AbstractGet full access to this articleView all access options for this article.Get accessReferences1. Graetz, R.D. 1991: Desertification: a tale of two feedbacks. In Mooney, H.A. , Medina, E. , Schindler, D.W. , Schulze, E.-D. and Walker, B.H. , editors, Ecosytem experiments, SCOPE 45, Chichester: John Wiley, 59-87.