Effects of restoration and management of Mediterranean traditional water systems on Odonata alpha diversity: a long-term monitoring survey

Abstract

The progressive abandonment and disappearance of traditional water uses and management of wetlands during the twentieth century has led not only to a loss of identity, heritage, and landscape values, but also to significant declines in the diversity and abundance of many organisms. Here, we take advantage of an existing project for the restoration and management of traditional irrigation infrastructures in the wetland of El Prado (Pinoso, south-eastern Spain) to evaluate the spatio-temporal effect of this action on the alpha diversity and abundance of Odonata. The wetland was organized in different sectors according to the coverage of riparian and aquatic vegetation, width and depth of watercourses, ditches and ponds, water flow, and restoration and management. Odonates were sampled every month for ten years. We used alpha diversity to measure biodiversity using Hill’s number diversity. To analyse how alpha diversity measures varied across all sectors sampled over the years, we determined diversity-time relationships. To assess the effects of the different variables on odonate biodiversity we used partial least squares regressions. Our results showed that restoration of traditional water infrastructures, encouraging the increase of aquatic vegetation cover, an adequate and regular management of riparian vegetation naturalizing the margins, as well as reducing speed of water flow have a positive effect on odonate diversity and abundance. Our study provides useful information for conservation and management of semi-arid wetlands and its associated water infrastructures by showing which actions are most successful to enhance biodiversity in one of the priority habitats for conservation in Europe.