use types (LUTs). The mainland use type (LUT) at HM catchment was mainly for livestock grazing, watering, and cropping. Run-off water samples were collected in duplicates using into a 20 mL plastic bottle and acidified with 0.1 N HCl. Following sample collections, samples were preserved in the icebox to restrain microbial activities before getting to the laboratory. All the parameters mentioned above were determined, based on standard methods [37] using the Atomic Absorption Spectrometer (Spectro AA 300). Four indicators—base cations (K, Ca, Mg & Na), total P (TP) and Total N (TN) were used to describe the water quality of samples. The base cations, TN and TP were analyzed in the laboratory.

#### **2.7 Vegetation sampling and analysis**

Nitrogen isotope (15N) was applied in the form of urea to wetlands at both sites located in the KHL and HM at the upper-slope (US), mid-slope (MS) and toe-slope (TS). At both sites, vegetation samples were collected in triplicates from the three sections of the toposequence. Dominant vegetation at KHL was *Helichrysum trilineatum* and at HM it was *Cyperus* spp. The enrichment of 15N (δ15N) is expressed in a conventional manner as parts per thousand relative to the isotopic ratio in standard air:

$$\mathbf{6^{15}N} = (\mathbf{R sample}/\mathbf{R standard} - \mathbf{1}) \ast \mathbf{1000} \tag{1}$$

where R-sample and R-standard are the ratios between 15N and 14N of the sample and the standard, respectively.

*Wetland Health in Two Agro-Ecological Zones of Lesotho: Soil Physico-Chemical Properties… DOI: http://dx.doi.org/10.5772/intechopen.101836*

Samples were collected at each site by clipping four healthy, intact, mature plants at the soil surface avoiding senescent plant leaves. Live samples were wiped cleaned to remove surface debris and then chopped into approximately 10-cm sections for drying. The vegetation samples were put into labeled paper bags and dried at a temperature of 55°C and subsequently sent by courier service to the International Atomic Energy Agency (IAEA), laboratory, Seibersdorf, Vienna, where they were then crushed, weighed, and analyzed for N15 and 13<sup>δ</sup> C isotope signatures.

### **2.8 Statistical analysis**

Data collected (soils, water) were subjected to summary statistics (N, max, min, range, standard deviation, standard error, kurtosis, and skewness) using the means procedure of SAS (PROC Means) [38]. Data (soils, water, and vegetation N15) were also subjected to one-way analysis of variance (ANOVA) using the general linear model procedure (PROC GLM) [38] and means were separated using Duncan multiple range test at 5% level of significance. Results of the selected soil properties were compared across sites using analysis of variance procedure of SAS (PROC ANOVA) [38] and means were separated using Duncan multiple range test at 5% level of significance.

## **3. Results and discussion**
