Land Use Impacts on Miombo Woodland Species in Wenimbi Resettlement Area of Macheke, Zimbabwe

The miombo woodlands are used in a diversity of ways that influence biodiversity and ecosystem stability most of which threaten woodland and agro-ecosystem sustainability. The study assessed the influence of three farming activities, namely tobacco, maize and horticulture production on Brachystegia spiciformis and Julbernadia globiflora tree species, which are dominant and are used in most household, construction and energy purposes. The fate of the timber harvested from the woodlands is important as it gives a clue on the most destructive farming activities and the size of trees required. Indicators to determine levels of deforestation, and capacity to regenerate were tree and stump populations per ha. For tree size preference, root collar diameter, stump and tree heights, and the ability of the remaining stumps to coppice were assessed. Residual tree density was lowest (P < 0.001) on the tobacco sites compared to the other two sites that also differed significantly. Stump population was highest in woodlands where maize is actively grown in comparison to horticultural and tobacco sites. However stump survival and coppicing capacity were significantly higher (P = 0.000) in woodlands of maize and horticulture active growing farms. Overall, there is selective and preferential utilization of woody biomass by size depending on the fate of the biomass though this does not reflect itself by species. It is concluded that the agricultural activities influence the cover of the two tree species and this could have detrimental effects on the miombo ecosystem and on the sustainability and viability of the farming activities especially tobacco production that has impacted mostly on bigger diameter trees whilst horticulture production is affecting the smaller diameter trees leaving the older trees.