Both SDD and LDD are crucial for population maintenance because they limit the risk of persistent extinction on one site by spreading local temporal dynamics of extinction and colonization on multiple sites. They also allow the maintenance of population dynamics in patches where species are already present and genetic mixing with other populations. They enable species to colonize new patches and expand the occupancy on their territory. Dispersal events have major consequences on population dynamics. The LDD often involve physical forces like wind and marine currents or rely on organisms with higher dispersal abilities. On the contrary, long distance dispersal (LDD) movements are generally rare and difficult to detect, except in migratory species. However, these SDD events may also allow distant populations to connect by a ‘step by step’ dispersal process. Most dispersal events cover only short distances (i.e., short distance dispersal SDD) and take place within the boundaries of defined geographic or population limits. Overall, the genetic diversity depends on gene flow that is conditioned by the frequency of dispersal events between populations. In rare species, the genetic diversity can also be constraint by specific habitat requirements that often induce isolation of populations. Some wide-ranging species with high dispersal capacities can have different genetic diversities at smaller scales, while other ones with low dispersal ability can have low genetic differentiation at larger spatial scales. The local genetic diversity can vary independently from the geographical distribution of the considered species. Genetic studies are crucial to drive species conservation measures because a low genetic diversity also increases the risk of population extinction due to environmental perturbations and demographic stochasticity. Consequently, many wildlife populations live in isolated habitat patches and often suffer a loss of genetic diversity due to inbreeding. Anthropogenic activities modify landscape characteristics leading to loss and fragmentation of natural habitats. The spatial structure of populations is generally conditioned by intrinsic life traits (e.g., dispersal capacities), distances between sites and environmental factors such as physical barriers or climate gradients. and France (Normandy), probably facilitated by prevailing winds. However, Bayesian analysis showed that some dispersal events could occur between the U.K. population presented a significant genetic differentiation from other European populations, suggesting that the English Channel might act as a barrier to gene flow for A. The populations presented a low genetic differentiation and no pattern of isolation by distance, suggesting historical or current movements of individuals. No pattern of isolation by distance was found at the European scale. French populations presented a low genetic differentiation indicating a high gene flow and confirming dispersal events of this species between ponds at regional scale. imperator were sampled in northwestern France and four populations were sampled in Italy (Sicily), Czech Republic, Switzerland and United Kingdom (U.K.). This study aimed to investigate genetic diversity and structure of Anax imperator Leach, 1815 populations at both regional and European scales using seven microsatellites markers. Identifying local genetic differentiations and understanding how gene flow occurs across these networks is essential to prevent risks associated with environmental perturbations. Pond ecosystems are scattered waterbodies that can interact as a network connected by dispersal events of freshwater organisms. Anthropogenic activities cause loss and fragmentation of natural habitats and have strong effects on population maintenance by increasing their isolation.
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