Fjölrit RALA - 05.12.1999, Blaðsíða 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