Artificial ponds in a Mediterranean region (Andalusia, southern Spain): agricultural and environmental issues

A total of 16 543 artificial ponds were inventoried. Ninety-one per cent of the ponds were classified as for farming use. Generally, the fraction of farm land converted to pond structures was close to that predicted from the average annual precipitation in the region. However, in several areas, this fraction was remarkably higher than the value predicted, probably due to excessive groundwater extraction. Overall, the naturalisation stage of ponds was poor. However, ponds sited on natural substrate basins had more structured-marginal vegetation, compared with ponds of artificial substrate basins. Furthermore, other factors related to pond management might seriously limit their naturalisation stage. Despite the high abundance of ponds in Andalusia, our results suggest that, in order to improve the potential for biodiversity conservation in these environments, substantial structural and management changes are required.