The importance of stormwater ponds for amphibians in the city of Miinster (North Rhine-Westphalia) [Die Bedeutung von Regenrückhaltebecken fur Amphibien in der Stadt Miinster (NRW)]

Abstract

The aim of this study in the city of Miinster was to determine whether artificial stormwater ponds, designed to control water flow, can act as refuges for amphibians. Moreover, we analysed the influence of habitat and landscape quality on amphibian species richness of 46 stormwater ponds (SP) in comparison to 46 control ponds (CP). Our study revealed that environmental conditions clearly varied between SP and CP. The most pronounced differences were that SP were larger, shallower, sunnier, more isolated by streets and had a greater cover of built-up area and lower cover of arable land surrounding them. Nevertheless, the amphibian assemblages of SP and CP were very similar. All nine amphibian species (including three threatened species) detected in this study were found in both pond types. Moreover, species richness (2.8 ± 0.2 vs. 2.3 ± 0.2) and the frequency of each species did not differ between SP and CP. The only exception was Pelophylax spp., which occurred more regularly in SP. Both habitat and landscape quality affected amphibian species richness; however, the explanatory power of the habitat models was about twice as high as those of the landscape models. In conclusion, stormwater ponds play an important role for amphibians in urban areas. In comparison to CP, the low landscape quality in the surroundings of SP seemed to be compensated by a higher habitat quality due to regular management. © 2018 Laurenti Verlag. All rights reserved.