How Grazing Could Restore Grasslands

From Conservation Magazine:

Herbivores, as you well know, eat plants. Some herbivores eat so many plants and so rapidly that they might as well be thought of as biological lawnmowers. But there’s a problem when biological lawnmowers meet invasive grasses. Together, the two can overwhelm native grasses, making them nearly impossible to restore. Indeed, the conversion of California grasslands from ones dominated by native, perennial bunchgrasses to ones dominated by exotic annual species is considered an “ecologically significant biological invasion.”

The invaders suppress the natives both as seedlings and as adults, but that’s not all. They alter the ecosystem’s response to disturbances, cause changes in soil carbon and other nutrients, cause changes in the community of soil microbes, and alter the profile of water in the soil. When combined with endless grazing by cows and other livestock, it’s no wonder that the native grasses can’t compete.

But Carlene Henneman, Nathaniel E. Seavy, and Thomas Gardali, researchers with Blue Point Conservation Science, have a plan. The idea is to sync the timing and intensity of grazing to the exotic annuals cycle, allowing the native perennials as much time to grow and seed as possible in between periods of grazing. While that all makes sense theoretically, the usefulness of the approach hasn’t actually been subject to much testing. So that’s what the researchers did, at a place called TomKat Ranch in Pescadero, California, south of the San Francisco Bay Area.

Click here to learn more: http://conservationmagazine.org/2015/01/how-grazing-could-restore-californias-grasslands/