The Global Change research of the Environmental Sciences group focuses on the following themes:
Water and nutrients
Soil and hydrological processes in terrestrial ecosystems are major components in the global cycling of carbon, water, nitrogen and phosphorus. Cycling of water and nutrients in ecosystems depends on environmental conditions, biotic processes and human interventions, and their interactions. Resource limitation, stress and competition and facilitation between plants determine ecosystem productivity and biodiversity. We study whether ecosystems become carbon sinks or sources, and how nutrient cycling is affected by global changes. Our eco-hydrological approach provides essential knowledge for ecosystem restoration and nature conservation.
Interactions and feedbacks over time and space
Understanding of feedbacks between different environmental components (ecosystems, elemental cycles, climate) and compartments (land, atmosphere, rivers, wetlands and oceans) is essential for assessing and predicting ecosystem functioning and ecosystem services. We analyze environmental interactions and feedbacks in paleo, actuo and future. We upscale local processes such as freshwater use, nitrogen and phosphorus enrichment to continental scales. Positive feedbacks between environmental compartments can lead to non-linear critical transitions and tipping points in ecosystems and climate. We contribute to the understanding of such ecosystem changes at various spatial scales and to the development of spatial indicators for ecosystem sustainability.
We develop models for climate, energy, water and elemental cycles. A challenge is to integrate such models with the dynamic human system (resource demand, economy, land use) in Integrated Assessment Models (IAMs). We generate knowledge to assess risks and uncertainties and develop methods for decision support systems aimed at sustainability. Elucidating the causes and effects of environmental problems, and using this scientific knowledge for environmental policy, bridges the gap between science and policy.