DUGi

L’Efecte de l’activitat agrícola a la comunitat d’amfibis d’un riu temporal mediterrani Riu Daró

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@26272

Amphibians are the most globally threatened group of vertebrates; climate change, habitat loss, and fragmentation are often the main causes of their decline. Their high sensitivity to environmental changes makes them excellent indicators of ecological status, serving as a good measure to evaluate the effect of changes in a habitat. Agricultural activity can alter amphibian habitats, especially if practiced on the perimeters of a watercourse, as is the case along much of the course of the temporary river in this study, the Daró River. Temporary rivers can contain a diversity of habitats ideal for promoting a good structure in the amphibian community, but the type and intensity of agricultural impact can play a key role, potentially degrading the ecosystem or generating habitat heterogeneity beneficial for biodiversity. However, some amphibian species can adapt to conditions of intense agricultural activity, even benefiting from them. This study shows that traditional agricultural activity can help maintain a high richness and abundance of amphibians, as it allows for high habitat heterogeneity and a good network of temporary ponds, the preferred habitats for most amphibian species in the Mediterranean region. On the other hand, it has been observed that more intense agricultural impact can alter the hydroperiod, hindering the formation of long-lasting temporary ponds or flooding the course with artificial water flow, reducing both the richness and abundance of amphibians. Nevertheless, when non-traditional agricultural activity is moderately intense, it allows the formation of ephemeral ponds both in the riverbed and on the perimeters, which become preferred habitats for some species, benefiting them. Lastly, it is observed that agricultural activity as intensive as that practiced in rice cultivation involves artificial water drainage through channels that promotes the introduction of invasive species and also causes a significant loss of habitat, drastically reducing the richness and abundance of amphibians. Overall, the results of this study suggest that effective amphibian conservation in Mediterranean temporary rivers requires maintaining traditional agricultural practices, preserving the full gradient of temporary water bodies that can form, from the most ephemeral to the most durable ones

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