Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Seasonal dynamics of soil CO₂ efflux across land-use types: Implications for climate mitigation in Ghana

¹Kwame Nkrumah University of Science and Technology (KNUST), Dept. of Civil Engineering (WASCAL), Ghana
²Council for Scientific and Industrial Research (CSIR), Forestry Research Institute of Ghana (FORIG), Ghana
³University of Kassel, Kassel Institute for Sustainability, Center for Environmental Systems Research (CESR), Germany
⁴Kwame Nkrumah University of Science and Technology (KNUST), Dept. of Wildlife & Range Management, Ghana
⁵GFZ German Research Center for Geosciences, Germany
⁶University of Potsdam, Inst. of Biochemistry and Biology, Biodiversity Research / Syst. Botany, Germany
⁷Kwame Nkrumah University of Science and Technology (KNUST), Dept. of Statistics and Actuarial Science, Ghana
⁸Kwame Nkrumah University of Science and Technology (KNUST), Dept. of Renewable Natural Resources, Ghana
⁹Kwame Nkrumah University of Science and Technology (KNUST), Dept. of Forest Resources Technology, Ghana
¹⁰Leibniz-Institut für Agrartechnik und Bioökonomie e.V., Science Management Unit, Germany

Abstract

Carbon dioxide (CO₂) is a major greenhouse gas driving climate change. In Ghana, the Agriculture, Forestry, and Other Land Use (AFOLU) sector contributes to national CO₂ emissions while also offering opportunities for carbon sequestration. Despite this dual role, there is limited empirical data on how land use and seasonal dynamics influence soil CO₂ fluxes in tropical forest landscapes. The study addresses this gap by assessing seasonal variations in soil respiration rates (SRR) across four land-use types, including forest, fallow, maize, and rice fields, in a semi-deciduous forest in Ghana. The aim was to provide baseline data and identify key soil factors influencing SRR to support mitigation strategies. Monthly measurements of soil respiration rates (SRR) were conducted over one year using a closed-chamber technique equipped with a CO₂ sensor. Simultaneously, soil physico-chemical properties, including organic matter (OM), pH, texture, and soil moisture (SM), were assessed to investigate their influence on CO₂ efflux. Stepwise multiple regression and correlation analyses were conducted to explore relationships between SRR and soil variables.
Results revealed significant seasonal and land-use-related differences in SRR, with higher emissions recorded during the wet season. Fallow and cropland areas (maize and rice fields) exhibited the highest CO₂ efflux, while forested areas showed the lowest emissions, likely due to reduced disturbance and higher soil carbon stability. Among the tested variables, OM, pH, SM, and silt content emerged as significant predictors, with the final model explaining 58% of the variation in SRR.
The findings highlight the importance of maintaining forest cover and adopting sustainable land use practices to mitigate CO₂ emissions in tropical regions. To further reduce emissions in the AFOLU sector, policies should also support reforestation, agroforestry, and reduced soil disturbance, which enhance soil carbon storage and promote sustainable land use.

Keywords: Bobiri forest reserve, climate change mitigation, land-use type, soil respiration rate

Contact Address: Famoussa Dembele, Kwame Nkrumah University of Science and Technology (KNUST), Dept. of Civil Engineering (WASCAL), Kumasi, Ghana, e-mail: Famoussad93gmail.com