Tropical Forest Goods and Ecosystem Services, CIRAD, France — Coordinator: Sylvie Gourlet-Fleury
Gembloux AgroBioTech, Liège University, Belgium
Institute of Evolution Sciences of Montpellier, CNRS/IRD, France
Geosciences Environment Toulouse, CNRS/IRD/ University Toulouse 3, France
Forest Resources Management (engineering company), France
Dept. of Plant and Soil Science, University of Aberdeen, UK
Oxford University Centre for the Environment, UK and subcontracted partners in 9 African institutions.
The Congo Basin hosts the second largest unfragmented area of rainforests, providing numerous services for local populations, states and the international community. In the coming decades, these forests will face increasing pressures from a changing climate and from human activities. The CoForChange team analysed how and where tree species could survive these increasing pressures to then produce diagnosis and decision-making tools to attenuate their effects on forests’ biodiversity. The main objectives of the research were to:
1. Assess whether climate or human activities are the main pressures on the region’s forests;
2. Project the impact of global change on forests’ characteristics;
3. Produce decision tools for conservation and management strategies to adapt to the consequences of global change.
CoForChange gathered a multi-disciplinary team of researchers (remote sensing, populations and communities ecology, functional ecology, hydrology/ climatology, pedology, paleoecology, anthropology and modelling), from 16 European and African institutions in partnership with 11 timber companies to conduct a large-scale study of semi-deciduous rainforests in Cameroon, the Central African Republic and the Republic of Congo. The team studied the influence of main environmental and historical factors shaping forest structure and composition: geological substrate, and past (up to 6,000 years) and recent climatic and human-induced disturbances influencing water availability, water table depth and light availability. The collected information was then crossed to propose diagnosis and decision-making tools to attenuate global change effects on these rainforests.
• CoForChange evidenced the predominant influence of geological substrate on the floristic and functional composition of Central African forest stands.
• It found that forest deciduousness increased with the severity of the dry season, but the increase was stronger on resource-rich than poor soils.
• It showed that tree species in the region are highly resistant to drought, at the juvenile and adult stages, with the exception of some short-lived pioneer species; highly disturbed forests might thus be more vulnerable in a context of increasing drought frequency and severity.
• Ancient and recent human activities were found to have had a significant effect on forest composition, leaving them dominated by long-lived pioneer species or giant herbs.
• The project is leading to the production of the CoForTraits database of traits for 1100 tree species (and over 300 other life form species), allowing to identify and map the different forest ecosystems and assess provided services (e.g. provision of food and medicine).
The CoForChange team then proposed a diagnosis of forest resilience to climatic and human-induced disturbance, identifying possible management options ranging from more intensive timber production in productive forests on rich soils to extensive timber production associated with protection measures for forests on poor soils.
CoForChange studied the effect of soil types (see picture) and physical constraints (soil depth and hydromorphy) on biomass in undisturbed rainforests in the Central African Republic, crossing the information with species’ wood densities*. Soil physical conditions constrain the amount of biomass stored in these forests, while contrarily to previous reports, biomass is similar on resource-poor and resource-rich soils. Both soil characteristics and species’ wood density have to be taken into account when trying to predict regional patterns of biomass. These results have implications for the evaluation of biomass stocks in tropical forests in international negotiations on climate change.
* Gourlet-Fleury et al. (2011) Environmental filtering of dense-wooded species controls aboveground biomass stored in African moist forests. Journal of Ecology 99: 981-990
• Forest Resources Management, a private forest engineering company, was part of the project members, helped framing the project, participated in mapping exercises and actively helped involving other stakeholders.
• CoForChange also involved a number of foresters, timber logging companies, national policy-makers and NGOs, in order to help frame stakeholder expectations from the project and disseminate knowledge produced. In particular, the project’s stakeholders discussed initial results and helped framing and then refining the list of tools and information awaited from the project in a dedicated workshop.
• A number of private forest managers in timber companies provided access to inventory data to constitute the CoForChange inventory dataset.
CoForChange produced a set of tools adapted for use by their stakeholders in a proactive manner, in particular:
• Thematic maps, presenting the oldest, the less resilient, the faster-developing, or the more diverse tree communities (Fayolle et al., 2014, Forest Ecology and Management);
• Ranking of species sensitivity according to future climate and/or anthropogenic changes (Bénédet et al., Cofortraits, African plant traits information database. version 1.0).
• Policy brief on “Improving tropical forest characterization for a more sustainable management”, including recommendations for policymakers based on a synthesis of project’s results (http://www.coforchange.eu/ products/policy_brief).
• Vegetation structure and greenness map (from MODIS imagery): it is a detailed mapping of 22 vegetation types, with enhanced vegetation index profiles and their seasonal dynamics (http://www.coforchange.eu/ products/maps), designed for an assessment of the types of forests and options available, would it be log- ging, community-based management or conservation to preserve carbon storage services.