Restoration and Conservation Biology Research Group, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Johannesburg, Wits 2050, South Africa
Kalema, V.N., Restoration and Conservation Biology Research Group, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Johannesburg, Wits 2050, South Africa; Witkowski, E.T.F., Restoration and Conservation Biology Research Group, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Johannesburg, Wits 2050, South Africa
The density and diversity of woody plant species were studied within grazing, cultivation and charcoal production land-use areas in a multiple-use savanna woodland, central Uganda, using 75 plots with an area of 0.1 ha (Whittaker plots). Plant density was significantly higher under charcoal production (7131 755 plants/ha) and cultivation (6612 665 plants/ha) compared with the grazing lands (4152 525 plants/ha). At the plot level, species richness and Fisher's alpha diversity () were relatively low, ranging 2-31 species and 0.34-6.34, respectively, but both were significantly higher under charcoal production and cultivation compared with grazing. Similarly, cumulative species richness and Fisher's alpha diversity were higher under charcoal production and cultivation compared with grazing. Community species composition differed significantly (Global R ANOSIM = 0.14, p=0.001; ANOSIM, ANalysis Of SIMilarity) among land uses. However, the distance of sampling plots away from households, the assumed source of human disturbance to woodlands, accounts for a very small fraction (<14.2%) of the variation in woody species diversity within this multiple-use savanna. Beta diversity was highest under grazing, followed by cultivation and charcoal production, suggesting a more heterogeneous spatial distribution of species under grazing. Within each land use, mean similarities were low, ranging 25-31%. Mean pairwise dissimilarities between land uses were relatively high, ranging 73-81%. This suggests that variations in species composition and diversity are to a great extent influenced by land-use and anthropogenic disturbances. The relatively low woody species diversity and richness in this savanna indicates woodland degradation, fragmentation and local species loss resulting from unsustainable harvesting for charcoal, and short interval shifting cultivation. © 2012 Copyright Taylor and Francis Group, LLC.
anthropogenic effect; charcoal; cultivation; ecological impact; environmental disturbance; grazing; habitat fragmentation; harvesting; land degradation; land use change; plant community; shifting cultivation; spatial distribution; species diversity; species richness; sustainable development; woody plant; Uganda
