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

摘要

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.