Assessment of forest regeneration across land tenure regimes in southeastern Tanzania

Background/Question/Methods

In miombo woodlands of sub-Saharan Africa, an estimated 100 million urban and rural people rely on forest productivity and reproductive success of select tree species for food, medicine, fuel, shelter, and livelihoods. At the same time, forest clearing for small-holder slash and burn cultivation, cooking fuel, and timber harvest result in the loss of an estimated half-million hectares of forest per year necessitating reliance on the regenerative capacity of forests for their future provision of goods and services.  An empirical understanding of how land use and governmental structures of land tenure effect forest population dynamics, particularly during establishment, is necessary to guide management decisions towards local and global sustainable livelihood goals. To research this I surveyed tree species composition, biomass and size class across fifty 1000 m² nested plots in both locally- and centrally-managed timber, charcoal, and reserve zones in the Kilwa District of coastal Tanzania. Bayesian generalized linear models were used to model the effect of land use and governmental structure on regeneration while taking into account fire history and abiotic site characteristics that determine plant growth. The best model to fit the data was chosen using DIC. 

Results/Conclusions

Forests in village general lands, which equate to an open-access management structure, had significantly lower amounts of regeneration when compared to areas that were within community-based forest management (CBFM) regimes. Areas with more intense land use histories, particularly charcoal and timber have less regeneration than comparable forested areas in reserves. Forest management structures in which there is more localized control (CBFM) and less intensive land uses have the highest regenerative capacities.