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  • Publication
    Accès libre
    Amphibian occupancy and abundance in beaver ponds in Switzerland
    (Neuchâtel : Université de Neuchâtel, 2024)
    Bolle, Patricia 
    ;
    Zemp, Clara 
    ;
    Schmidt, Benedikt
    ;
    Angst, Christof
    As ecosystem engineers, beavers are capable of creating heterogeneous environments that have a positive impact on many species. They increase habitat availability that can be colonised by species (endangered or not) and reduce fragmentation. Amphibians, one of the most threatened groups of vertebrates, are part of the species that could use and colonise the beaver ponds. The aim of this study is to analyse the occupancy and abundance of amphibians in beaver ponds in Switzerland. This analysis addressed the following questions: 1) What is amphibian abundance and occupancy at beaver ponds, 2) Does Rana temporaria use beaver ponds as ovipositional sites, 3) What are the factors (e.g., dam age) that drive amphibian occupancy and abundance in beaver ponds, and 4) if beaver ponds increaseconnectivity. Results of the occupancy analysis revealed that there were some preferences for the type of beaver pond occupied, most of them being flooded forests. Then, results from both abundance and occupancy showed that the strongest predictor that always came up was the dam age. Indicating that the older the dam is, the better, with more individuals in middle aged dams. Results from the connectivity revealed that beaver ponds had higher diversity if there were at least two amphibian breeding ponds nearby (less than one kilometre). Meaning that beavers could extend the already existing amphibian network by creating new ponds. Consequently, they have a good potential for conservation goals by maintaining stable and increasing amphibian populations.
  • Publication
    Accès libre
    Land-use trajectories for sustainable land system transformations: Identifying leverage points in a global biodiversity hotspot
    (2022)
    Dominic Andreas Martin
    ;
    Fanilo Andrianisaina
    ;
    Thio Rosin Fulgence
    ;
    Kristina Osen
    ;
    Anjaharinony Andry Ny Aina Rakotomalala
    ;
    Estelle Raveloaritiana
    ;
    Marie Rolande Soazafy
    ;
    Annemarie Wurz
    ;
    Rouvah Andriafanomezantsoa
    ;
    Harilala Andriamaniraka
    ;
    Aristide Andrianarimisa
    ;
    Jan Barkmann
    ;
    Saskia Dröge
    ;
    Ingo Grass
    ;
    Nathaly Guerrero-Ramirez
    ;
    Hendrik Hänke
    ;
    Dirk Hölscher
    ;
    Bakolimalala Rakouth
    ;
    Hery Lisy Tiana Ranarijaona
    ;
    Romual Randriamanantena
    ;
    Fanomezana Mihaja Ratsoavina
    ;
    Lala Harivelo Raveloson Ravaomanarivo
    ;
    Dominik Schwab
    ;
    Teja Tscharntke
    ;
    Zemp, Clara 
    ;
    Holger Kreft
    Finding entry points where policy has strong leverage to transform land systems for people and nature is pivotal. We develop an innovative framework to identify and evaluate such leverage points along land-use trajectories that account for path dependency. Applied to the biodiversity hotspot Madagascar, the framework reveals three leverage points: Two leverage points are associated with trade-offs between biodiversity, ecosystem services, and agricultural productivity, while the third entails cobenefits. Swift policy action is required, as path dependency caused by forest loss may soon put two leverage points out of reach. We argue that such closing windows of opportunity may be common, but often overlooked, calling for a wider consideration of path dependency in land-system science.