Experimental test of corridor effects on plant-insect interactions

Habitat fragmentation may disrupt plant-animal interactions by restricting animal movement or by creating edge effects that alter the local environment.  I synthesize results from a large-scale habitat fragmentation experiment focusing on the role of corridors in restoring plant-animal interactions.  Because habitat fragmentation increases edge effects, and because narrow corridors create edges, I separate the role of corridors in enhancing connectivity from their role in exacerbating edge effects.  I show how corridors increase movement rates of pollinators and herbivores, and how, by creating edges, corridors can alter the abundance of herbivores, pollinators, and seed predators.  Considering both positive and negative effects of interactions on plants, I discuss the implications of restoring connectivity for plant population demography.  The benefits incurred by plant species in restoring connectivity to fragmented landscapes may vary by plant species’ dependence on insects at various stages of their life history.