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UC Davis Natural Reserve System

UC Davis Natural Reserve System

The Barn
University of California, Davis
One Shields Avenue
Davis, CA 95616

(530) 754-7990
(530) 754-9141 Fax

Featured Classes - Stebbins Cold Canyon & Jepson Prairie Reserves

The steep slopes of Stebbins Cold Canyon.

The steep slopes of Stebbins Cold Canyon Reserve.

Goldfields at Jepson Prairie Reserve.

Goldfields at Jepson Prairie Reserve.

Marcel Rejmanek
Department of Evolution and Ecology,
ECL 206 & PLB 117, UC Davis

Teaching Plant Ecology at Stebbins Cold Canyon and Jepson Prairie

Steep and densely vegetated slopes might discourage some people, but for Professor Marcel Rejmanek (Evolution & Ecology), they are a big part of the reason he’s taken his graduate plant ecology class (ECL 206) to the Stebbins Cold Canyon Reserve for the past 18 years. “It’s one of the few places you can reach all possible slopes from one point,” he says of Wildhorse Canyon, a tributary of Cold Canyon. “We divide the students into groups and send them to the riparian zone plus three or four different slopes. They sample the vegetation and discover how it diverges on different slopes, but converges when you get to the upper slopes, where it all becomes chamise chaparral. ”  The lucky students are sent to the more northerly slopes, where the dense oak forest discourages poison oak, “but surprisingly, I’ve had only three or four students get poison oak,” he smiles.

Topography on far more subtle scales can fascinate plant ecologists too. Rejmanek brought ECL 206 to Jepson Prairie for over 10 years, where his students focused on mapping plants in study plots of different sizes to test for competition. But they discovered that a fine-scale negative association between species – seemingly suggesting competition – actually reflected how Phyla nodiflora and other tiny plants responded to mere inches of differences in elevation and drainage.

The wildfire at Stebbins Cold Canyon in 1986 was a less expected attraction. After the fire, his undergraduate plant ecology class (PLB 117) observed increases in wild cucumber (Marah fabaceus) and deerbrush (Lotus scoparius), and examined the regeneration strategies  of gray pine (Pinus sabiniana) and shrubs. In other years, the responses of toyon (Heteromeles arbutifolia) leaves to the light environment, differences between female and male coyotebrush (Baccharis pilularis) in environmental preferences, how competitors affect production of the huge fruits of the buckeye (Aesculus californicus), and the trajectory of invasions by yellow starthistle (Centaurea solstitialis) have consistently engaged his undergraduate students.

“It’s great to have places that are safe and you know you can come back every year and get to know well, so that when students have questions you know many of the answers,” concludes Rejmanek, “and you get so many opportunities to see and learn from changes. ”