BERKELEY, Calif., Jan. 15 (UPI) -- U.S. researchers say fencing blue oak seedlings can prevent them from succumbing to grazing by deer and livestock while limiting rodent damage.
In an eight-year study, University of California-Berkeley researchers found blue oak seedlings surrounded by 2-foot or 4-foot "exclosures" had significantly higher growth rates than unprotected seedlings.
The researchers say they believe larger exclosures are less effective. While they exclude grazing animals, they also encourage dense groundcover that serves as habitat for small rodents. The rodents eat the seedling's bark and kill or severely stunt their growth.
"We did not observe any rodent girdling of seedlings in the study of 2-foot and 4-foot exclosures, apparently because there was not sufficient groundcover in the smaller exclosures for good rodent habitat," lead author Ralph Phillips said.
There are about 10 million acres of oak woodlands in California.
The study appears in the January-March issue of the journal California Agriculture.
