Utilisation and conservation status of indigenous woody plant species in a sedentary pastoral production system in south-western Uganda
Indigenous woody plant species play a significant role in sustaining pastoral production systems in sub-Saharan Africa. Outside protected areas in Uganda, populations of useful naturally growing woody species are threatened with extinction. Moreover, little is known about the population structure of woody plant species in such unprotected sites to guide conservation strategies. The objective of this study was to identify indigenous woody plant species utilised by the pastoralists in the dry lands of south western Uganda and assess the population structure of the species utilized. A survey involving 100 households was conducted to inventorise woody plants in 55 nested plots of 50 m × 50 m. A total of 70 indigenous woody plant species were utilised by the pastoralists to serve nine purposes. High utilisation of the plant species was in the order of medicine for humans and livestock, firewood, fodder, timber, poles, shade, food and least in crafts. The major woody plant species utilised included Vernonia ammygdalina, Acacia sieberriana, Acacia hockii, Carissa edulis and Albizia coriaria. Allophylus sp was valuable for all the nine purposes, though particularly for human medicine and poles. In terms of conservation status, trees conformed to inverse J shape and bimodal patterns of population structure, indicating current sustainable conservation in some species and an imbalance in pecies with a bimodal pattern. Most shrubs reflected irregular population structure indicative of unsustainable conservation status. Seedlings for both trees and shrubs were in the low level of abundance, according to Braun- Blanquette cover scale. Sustainable conservation of indigenous woody plant species in a sedentary pastoral system requires aided regeneration that involves supplementing natural regeneration with similar plant species, as well as zoning sites with high woody species diversity. Promotion of community based conservation platforms where pastoralists can be trained on sustainable plant conservation is recommended.
Key words: Population structure, Vernonia ammygdalina, woody plants