Land use and climate are the main global change drivers influencing and shaping terrestrial communities. A combination of fertilization and drought could exacerbate or dampen their effects, with pervasive consequences for community composition and productivity. However, our understanding of combined effects of nutrients and drought remains severely limited. The primary objective of this project is to improve our capability of projecting consequences of global change for grasslands.
Thus, we will address the following questions:
1. How does the expression of traits relevant for plant drought resistance change with nutrients? How are these changes coordinated? How do species or resource use strategies vary in plasticity?
2. How do differences in nutrient conditions affect whole plant responses to drought?
3. What is the role of nutrients for community drought resistance and resilience across land use gradients in grasslands?
To address these questions we conduct:
- A greenhouse experiment, to assess the plasticity of drought resistance traits in response to different nutrient availabilities
- A common garden field experiment, to quantify the combined effects of nutrients and drought on whole plant performance (growth and survival)
- Analyses of a previous field experiment in the Biodiversity Exploratories (Rangeshift, 2009-2012,Bütof et al. 2012), which manipulated precipitation along a land-use gradient.
We combine the results with data from vegetation surveys in the Biodiversity Exploratory, to assess the role of nutrients for drought effects on community composition, diversity and productivity across a land use gradients in grasslands.
A. Bütof, L. R. von Riedmatten, C. F. Dormann, M. Scherer-Lorenzen, E. Welk, and H. Bruelheide. 2012. The responses of grassland plants to experimentally simulated climate change depend on land use and region. Global Change Biology 18:127–137.