Corridors affect plants, animals, and their interactions in fragmented landscapes

Abstract

Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical studies addressing the effects of corridors have either been small in scale or have ignored confounding effects of increased habitat area created by the presence of a corridor. These methodological difficulties, coupled with a paucity of studies examining the effects of corridors on plants and plantanimal interactions, have sparked debate over the purported value of corridors in conservation planning. We report results of a large-scale experiment that directly address this debate. In eight large-scale experimental landscapes that control for patch area and test alternative mechanisms of corridor function, we demonstrate that corridors not only increase the exchange of animals between patches, but also facilitate two key plant-animal interactions: pollination and seed dispersal. Our results show that the beneficial effects of corridors extend beyond the area they add, and suggest that increased plant and animal movement through corridors will have positive impacts on plant populations and community interactions in fragmented landscapes.

Spatially cascading effect of perturbations in experimental meta-ecosystems

“…We experimentally demonstrated, and showed also in a mathematical model, that the direction of the effects depend on the temporal unfolding, the magnitude of disturbance and the type of connected ecosystems (autotrophic versus heterotrophic dominated). Increasing dispersal rate by maintaining habitat connections can mitigate the deleterious effects of perturbation on local communities [50], however, our results suggest that high perturbation pressure can hinder rescue effects when the dispersing populations are too slow to recover. Our study calls for more integrative management that takes into account regional dynamics related to species and resource flows [51], and spatial variations in ecosystem functions [52,53].…”

Constraints to and conservation implications for climate change adaptation in plants

“…1b, c) by connecting fragmented patches thus aiding seed and pollen dispersal and increasing effective population sizes (Tewksbury et al 2002;Townsend and Levey 2005;Gilbert-Norton et al 2010). In an experimental study into the effectiveness of corridors for connecting fragmented populations, it was shown that corridors increased movement of insects and birds between patches resulting in greater levels of pollen and seed dispersal respectively, thus increasing gene flow among fragmented populations (Tewksbury et al 2002). The flow of adaptive alleles along corridors by connecting fragmented populations may assist in boosting population adaptive capacity as climate shifts (Fig.…”

Estación Biológica Senda Darwin: Investigación ecológica de largo plazo en la interfase ciencia-sociedad

“…En los paisajes rurales, los bosques ribereños y zonas de matorral denso conforman "corredores biológicos" que conectan parches de bosque aislados por praderas (Argent & Zwier 2007), constituyendo vías potenciales para la dispersión activa y pasiva de plantas y animales silvestres (Johansson et al 1996, Tewksbury et al 2002, Haddad et al 2003. Por esto, cabe esperar que su presencia en el paisaje incremente el desplazamiento de organismos y la conectividad de los hábitats silvestres.…”