Evaluating the desertification vulnerability of a semiarid landscape under different land uses with the environmental sensitivity index
Publication year
Resource type
UNCCD Library
Material Type
article
The objective of this study was to evaluate the desertification vulnerability of an approximately 1000‐ha area in Anatolia, Turkey, comprising semiarid oak (Quercus spp.) and pine (Pinus spp.) forests and the adjacent cultivated lands using the environmental sensitivity index (ESI).
The authors calculated the ESI values for 632 randomly selected sites in the study area by entering the desertification indicators vegetation cover, plant type, soil depth, rock fragments, soil texture, slope gradient, drainage, parent material, mean annual precipitation, slope aspect, aridity index, land use intensity, and policy enforcement into the web‐based model Desertification Indicators for Mediterranean Europe (DIS4ME).
The spatial structure of the ESI values was then evaluated using semivariograms and kriging‐interpolated surface maps. The mean ESI value was significantly greater in the cultivated areas (1.47; range = 1.25–1.61) than in the pine (1.32; 1.03–1.45) and oak (1.28; 1.18–1.57) forests (P < 0.01). The ESI was moderately spatially dependent in the oak forests and cultivated areas and strongly spatially dependent in the pine forests, as evidenced by the corresponding semivariograms.
The ordinary kriging interpolated maps showed that most of the cultivated areas were critically vulnerable to desertification, while the majority of the forested areas were moderately vulnerable.
The authors examined how the ESI values varied with soil organic matter (OM) content as an independent variable and found that the OM content was significantly moderately correlated with the ESI (n = 632, r = ‐0.51, P < 0.01), suggesting that the ESI could be used to evaluate the desertification vulnerability of similar landscapes across Turkey.
The lessons learned from this study can be used in future studies that aim to evaluate the desertification vulnerability of various dryland types, and the resulting information can be compiled into spatial maps not only in similar geographic regions in Turkey but also under similar ecological conditions across the world. However, these indicators should not be considered final because the indicator set should be improved with advancing scientific knowledge and changing policy concerns. In addition, the indicators should be tested at different scales to assess their adaptability.
The authors calculated the ESI values for 632 randomly selected sites in the study area by entering the desertification indicators vegetation cover, plant type, soil depth, rock fragments, soil texture, slope gradient, drainage, parent material, mean annual precipitation, slope aspect, aridity index, land use intensity, and policy enforcement into the web‐based model Desertification Indicators for Mediterranean Europe (DIS4ME).
The spatial structure of the ESI values was then evaluated using semivariograms and kriging‐interpolated surface maps. The mean ESI value was significantly greater in the cultivated areas (1.47; range = 1.25–1.61) than in the pine (1.32; 1.03–1.45) and oak (1.28; 1.18–1.57) forests (P < 0.01). The ESI was moderately spatially dependent in the oak forests and cultivated areas and strongly spatially dependent in the pine forests, as evidenced by the corresponding semivariograms.
The ordinary kriging interpolated maps showed that most of the cultivated areas were critically vulnerable to desertification, while the majority of the forested areas were moderately vulnerable.
The authors examined how the ESI values varied with soil organic matter (OM) content as an independent variable and found that the OM content was significantly moderately correlated with the ESI (n = 632, r = ‐0.51, P < 0.01), suggesting that the ESI could be used to evaluate the desertification vulnerability of similar landscapes across Turkey.
The lessons learned from this study can be used in future studies that aim to evaluate the desertification vulnerability of various dryland types, and the resulting information can be compiled into spatial maps not only in similar geographic regions in Turkey but also under similar ecological conditions across the world. However, these indicators should not be considered final because the indicator set should be improved with advancing scientific knowledge and changing policy concerns. In addition, the indicators should be tested at different scales to assess their adaptability.
Geographical Keywords
Turkey
Keywords
desertification databases
desertification
science and research