Habitat filtering by landscape and local forest composition in native and exotic New Zealand birds : Habitat filtering in New Zealand birds

Untangling the relative influences of environmental filtering and biotic interactions on species coexistence at various spatial scales is a long-held issue in community ecology. Separating these processes is especially important to understand the influences of introduced exotic species on the composition of native communities. For this aim, we investigated coexistence patterns in New Zealand exotic and native birds along multiple-scale habitat gradients. We built a Bayesian hierarchical model, contrasting the abundance variations of 10 native and exotic species in 501 point counts spread along landscape and local-scale gradients of forest structure and composition. Although native and exotic species both occurred in a wide range of habitats, they were separated by landscape-level variables. Exotic species were most abundant in exotic conifer plantations embedded in farmland matrices, while native birds predominated in areas dominated by continuous native forest. In exotic plantation forests, and to a lesser extent in native forests, locally co-occurring exotic and native species were segregated along a gradient of vegetation height. These results support the prediction that exotic and native bird species are segregated along gradients related to anthropogenic disturbance and habitat availability. In addition, native and exotic species overlapped little in a multivariate functional space based on 10 life history traits associated with habitat selection. Hence, habitat segregation patterns were probably mediated more by environmental filtering processes than by competition at landscape and local scales

Exploration de modèles en épidémiologie des paysages agricoles

Exploration de modèles en épidémiologie des paysages agricoles. Journée Exploration, calibration et validation de modèles numériques complexes pour l'environnement de la SFD

Coupling SDM and observation processes via mechanistic-statistical modelling

National audienc

Dynamic mechanistic species distribution model of wolf recolonization in France

National audienc

Modélisation mécanistico- statistique de la dynamique du Coffee Berry Disease et élucidation des mécanismes épidémiologiques affectés par la culture sous ombrage

Modélisation mécanistico- statistique de la dynamique du Coffee Berry Disease et élucidation des mécanismes épidémiologiques affectés par la culture sous ombrage. Journées du GDR Ecologie Statistique EcoSta

Mechanistic-statistical modelling of Coffee Berry Disease (CBD) dynamics and elucidation of the epidemiological mechanisms affected by shade

National audienc

When sinks become sources: adaptive colonization in asexuals

The successful establishment of a population into a new empty habitat outside of its initial niche is a phenomenon akin to evolutionary rescue in the presence of immigration. It underlies a wide range of processes, such as biological invasions by alien organisms, host shifts in pathogens or the emergence of resistance to pesticides or antibiotics from untreated areas.[br/] In this study, we derive an analytically tractable framework to describe the coupled evolutionary and demographic dynamics of asexual populations in a source-sink system. In particular, we analyze the influence of several factors — immigration rate, mutational parameters, and harshness of the stress induced by the change of environment — on the establishment success in the sink (i.e. the formation of a self-sufficient population in the sink), and on the time until establishment. To this aim, we use a classic phenotype-fitness landscape (Fisher’s geometrical model in n dimensions) where source and sink habitats determine distinct phenotypic optima. The harshness of stress, in the sink, is determined by the distance between the fitness optimum in the sink and that of the source. The dynamics of the full distribution of fitness and of population size in the sink are analytically predicted under a strong mutation strong immigration limit where the population is always polymorphic.[br/] The resulting eco-evolutionary dynamics depend on mutation and immigration rates in a non straightforward way. Below some mutation rate threshold, establishment always occurs in the sink, following a typical four-phases trajectory of the mean fitness. The waiting time to this establishment is independent of the immigration rate and decreases with the mutation rate. Beyond the mutation rate threshold, lethal mutagenesis impedes establishment and the sink population remains so, albeit with an equilibrium state that depends on the details of the fitness landscape. We use these results to get some insight into possible effects of several management strategies

Effets de la structure spatiale des poulations hôtes sur la dynamique épidémique à l'échelle d'un paysage, une approche par modélisation

National audienc

Assessing the future and potential for adaptation of Atlantic salmon facing climate change in Southern Europe

International audienc