Search results for "Ecological connectivity"
showing 4 items of 4 documents
Seascape connectivity of European anchovy in the Central Mediterranean Sea revealed by weighted Lagrangian backtracking and bio-energetic modelling
2020
AbstractEcological connectivity is one of the most important processes that shape marine populations and ecosystems, determining their distribution, persistence, and productivity. Here we use the synergy of Lagrangian back-trajectories, otolith-derived ages of larvae, and satellite-based chlorophyll-a to identify spawning areas of European anchovy from ichthyoplanktonic data, collected in the Strait of Sicily (Central Mediterranean Sea), i.e., the crucial channel in between the European and African continents. We obtain new evidence of ecosystem connectivity between North Africa and recruitment regions off the southern European coasts. We assess this result by using bio-energetic modeling, …
Impacts écologiques des formes d'urbanisation : modélisations urbaines et paysagères
2015
The global increase of urbanization during the past decades have induced a progressive artificialization of natural environments. The building of transport infrastructures and new housings causes a landscape fragmentation in an irreversible way and a strong decrease of the connectivity of ecological habitats. Maintaining the functionality of ecological networks is becoming a major goal of sustainable urban planning policies. With a special focus on urban evolutions in the horizon 2030 in the urban area of Besançon in eastern France (residential development and road traffic evolutions), this thesis aims to assess the potential impact of urban forms on landscape connectivity of animal species…
Expanding genetic graphs' potential to analyse ecological connectivity: assessment of graphs construction methods
2019
International audience; Dispersal movements are often constrained in human-shaped landscapes, thereby threatening species survival. Landscape genetics approaches are commonly used to analyse ecological connectivity because genetic data well reflect dispersal capacities. When species occupy discrete habitat patches, graph-theoretic methods are a particularly relevant approach to study dispersal-driven gene flow. The links of a genetic graph can be weighted using different genetic distances between populations (nodes). Similarly, graph pruning (link set selection) can rely on different criteria. However, despite growing interest in genetic graphs, the influence of these parameters remains mos…
Analysing gene flow in heterogeneous landscapes: why and how to use genetic graphs?
2019
International audience; In heterogeneous landscapes, when species occupy discrete habitat patches, ecological connectivity is influenced by populations’ topology. Graph-theoretic methods constitute a relevant tool to reveal this topology and better analyse gene flow. Despite growing interest in genetic graphs, a better understanding of when and how to use them is lacking.To fill this gap, we simulated gene flow between 50 populations in different landscape configurations and constructed genetic graphs using various genetic distances and pruning (link selection) methods. We then compared metrics derived from these graphs to analogous metrics describing the topology and connectivity of the di…