Measuring the Condition of Saline Wetlands Threatened by Agricultural Intensification

The saline wetlands, or "saladas", of Monegros Desert, NE Spain, contain biodiversity that depends on the establishment of a prognostic monitoring system that can warn of approaching irreversible damage. In the context of a lack of existing biodiversity inventories for the saladas, we determined their state of conservation and vulnerability using seven physical indicators: escarpment continuity, cropping, stone dumping, size, water occurrence, distance to roads, and proximity to irrigated areas. These features were combined into three meaningful indexes, i.e., conservation, current vulnerability, and future vulnerability, thus creating an assessment of the preservation or degradation of saladas in the context of encroaching agricultural irrigation projects. The proposed indexes produced consistent results and showed that a great number of the Monegros wetlands were threatened, regardless of their size or frequency of water occurrence. Only 20% of the saladas studied were classified as being in a good or very good conservation, whereas 50% were in bad or very bad shape. A high current vulnerability was found for 60% of the saladas. For saladas located in land to be irrigated, we predicted that 73% would have a high or very high future vulnerability. Currently, 58% of the saladas were in bad or very bad condition and fully 65% of the saladas, variable in size, presented a bad or very bad prognosis. Our approach provides a monitoring strategy for the conservation of saline wetlands threatened by agricultural intensification, especially irrigation.