1. Landscape Ecology Institute of Terrestrial Ecosystems Department of Environmental Systems Science ETH Zürich Zürich Switzerland
2. Swiss Federal Institute for Forest Snow and Landscape Research WSL Birmensdorf Switzerland
3. Laboratory of Functional Ecology Institute of Biology University of Neuchâtel Neuchâtel Switzerland
4. Neuchâtel Platform of Analytical Chemistry University of Neuchâtel Neuchâtel Switzerland