Conservation of amphibians in the alpine Rhine valley: a proposal

Many species at risk of extinction suffer from decreasing abundance and deteriorating habitats. In fact, the degree of habitat fragmentation and the quality of environments that connect the habitats become critical factors for species persistence. Metapopulation models with explicit spatiality can consider combined environmental effects and hence, are useful for representing the dynamics of populations. Nevertheless, these models are rarely studied with respect to derivation of useful indices for population viability analyses. Some of the model features including the duration until the expected extinction or the capacity of metapopulation persistence have serious limitations that constrain model use for the evaluation of different management options. In this work, we focus on the direct comparison of the incidence functions associated with different intervention scenarios. For this purpose, we suggest an approach based on the Kullback-Leibler information (or divergence), a quantity which is well known in statistics but has only been recently used in ecology. The combination of a metapopulation model with the Kullback-Leibler information is illustrated by the evaluation of intervention strategies aiming at the conservation of amphibians in the alpine Rhine valley (Canton of the Grisons, Switzerland).