| Popis: |
Doñana National Park is considered as paradigm of the conservation of the biodiversity in Spain. However, some vertebrate groups remain poorly studied, and concretely the knowledge on the fish assemblage is scarce. In this study, the composition and structure of fish assemblage in the typical temporal pond ecosystems from the marshland were studied. To that end, 26 temporal ponds were sampled in July 2012. In each pond physicochemical and environmental variables were taken, together with metrics related to the connectivity between ponds and other bodies of water. To explore a possible spatial correlation pattern between the ponds, a multivariate, non-parametric correlation analysis was conducted. The relationships between fishes and habitat variables were analysed through BIO-ENV. The fish community in the ponds consisted of 10 species, with exotic species being the most frequent (Cyprinus carpio, Fundulus heteroclitus and Gambusia holbrooki) and also contributing the most abundance and biomass. The existence of spatial correlation between ponds indicated that structure of the fish community varied in relation to its location. This was corrected through the inclusion of spatial variables (connectivity variables). Results of BIO-ENV showed that the connectivity variables were the most correlated with the structure of the fish community, and the variables vegetative cover and pond area were also important. The best possible combination of the variables in relation to the distribution patterns of the fish community showed a correlation index of about 50%, while other factors such as predation and the biology of the species could be fundamental mechanisms affecting the fish composition in the temporal ponds of the marshland of Doñana National Park. |
