1. Centre for Environmental Systems Research (CESR), University of Kassel, Kurt-Wolters-Strasse 3, D-34125, Kassel, Germany
2. Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251, Helsinki, Finland
3. Finnish Environment Institute (SYKE), Jyväskylä Office, P.O.Box 35, FI-40014, University of Jyväskylä, Finland
4. Lammi Biological Station (LBS), University of Helsinki, Pääjärventie 320, FI-16900, Lammi, Finland