At Point Reyes National Seashore in Marin County, Calif., a fierce battle is taking place under the oblivious, peeling noses of beachgoers.
It's a battle between an invasive plant and a native plant, but with a new twist. The two plants, European beachgrass and Tidestrom's lupine, are not in direct competition, and yet the beachgrass is helping to drive the lupine over the cliff.
European beachgrass provides cover that allows a timid deer mouse to get close enough to the lupine to snip off stalks of lupine fruits without being nabbed by overflying birds.
In the August issue of Ecology, biologists at Washington University in St. Louis report on the interplay between these species in three lupine populations over a period of four years. Emily Dangremond, Eleanor Pardini and Tiffany Knight used field data to construct a mathematical model of lupine populations. The model predicts that if things go along as they have been so far, all three populations of lupines will be driven to extinction.
But it also predicts that if the mice eat just a few less seeds, the largest population of lupines, which is under the greatest pressure from seed consumption, will remain stable.
The scientists will have a rare opportunity to test the fidelity of their model to the living communities. Point Reyes National Seashore is removing the beachgrass from the prime lupine site as part of an effort to restore native dune habitat. Will the lupine population in the restoration site recover as the model predicts?
Trouble in paradise
Point Reyes, an anvil-shaped peninsula north of San Francisco that separated by the rift zone of the San Andreas Fault from Marin County, includes spectacular coastal beaches and headlands, estuaries and uplands. When it was threatened by residential development in 1962, Clem Miller, a U.S. Congressman sponsored a bill to preserve it.
Maintained by the National Park Service
|Contact: Diana Lutz|
Washington University in St. Louis