Linking biodiversity, ecosystem services and social actors to promote agroecological transitions
The landscape in Zona da Mata region (Atlantic forest biome; Brazil) can be understood as a dynamic mosaic of land uses, including secondary forest, pastures and coffee fields. Spatial patterns of such mosaics are determined by heterogeneous physical landscape features and shaped by the diversity in management practices and decisions made by individual farmers.
Thus, a gradient of more biodiverse to overly simplified farms can be found in the region. These farming systems contribute differently to local livelihoods and to the provision of ecosystem services (ES). Currently, we lack understanding of the incentives that farmers have to manage agrobiodiversity and the consequences of management for functional diversity and the provision of multiple ES.I used a combination of social and ecological methods to link biodiversity, ES and social actors for informing the development of sustainable agroecological systems.
The agroecological movement enabled farmers to develop a complex perception about ecosystem functioning, which in turn, led to the adoption of management practices that enhance biodiversity conservation and the provision of multiple ecosystem services.
First, a farm typology was conducted in the region to explore implications of farm diversity for promoting agroecology and agrobiodiversity. Second, fuzzy cognitive maps were used to unravel and contrast farmers` perceptions on ES and their management. Third, coffee fields and pastures were selected on different farm types to evaluate the direct and indirect impact of management on biodiversity and ES.
A variety of indicators were measured in each system and grouped in three components: soil-based ES; plant diversity (taxonomical, functional and structural); and management practices. Fourth, the effects of forest regeneration on biodiversity and soil functions were assessed along a successional gradient. The results showed that changes in the cognitive perception of farmers on ES led to changes in management strategies, that in turn, influenced biodiversity and the provision of ES.
Agroecological farmers had a more complex perception on ES than other farm types, which was associated to greater access to public policies and participation in social organisations as well as higher biodiversity in their agroecosystems. Thus, the transition to agroecology in Zona da Mata was successful to help a group of farmers to enhance biodiversity-based ecological processes, moving away from the dependence of industrial inputs without compromising soil quality and plant health.
In addition, I demonstrated the potential of secondary forest succession as a strategy to help farmers to increase on-farm forest cover and recover the associated biodiversity and soil functions. The outcomes from this thesis were useful both to answer more fundamental research questions and also to support land users, managers, policy-makers, technicians and other actors to take informed decisions based on a multilevel scientific assessment of agroecosystems.