Posts Tagged: oaks
Even though California's majestic oak trees are generally considered drought tolerant, the last four years of well-below-average rainfall are taking a toll, reported the Sierra Sun Times.
"In some parts of the state, oaks are being deprived of water for as long as nine months, creating extreme water stress," said Greg Giusti, a forest and wildlands advisor for UC Agriculture and Natural Resources. Giusti is headquartered in the UC ANR Cooperative Extension office in Mendocino County.
Giusti and Kris Randal, the UC Master Gardener coordinator for Mariposa County, suggest that California residents with oaks on their property give the trees a good soaking once a month during the summer.
The water should be applied around the drip line - the area below the outstretched branches - but not near the trunk. A permeable soaker hose is an ideal tool for slow application over the wide area. Allow the water to run until it has soaked down to a depth of 12 to 18 inches, which can be detected with a long probe such as a screwdriver. "If it comes up with signs of moisture at the tip, you're good," the article says.
Randal said it is important to let the soil dry out completely between waterings, because oaks are susceptible to root fungus that can grow in warm, damp soil.
Even if water is unavailable and the leaves begin to turn brown or fall, the experts suggest waiting for spring before considering removing the tree.
"If you tree leafs out, it's still alive," Randall said. "And in this drought, give it extra time to leaf out."
The goldspotted oak borer continues to threaten oak trees, Tom Scott, area natural resource specialist located at UC Riverside, told participants at conference on sustaining native oak woodlands in Los Angeles, the Monrovia Patch reported.
Scott said there is still a quarantine on moving firewood out of San Diego County to prevent the spread of the damaging insect.
Reporter Sandy Gillis wrote that Larry Costello, UC Cooperative Extension environmental horticulture advisor emeritus, described the power of oaks to access water deep in the soil.
UC adds 4,584 acres of forest to its research lands
The Los Angeles Times and San Francisco Chronicle reported on UC's acquisition of 4,584 acres of Northern California mixed-conifer forest as part of a PG&E bankruptcy settlement.
Debra Levi Holtz, who wrote the article for the Chronicle, quoted Keith Gilless, dean of the UC Berkeley College of Natural Resources, which houses the UC Center for Forestry, as saying, "For us, this is a dream come true to have a network of research sites on a north-south transection through the Sierra Nevada and Cascade ranges that will dramatically improve our capacity to do work on forest ecosystems that is responsive to the questions we all have about the impacts of climate change on those regions."
The cover story in the Feb. 4 edition of the color magazine New Times is a well-written 2,300-word history of Avenales Ranch, east of San Luis Obispo, which has been the site of UC collaborative research for decades.
The story centered on 92-year-old family patriarch Jim Sinton, who inherited the 12,000-acre ranch from his grandfather. The owner of a local general store, Sinton's grandfather provided goods on credit to homesteaders who held the property in the late 1800s. As they went broke, he acquired the land and assembled the vast acreage where today cattle run, majestic oaks dot the landscape and a hunting club helps generate income.
Sinton, a UC Berkeley agricultural economics alum, helped design and execute an experiment in the early ’60s to test the validity of ranchers’ then-accepted belief that acorns were harmful for cattle to eat. According to the story, he concluded that the presence of oak trees on a grazing range is beneficial.
Writer Kathy Johnston spoke to San Luis Obispo County-based UC Cooperative Extension natural resouces specialist Bill Tietje, who said the ranch is “one of the hotspots in the county” for mountain lions and bears. He told the reporter that 100 species of birds, a dozen types of small mammals, plus bobcats, gray foxes, and a variety of reptiles and amphibians can be found on the ranch. The mix of wooded areas, chaparral and grassland the Sintons have maintained supports the wildlife, he said.
The article mentioned that the Sinton family occasionally opens the Avenales Ranch to the public by hosting UC Cooperative Extension workshops on oak regeneration.
The first indicator cited in a San Jose Mercury-News story about the 2008 drought is the number of phone calls coming into the local UC Cooperative Extension office.
The second paragraph of the article says the "unusual number of calls" are from people asking why their camphor trees and liquid ambars are wilting.
"This year we've had so little rain that for trees that are not adapted — and even those that are — there is simply no moisture in the ground except for (what) we are applying," the Mercury-News quoted Bethallyn Black, UCCE urban horticulture advisor in Contra Costa County.
She said some areas have even less water in the ground because the water table has fallen below the reach of trees whose roots have not adapted to a Mediterranean climate, according to the article.
The Mercury-News article, written by Rowena Coetsee, runs parallel to a press release distributed by the UCCE News and Information Outreach office last week that noted native blue oak trees in foothill areas are losing their leaves and turning color way before normal.
According to UCCE oak specialist Douglas McCreary, the ability to shed foliage early is a survival mechanism of the native trees. When faced with low soil moisture, the trees can either keep their foliage and continue losing water through leaf pores, or drop their leaves and conserve moisture. In the long term, shedding leaves keeps the trees from drying out completely and dying.
Native blue oak trees.
UC Berkeley Cooperative Extension natural resources specialist Doug McCreary knew it was a matter of life or death . . . . This spring, landowners were wondering whether they should yank out oak trees that were uncharacteristically brown or bare.
McCreary took quick action to save trees' lives. He gathered information for a news release assuring people the die-back was probably not a sign of Sudden Oak Death and urging them to wait at least a year before pulling out trees. The story was picked up by the Associated Press and run in several Northern California newspapers, including the San Francisco Chronicle and San Jose Mercury News.
The AP article included McCreary's points that many oaks in the Sierra foothills and along the North Coast have been left leafless this spring because of a cold snap, not disease. Most trees should recover.
Meg McConahey of the Santa Rosa Press Democrat called McCreary to localize the story. Her article said landowners and forest stewards on the North Coast are particularly sensitive to oak health because of the devastating spread of SOD. "Sonoma is by far the hardest hit of 14 counties now under state quarantine in California," the article said.
Oak tree damaged by spring frost.