Limnetica 33

Geomorphological and hydrological features can provide a sound basis for global wetland classification. Temporary ponds located on the sandy area of Doñana can be classified into five different geomorphological areas. We hypothesised that these ponds would differ in soil characteristics, which may also explain differences in the composition of their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.