Thu, Aug 05, 2021:On Demand
Background/Question/Methods
Several researches have investigated butterfly population dynamics, by studying species dispersal ability, population connectivity and gene flow. One of the crucial factors affecting those dynamics is fragmentation, especially in the Alps where it is linked to pastoral and agricultural abandonment. Zerynthia polyxena is a protected butterfly listed in the Habitats Directive (92/43/EEC, Annex IV). The species is generally subjected to metapopulation dynamics, that include a balance between extinctions and recolonizations. However, likely linked to the undergoing increase of fragmentation, the species has already experienced decline all over Europe and some populations became extinct in Italy. In this framework, to maintain species’ resilience to global changes, it is pivotal to understand which environmental factors influence connectivity and gene flow among subpopulations. We combined environmental, populational and genetic data to understand the current metapopulation dynamics and thus to plan possible management actions. We investigated 13 Z. polyxena subpopulations within an area of about 55km length in Susa Valley, collecting genetic samples for each subpopulation through a non-lethal method. Among these subpopulations, 6 of them, included in a subarea of about 513ha, were surveyed through Mark-Release-Recapture (MRR) method to investigate the spatial distribution and connectivity of the species.
Results/Conclusions We found that the gene flow is large enough to maintain a balanced metapopulation dynamics, although the species has a low dispersal ability. Furthermore, our results show that the current environmental conditions are suitable for the resilience of the species. Moreover preliminary results show that altitude and forest presence affect connectivity among populations (work in progress). In conclusion, our study suggests that a metapopulation investigation that combines ecological and genetic data might be applied to define which environmental factors increase fragmentation disrupting connectivity and, thus, to address appropriate conservation measures.
Results/Conclusions We found that the gene flow is large enough to maintain a balanced metapopulation dynamics, although the species has a low dispersal ability. Furthermore, our results show that the current environmental conditions are suitable for the resilience of the species. Moreover preliminary results show that altitude and forest presence affect connectivity among populations (work in progress). In conclusion, our study suggests that a metapopulation investigation that combines ecological and genetic data might be applied to define which environmental factors increase fragmentation disrupting connectivity and, thus, to address appropriate conservation measures.