1. CERNAS, Escola Superior Agrária de Coimbra; Instituto Politécnico de Coimbra; Bencanta P-3040-316 Coimbra Portugal
2. CESAM; Departamento de Ambiente e Ordenamento da Universidade de Aveiro; P-3810-193 Aveiro Portugal
3. Sustainability Research Institute, School of Earth and Environment; University of Leeds; Woodhouse Lane Leeds LS2 9JT UK
4. Soil Physics and Land Management Group; Wageningen University; P.O. Box 47 6700 AA Wageningen The Netherlands
5. Centro de Investigaciones sobre Desertificación; CIDE (CSIC, Universitat de Valencia, Generalitat Valenciana); Carretera Moncada-Naquera Km 4,5 Apartado Oficial 46113 Moncada Valencia Spain
6. Department of Biological and Environmental Engineering; Cornell University; B62 Riley-Robb Hall Ithaca NY 14853 USA