Rangeland Condition and Herbage Utilization by Herbivores of the Kafue Flats North Bank: A Historical Perspective before the Construction of the Itezhi-Tezhi Dam, Zambia

摘要

This study was carried out in Blue Lagoon National Park and the North Bank portion of the Kafue Flats Game Management Area along the Kafue River in Zambia. The aim of the study was to determine rangeland condition and utilization by wildlife as well as livestock grazing in Kafue Flats, to establish the baseline data for monitoring after the construction of the Itezhi-Tezhi dam.? Line intercept method and enclosure plots were used to sample in all recognized vegetation types and basal cover and frequency measurements were taken using line intercept method while enclosure plots were used to determine rangeland utilization. Data obtained from records showed that the area had annual mean rainfall of 535 mm at Itezhi-Tezhi, but the lowest rainfall recorded was 214 mm in the 1978-1979 rainy season and the highest was 1, 184 mm in the 1975-1976 season. With regard to range condition, bare ground was highest in the Termitaria vegetation at Nakenda-Critchley (62%), Bowa (57.6%) and Muwezwa (48.45%) while basal cover was relatively high in the flood plain at Namunyona (47.8%). Litter had an almost even distribution in all vegetation types and percent standing crop biomass was relatively high in all sample plots. Rangeland utilization was relatively high around Nakenda-Chitanda (43.54%) in the flood plain and Bowa (31.42%) in the Termitaria vegetation. It was concluded that Termitaria vegetation was largely at high risk of degradation due to overgrazing. While the impact of dams, environmental flows and flood pulse are discussed, detailed research and monitoring should be introduced in addition to the promotion of management of pastures in this rangeland.