Anthropogenic activities have released huge amounts of greenhouse gases namely carbon dioxide, methane and nitrous oxide into the atmosphere. The build-up of these greenhouse gases (GHG) into the atmosphere causes climate change which has significant impacts on ecosystems functioning, human health and welfare. As such, much work on reducing GHG emissions and carbon (C) is mainly conducted in forest systems. This is because of the significant role played by forests in the natural global carbon cycle by capturing C from the atmosphere through photosynthesis and converting the photosynthate to forest biomass, and emitting C back into the atmosphere during respiration and decomposition. As such, as a way of maintaining and conserving forests, there have been global efforts aimed at sustainable forest management practices to enhance forest carbon stocks, especially in developing countries to reduce GHG emissions and forest degradation. Consequently, Ghana’s participation in carbon reduction initiatives such as the Reducing Emissions from Deforestation and forest Degradation (REDD+) programme, Emission Reductions Payment Agreement (ERPA) and the Forest Carbon Partnership Facility (FCPF) through the Green Climate Fund has brought about the huge demand for data on forest carbon stocks.
Direct measurements of forest-atmosphere exchanges of carbon dioxide, water, energy, and other trace gases allow us to observe whole-ecosystem metabolism as well as quantify the role of forests as sources of trace gases, the input of gaseous pollutants and nutrients, and the role of forests in cleansing the atmosphere. Yet, despite the significant role that African tropical forests play in global carbon sequestration, few studies on GHG measurements over forest ecosystems have been conducted in Africa. These African tropical forests have their own unique and specific forest biogeocenosis, that differ both physiologically and ecologically from other tropical forests. Thus, the establishment of an eddy covariance (EC) experimental station in the Bia Tano forest reserve within the Ahafo region of Ghana, will provide a direct and accurate means to measure carbon dioxide (CO2) and water vapour (H2O) exchange between a typical African tropical forest ecosystem and the atmosphere with its dynamic response to environmental variables. This is one of the few flux towers on the African continent to collect carbon flux data over a tropical primary forest. The activity of the Bia Tano forest station is expected to shed light on carbon cycling in this kind of ecosystems in Africa and more generally on the ecological feedbacks of tropical forests with respect to climate change.
The station comprises a 70-m flux tower that lies within the western part of Ghana between moist-evergreen and moist semi-deciduous forest types. Moreover, studies on the transfer of water and energy between the land surface and the lower atmosphere will also be assessed at the forest ecosystem site applying the EC technique. Basic meteorological parameters (air and soil temperature, humidity, photosynthetically active and global radiation) will be measured continuously above the tropical forest canopy and within the vertical profile at the station to derive the sensible and latent heat storage flux. Additionally, soil water content and groundwater level will be measured automatically in a representative position in four different depths (0, 5, 10, 20 and 30 cm). To also better understand the hydraulic function of different plant species found within such a humid mixed tropical forest ecosystem, sap flow measurements will also be carried out in 5 different tree species, through the application of a sap flow system that implores the heat pulse velocity and/or ratio method. Furthermore, for analysis of biomass allocation during the growing season, the stem diameter increment at the breast height (DBH) of 45 trees of 5 main tree species will be measured by mechanical dendrometer bands.
The overall goals of the project are to monitor, understand, quantify and model CO2 exchange between the atmosphere and a typical tropical Ghanaian forest ecosystem in the estimation of the total carbon balance. To achieve the goals of the project a combination of different techniques and multidisciplinary approaches will be applied.
The scientific working objectives are;
- To quantify CO2 flux exchange at a forest ecosystem level
- To understand the regional variability of this greenhouse gas
- To assess the carbon sequestration capacity of these forest ecosystems and enhance Africa‘s capabilities to undertake mitigation and adaptation actions.
The technical working objectives of the project are to;
- Set up a long-term station for monitoring of greenhouse gases exchange, including meteorological variables in Ghana
- Provide capacity building and transfer of knowledge between participant institutions and local communities to fill the gaps and needs in greenhouse gases research.
- Introduction & Socio-Economic Impacts
Climate projections suggest serious socio-economic and environmental-related challenges in Africa. However, due to the lack of representation, systematic and harmonized ground observations across the continent, the assessment of the relative role of Africa in the current global change paradigm may be hampered (López-Ballesteros et al., 2018).
Economic analysis reveals that forestry projects involving the accurate estimation of carbon capture and storage from the atmosphere have the potential to mitigate the impacts of climate change, reduce net emissions while allowing time for adaptation and technological innovation. As such, the carbon flux data from this project will further strengthen the underlying greenhouse gas inventory management and Measurement, Reporting and Verification (MRV) systems of Ghana’s annual report to the Intergovernmental Panel on Climate Change (IPCC). This will also support the government’s efforts in promoting sustainable forest management practices as a way to regulate deforestation and provide access to funding opportunities from the Agriculture, Forestry, and Other Land Use (AFOLU) carbon projects to support national development. With the reduced deforestation from the above-mentioned initiatives, the main river (Goa River) which is situated in the Bia-Tano and serves as the main source of drinking water to about 124,685 people within the Goaso Municipality would also be preserved.
The settlements within a 5 km radius of the Bia Tano Forest Reserve are Fianko, Dominase, Kokofu, Gambia No.1, Nsuta, Tokurom, Duase, Aboagyaa and Bediako with a population of about 30, 000 people. The main economic activities associated with the communities around the forest reserve are farming or agro-based businesses. Cocoa farming is predominant among the communities (85%) whilst the remaining 15% undertake both farming and other economic activities such as petty trading (farm produce & small shops), artisans, palm oil production, gari processing, animal rearing, basket weaving and hunting. Thus, the implementation of such sustainable forest management practices in this area will support these communities especially those inhabitants that rely on Non-Timber Forest Products (NTFP) and raw materials from the forest reserve.
- Capacity Building (On-going)
The project has provided opportunities for capacity building of 4 staff personnel of UENR: 3 are undertaking a PhD program in the Czech Republic and 1 has also been trained as a Technician on the project.
- Stakeholder Engagements (Completed)
The successful implementation of any project requires the active involvement and participation of all key stakeholders. In this regard, relevant outreaches to neighbouring communities around the forest site and the signing of a Memorandum of Understanding with stakeholders have been done. We are currently seeking the technical support of the Environmental Protection Agency (EPA) on this project for data sharing and to contribute to the National Greenhouse Gas Inventory.
- Infrastructure (Completed)
In terms of the infrastructure, the carbon flux tower has been mounted after site clearance, surface scraping and major excavation have been done. There has also been the provision of security fencing and shelter to house various equipment. Other relevant items such as security cameras, heat extractors and internet devices have also been purchased and awaiting installation. Find below and in the appendix some pictures of the current state of the station.
- Power Connection (Pending)
The only outstanding need to be addressed is the provision of a reliable source of electricity.
The results of the project will
- improve our knowledge and understanding of forest CO2 flux exchange and their interaction at the regional scale.
- bring new data for model application at a regional and international scale and also for the management of world environmental policy integration.