Status of vegetation structure and composition of Mukuvisi Woodlands in Harare (Zimbabwe)

Abstract

Vegetation structure and composition influence the suitability and availability of unique habitats for different wildlife species especially in closed environments. The main objective of this study was to establish the current status of vegetation structure and composition, in Mukuvisi Woodlands, an urban green space in Harare (Zimbabwe). Three distinct vegetation types were selected; riverine, woodland and grassland. Random sampling within the strata was employed so as to cover as much disparity in landscape as possible. A total of 15 plots measuring 20m x 30m were sampled for the woody vegetation while four 1m x 1m plots were sampled for the grasses within each of the 15 vegetation plots in Mukuvisi Woodland between February and May 2017. A total of 33 tree species were recorded in all the plots. The average tree height was 5.88m and 7.39m in woodland and riverine vegetation respectively. Dominance and evenness significantly differed between habitat types with woodlands having the highest dominance and riverine vegetation having the lowest evenness (p<0.05). A total of 30 grass species were recorded. Diversity and evenness of grass species was not significantly different in the three vegetation types (woodland, grassland and riverine; ANOVA, p>0.05). The percentage grass cover was 67.5% for woodland, 67.29% for riverine and 88.25% for the grassland. The grassland in Mukuvisi Woodland is mixed but is currently dominated by decreaser grass species of low palatability with high moribund accumulation. Active management should be applied and also aim at controlling decreaser species such as S. Pryamidallis as well as to maintain good number of grazers and browsers.