Biodiversity and ecosystem services in the Earth system

• Applicant: Dr. Simon Scheiter
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 250938093

Climate change has vast impacts on biodiversity and the provision of ecosystem services required for human well-being. Extreme event such as droughts are of particular concern as it has been shown that repeated drought can lead to substantial tree mortality and thereby to biome shifts, species migration, loss of habitats and loss of biodiversity. The strength of vegetation responses to drought is, however influenced by pre-disturbed biodiversity, and whether communities comprise species that can cope with drought. Predicting the impacts of drought and other climatic drivers on ecosystems is a key challenge to develop adaptation and mitigation strategies to anticipated climate change caused by anthropogenic emissions of greenhouse gasses. This project will use a complex dynamic vegetation model, the aDGVM2, to study drought effects in tropical and subtropical Asia. The aDGVM2 is a state-of-the art ecosystem model that is based on concepts of community assembly and evolution. Trait filtering, trait inheritance, mutation and cross-over generate plant communities that are well adjusted to prevailing biotic and abiotic conditions. In contrast to alternative models, ecological strategies emerge from the modeled vegetation dynamics and they are not pre-defined. The model has been shown to simulate broad vegetation patterns in south and southeast Asia as well as observed responses to drought.The model will first be benchmarked against plot data from the study region to test if it can simulate broad patterns of plant traits and drought responses. Then, we will explore if vegetation is resilient to repeated drought events and changes in rainfall seasonality, or if tipping point behavior occurs that shifts vegetation into an alternative vegetation state. Next, we will modify pre-drought plant communities by removing plants with different adaptation strategies to drought, particularly deciduousness, multi-stemmed architecture, and high capacity to extract water from dry soils, to test if historic legacies effects influence vegetation response to drought and resilience. Finally, simulations will be conducted to determine the equilibrium vegetation state at given environmental conditions in different RCP scenarios. We will quantify differences between these equilibrium states and vegetation states in transient simulations to identify lags between climate and vegetation.This project will contribute to our understanding how biodiversity influences vegetation response to climate change and to drought in tropical and subtropical Asia. This knowledge is essential for policy and decision making. The development of sustainable adaptation and mitigation strategies for future climate change requires a sound knowledge base of the underlying ecosystem dynamics.

• DFG Programme: Independent Junior Research Groups
• International Connection: China
• Cooperation Partner: Professor Dr. Kyle Tomlinson