Fjölrit RALA - 05.12.1999, Qupperneq 9

Fjölrit RALA - 05.12.1999, Qupperneq 9
RALA ReportnO. 200 Introduction Olafur Arnalds1 and Steve Archer2 1 Agricultural Research Institute. Keldnaholt, 1S-JJ2 Reykjavifc, lceland Tel: 354 5771010; Fax: 354 577 1020; E-mail: olafayala.is ‘ Department of Rangeland Ecologv & híanagemeni, Texas A&M University, College Station, TX 77843-2126, USA Tel: 409 845 7332; Fax: 409 845 6430; E-mail: sarcher@ymsl.tamu.edu The ever-increasing demand for food and natural resources by a rapidly growing hu- man population has exerted environmental stress resulting in widespread ecosystem degradation. An extreme form of such degradation, termed 'desertifícation'. is esti- mated to affect the living conditions of about one billion people. As a result, this topic spawned the United Nations Convention to Combat Desertification (UN-CCD) in 1994. The term 'desertification' encompasses a variety of processes driven both by natu- ral and anthropogenic forces. Desertification has occurred in most regions of the world, cutting across a broad spectrum of contrasts in climate, ecosystem types, land uses and socio/economic settings. The complexity of this phenomenon has challenged our ability to categorize, inventory, monitor and repair the condition of the land. Short-comings in communication and understanding are magnified by the improper, incomplete or ‘out of context’ transfer of knowledge from one region or land use cate- gory to another. One of the most important distinctions to be made in relation to land degradation is between cultivated land used for annual crop production and ‘range- lands’. Rangelands represent a variety of ecosystems and landforms not suited for in- tensive agriculture or forestry, because of limitations imposed by climate, soils or to- pography (Stoddardt et al. 1975, Holecheck et al. 1989). Grazing by free-ranging live- stock is the traditional primary use of the world’s rangelands. However, there is growáng recognition of the importance of these vast acreages for wildlife habitat, hy- drology and ground water recharge, recreation and aesthetics. Historic approaches to halting, mitigating or reversing rangeland degradation were agronomically-based rather than ecologically-based. Agronomic approaches were typically intensive, costly and non-sustainable. As such, they were ill-suited to exten- sively managed rangelands characterized by variable or extreme climatic conditions, poor soils, and/or rugged topography. Agronomic efforts at rangeland improvement often consisted of practices such as broadcast seeding and fertilization with little re- gard for spatial and temporal heterogeneity or the status of underlying ecosystem pro- cesses that promote or retard degradation and restoration. In recognition of these short-comings, a group of about 80 experts from over 40 countries were assembled in Iceland in September 1997 for a workshop on rangeland desertification. The goal of the workshop was to bring together a broad spectrum of scientific expertise representing bioclimatically and culturally diverse regions to com- pare and contrast ecological perspectives on rangeland desertification. Why convene a desertification workshop in Iceland? As noted in the book “Range- land Desertification” (Amalds and Archer 2000) published concurrently with these proceedings, severe land degradation has radically impacted most of Iceland’s range- land ecosystems. Iceland thus exemplifies the fact that the problem of desertification extends beyond Africa and the dryland regions of the world. Ongoing degradation
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