Plant Species Composition and Diversity in Dalbergia melanoxylon Dominated Zones in Mitarure Forest Reserve in Kilwa District

Abstract

The study was designed to assess the plant species composition and diversity  in  the  Dalbergia  melanoxylon  dominated  zone  in  Mitarure Forest Reserve and the nearby community forests particularly Ngea and Nambawala in Kilwa District, Tanzania. Thirty (30) circular concentric plots were established in the forest reserve and fifteen (15) plots in each of the two-community forest and used to collect vegetation data. The plant species diversity was determined using Shannon-Wiener diversity index, evenness, richness and Simpson and their indices were compared using ANOVA. Plant species diversity and evenness assessed in Mitarure Forest Reserve did not differ significantly from those from community forests. However, the plant species diversity based on Simpson index and richness were significantly higher in the Mitarure Forest Reserve compared to those in community forests. A total of 56 plant species were recorded in Mitarure forest reserve, 39 plant species in Ngea forest and 36 plant species in Nambawala forest. Mitarure forest reserve and the nearby community forests have high plant species diversity with a good stand characteristic of a typical natural forest. However, with an intensive human disturbance, the tree species composition decreases that needs an intervention through local community involvement. This strategy may contribute in the future survival of species and the natural forests in Kilwa District. Data from this study stand as baseline information for the future monitoring of the performance of stands in the natural forest ecosystem in the Dalbergia melanoxylon-dominated zones in Kilwa District.