The chapters in this section place the problems of vegetation and climate interactions in semi-arid regions into the context which recur throughout the book. First, Verstraete and Schwartz review desertification as a process of global change evaluating both the human and climatic factors. The theme of human impact and land management is discussed further by Roberts whose review focuses on semi-arid land-use planning. In the third and final chapter in this section we return to the meteorological theme. Nicholls reviews the effects of El Nino/Southern Oscillation on Australian vegetation stressing, in particular, the interaction between plants and their climatic environment. Vegetatio 91: 3-13, 1991. 3 A. Henderson-Sellers and A. J. Pitman (eds). Vegetation and climate interactions in semi-arid regions. © 1991 Kluwer Academic Publishers. Desertification and global change 2 M. M. Verstraete! & S. A. Schwartz ! Institute for Remote Sensing Applications, CEC Joint Research Centre, Ispra Establishment, TP 440, 1-21020 Ispra (Varese), Italy; 2 Department of Atmospheric, Oceanic and Space Sciences, The University of Michigan, Ann Arbor, MI48109-2143, USA Accepted 24. 8. 1990 Abstract Arid and semiarid regions cover one third of the continental areas on Earth. These regions are very sensitive to a variety of physical, chemical and biological degradation processes collectively called desertification.