Restoration and Rehabilitation of Degraded Ecosystems in Arid and Semi‐Arid Lands. II. Case Studies in Southern Tunisia, Central Chile and Northern Cameroon

Abstract

A model of ecosystem degradation and three possible responses to it—restoration, rehabilitation, and real‐location—is applied to ongoing projects in the arid mediterranean region of southern Tunisia, the subhumid mediterranean region of central Chile, and the semiarid tropical savannas of northern Cameroon. We compare both nonhuman and human determinants of ecosystem degradation processes in these contrasted regions, as well as interventions being tested in each. A number of quantifiable “vital ecosystem attributes” are used to evaluate the effects of ecosystem degradation and the experimental responses of rehabilitation on vegetation, soils and plant‐soil‐water relations. We argue that attempts to rehabilitate former ecosystem structure and functioning, both above‐ and below ground, are the best way to conserve biodiversity and insure sustainable long‐term productivity in ecosystems subjected to continuous use by people in arid and semi‐arid lands of “the South.” The success of such efforts, however, depends not only on elucidating the predisturbance (or slightly disturbed) structure and function of the consciously selected “ecosystem of reference,” but also on understanding and working with the socioeconomic, technical, cultural, and historical factors that caused the degradation in the first place.

Seed Germination Characteristics ofRhus tripartitum(Ucria) Grande andZiziphus lotus(L.): Effects of Water Stress

“…Arid zones in Tunisia, which cover more than 70% of the total area [2], are characterized by drought and high temperature and more or less general salinity. In addition many shrub species such as Z. lotus, R. tripartita, Periploca angustifolia, Retama raetam, Acacia raddiana, Ceratonia siliqua, and Lycium shawii are valuable species for afforestation in arid area of Tunisia as they withstand the harsh climatic conditions, improve the stability of ecosystems where they are present and contribute to reduce the risks of desertification, and are helpful in restoring degraded ecosystems [6,[13][14][15][16].…”

“…In addition, they improve the stability of ecosystems where they are present, contribute to reduce the risks of desertification, and are helpful in restoring degraded ecosystems [6,[13][14][15][16]. These shrubs are also a feeding resource for livestock especially during the summer, when the alternative herbaceous species have wilted [17].…”

Effects of ecological restoration on Orthoptera assemblages in a Mediterranean steppe rangeland

“…These habitats are also known to be important for biodiversity. However, when thresholds of irreversible damage to these ecosystems are crossed, ecological restoration provides the opportunity to study the impact of restoration processes on degraded ecosystems in Europe (Aronson et al 1993). Ecological restoration takes into account not only ecosystem functions but also overall biodiversity, insofar as its different compartments can be studied.…”

Ecological restoration for future sustainability in a changing environment

“…These characteristics will likely be intensified in our future environment, making the need for a shift in restoration approach from "historic" to "futuristic" greater than ever (Choi, 2004). Earlier definitions of ecological restoration (e.g., Jordan, Peters & Allen, 1987;National Research Council, 1992; Society for Ecological Restoration International as cited by Aronson et al, 1993;Jackson, Lopoukhine & Hillyard, 1995) clearly set the goals of restoring the natural, historic, or prehistoric ecological communities and ecosystems that preceded disturbance by human activities. Cairns (2002) noted that ecosystem restoration is possible when climate conditions suit the species that once inhabited the area.…”