Dependence on forest and its impacts on species composition and cover in Dindili Forest Reserve, Morogoro Tanzania

Abstract

The specific objectives of the study were to: identify forest human disturbance, identify forest products used for house construction by  adjacent communities, assess stand density and diameter distribution and hence basal area and wood volume. Other objectives were to  assess: species composition, regeneration and forest cover changes over time. Systematic sampling design involving poststratification of  the forest reserve into dry evergreen forest and miombo woodland was used in the inventory. Microsoft Excel spreadsheet software and, remote sensing and GIS technologies were used to analyze quantitative data for various forest parameters and forest cover respectively.  Identified human disturbances included charcoal production, cultivation and logging especially in miombo woodland stratum evidenced  by higher number of stumps, observed pit-sawing platforms and charcoal kilns. Results from forest inventory showed that in the  woodland stratum of the study area, stocking levels were 365 ± 72 stems ha ^-1 , 7.74 ± 1.82 m² basal area and volume of 52.76 ± 14.48 m³ ha^-1 . In dry evergreen forest, values of 1256 ± 105 stems, 25.48 ± 2.34 m² basal area and volume of 200.75 ± 25 m³ ha ^-1 were observed.  Values of Shannon-Wiener index of diversity (H’) of 3.05 and Index of Dominance (ID) value of 0.065 were observed in miombo woodland  stratum. In dry evergreen forest stratum, values of 3.18 and 0.064 respectively were observed. It was also observed that the original  closed forest cover of the study area declined by 14% between 1991 and 2000. The most tree species extracted included Afzelia  quanzensis, Dalbergia melanoxylon, Julbernardia globiflora and Pterocarpus angolensis. Stocks of tree species such as Burkea africana  and Milicia excelsa were depleted. It was concluded that Dindili Forest Reserve had been highly affected by forest dependence, reflected  by the lower stocking levels, diversity indices and reduced forest cover. In order to subjugate the current scenario, special efforts are  needed to promote regeneration of the over-exploited species and put in place sound management plans for Dindili Forest Reserve  which encourage full participation of the communities around it.