- Author: Jeannette Warnert
Reposted from UCANR News
Given California's changing climate, should Sierra Nevada residents replant pine trees after so many died during the 2010-2016 drought? The short answer is yes, says Susie Kocher, UC Cooperative Extension forestry advisor.
“We have every reason to believe that pines will continue to be an important part of mixed conifer forests in the Sierras,” Kocher said.
Kocher spoke at a meeting for UC Master Gardeners, volunteers who provide landscape advice to the public in California. Questions have been coming in to Master Gardener hotlines from mountain residents wondering what to do after unprecedented tree loses in the last few years.
Most California forests are suffering from severe overcrowding due to 100 years of aggressive fire suppression and selective harvesting of the largest and most resilient trees. They were then subjected to five years of drought.
“There were just too many stems in the ground,” Kocher said. “The drought was very warm, so trees needed more water, but got less. These were optimal conditions for bark beetles.”
Western pine beetle is a native pest that attacks larger ponderosa pine and Coulter pine trees weakened by disease, fire, injury or water stress. Bark beetles are tree species specific, so other beetles target other species of trees in California's mixed conifer forests. Typically, bark beetles bore through tree bark and create long winding tunnels in the phloem. An aggregating pheromone attracts additional bark beetles to the tree, and heavily attacked trees invariably die.
During the drought, 102 million Sierra Nevada trees died from bark beetle attack or simply lack of water; 68 million of those died in 2016 alone. But after the abundant rainfall in the 2016-17 season, the bark beetle population seems to have crashed.
Landowners with 20 acres or more may be eligible for a state cost-sharing program to remove trees, reduce the fire hazard and replant new seedlings. Landowners in mountain communities who wish to revitalize their properties can contact local UC Master Gardeners for recovery advice.
UC Master Gardeners are plant enthusiasts who have passed an intense training program presented by UC academics. They participate in continuing education annually to update and maintain their knowledge. More than 60 Master Gardeners from Mariposa, Madera and Fresno counties gathered in Oakhurst in October to learn from UC scientists how to work with mountain homeowners whose towering trees have died. Similar training sessions, all funded by a grant from UC Agriculture and Natural Resources, were held in El Dorado and Tuolumne counties in June.
“There is life after beetles,” said Jodi Axelson, UC Cooperative Extension forestry specialist at UC Berkeley.
“Eco systems are stretched, and then they come back,” she said. “You must remember the time scale of forest change is long and pines have been a major species in the Sierra Nevada for at least 28,000 years. As long as there have been pines, there have been bark beetles.”
The scientists suggest that people who own forestland take a step back and assess the landscape after their dead trees have been removed.
“We're seeing a lot of young cedar and white fir surviving the drought. Oaks seems to be doing really well,” Kocher said.
She suggests landowners thin young trees so available sun and soil moisture are focused on the healthiest trees. Water seedlings that are receiving more sun than before to reduce stress. Planting native conifers is the best option. Due to climate change, she recommends choosing trees from a slightly lower elevation to hedge against warmer temperatures in the future.
Pines are adapted to the California forest, but may need help to regenerate. When the ground is moist in the late fall or spring, plant seedlings 10 to 14 feet apart. New trees should be planted well away from homes to maintain defensible space and at least 10 feet from power lines.
“Please don't set them up for future torture,” Kocher said. “That's just sad.”
To help the new trees become established, cover the ground around the tree, but not touching the bark, with two or three inches of mulch and irrigate weekly during the dry season for the first few years.
Questions about special circumstances may be directed to local UC Master Gardeners. Find the local program here: http://mg.ucanr.edu/FindUs/
- Author: Jeannette Warnert
A half-block from the highway that brings thousands of tourists to Yosemite National Park each year, the UC Agriculture and Natural Resources (UC ANR) Master Gardeners landscaped a short and scenic hiking path that provides the perfect break on a long drive.
The quarter-mile-long Mariposa Creek Parkway runs parallel to State Route 140 (Main Street in downtown Mariposa) on Stroming Road between Eighth and Sixth streets. Along the path, the Master Gardeners created the California Native Plant Demonstration Garden, which includes dozens of beautiful, drought-tolerant plants labeled for easy identification.
The path, which follows a short stretch of Mariposa Creek, was designed to increase appreciation for native flora and encourage Californians to consider “going native” in their own landscapes, saidKris Randal, coordinator of the Master Gardener program for UC ANR Cooperative Extension in Mariposa and Merced counties. Water shortages associated with the ongoing California drought are also driving interest in landscaping with native plants.
“Many natives are drought-tolerant, adapted to local soils, and rarely need fertilizers or pesticide treatments,” Randal said. “With some care and irrigation to get them started, they create a beautiful natural setting that brings pollinators and wildlife into your backyard.”
Randal was an advocate for native plants even before joining UC ANR. As a community educator for the Resource Conservation District in Mariposa County, she coordinated the transformation of a weedy parking lot around the district's building on the Mariposa Fairgrounds into a beautiful display of plants and wildflowers that occur naturally in the surroundings.
She did the same thing in her own Mariposa yard, bringing in and nursing the plants that flourish in natural areas.
“After I planted native brush and wildflowers, it was a joy for me to watch diversity come into my yard. Plant it, and they will come,” Randal said.
Randal suggests growing California native plants, even over native plants from other parts of the world with Mediterranean climates – such as Australia, Chile and South Africa – which also are often recommended because of their low water needs.
The California natives, she said, support local wildlife and pollinators, have historical and cultural importance, and save time and expense while adding beauty and ecological health to the environment. Native plants attract native bees, butterflies and hummingbirds and provide seeds, nuts and fruits for other native birds and wildlife. Native plants promote soil health by supporting flora and fauna that flourish underground.
“There's all kinds of magic going on under the soil,” Randal said.
As a first step toward converting to native landscaping, Randal suggests finding a natural area close to home and visiting it every few weeks to see what is growing, and what is blooming. Take notes and consult a plant guide or the Internet to identify the plants.
“It sounds like a lot of work, but it's not,” Randal said. “It's fun.”
This task is particularly convenient for Mariposa County residents, where the UC ANR Master Gardeners planted a wide array of beautiful native plants in one place.
Under the auspices of UC ANR Cooperative Extension, Master Gardeners are trained by UC ANR academics in research-based and sustainable gardening and landscaping practices. They become volunteer educators for non-commercial gardeners. In Mariposa County, a significant amount of volunteer time goes into tending the native plant garden.
In early spring, one of the first deciduous shrubs to leaf-out on the pathway is California buckeye. The leathery, pear-shaped fruits contain seeds that are easily sprouted, or they can be used in dried flower arrangements.
Along the trail, visitors will find California fuchsia, known by many as a natural hummingbird feeder. Blue elderberry, columbine and manzanita also attract hummingbirds to the demonstration garden.
Randal points out soap root, which looks like a grouping of long spindly leaves growing from the ground. Native Americans used pulp from the bulb to make a soapy lather, and they used the fibrous and hairy husks of the bulb to make small brushes to whisk out acorn shell debris from grinding holes.
One of Randal's favorite natives, she said, is a low creeping sage. The fragrant plant forms a low mat as big as 10 feet across with blue-violet flowers May to June. “This is great in a pine forest where it will get afternoon shade,” Randal said.
A lovely shrub known as Ceanothus blue jeans produces profuse powder-blue clustered flowers. The tall evergreen provides a colorful show of flowers with no care or irrigation. Western redbud explodes with magenta blossoms in the spring. Native Americans used the branches for basket weaving and made a red dye from the bark. Red Twig dogwood produces beautiful white blooms in early summer, and its bright red branches are a unique display in the winter.
“Growing native plants help you appreciate your surroundings and feel more connected to the natural world,” Randal said. “It attracts more life and that's why many of us garden.”
An initiative to maintain and enhance healthy families and communities is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.