Artificial ponds: a substitute for natural Beaver ponds in a Central European Highland (Eifel, Germany)?

摘要

The European Beaver, once widely distributed across Europe, was almost completely eradicated in the nineteenth century. In the meantime, it has recovered large parts of its distribution range and has increasingly resettled the valleys of the Central European Highlands. In the past, in these same valleys, countless artificial fish and fire-fighting weir ponds, with a water regime similar in size and location to those of the Beaver, were created. In order to assess how near-natural the newt communities of the artificial ponds are, we studied 21 artificial and 22 Beaver ponds in the Eifel, a typical Central European Highland in Germany, using funnel traps. In general, artificial and Beaver ponds supported the same eight amphibian species, whereby the Beaver ponds had on average a larger number of species (4.8 species as opposed to 3.6). The average population size of the two dominant Urodela species, determined by a mark-recapture method, was higher than is usually recorded in other pond types, whereby the influence of the factor “Beaver” pond proved to be either neutral (Triturus alpestris) or positive (Triturus helveticus). The decisive factor for the activity density of both species in the ponds studied was the presence of fish. Artificial ponds probably provide an important substitute for the once common Beaver ponds for at least the majority of woodland species in large areas of Central Europe. This leads to the following conclusions: (1) The destruction of artificial weir ponds in line with the EU Water Framework Directive needs to be critically called into question to prevent avoidable damage to biodiversity. (2) Beaver ponds open undreamt opportunities for amphibian conservation in Europe. The Beaver should therefore be given special consideration and considered a key species for the preservation of biodiversity when preparing relevant EU programmes. Keywords Castor fiber - Amphibia - Water Framework Directive - WFD - Triturus (Mesotriton) alpestris - Triturus (Lissotriton) helveticus Handling editor: B. Oertli