Development paths of drylands: thresholds and sustainability

Abstract

Drylands (41 and 35% of global land and population, respectively) have the lowest biological productivity of any ecosystem, contain populations with the highest growth rates on earth, and share a significant fraction of global poverty for which desertification is implicated. A global assessment of the available information indicates that the inherent low productivity of drylands, when combined with other adverse factors, can generate poverty. It additionally indicates that while the drylands may exist in a locally stable and sustainable state, this is readily destabilized by non-linear, threshold-crossing transitions to an alternative steady-state leading to desertification, poverty and conflicts. The ''desertification paradigm'' (human and climatological pressures driving overexploitation of land resources, leading to desertification, poverty and reduced security) is challenged by its ''counter-paradigm'' (adversity elicits innovation, leading to ingenuous solutions for avoiding desertification). But the latter does not account for the inevitability of continued and increasing pressure on the finite dryland resources, expected to be further exacerbated by a globally increasing need for agricultural land. A companion paper points out that this situation can be avoided by reducing dependence on land productivity, through adoption of ''alternative livelihoods.'' These livelihoods, while economically advantageous, reduce pressure on land resources.

Geospatial Techniques for Improved Water Management in Jordan

“…They show a gradient of increasing primary productivity in the order of hyper-arid, arid, and semiarid to dry sub-humid areas [1]. Drylands represent fragile ecosystems that are highly susceptible to environmental changes.…”

The local-scale impact of soil salinization on the socioeconomic context: An exploratory analysis in Italy

“…Rather, the results suggest that each soil degradation process is characterized by specific relations with the local socio-demographic and economic context (Boardman et al, 2003;Iosifides and Politidis, 2005;orbelle-Rico et al, 2012). Identifying socioeconomic factors and understanding the relation with the environment are multifaceted issues that require a careful definition of the ecological processes under investigation (Safriel and Adeel, 2008). They usually have effects on the environmental context through non-linear paths, and to feedback interactions with exogenous variables affected by broader forces (Patel et al, 2007).…”

“…Although raising concern at both global and regional levels, soil degradation cannot be convincingly explained as a phenomenon depending on changes in biophysical factors alone (Wessels, 2007), since it rarely occurs without the action of anthropogenic drivers (Sivakumar and N'diangui, 2007;Safriel and Adeel, 2008;Romm, 2011). Soil salinization provides an indirect confirmation to this hypothesis, since it is influenced by the socioeconomic context and in turn affects it in a variable manner according to the geographical context and the degree of development (Montanarella, 2007).…”

Land Cover Change in Northern Botswana: The Influence of Climate, Fire, and Elephants on Semi-Arid Savanna Woodlands

“…Dryland ecosystems [1,2] occupy 41% of the global land surface and support nearly one third of the world's population, concentrated primarily in countries that share a significant portion of the global poverty burden [3][4][5][6]. Across Southern Africa, an estimated 150 million rural and urban residents support their livelihoods through extracting natural resources from semi-arid savannas [7], including firewood, food, fresh water, traditional medicine, thatching grass, reeds, poles, and other materials for building and crafts [8][9][10].…”