[Currents header graphic]

March 1, 1999

Researchers use meadow site to study impact of grazing on plants

By Jennifer McNulty

Karen Holl, assistant professor of environmental studies, wasn't surprised to get a call last week about her research in the lower east meadow. In fact, she'd been expecting it. Any activity in the meadow generates curiosity on campus, and the small plot of land fenced with posts and barbed wire was no different.

Holl and her graduate student Grey Hayes are using the 2,500-square-meter plot for at least three years to research the effects of cattle grazing on rare annual plants that grow on coastal prairies.

There is considerable debate nationally about the impact of cattle on wildlands. In California, there is a growing movement toward removing cattle from public lands because of the negative environmental impacts of overgrazing, Holl said.

"Cattle grazing is being viewed negatively altogether, when it may turn out that mismanaged grazing is the problem," said Holl.

The site on campus is one of three being studied on the Central Coast--the others are on Swanton Pacific Ranch north of Davenport and on private land near Elkhorn Slough.

"The areas of natural land on the UCSC campus provide an excellent opportunity to combine research and teaching on land management," said Holl.

Holl and Hayes are testing the impact of "disturbances" on several plant species, including bearded clover and the Santa Cruz tarplant, which is on the state's list of endangered species.

The idea is to mimic the different disturbances due to cattle grazing, said Hayes.

"Our hypothesis is that disturbances are important to the maintenance of some species," explained Hayes. "During the Pleistocene, ground sloths and mastodon grazing disturbed plants, and Native Americans burned these areas more recently."

To begin testing their ideas, Holl, Hayes, and a team of students and volunteers spent the last weekend of January planting more than 5,000 plants in the three research plots. At UCSC, they chose the lower east meadow because they needed a site away from the road in an area that has been grazed but won't be developed in the near future.

Each site is divided into 30 different plots, where the effects of various treatments will be observed year-round, including different frequencies of clipping, vegetation removal, and soil disturbance. Because of logistical problems, instead of actual cattle grazing in the small plots, humans will use cow hooves to mimic their habits, said Holl.

After establishing the ecological impacts of different disturbances, Holl and Hayes hope to ascertain the economic feasibility of implementing different cattle-grazing regimes.

To the Currents home page

To UCSC's home page