Traditional farming and plant species diversity in agricultural landscapes of south-western Uganda

An effort was undertaken in Bushwere Parish (Mbarara district, south-western Uganda) between 1999 and 2000 to develop sustainable and participatory approaches to plant biodiversity conservation at the farm level. One hundred farmers were interviewed on their socio-economic profiles and plant use strategies. Plant diversity was assessed in 400 plots of 5 m×5 m established in 53 field types of seven land-use categories. The most species-rich land-use category was under annual crops (149 plant species) while the most species-rich field type was planted with bananas (118 species). Shannon diversity and Sørensen’s similarity indices were used to compute species diversity and similarity, respectively, between field types and land-uses. The most plant diverse land-use was natural woodland, the least fallow. Canonical correspondence analysis (CCA) showed that occurrence of species, field type or land-use depended upon environmental factors such as elevation, position on the slope and soil type. Redundancy analysis (RDA) showed that species utility and occurrence were related to the socio-economic status of farmers. Plant species were most diverse in land-uses located on hill tops and steep slopes. Farmers should therefore be advised on how to maintain plant diversity in agricultural landscapes.