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Grantee Research Project Results

Grantee Research Project Results

The Role of Corridors in Affecting Predator-Prey Interactions: The Interplay Between Seed Deposition, Seed Predation, and Seedling Establishment in Experimentally Fragmented Landscapes

EPA Grant Number: U916182
Title: The Role of Corridors in Affecting Predator-Prey Interactions: The Interplay Between Seed Deposition, Seed Predation, and Seedling Establishment in Experimentally Fragmented Landscapes
Investigators: Orrock, John L.
Institution: Iowa State University
EPA Project Officer: Graham, Karen
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $93,804
RFA: STAR Graduate Fellowships (2003)
Research Category: Academic Fellowships , Fellowship - Terrestrial Ecology and Ecosystems , Ecological Indicators/Assessment/Restoration

Description:

Objective:

The objective of this research project is to examine how patch shape and connectivity affect predator-prey interactions in a large-scale experimental landscape. Habitat fragmentation and species loss are occurring at global scales, yet few experimental studies have examined the effects of fragmentation on ecological communities. Corridors connect habitat fragments and are thought to promote population persistence by gene flow, population rescue, and increasing abundance. Corridors have been criticized because the mechanisms that lead to corridor effects are unknown. Perhaps more worrisome, the population-level focus of most corridor studies neglects the rest of the ecological milieu, making their usefulness questionable. In an age when corridors are considered to have positive effects on target populations, my research is an attempt to more thoroughly evaluate the potential effects of corridors on populations and communities, mediated through indirect effects of corridors on nontarget populations.

Approach:

Using seed predators and seeds as a model system, I have shown that seed predation is capable of changing the distribution of seeds in the landscape. Moreover, vertebrate and invertebrate seed predators respond differently to patch shape and connectivity. Because vertebrate and invertebrate seed predators may select different seeds, corridor-mediated shifts in predation pressure could lead to different impacts on the seed bank and shifts in competitive interactions. I currently am focusing on how corridors and patch shape influence seed predators, and how this may ultimately lead to changes in synthetic communities of seeds and seedlings.

This research will reveal if corridors affect ecological communities by altering the nature of competition and predation. Most importantly, it offers a first step towards a rigorous test of corridors as a potentially powerful conservation tool.

Supplemental Keywords:

fellowship, ecological corridors, preditor-prey interactions, habitat fragmentation, species loss, corridor effects, patch shape, seed predators, seeds, seedlings., Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Ecology, Habitat, Ecology and Ecosystems, Biology, urban habitat, land use effects, habitat loss, anthropogenic stressors, habitat fragmentation, conservation biology, effects of fragmentation, forest fragmentation, amphibian population, predation

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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