Tropical forest patches under pressure: Dynamics, functions and sustainable management in agricultural landscapes of the West African forest and savannah zones

Project Information

SUSTAINFORESTS

Grant agreement ID: 101001200

DOI

10.3030/101001200

Project closed

EC signature date 16 February 2021

Start date 1 June 2021

End date 31 May 2026

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 998 512,00

EU contribution

€ 1 998 512,00

Coordinated by

UNIVERSITAET BERN
Switzerland

Periodic Reporting for period 3 - SUSTAINFORESTS (Tropical forest patches under pressure: Dynamics, functions and sustainable management in agricultural landscapes of the West African forest and savannah zones)

Reporting period: 2024-06-01 to 2025-11-30

Summary of the context and overall objectives of the project

SUSTAINFORESTS addresses the challenge of sustaining tropical forest patches, outside protected areas, and in predominantly agricultural landscapes in Togo, Benin, Nigeria, and Cameroon. These forest patches still provide crucial ecological functions, serve as habitats for biodiversity, contribute globally to carbon sinks, and are important for livelihoods.
Forest patches mainly face a threat of conversion to agricultural land use, for food crop farming, but also for cash crop production of cocoa, oil palm, coffee, and rubber, among others. From global land use, biodiversity, and climate change perspectives, analysing forest patches can help identify practical actions and policy measures to reduce biodiversity loss, deforestation, land use conversion, and promote sustainable forest use and conservation.
While theories of agricultural expansion, intensification, and forest transition explain agriculture-induced deforestation well, they do not explain the persistence of forest patches in a context of agricultural expansion. Knowing how they became forest patches and why they continue to exist will provide knowledge on how to sustain them. SUSTAINFORESTS studies and analyses the interactive roles of forest patches outside protected areas, of size 0.5 hectares (ha) to about 1000 ha in predominantly agricultural landscapes of the rainforest and savannah zones in Togo, Benin, Nigeria, and Cameroon. The major objectives are to (1) analyse the spatiotemporal dynamics and conditions of forest patches; (2) assess the contributions of forest ecosystem services to human-wellbeing and livelihoods; (3) analyse the context, framing conditions, and key drivers with regard to sustainable use, management, and governance of the forest patches; and (4) to identify pathways to promote the sustainable use, management, and governance of the forest patches. SUSTAINFORESTS examines why the forest patches exist or persist, or in some places even grow, how they maintain ecosystem services and livelihood functions, and are even providing new ecosystem services such as forest foods. SUSTAINFORESTS studies the conditions under which they can have a sustainable future, given their importance for the environment and livelihoods. Insights gained will inform and trigger region-wide efforts to preserve forest patches and help initiate transformative actions on sustainable land and forest management.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

To gain a comprehensive overview of forest patches in the study countries, SUSTAINFORESTS developed a spatially explicit inventory and mapping of forest patches. Due to a lack of archived satellite remote sensing data for analysing land use dynamics (Ifejika Speranza et al., 2023), we used satellite remote sensing-derived forest products, to inventory for the year 2020, 3,942 forests patches (9,770 km2) outside protected areas with a tree cover ≥ 30%, a tree height of ≥ 5 m, an area ≥ 1 km2 (100 ha) and ≤ 10 km2 (1000 ha) across the four countries. Results showed that over a 45-years period (1975–2020), forest regrowth from arable land was rare, as current forest patches are largely remnants of previously larger forests, confirming a deforestation trend (Wingate et al., 2022).
A social-ecological archetype analyses of the forest patches in the four countries identified 10 forest patch typologies (Wingate et al., 2023). Through reconnaissance surveys, support from local partners, and consideration of local realities, and available funds and time, nine forest patches were selected for field research, three in Togo, and two each in Benin, Nigeria and Cameroon. We conducted a six-month field study from September 2022 to March 2023, working with local scientists, field research assistants, and local guides.
In total, 129 forest plots (50m x 50m) were established. We inventoried tree species and collected soil and forest litter samples. Using a terrestrial laser scanner for the first time in the nine forests, we conducted single and multiple scans of forest structure. We mapped seven forests using LIDAR (Light Detection and Ranging) and multispectral cameras on Unmanned Aerial Vehicles. Data on ecosystem services, livelihoods, forest use, management, and governance were collected through household surveys, key informant interviews, oral history interviews, expert interviews, focus group discussions, participatory workshops, and group modelling exercises. In total, we covered 31 communities and 2,626 respondents.
Emerging results have been communicated and disseminated in seminars, workshops, conferences, and are being published. The SUSTAINFORESTS website (https://www.sustainforests.giub.unibe.ch/) provides information and an open-access forest inventory database on the four countries. A video documentary of the fieldwork (Hepner et al., 2023), has been shown in research communication and dissemination events and will be used in further science communication.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

SUSTAINFORESTS is thematically, conceptually, and methodologically innovative. The focus on small forest patches (0.5 to 1000 ha) in agricultural landscapes fills a research gap.
SUSTAINFORESTS is multi-dimensional and integrative. A novel integrated object-based sampling approach for validating the accuracy of non-contiguous tropical forest cover data was developed. We also developed a novel method for mapping small forest patches using satellite remote sensing products (Wingate et al., 2022). Combining traditional forest inventory with modern data collection technologies such as terrestrial laser scanning and an unmanned aerial vehicle has been the first attempt for those nine forests. This experience will inform the improved use of such technologies in tropical forest landscapes.
SUSTAINFORESTS adopts a bioregional approach spanning a gradient from the Guineo-Sudanian (Togo, Benin) to the Guineo-Congolian forests (Nigeria and Cameroon). This bioregional approach enables comparing across bioregions and tailoring conservation actions and sustainable forest use and management. The integrative social-ecological approach underpinned by mixed data collection and analyses methods enables capturing the interactive effects of various factors and processes on the conversion, persistence, or regrowth of forest patches.
Emerging results confirm the continued degradation of some of the nine forests. Certain forest management and governance forms seem to be associated to distinct outcomes in terms of land use conversion and forest loss, forest persistence, or re-emergence. Expected results until the end of the project include insights on the tree species composition and implications for sustainable forest use and conservation, forest soil conditions and interrelations with litter samples. Other results will be on stakeholder perceptions of forest conditions, ecosystem services and transformative actions towards sustainable use, forest scenarios and links to governance arrangements, models of forest futures and decision tools for assessing sustainable forest use and identifying associated transformative actions. In the future, SUSTAINFORESTS plans results exchange and dissemination workshops and actions in communities associated to the nine forests and at policy levels, to discuss and reflect on the research results and identify potential transformative actions.

Hlanzoun (Lokoli) Sacred Swamp Forest, Benin: Forest-agriculture landscape

Iko Forest, Nigeria: Land use conversion from forest to croplands (plantain/banana, cocoa)

Ikot Swamp Forest, Nigeria: Degraded forest on one riverbank and mostly oil-palms on the other

Mbagassina Forest, Cameroon: Forest edge and farms (food crops, plantain/banana, cocoa agroforestry)