Effect of Water Harvesting on Species Diversity and Overall Rangeland Recovery in Kagera Microcatcbement
Plant species diversity was investigated on ridges with and without water harvesting structures. The effect of water harvesting technology on the soil properties and rangeland recovery was also investigated. The experimental sites are located in Kifamba, Kakuuto County Rakai District. Plant species were recorded on a 50m horizontal transect aligned on the main transect running S-N on a 20m lag. The quadrat method was used to sample grasses and herbs, whereas shrubs and trees were sampled on twenty five meter plots on consecutive horizontal transects. Soil physical and chemical properties, plant biomass and ground cover were determined along the landscape. Results indicate that, ridges with water harvesting structures bad higher species diversity than those without water harvesting structures (p<0.05). The plant diversity on ridges with water harvesting (Shannon Diversity index) was H' =4.46, while the diversity of ridges without water harvesting was H' =3.93. The two types of ridges were significantly different (p<0.001) in terms of the diversity of plant species. The results further reveal that the introduction of water harvesting structures did not induce a landscape position pattern in the distribution of species, but that of grass biomass, despite the uniformity of chemical properties along the landscape (p<0.05).
Keywords: Ecology, Rangeland restoration, Species diversity, Land productivity .