Farming does not necessarily conflict with tree diversity in the mid-Zambezi valley, Zimbabwe

Abstract

We tested whether cultivation and fallowing have any significant effect on tree species diversity and dominance in semi-arid Zimbabwe. To this end, we quantified tree species diversity and physiognomy on two soil types (mutapo and bandati) stratified into three land-use categories, i.e., cultivated land, fallow land and woodland. Results showed that tree species diversity was significantly different of the two soil types. Tree species diversity was high on bandati soil and low on mutapo soil. Results also showed that there was significant difference in tree species diversity among the three land-use categories on mutapo soil but no differences on bandati soil. Pairwise comparisons revealed significant differences in species diversity between paired categories on mutapo soil but no significant differences on bandati soil. Tree physiognomy was significantly different among all three land use categories. Colphospermum mopane and Diospyros kirkii were the dominant species within woodlands, while Acacia tortilis subsp. Spirocarpa replaced them as the dominant species within the fallow land category. These results indicate that woodland conversion for cultivation purposes has no immediate significant effect on tree species diversity on bandati soil, while it has a pronounced effect on mutapo soil, at least in the short term.