Woody vegetation stocking, composition and diversity in Miombo Woodlands in Tanzania: A case study of Mgori forest reserve in Singida District

Abstract

Participatory forest management (PFM) model is aimed at improving both forest resources conservation and livelihoods of local communities. In Tanzania, PFM is widely spread in forest reserves bearing the names of joint forest management, co forest management and community based forest management. However, despite the wide spread, less so far has been done to assess its contribution to conservation of the forest resources and livelihoods of local communities. The study, however, majored on assessment of forest resources by describing woody stocking, and species composition and diversity at Mgori Forest Reserve, in Tanzania. Mgori forest reserve (MFR) is one of the reserves in Tanzania, which are under the model. MFR is within miombo woodlands of Tanzania allocated along the western side of the country. Inventory data were collected from four village forest reserves, which are part of MFR. A
total of 136 plots of the size 20 x 50 m (0.1ha) were laid in different clusters. The study enumerated a total number of 79 tree/shrub species. DBH distribution followed an inverse ‘J’ shape. Stem density in the study ranged between 494 and 885 N ha-1, while basal area and woody volume
distribution followed a ‘J’ shape. The basal area varied from 9.65 to 18.50 m2 ha-1, while the woody volume was averaged to 65.99 m3 ha-1 with a range of 54.49 to 104.47 m3 ha-1. The most dominant tree species in the study were Brachistigia spiciformis and Jubernadia globifolia. Important
value index of tree species ranged between 4.29 and 10.00, while Shannon Weiner index was between 2.54 and 3.04. Index of dominance in this study was between 0.03 and 0.11, while species diversity index ranged from 38.46 to 89.36 and species richness and evenness ranged between 9.65 and 21.04 and 1.55 and 1.81 respectively. The study concludes that woody stocking parameters as well as tree/shrub species composition and diversity indices are normal and similar to any other reserved forests in miombo woodlands.

Key words: miombo woodland, stem density, basal area, woody volume, species composition, diversity, participatory forest management, village forest reserves