Miombo of Tanzania: Implications on conservation and

carbon stock

Woodlands degradation in the Southern Highlands, Miombo of Tanzania: implications on conservation and carbon stocks

Miombo woodlands is one of the major forest vegetation types covering about two thirds of the country forest land and form an integral part of the rural landscape in Tanzania, also they play crucial role in providing wide range of ecosystem services including carbon sequestration. This study aimed at assessing the effects of degradation on the structure and carbon stocks of miombo woodlands. Data were collected from 50 rectangular plots measuring 40×20 m. Stump diameter, diameter at breast height, tree height and species local and botanical names were recorded. Analysis was done by using R software and excel spread sheet. Results showed total harvesting of 10.53 m3ha-1 as compared to standing volume of 32.6 ± 2.3 m3ha-1 with basal area of 4.73 ± 0.5 m2ha-1. Estimated annual harvesting was found to be 6.63 ± 3.0 m3 ha-1 which exceeds mean miombo annual increment of 4.35 m3 ha-1 year1, this is indicator for unsustainable utilization which could results into woodland change. Harvesting resulted into total loss of 4.1±0.9 tCha-1 equivalent to 15.05 ± 3.3 tCO2eha,-1 new harvesting presenting 9.91 tCO2e ha-1 and old 5.14 tCO2eha-1. Managing the miombo woodlands carbon stocks for emissions and climate change mitigation in Tanzania and elsewhere requires rigorous effort to reduce anthropogenic degradation.This article is also available at http://www.academicjournals.org/IJBCCCIAM programme in Tanzania jointly implemented by Norwegian government and Tanzania government

Variations in the Forest Productivity of <i>Pinus patula</i> Plantations in Tanzania: The Need for an Improved Site Classification System

The productivity of forests in sub-Saharan Africa is often summarized into large compartments or site classes. However, the classification of forest productivity levels based on the original site index model in Tanzania and the techniques applied to generate the model did not include the micro-toposequence variations within compartments. This may create false expectations of wood supply and hinder the estimation of sustainable harvesting processes. This study analyzed variations in forest productivity and the site index in P. patula stands in two forest plantations of Tanzania to assess the applicability and generality of the present site classification system. We used dominant height as a proxy for forest productivity in 48 plots at the Sao Hill forest plantation (SHFP) and 24 plots at the Shume forest plantation (SFP). We stratified the sampling plots in each site class along the soil catena and recorded the elevation, slope, and slope positions (summit, mid, and lower). Our results showed that the site classes did not generally match the previously assigned site classes and the productivity of a given site class varied between the two plantations. We found a consistently higher productivity than that implied by the original site index in SFP, while in SHFP, the productivity was both higher and lower than estimated in different compartments. Both elevations and slope significantly contributed to predicting the productivity variations within site classes. Overall, the results indicate that physiographic factors affect variations in forest productivity within the assigned site classes. We recommend a more comprehensive site productivity assessment that takes into account physiographic variations and hence provides more accurate information for sustainable forest plantation management in Tanzania and in the region at large