Does shifting Carbon Use Efficiency determine the Growth Rates of intact and disturbed Tropical Forests? Gathering new evidence from African forests

Project Team: Adu-Bredu, S., Owusu-Afriyie, K., Duah-Gyamfi , A., Addo-Danso, S.D., Djagbletey,G.D., Amponsah Manu, E. and Adu-Opoku, A.

Collaborators: School of Geography and the Environment, Environmental Change Institute, University of Oxford

Background

Tropical forests play a major role in the global carbon cycle, by storing a substantial amount of carbon in biomass and soil, and by regulating transfer of this stored carbon into the atmosphere as greenhouse gas carbon dioxide (CO2). Tropical forests in Amazonia and Africa appear to be increasing in biomass, absorbing around 12±3 % of current anthropogenic CO emissions (and the rate of rise of atmospheric CO2 would be about 17% higher without this tropical sink), but the continuity of this biomass carbon sink is uncertain. Improved understanding of productivity, carbon cycling and carbon use e fficiency (the ratio of net primary production to gross primary production), and their controlling factors is essential to improve att empts to accurately model tropical forest
carbon cycling, and their potential responses to future environmental changes. Th e project therefore seeks to address the relative importance of photosynthesis and autotrophic respiration in determining forest function in intact and disturbed tropical African forests. To achieve this comprehensive carbon cycle assessment plots have been established and replicated across two contrasting countries in Africa namely, Ghana (West Africa) and Gabon (Central Africa). In Ghana, the project is implemented in di fferent ecological zones namely: the Bobiri Forest Reserve (moist semi-deciduous zone), Ankasa Forest Reserve (wet evergreen zone) and the Kogyae Strict Nature Reserve (dry semi-deciduous zone).