Droevendaalsesteeg 10
6708 PB Wageningen
The Netherlands
About
My research focus is on Ecohydrology and I aim to work on integrated solutions on sustainable water, sustainable land and halting biodiversity loss.
Biography
Stefan Dekker is director of NIOO-KNAW, the Netherlands Institute of Ecology. He is also professor of Ecohydrology at the Copernicus Institute of Sustainable Development at Utrecht University. His main research lines are:
1. To fundamentally understand the direct drivers of interactions between the atmosphere, biosphere and hydrosphere. He hereby aims (i) to understand the resilience and water use of current and future forest types, including the role of forestation and deforestation and (ii) to fundamentally understand how plants adapt to changes in carbon, nutrient and water resources, and how those processes can be upscaled.
2. Understanding how indirect drivers impact the interactions between atmosphere, hydrosphere and biosphere. Indirect drivers play a major role in influencing direct drivers of biodiversity loss, ecosystem change and the ecohydrological processes. Therefore, socio-economic and demographic development, but also sustainable and technological innovations are important to include in future scenarios.
Stefan Dekker studied physical geography at the University of Amsterdam and he did his PhD at the Institute of Biodiversity and Ecosystem Dynamics (UvA-IBED) on forest ecohydrology. After his graduation, Stefan was staff member at Utrecht University, the Copernicus Institute of Sustainable Development. He successfully supervised 20 PhD candidates, was full professor of Global Ecohydrology and Sustainability and was visiting professor at the Max Planck Institute for Meteorology, Exeter University and Stockholm Resilience Center.
Dekker was director of education and director of research at the department of Sustainable Development in Utrecht between 2019 and 2025 and was head of the Environmental Sciences group at the Open Universiteit from 2018 to 2019.
Publications
Peer-reviewed publications
Forest favours conditions for convective precipitation in the Mediterranean Basin
https://doi.org/10.5194/bg-22-6913-2025The Mediterranean Basin is identified as a climate change hotspot and prone to future drying. Through carbon sequestration, forests may mitigate climate change and reduce future drying. Nevertheless, the effect of forests on freshwater availability in the Mediterranean Basin is uncertain. Trees contribute to enhanced evapotranspiration, which may enhance drying; the resulting impact on precipitation in the Mediterranean Basin, however, remains unclear. Here we use a simple model to simulate the development of the atmospheric boundary layer (ABL) to determine the impact of forest on convective rainfall potential. There is convective rainfall potential when (1) the ABL reaches the lifting condensation level, and (2) there is sufficient convective available potential energy. We model the ABL development over the Mediterranean Basin for a bare soil scenario (covered fully with bare soil) and a forest scenario (covered fully with forest) to determine its land cover sensitivity. In addition, we examine the sensitivity of the ABL to variations in soil moisture for the forest scenario specifically. We identify two distinct responses to forest in the Mediterranean Basin dependent on soil moisture content. Forest contributes to warming and drying in relatively dry regions (low soil moisture content) and to cooling and wetting in relatively wet regions (high soil moisture content). We find that both forest cover and soil moisture contribute to convective rainfall potential. In regions with a relatively high soil moisture content, forest cover positively influences both the convective available potential energy, and the crossing of the ABL and lifting condensation level. The results suggest that forestation in the Mediterranean Basin may contribute to local precipitation in relatively wet regions and reduce local precipitation in relatively dry regions.
Trade-Offs and Synergies Between Climate Change Mitigation, Biodiversity Preservation, and Agro-Economic Development Across Future Land-Use Scenarios in Brazil
Land-use change is a major driver of biodiversity loss and a key contributor to GHG emissions, making sustainable land use essential for biodiversity preservation and climate change mitigation. The impacts of land use change are location-specific, shaped by the biophysical context. Consequently, the extent and nature of these impacts are deeply influenced by the spatial configuration of land-use change. This is particularly relevant for Brazil, a global agricultural powerhouse, where agricultural expansion impacts biodiversity-rich and carbon-rich biomes. Understanding the future land-use trade-offs and synergies between agro-economic development, biodiversity preservation, and climate change mitigation is crucial to support sustainable land use in Brazil. In this study, we quantified these trade-offs and synergies for three SSP-based land-use change scenarios projected for 2050. For each scenario, we assessed the spatial variation in impacts on carbon stocks, mammal distributions, and agricultural revenues. Our results show that the agricultural economy is projected to grow at the expense of biodiversity preservation and climate change mitigation objectives, and vice versa. These trade-offs and synergies result from changes in natural vegetation and agricultural land, driven by shifting demand for agricultural products. In particular, under the SSP3-7.0 scenario, rising agricultural demand between 2015 and 2050 is projected to drive agricultural expansion into natural areas, increasing annual agricultural revenue by 36.5 billion USD2015 but reducing carbon stock by 4.5 Gt and mammal distribution areas by 3.4%. In contrast, the SSP1-1.9 scenario projects a decline in agricultural demand over the same period, driving the conversion of agricultural land to natural vegetation. This shift increases carbon stocks by 5.6 Gt and expands mammal distribution areas by 6.8%, although it would lower annual agricultural revenue by 33.4 billion USD2015. Our findings further highlight opportunities to reduce trade-offs by containing agriculture outside biodiversity-rich and carbon-rich biomes, in combination with strategic restoration of these regions.https://doi.org/10.1111/gcb.70418
Outreach
Categories
Featured in
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Stefan Dekker named new director of the Netherlands Institute of Ecology
Ecohydrologist Stefan Dekker has been named the new director of the Netherlands Institute of Ecology (NIOO-KNAW), the Royal Netherlands Academy of Arts and Sciences' national institute for ecological research, effective 15 June 2025. Dekker is currently serving as professor of Global Ecohydrology and Sustainability at Utrecht University and as research director of the Copernicus Institute of Sustainable Development. He will succeed NIOO’s interim director Wim van der Putten.
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Honorary fellows of NIOO-KNAW
The Netherlands Institute of Ecology (NIOO-KNAW) collaborates with many researchers in the Netherlands and abroad. The honorary fellows are a special category in this respect. From within their own institute or university, they collaborate with NIOO colleagues to strengthen the working field by sharing knowledge and ideas. Consequently, they also regularly conduct joint research at NIOO, set up new projects or publish research results together. We currently have eight talented honorary fellows.
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Mission, vision and core values
To perform leading ecological research on biodiversity, climate change and sustainable use of land and water, to stimulate ecological research in The Netherlands and to share ecological knowledge with society.
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Sustainable use of land & water
Healthy surface water and soils are essential for life on earth, providing diverse life-support functions. How are these ecosystem services affected by human activity, and how can we change this?
