Aboveground carbon storage in Adansonia digitata L. (Baobab) in Mkanana agroforestry and Mangalisa forest reserve in Mpwapwa District, Tanzania

Woodlands are important sinks for the ever increasing levels of atmospheric carbon dioxide, which is directly linked to climate change. Baobab (Adansonia digitata L.) is among the vascular tree species with a long lifespan of 1250 years thus potential for carbon storage though inadequately studied. This study therefore aimed to account for aboveground biomass and carbon in an agroforestry of Mkanana village (with baobabs and sunflower) and Mangalisa forest reserve in Mpwawa District. The allometric model developed for baobabs in dry areas was used for estimation of biomass which was computed as 50% carbon. The mean aboveground biomass of baobabs of 6.952 ± 0.09546 tonnes/tree in Mangalisa forest reserve was higher than 5.538 ± 0.3064 tonnes/tree recorded in Mkanana agroforestry (Mann-Whitney U-Statistic = 94.000, U’ = 531.00, P ˂ 0.0001). On the other hand, the mean aboveground carbon of 3.476 ± 0.09546 tonnes/tree in Mangalisa forest reserve was significantly higher than 2.769 ± 0.1533 tonnes/tree recorded in Mkanana agroforestry (Mann-Whitney U-Statistic = 93.000, U’ = 532.00, P ˂ 0.0001). The results of this study positively contribute to vegetation carbon storage. Sustainable carbon storage in baobabs can be achieved by planting them in reserve areas rather than in agroforestry.