| Title | Concepts and real issues of desertification and remediation in the Mediterranean and the southwestern United States: transcending local values through a focus on ecological functions |
| Publication Type | Conference Paper |
| Year of Publication | 1997 |
| Authors | Imeson A.C., Havstad K, Herrick JE |
| Conference Name | International Symposium and Workshop Combating Desertification: Connecting Science with Community Action |
| Date Published | May 12-16, 1997 |
| Conference Location | Tucson, AZ |
| Abstract | Desertification is perceived to be a major problem in both the area surrounding the Mediterranean basin and in the southwest United States. A consensus exists in both regions that these regions are experiencing severe physical and biological land and socioeconomic degradation. There is also a consensus, arrived at during recent symposia (Tucson, October 1994), that the underlying causes and processes are similar. In attempting to further understand the similarities by comparing research results from field studies, however, it became clear that perceptions of desertification in these two regions are based on two completely different concepts. In Europe, there is the classic idea that the dry Mediterranean regions were once extensively forested and that a combination of grazing, fire, and cultivation have through history led to a loss of forests. In response, policy is often directed at restoring forest and woody vegetation irrespective of climate or the impact of restoration on key ecosystem functions. Grassland vegetation is seldom perceived as a potential and desirable objective. In the southwest U.S., by contrast, the loss of the desert grass ecosystem and invasion of woody species are regarded as signs of desertification. Consequently, U.S. policy is directed at reversing the development of ecosystems that in Europe are considered desirable. To develop appropriate remediation approaches, we need to clearly define the objectives and criteria to be used to assess the remediation. We believe that these criteria must be developed independently of preconceived notions of an "ideal" or "historic" vegetative community. Rather, these criteria should be based on the relative capacity of the current system to perform specific functions. These functions fall into two closely related categories: (1) functions that make the system sustainable, and (2) functions that provide a specific use-value for the broadly defined needs of human society. In desertified systems the first set of functions may be defined more specifically as those that contribute to the capacity of the system to retain soil and water and therefore to continue to support biological production. As such, they are relatively independent of specific human values. The second set of functions are germane only after the criteria for the first set of functions are satisfied. The second set may include a wide variety of value-related services that these systems provide, including production of food and fiber, conservation of biological species and/or communities, water management, carbon storage, and recreation opportunities. |
Jornada
Science-based management strategies for sustainability of agriculture and other land uses
