[1] North West Univ, Unit Environm Sci & Management, Potchefstroom, South Africa
[2] Pyrenean Inst Ecol, Higher Council Sci Res, Huesca, Spain
[3] Rey Juan Carlos Univ, Dept Biol & Geol, Biodivers & Conservat, Phys & Inorgan Chem, Madrid, Spain
[4] Gobabeb Namib Res Inst, Walvis Bay, Namibia
[5] Pyrenean Inst Ecol, Higher Council Sci Res, Zaragoza, Spain
[6] Calif Polytech State Univ San Luis Obispo, Biol Sci Dept, San Luis Obispo, CA USA