Structure and composition of woody vegetation in two important bird areas in southern Zimbabwe

This study assessed the status of woody vegetation structure and composition in two Important Bird Areas (IBA) i.e. Manjinji Pan and Save-Runde Junction located in southeastern Zimbabwe. The objectives of this study were to: (i) determine the woody vegetation structure and composition of the study areas and (ii) find out any differences and similarities in woody vegetation between the two IBAs. Data about woody vegetation were collected from 40 randomly placed sample plots from both study areas. Tree density was higher in Manjinji Pan IBA (406.67 +/- 16.86 trees ha(-1)) than Save-Runde Junction IBA (275.83 +/- 17.62 trees ha(-1)). In contrast, Save-Runde Junction IBA had higher numbers of stems per plant (2.88 +/- 0.22), species richness (59) and diversity (H' = 3.28) than Manjinji Pan IBA: numbers of stems per plant (2.16 +/- 0.12), species richness (43) and diversity (H' = 2.90). No significant differences were recorded in woody plant height, shrub and dead plant densities. The findings suggest that several factors including fires, herbivory and human activities could be influencing the woody vegetation in the two IBAs. However, further research is suggested to better understand the drivers of woody vegetation variation in IBAs occurring in savanna ecosystems. It is recommended that species richness and diversity of woody plants should be maintained and invasive plant species controlled for the conservation of endemic and migratory avifauna

Variation in woody vegetation structure and composition in a semi-arid savanna of southern Zimbabwe

The objectives of this study were: i) to establish the status of woody vegetation structure and composition, and ii) to determine the main factors influencing woody vegetation structure and composition across Gonarezhou National Park, Zimbabwe. We divided the park into three large strata based on natural and artificial features. A total of 137 sample plots were randomly placed to gather data on woody vegetation in the three study strata across Gonarezhou National Park from May to June 2011. Trees constituted 66% and shrubs 34% of the woody plants sampled. A total of 132 woody plant species were recorded. Significant differences were found in basal area, shrub density, browsed plants density and woody species diversity across Gonarezhou National Park. In contrast, no significant differences were recorded in tree height, densities of trees, stems, dead plants and fire damaged plants. Our results suggest that there are some variations in woody vegetation structure and composition across Gonarezhou National Park. These variations could be attributed to both natural and anthropogenic disturbance factors including elephant (Loxodonta africana Blumenbach) browsing, fires, droughts and previous tsetse fly (Glossina spp.) (Diptera: Glossinidae) eradication activities in the park

Vegetation structure and composition across different land use in a semi-arid savanna of southern Zimbabwe

We compared the structure and composition of vegetation communities across different land uses in the northern Gonarezhou National Park and adjacent areas, southeast Zimbabwe. Vegetation data were collected from 60 sample plots using a stratified random sampling technique from April to May 2012. Stratification was by land use, and sample plots in all three strata occurred on predominantly siallitic soils. Our results show that the communal area had higher woody plant species diversity (H' = 2.66) than the protected area (H' = 1.78). However, the protected area had higher grass species richness per plot than the communal area and resettlement area. Overall, the protected area had more structural and compositional diversity than the other land use areas. These findings suggest that the areas adjacent to protected areas contribute to plant diversity in the greater ecosystem; hence conservation efforts should extend beyond the boundaries of protected areas. We recommend that protected area management should engage community-based institutions in neighbouring areas for effective monitoring of woody vegetation structure and composition