Uncovering How Wildlife Corridors Work

Uncovering How Wildlife Corridors Work

Susan Cosier
Published: 12/11/2008

Pathways between islands of undeveloped land, or wildlife corridors, are crucial to ecosystem biodiversity. New research reveals more about how these strips of wilderness benefit the environment, and the results may even help land managers determine how long it will take for seeds to travel from one area to another and take hold.

The research “allows us to predict when and how fast corridors should work because we know that all species don’t respond in the same way,” says Ellen Damschen, the lead researcher of a study published in the latest issue of the Proceedings of the National Academy of Sciences.
 
Over seven years, Damschen and her team looked at how 300 species of plants moved through wildlife corridors of different shapes and sizes. The researchers put the seeds of plants into three categories—bird dispersed, wind dispersed, and unassisted—to see how quickly they took root in different sections of the ecosystem.

As expected, they found that corridors are good for seeds spread by birds because the animals can easily move from one area to another. They also found that the location of the corridor relative to wilderness patches can determine how wind dispersed varieties, like dandelion seeds, move. When a 150-meter corridor connects two islands, there are more wind-dispersed species because the air funnels the seeds from one area to another.

The most surprising result, says Damschen, was that there was no way the unassisted species could have moved from one place to another so quickly without help. Other studies show that mammals may play a part in distributing unassisted species by eating them while foraging, which would help the seeds move through the habitat.

The experiment was done on test plots, which are generally smaller than existing wildlife corridors, so outside of the outdoor laboratory it might take longer for birds, wind, and mammals to move the seeds around than it did over the course of the study.

Damschen is hopeful that land managers can extrapolate the data and that the information can help them more accurately estimate how corridors work and over what timeframe. “We are helping land managers to make better, more informed and more effective decisions as they use corridors in their designs,” she says.