SANTA BARBARA, California, September 10, 2002 (ENS) - Native grasslands in California may be able to be restored without first eradicating invasive plants from Europe, show preliminary results from a new study. The study by researchers from the University of California at Santa Barbara (UCSB) and the University of Minnesota suggests that the native grasslands may only need to be reseeded with native seeds, according to a presentation at the recent annual Ecological Society of America meeting.
"We used experimental seed introductions of native and exotic species to investigate one of the most dramatic plant invasions worldwide, the invasion of 23 percent of California by annual plant species introduced from Mediterranean Europe," said Eric Seabloom, of the National Center for Ecological Analysis and Synthesis (NCEAS) at UCSB.
The experiments were conducted at Santa Barbara County's Sedgwick Reserve, part of the University of California's Natural Reserve System, which is managed by UCSB.
Jim Reichman, director of NCEAS, said that the researchers found that the "native plants are actually better competitors than the invasives, but that the seed availability of natives is extremely low - probably due to grazing and drought 150 years ago."
Reichman explained that when the researchers provided seeds of native grasses, they were able to outcompete the exotic species for space and nutrients.
"This is encouraging news," Reichman explained, "because it suggests that in many places, providing seeds will be enough to reestablish native species. There may be no need to exclude the invasives first, a profoundly difficult task."
The research team also included Stan Harpole and David Tilman of the University of Minnesota.:
