[1] Univ Tubingen, Inst Evolut & Ecol, D-72072 Tubingen, Germany
[2] Ctr Ecol & Hydrol, Wallingford OX10 8BB, Oxon, England
[3] Univ Oxford, Dept Mat, Oxford OX1 3PH, England
[4] Transfer Ctr Ecotoxicol & Ecophysiol, D-72108 Rottenburg, Germany
[5] Univ Tubingen, Inst Evolut & Ecol, D-72076 Tubingen, Germany