نتایج جستجو برای: metapopulation
تعداد نتایج: 1826 فیلتر نتایج به سال:
BACKGROUND AND AIMS Transgene introgression from crops into wild relatives may increase the resistance of wild plants to herbicides, insects, etc. The chance of transgene introgression depends not only on the rate of hybridization and the establishment of hybrids in local wild populations, but also on the metapopulation dynamics of the wild relative. The aim of the study was to estimate gene fl...
Metapopulation theory provides a framework for understanding population persistence in fragmented landscapes and as such has been widely used in conservation biology to inform management of fragmented populations. However, classical metapopulation theory [Levins, R. (1970) Lect. Notes Math. 2, 75-107] ignores metapopulation structure and local population dynamics, both of which may affect extin...
Continuous colonization and re-colonization is critical for survival of insect species living in temporary habitats. When insect populations in temporary habitats are depleted, some species may escape extinction by surviving in permanent, but less suitable habitats, in which long-term population survival can be maintained only by immigration from other populations. Such situation has been repea...
Ernst Mayr played a central role in the establishment of the general concept of species as metapopulation lineages, and he is the author of one of the most popular of the numerous alternative definitions of the species category. Reconciliation of incompatible species definitions and the development of a unified species concept require rejecting the interpretation of various contingent propertie...
We construct a stochastic patch occupancy metapopulation model that incorporates variation in habitat quality and an Allee-like effect. Using some basic results from stochastic ordering, we investigate the effect of habitat degradation on the persistence of the metapopulation. In particular, we show that for a metapopulation with Allee-effect habitat degradation can cause a dramatic decrease in...
Dispersal can have positive and negative effects on metapopulation stability and persistence. One prediction is that high levels of dispersal synchronize density fluctuations between subpopulations. However, little is still known about how biotic and abiotic factors combine to modify the effects of dispersal rate on synchrony and metapopulation dynamics. In a fully factorial experimental design...
Despite recent advances in biodemography and metapopulation ecology, we still have limited understanding of how local demographic parameters influence short- and long-term metapopulation dynamics. We used long-term data from 17 local populations, along with the recently developed methods of matrix metapopulation modeling and transient sensitivity analysis, to investigate the influence of local ...
Ecological theory suggests that several demographic factors influence metapopulation extinction risk, including synchrony in population size between subpopulations, metapopulation size and the magnitude of fluctuations in population size. Theoretically, each of these is influenced by the rate of migration between subpopulations. Here we report on an experiment where we manipulated migration rat...
Habitats used by most species are becoming increasingly fragmented, requiring a metapopulation modelling approach to population viability analysis. Recognizing habitat patchiness from an endangered species' point of view requires utilization of spatial information on habitat suitability. Both of these requirements may be met by linking metapopulation modelling with landscape data using GIS tech...
Metapopulation models that incorporate both spatial and temporal structure are studied in this paper. The existence and stability of equilibria are provided, and an extinction threshold condition is derived which depends on patch dynamics (patch destruction and creation) and metapopulation dynamics (patch colonization and extinction). These results refine threshold conditions given by previous ...
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