The Experts below are selected from a list of 23739 Experts worldwide ranked by ideXlab platform
Franck Brignolas - One of the best experts on this subject based on the ideXlab platform.
-
Genetic variation for leaf morphology, leaf structure and leaf carbon isotope discrimination in European populations of black poplar Populus nigra
Tree Physiology, 2015Co-Authors: Justine Guet, Francesco Fabbrini, Maurizio Sabatti, Catherine Bastien, Régis Fichot, Franck BrignolasAbstract:To buffer against the high spatial and temporal heterogeneity of the riparian habitat, riparian tree species, such as black poplar (Populus nigra L.), may display a high level of genetic variation and phenotypic plasticity for functional traits. Using a multisite common garden experiment, we estimated the relative contribution of genetic and environmental effects on the phenotypic variation expressed for individual leaf area, leaf shape, leaf structure and leaf carbon isotope discrimination (Delta C-13) in natural populations of black poplar. Twenty-four to 62 genotypes were sampled in nine Metapopulations covering a latitudinal range from 48A degrees N to 42A degrees N in France and in Italy and grown in two common gardens at Orl,ans (ORL) and at Savigliano (SAV). In the two common gardens, substantial genetic variation was expressed for leaf traits within all Metapopulations, but its expression was modulated by the environment, as attested by the genotype x environment (G x E) interaction variance being comparable to or even greater than genetic effects. For LA, G x E interactions were explained by both changes in genotype ranking between common gardens and increased variation in SAV, while these interactions were mainly attributed to changes in genotype ranking for Delta C-13. The nine P. nigra Metapopulations were highly differentiated for LA, as attested by the high coefficient of genetic differentiation (Q(ST) = 0.50 at ORL and 0.51 at SAV), and the pattern of Metapopulation differentiation was highly conserved between the two common gardens. In contrast, they were moderately differentiated for Delta C-13 (Q(ST) = 0.24 at ORL and 0.25 at SAV) and the Metapopulation clustering changed significantly between common gardens. Our results evidenced that the nine P. nigra Metapopulations present substantial genetic variation and phenotypic plasticity for leaf traits, which both represent potentially significant determinants of populations' capacities to respond, on a short-term basis and over generations, to environmental variations.
-
Phenotypic plasticity and genetic differentiation for morphological and functional leaf traits in nine Metapopulations of black poplar (Populus nigra L.)
2014Co-Authors: Justine Guet, Francesco Fabbrini, Maurizio Sabatti, Catherine Bastien, Franck BrignolasAbstract:Black poplar (Populus nigra L.) is a major tree species of riparian ecosystems in Europe that covers a wide range of pedoclimatic conditions and river dynamics, which may have promoted the development of adaptive strategies in natural populations. This species is of economic importance as a parental pool used in many breeding programs for the development of P. deltoides × P. nigra hybrids cultivated for biomass and wood production. The present study aimed at deciphering the components of phenotypic variation for a set of morphological, structural and functional leaf traits related to growth and water-use efficiency. Twenty-four to 62 P. nigra individuals sampled in nine European natural Metapopulations were established in replicated clonal tests in two experimental sites contrasted for soil texture and fertility. The relative importance of site, genetic and Genotype × Site (G × S) interaction effects on total phenotypic variation of leaf traits was estimated. In the most favourable site for growth, individual area of mature and fully illuminated leaves increased by an average of 150 % while bulk leaf carbon isotope discrimination (Δ13C) decreased by an average of 2.5 ‰. In the two sites, substantial genetic variation was expressed within the nine P. nigra Metapopulations for leaf traits. As indicated by G × S interaction variance comparable or even greater than genetic effects, the expression of genetic variation was significantly modulated by the site for all Metapopulations. For individual leaf area, G × S interactions were explained by both changes in genotype ranking and increased genetic variation in the most favourable site while these interactions were mainly attributed to changes of genotype ranking across sites for Δ13C. Despite high intra-Metapopulation genetic variation, the genetic differentiation among the nine Metapopulations was high (0.42 ≤ QST ≤ 0.51) for all traits related to leaf morphology, such as individual leaf area, petiole length and leaf shape, and its pattern was conserved in the two experimental sites. In contrast, Δ13C exhibited a moderate level of Metapopulation differentiation (QST ≈ 0.25) with significant changes of Metapopulation clustering between the two sites. These results will be discussed considering the adaptive potential of black poplar to variations in environmental conditions.
Justine Guet - One of the best experts on this subject based on the ideXlab platform.
-
Genetic variation for leaf morphology, leaf structure and leaf carbon isotope discrimination in European populations of black poplar Populus nigra
Tree Physiology, 2015Co-Authors: Justine Guet, Francesco Fabbrini, Maurizio Sabatti, Catherine Bastien, Régis Fichot, Franck BrignolasAbstract:To buffer against the high spatial and temporal heterogeneity of the riparian habitat, riparian tree species, such as black poplar (Populus nigra L.), may display a high level of genetic variation and phenotypic plasticity for functional traits. Using a multisite common garden experiment, we estimated the relative contribution of genetic and environmental effects on the phenotypic variation expressed for individual leaf area, leaf shape, leaf structure and leaf carbon isotope discrimination (Delta C-13) in natural populations of black poplar. Twenty-four to 62 genotypes were sampled in nine Metapopulations covering a latitudinal range from 48A degrees N to 42A degrees N in France and in Italy and grown in two common gardens at Orl,ans (ORL) and at Savigliano (SAV). In the two common gardens, substantial genetic variation was expressed for leaf traits within all Metapopulations, but its expression was modulated by the environment, as attested by the genotype x environment (G x E) interaction variance being comparable to or even greater than genetic effects. For LA, G x E interactions were explained by both changes in genotype ranking between common gardens and increased variation in SAV, while these interactions were mainly attributed to changes in genotype ranking for Delta C-13. The nine P. nigra Metapopulations were highly differentiated for LA, as attested by the high coefficient of genetic differentiation (Q(ST) = 0.50 at ORL and 0.51 at SAV), and the pattern of Metapopulation differentiation was highly conserved between the two common gardens. In contrast, they were moderately differentiated for Delta C-13 (Q(ST) = 0.24 at ORL and 0.25 at SAV) and the Metapopulation clustering changed significantly between common gardens. Our results evidenced that the nine P. nigra Metapopulations present substantial genetic variation and phenotypic plasticity for leaf traits, which both represent potentially significant determinants of populations' capacities to respond, on a short-term basis and over generations, to environmental variations.
-
Phenotypic plasticity and genetic differentiation for morphological and functional leaf traits in nine Metapopulations of black poplar (Populus nigra L.)
2014Co-Authors: Justine Guet, Francesco Fabbrini, Maurizio Sabatti, Catherine Bastien, Franck BrignolasAbstract:Black poplar (Populus nigra L.) is a major tree species of riparian ecosystems in Europe that covers a wide range of pedoclimatic conditions and river dynamics, which may have promoted the development of adaptive strategies in natural populations. This species is of economic importance as a parental pool used in many breeding programs for the development of P. deltoides × P. nigra hybrids cultivated for biomass and wood production. The present study aimed at deciphering the components of phenotypic variation for a set of morphological, structural and functional leaf traits related to growth and water-use efficiency. Twenty-four to 62 P. nigra individuals sampled in nine European natural Metapopulations were established in replicated clonal tests in two experimental sites contrasted for soil texture and fertility. The relative importance of site, genetic and Genotype × Site (G × S) interaction effects on total phenotypic variation of leaf traits was estimated. In the most favourable site for growth, individual area of mature and fully illuminated leaves increased by an average of 150 % while bulk leaf carbon isotope discrimination (Δ13C) decreased by an average of 2.5 ‰. In the two sites, substantial genetic variation was expressed within the nine P. nigra Metapopulations for leaf traits. As indicated by G × S interaction variance comparable or even greater than genetic effects, the expression of genetic variation was significantly modulated by the site for all Metapopulations. For individual leaf area, G × S interactions were explained by both changes in genotype ranking and increased genetic variation in the most favourable site while these interactions were mainly attributed to changes of genotype ranking across sites for Δ13C. Despite high intra-Metapopulation genetic variation, the genetic differentiation among the nine Metapopulations was high (0.42 ≤ QST ≤ 0.51) for all traits related to leaf morphology, such as individual leaf area, petiole length and leaf shape, and its pattern was conserved in the two experimental sites. In contrast, Δ13C exhibited a moderate level of Metapopulation differentiation (QST ≈ 0.25) with significant changes of Metapopulation clustering between the two sites. These results will be discussed considering the adaptive potential of black poplar to variations in environmental conditions.
Ilkka Hanski - One of the best experts on this subject based on the ideXlab platform.
-
1 – Metapopulation Biology: Past, Present, and Future
Ecology Genetics and Evolution of Metapopulations, 2004Co-Authors: Ilkka Hanski, Oscar E. GaggiottiAbstract:Publisher Summary The term Metapopulation stems from the general notion of the hierarchical structure of nature. Just like the term population is needed to describe an assemblage of interacting individuals, it seems apt to have a term for an assemblage of spatially delimited local populations that are coupled by some degree of migration—the Metapopulation. It is conceptually attractive and helpful for the study of population biology to explicitly consider the sequence of entities from individuals to local populations to Metapopulations. A Metapopulation approach refers to research or management that adopts the view that local populations, which the Metapopulations consist of, are discrete (or relatively discrete) entities in space, and that these local populations interact via migration and gene flow. Metapopulation biology represents a way of explicitly putting population biology into a spatial context. The basic tenet of spatial ecology, which includes Metapopulation ecology as well as other approximations, is that the spatial positions of individuals and populations matter in the sense of influencing the growth rate and dynamics of populations and Metapopulations and their competitive, predator–prey, and other interactions.
-
Spatially realistic theory of Metapopulation ecology
Die Naturwissenschaften, 2001Co-Authors: Ilkka HanskiAbstract:Much of spatial ecology since the late 1960s has been dominated by two theories, the dynamic theory of island biogeography and the classical Metapopulation theory. The latter theory largely replaced the former one in the 1980s, especially in conservation applications. It is only recently that ecologists have fully realized that a relatively simple general theory can be readily constructed that makes some of the simplifying assumptions of the two earlier theories unnecessary. The spatially realistic Metapopulation theory thereby provides a more unified framework for spatial ecology than the island theory or the classical Metapopulation theory. This article describes the application of the spatially realistic Metapopulation theory to real Metapopulations living in highly fragmented landscapes. I discuss the principal messages for population ecology and conservation biology, and I also place this theory into a broader context of other approaches to spatial ecology.
-
The Metapopulation capacity of a fragmented landscape
Nature, 2000Co-Authors: Ilkka Hanski, Otso OvaskainenAbstract:Ecologists and conservation biologists have used many measures of landscape structure to predict the population dynamic consequences of habitat loss and fragmentation, but these measures are not well justified by population dynamic theory. Here we introduce a new measure for highly fragmented landscapes, termed the Metapopulation capacity, which is rigorously derived from Metapopulation theory and can easily be applied to real networks of habitat fragments with known areas and connectivities. Technically, Metapopulation capacity is the leading eigenvalue of an appropriate 'landscape' matrix. A species is predicted to persist in a landscape if the Metapopulation capacity of that landscape is greater than a threshold value determined by the properties of the species. Therefore, Metapopulation capacity can conveniently be used to rank different landscapes in terms of their capacity to support viable Metapopulations. We present an empirical example on multiple networks occupied by an endangered species of butterfly. Using this theory, we may also calculate how the Metapopulation capacity is changed by removing habitat fragments from or adding new ones into specific spatial locations, or by changing their areas. The Metapopulation capacity should find many applications in Metapopulation ecology, landscape ecology and conservation biology.
-
Metapopulation biology ecology genetics and evolution
Ecology, 1997Co-Authors: Chris Ray, Ilkka Hanski, Martha F Hoopes, Michael E. GilpinAbstract:Conceptual Foundation: Introduction. Empirical Evidence for Metapopulation Dynamics. Metapopulation Dynamics and Landscape Ecology. Theory of Metapopulation Dynamics. Metapopulation Dynamics: Form Concepts and Observations to Predictive Models. Structures Metapopulation Models. Two-Species Metapopulation Models. From Metapopulation Dynamics to Community Structure: Some Consequences of Spatial Heterogeneity. Genetic Effective Size of a Metapopulation. The Evolution of Metapopulations. Metapopulation Processes: Extinction Models for Local Populations. Studying Transfer Processes in Metapopulations: Immigration, Migration, And Colonization. Migration Within Metapopulations: The Impact Upon Local Population Dynamics. Evolution of Migration Rate and Other Traits: The Metapopulation Effect. Spatial Processes in Host-Parasite Genetics. Case Studies: Butterfly Metapopulations. Tritrophic Metapopulation Dynamics: A Case Study of Ragworth, The Cinnabar Moth, And the Parasitoid Cotesia Popularis. Spatially Correlated Dynamics in a Pika Metapopulation. A Case Study of Genetic Structure in a Plant Metapopulation. Subject Index.
-
The Metapopulation Approach, Its History, Conceptual Domain, and Application to Conservation
Metapopulation Biology, 1997Co-Authors: Ilkka Hanski, Daniel SimberloffAbstract:Publisher Summary This chapter reviews and analyzes the spread of the Metapopulation concept to conservation biology and applications. The Metapopulation concept has now been firmly established in population biology. Two key premises in this approach to population biology are that populations are spatially structured into assemblages of local breeding populations, and that migration among the local populations has some effect on local dynamics, including the possibility of population reestablishment following extinction. These premises contrast with those of standard models of demography, population growth, genetics, and community interaction that assume a panmictic population structure, with all individuals equally likely to interact with any others. The focus on Metapopulations, combined with that on genetics, has led to the population and the species becoming the dominant levels of concern in conservation. It is striking that the recent explosion of interest in ecosystem management is quite antithetic to a primary interest in populations and to single species management. Ecosystem management and Metapopulation models share a concern with landscapes and regions, rather than highly local settings, and one could imagine a landscape with a distribution of habitat patches that would maintain many Metapopulations simultaneously.
Dries Bonte - One of the best experts on this subject based on the ideXlab platform.
-
The importance and adaptive value of life history evolution for Metapopulation dynamics
2017Co-Authors: Dries Bonte, Quinten BafortAbstract:The performance of populations is affected by environmental change and the resulting evolutionary dynamics. The spatial configuration and size of patches is known to directly influence Metapopulation dynamics (spatial forcing). These Metapopulation dynamics are also affecting and affected by life history evolution. Given the relevance of Metapopulation persistence for biological conservation, and the potential rescuing role of evolution, a firm understanding of the relevance of these eco-evolutionary processes is essential. We here follow a systems modelling approach to disentangle the role of Metapopulation structure relative to evolution for Metapopulation performance. We developed an individual based systems model that is strongly based and parameterized by results from experimental Metapopulations with spider mites. This model enables us to perform virtual translocation and invasion experiments that would have been impossible to conduct in our experimental systems. We show that (1) Metapopulation demography is more affected by spatial forcing than by observed life history evolution, but that life history evolution contributes up to 20 percent of the variation in demographic measures related to spatiotemporal variance in population sizes, (2) Metapopulation performance is not enhanced by evolution, and (3) evolution is optimising individual performance in Metapopulations when considering the importance of so far overlooked stress resistance evolution. We thus provide evidence that Metapopulation-level selection maximises individual performance and more importantly, that - at least in our system - evolutionary changes impact Metapopulation dynamics, especially factors related to local and Metapopulation sizes.
-
Life-history evolution in response to changes in Metapopulation structure in an arthropod herbivore
Functional Ecology, 2016Co-Authors: Annelies De Roissart, Nicky Wybouw, D Renault, Thomas Van Leeuwen, Dries BonteAbstract:The persistence and dynamics of populations largely depend on the way they are configured and integrated into space and the ensuing eco-evolutionary dynamics. * We manipulated spatial and temporal variation in patch size in replicated experimental Metapopulations of the herbivore mite Tetranychus urticae and followed evolutionary dynamics over approximately 30 generations. * A significant divergence in life-history traits, physiological endpoints and gene expression was recorded in the spatially and spatiotemporally variable Metapopulation, but also a remarkable convergence relative to the stable reference Metapopulation in traits related to size and fecundity and in its transcriptional regulation. * The observed evolutionary dynamics are tightly linked to demographic changes, more specifically frequent episodes of resource shortage that increased the reproductive performance of mites on tomato, a challenging host plant. This points towards a general, adaptive stress response in stable spatial variable and spatiotemporal variable Metapopulations that pre-adapts a herbivore arthropod to novel environmental stressors
-
Spatial and spatiotemporal variation in Metapopulation structure affects population dynamics in a passively dispersing arthropod
Journal of Animal Ecology, 2015Co-Authors: Annelies De Roissart, Shaopeng Wang, Dries BonteAbstract:The spatial and temporal variation in the availability of suitable habitat within Metapopulations determines colonization–extinction events, regulates local population sizes and eventually affects local population and Metapopulation stability. Insights into the impact of such a spatiotemporal variation on the local population and Metapopulation dynamics are principally derived from classical Metapopulation By manipulating spatial structure in artificial Metapopulations of the spider mite Tetranychus urticae, we test to which degree spatial (mainland–island Metapopulations) and spatiotemporal variation (classical Metapopulations) in habitat availability affects the dynamics of the Metapopulations relative to systems where habitat is constantly available in time and space (patchy Metapopulations). Our experiment demonstrates that (i) spatial variation in habitat availability decreases variance in Metapopulation size and decreases density‐dependent dispersal at the Metapopulation level, while (ii) spatiotemporal variation in habitat availability increases patch extinction rates, decreases local population and Metapopulation sizes and decreases density dependence in population growth rates. We found dispersal to be negatively density dependent and overall low in the spatial variable mainland–island Metapopulation. This demographic variation subsequently impacts local and regional population dynamics and determines patterns of Metapopulation stability. Both local and Metapopulation‐level variabilities are minimized in mainland–island Metapopulations relative to classical and patchy ones.
-
Evolution of body condition-dependent dispersal in Metapopulations
Journal of evolutionary biology, 2009Co-Authors: Dries Bonte, E. De La PeñaAbstract:Body condition-dependent dispersal strategies are common in nature. Although it is obvious that environmental constraints may induce a positive relationship between body condition and dispersal, it is not clear whether positive body conditional dispersal strategies may evolve as a strategy in Metapopulations. We have developed an individual-based simulation model to investigate how body condition-dispersal reaction norms evolve in Metapopulations that are characterized by different levels of environmental stochasticity and dispersal mortality. In the model, body condition is related to fecundity and determined either by environmental conditions during juvenile development (adult dispersal) or by those experienced by the mother (natal dispersal). Evolutionarily stable reaction norms strongly depend on Metapopulation conditions: positive body condition dependency of dispersal evolved in Metapopulation conditions with low levels of dispersal mortality and high levels of environmental stochasticity. Negative body condition-dependent dispersal evolved in Metapopulations with high dispersal mortality and low environmental stochasticity. The latter strategy is responsible for higher dispersal rates under kin competition when dispersal decisions are based on body condition reached at the adult life stage. The evolution of both positive and negative body condition-dependent dispersal strategies is consequently likely in Metapopulations and depends on the prevalent environmental conditions.
Larissa L Bailey - One of the best experts on this subject based on the ideXlab platform.
-
using bayesian population viability analysis to define relevant conservation objectives
PLOS ONE, 2015Co-Authors: Adam W Green, Larissa L BaileyAbstract:Adaptive management provides a useful framework for managing natural resources in the face of uncertainty. An important component of adaptive management is identifying clear, measurable conservation objectives that reflect the desired outcomes of stakeholders. A common objective is to have a sustainable population, or Metapopulation, but it can be difficult to quantify a threshold above which such a population is likely to persist. We performed a Bayesian Metapopulation viability analysis (BMPVA) using a dynamic occupancy model to quantify the characteristics of two wood frog (Lithobates sylvatica) Metapopulations resulting in sustainable populations, and we demonstrate how the results could be used to define meaningful objectives that serve as the basis of adaptive management. We explored scenarios involving Metapopulations with different numbers of patches (pools) using estimates of breeding occurrence and successful metamorphosis from two study areas to estimate the probability of quasi-extinction and calculate the proportion of vernal pools producing metamorphs. Our results suggest that ≥50 pools are required to ensure long-term persistence with approximately 16% of pools producing metamorphs in stable Metapopulations. We demonstrate one way to incorporate the BMPVA results into a utility function that balances the trade-offs between ecological and financial objectives, which can be used in an adaptive management framework to make optimal, transparent decisions. Our approach provides a framework for using a standard method (i.e., PVA) and available information to inform a formal decision process to determine optimal and timely management policies.
