Importance of a traditional irrigation system in amphibian conservation in the Cinque Terre National Park (NW Italy)

Abstract

In Mediterranean agricultural landscapes the impact of irrigation on biodiversity, and in particular on wildlife, remains controversial. This study investigated the role of traditional irrigation in the conservation of amphibians in the smallest and most densely populated national park in Italy, the Cinque Terre National Park (CTNP). The coastline in this area is so steep that dry stone walls were built to create arable land surfaces, irrigated by water stored in small open tanks. An almost complete census of these tanks and a survey of amphibian populations in natural and artificial habitats were undertaken from 2009 to 2012. A total of 58 water tanks were censused, 12 of them being empty, damaged or abandoned. All the tanks containing water were built in concrete and had small volume capacities (mean=3.6, range 0.3–12.4m3) but, overall, hosted all the seven aquatic amphibian species still present in the Park's natural freshwater habitats. Amphibians bred in 66% of the tanks still used for irrigation; large tanks were occupied more often than small tanks and hosted a different, more species-rich amphibian community. These results have management implications and confirm that, in the CTNP, extensive agriculture and biodiversity are compatible, and that maintaining traditional irrigation systems will benefit amphibian populations, especially in the case of drier climate scenarios.