REsilience of marginal GrAsslands and biodiveRsity management Decision Support – Regards

European marginal grasslands are biodiversity hot spots owing to ecological constraints, biophysical heterogeneity, and centuries of agriculture. Currently it is not clear whether these unique systems are vulnerable to ongoing environmental, socio-economic and political changes, or if they have developed a high resilience over their history of co-evolution between humans and ecosystems. In the latter case the limits to this resilience are unknown, and their prediction hazardous. This uncertainty lies largely in the poor knowledge of resilience mechanisms of both the ecological and human sub-systems, as well as those underpinning robustness or vulnerability of the entire system coupled through land management decisions and ecosystem services.
REGARDS aims to unravel the mechanisms underpinning resilience of marginal grassland systems to global environmental and social change in order to enhance socio-ecological resilience from farm to regional level. We ask the following questions: (1) Can we identify safe areas vs. tipping points in the combined effects of changing climate, including extremes, and management on grassland ecosystems? (2) How does coupled above-belowground functional diversity buffer or amplify grassland ecosystem responses to combined changes in climate and management? (3) Which landscape structures enhance or decrease ecosystem resilience, and thereby the resilience of ecosystem service provision? (4) Can multi-level governance structures react faster to socioeconomic changes that affect biodiversity and the related ecosystem services? (5) Can system openness, which increases with regional integration and globalization, enhance resilience through its effects on flows of goods and ecosystem services, people and information, or does it threaten a historically resilient system? (6) How can such knowledge support pathways towards increased resilience?
REGARDS will address these questions for mountain grassland sites in Austria, France and Norway, where contrasted biophysical and human situations will allow us to explore complementary dimensions of socio-ecological resilience. Questions (1) and (2) will be addressed using an experimental approach combining manipulations of plant functional diversity, climate and management with state-of-the art analyses of soil microbial diversity, transcriptomics, and fluxomics. Remote sensing will be used to quantify landscape functional structure and its role in facilitating or impeding flows of ecosystem services (question 3). Question (4) will be addressed by an assessment of how local, regional, national and EU programs affect farmers responses and resilience in the context of the variety of socio-ecological factors influencing decisions at farm level. Question (5) will be addressed by reconstructing past land uses and exchanges with other regions of each site, and by comparing indicators of socio-ecological resilience through time and across sites. Finally we will build on this mechanistic knowledge (questions 1-5) to address question (6) using a participative scenariobased approach. Scenarios varying openness of the human-environment system and governance structures will be defined with key local and regional stakeholders and decision makers. Evaluation of scenario outcomes in terms of biodiversity, ecosystem services and material well-being, and associated tipping points will be used to foster knowledge building about socio-ecological resilience at farm and local/regional level.