Factors driving the distribution of an amphibian community in stormwater ponds: a study case in the agricultural plain of Bas-Rhin, France

Jonathan Jumeau (1, 2) , Julien Lopez (1) , Alain Morand (3) , Lana Petrod (1) , Françoise Burel (4) , Yves Handrich (2)

1 Conseil Départemental du Bas-Rhin
2 DEPE-IPHC - Département Ecologie, Physiologie et Ethologie
3 Cerema Direction Est - Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement - Direction Est
4 ECOBIO - Ecosystèmes, biodiversité, évolution [Rennes]

During road construction, stormwater ponds are created to address sanitation, water treatment and the containment of any accidental pollution issues. These environments are not intended to be habitats, so exclosure measures (e.g. fences, barriers) are implemented to prevent animals to gain access to them. However, the modification of the natural landscape for human needs resulted in the disappearance of most wetlands. Our hypothesis was that depending on the water pollutant concentrations, the stormwater water ponds could serve as refuge habitat for wetland species like amphibians. Thus, we evaluated the suitability of stormwater ponds as a habitat for amphibians by studying 82 such structures in the agricultural plain of Bas-Rhin. The proportion of stormwater ponds hosting amphibians and specific species abundances and richness were quantified as community parameters. They were explained using factors such as pond design (e.g. size, depth, slopes), road-induced pollutants, land use and exclosure measures. Significance of these factors was assessed by boosted regression tree models. Species-dependent effects were studied using detrended correspondence analysis. Amphibians were found in 84% of stormwater ponds, with an average of 19.51 adults and 2.44 species per pond. We found 83% of species previously detected in Bas-Rhin, including rare and protected ones. Neither exclosure measures nor pollutant concentrations were correlated with community parameters. The best explanatory factors were land use and pond design. For ponds with pollutant concentrations similar to those quantified in this study, we recommend reallocating the efforts made for exclosure to improve pond design and to the creation of semi-natural ponds as additional compensatory measures. Design of stormwater ponds should be systematically validated by a herpetologist to avoid mortal traps. Ponds should be large and have a permanent minimum water level even in droughts.

Domaines: Sciences de l'environnement

Jonathan Jumeau, Julien Lopez, Alain Morand, Lana Petrod, Françoise Burel, et al.. Factors driving the distribution of an amphibian community in stormwater ponds: a study case in the agricultural plain of Bas-Rhin, France. European Journal of Wildlife Research, 2020, 66 (2), pp.33. ⟨10.1007/s10344-020-1364-5⟩. ⟨hal-02556439⟩