[2016] CERISE Factors determining the distribution of an amphibian community in stormwater basins: a case study in the agricultural plain of Bas-Rhin, France

Factors determining the distribution of an amphibian community in stormwater basins: a case study in the agricultural plain of Bas-Rhin, France
Projet: Labellisé
En cours

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Jumeau
Jonathan
/ Organisation: CNRS
jumeau.jonathan@gmail.com

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Présentation

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For several years, the CERISE research program has been studying statistical prediction methods for collisions with wildlife, the study (technical and temporal variations) and the improvement of passages for small-wildlife, as well as the habitats created by the road. .

Roadside storm ponds, built along the shorelines to store polluted runoff from roads, would be one of these habitats. To prevent amphibians from colonizing them (pollutants with serious genotoxic effects), partitioning measures are installed. However, it is clear that amphibians are regularly recorded in these basins, despite these measures. And for good reason, in the landscape studied, the agricultural plain of Bas-Rhin, there is hardly any wetlands, habitats of these species, which would have no choice but to colonize these artificial habitats.

The extent of this phenomenon of use of roadside storm ponds by amphibians, in this context of anthropised landscape, is studied.

Initially, all 84 open-cast basins of the Lower Rhine departmental road network were prospected during a breeding season according to a POPAmphibiens Community protocol in order to establish the proportion of colonized basins as well as the number of species and individuals living there. These ecological indices (species richness and abundance) were compared with those of semi-natural pools surveyed at the same time but free of road pollution. Morphological malformations have also been sought on adults. In a second time, the factors influencing these ecological indices were sought. For this, models of boosted regression trees were created using different basin design parameters (including partitioning measures), the concentration of different pollutants, the land cover around the basins and various biological parameters, as explanatory factors. .

Amphibians were found, at different stages of development, in 84% of the basins (a result statistically identical to the semi-natural pools surveyed), corresponding to 14 of the 15 species in the area whose biology is adapted to the permanent water points ( against 9 out of 15 in semi-natural pools), including rare and protected species. On average, there were as many adults per site in basins as in semi-natural pools.

{Mp4} ITWCERISE720 {/ mp4}