Increased Biomass for Carbon Stock in Participatory Forest Managed Miombo Woodlands of Tanzania

Miombo (Zambezian savanna) woodlands are important forest vegetation in Tanzania. The forests contain biomass which is vital for climate change mitigation strategy. However the extent of increasing biomass under participatory forest management for carbon sequestration and storage is not clear. Understanding of this biomass will aid development of effective climate change mitigation strategies and promote sustainable forest management. This study involved 276 systematically determined concentric sample plots laid out in eight miombo woodland forests (four in Mbeya region and four in Iringa region). Of these plots, 145 were laid in participatory managed forests and 131 in reference scenario, called business as usual (BAU) or open access forest selected in proximity. The main finding was that most of PFM forests had significant increase in biomass (P < 0.05) as compared to the reference scenario. Mean biomass increased from 48.05 t/ha ± 0.03 to 37.91 t/ha ± 0.19 in PFM forests. Likewise mean biomass was 37.91 t/ha ± 0.11 to15.79 t/ha ± 0.13 for reference scenario BAU forests. This implied higher average carbon stock in participatory managed forests (21.37 t/ha) against the reference scenario (11.28 t/ha). The results provide evidence that participatory forest management approach in miombo woodlands of Tanzania have potential for climate change mitigation strategies. Despite the challenge in determining reference scenario, these findings present useful benchmark against which further study can be performed.