[1] Univ Rey Juan Carlos, Escuela Super Ciencias Expt & Tecnol, Dept Biol & Geol Fis & Quim Inorgan, Mostoles 28933, Spain
[2] Univ New South Wales, Sch Biol Earth & Environm Sci, Ctr Ecosyst Sci, Sydney, NSW, Australia
[3] Univ Bern, Inst Plant Sci, CH-3013 Bern, Switzerland
[4] Univ Montpellier, Inst Sci Evolut, CNRS,IRD, Ecole Prat Hautes Etud, F-34095 Montpellier 05, France
[5] Univ Western Sydney, Hawkesbury Inst Environm, Penrith, NSW 2751, Australia
[6] No Arizona Univ, Sch Forestry, Flagstaff, AZ 86011 USA
[7] Inst Nacl Tecnol Agr, Inst Suelos, RA-1686 Hurlingham, Buenos Aires, Argentina
[8] Univ Pablo Olavide, Dept Sistemas Fis Quim & Nat, Seville 41013, Spain
[9] CSIC, Dept Desertificac & Geoecol, Estn Expt Zonas Aridas, Almeria 04120, Spain