info:eu-repo/semantics/article
Where does environmental stochasticity most influence population dynamics? An assessment along a regional core-periphery gradient for prairie breeding ducks
Autor
Richard Feldman
Michael Anderson
DAVID W. HOWERTER
DENNIS L. MURRAY
Institución
Resumen
Geographical disparities in the effect of the environment on population dynamics have been shown to follow a core-periphery gradient when peripheral populations are less abundant and occur in marginal habitat. Whether the gradient in environmental influence occurs in the absence of a gradient in abundance is not known. We tested whether duck populations on the periphery of their main breeding region were more strongly affected by environmental stochasticity and less abundant than at the core. Location: The Prairie Pothole Region of central United States and Canada Methods: We used the North American Waterfowl Breeding Population and Habitat Survey to model the dynamics of 10 duck species at 1059 sites spanning 1961-2012. We used the North American Breeding Bird Survey to measure abundance at the same sites, averaged over the same time span. We used structural equation models to characterize relationships among a site's distance from the regional centre, a site's abundance, and the degree to which a site's ducks were affected by environmental stochasticity. Results: Environmental stochasticity never strongly contributed to population dynamics in the region's core. However, we did not find a linear increase in environmental stochasticity with increasing distance from the core. For seven species, we found that environmental stochasticty was stronger in sites of lower abundance. For only two species did average abundance decline from the region's core to periphery. Main conclusions: Variability in the magnitude of environmental stochasticity follows coarse spatial differences in wetland productivity. Yet, among peripheral sites, the contribution of the environment to population dynamics varies, possibly reflecting the importance of the local environment and dispersal.
Materias
Ítems relacionados
Mostrando ítems relacionados por Título, autor o materia.
-
Preparación de materiales compuestos mediante la funcionalización covalente de nanotubos de carbono (CNTs) con polímero
CLAUDIA GUADALUPE ESPINOSA GONZALEZ -
Attachment of transition metal nanoparticles on nitrogen doped carbon nanotubes (MWNTs-CNx) and their further reactions.
XAVIER NORBERTO LEPRÓ CHÁVEZ -
Alternativas sustentables para uso de residuos de explotación de tobas volcánicas en materiales de construcción
REBECA GUADALUPE ORTIZ MENA; MARIA GUADALUPE NAVARRO ROJERO; T. LOPEZ-LARA; Juan Bosco Hernández Zaragoza; DANIEL NAPOLEON GOMEZ BALBUENA