Posts Tagged: Susie Kocher
This winter, a generous amount of rain and snow has fallen on California, but it can't erase the brown swaths of dead and dying trees in the Sierra Nevada caused by five years of drought and decades of forest mismanagement.
Fire suppression and the harvest of the largest and most resilient trees in the forest led to a large population of weak trees. The prolonged drought further weakened the trees' defenses against native insects. Aerial detection surveys show that more than 102 million trees have died since 2010; more than 62 million died in 2016 alone. Public and private landowners are now struggling to recover from this natural disaster.
UC Cooperative Extension forester and natural resources advisor Susie Kocher recommends dead trees be removed and the landscape reevaluated.
“The dead trees will eventually fall,” Kocher said. “Removing trees around homes and other buildings is especially important for safety. Also, when they fall on the ground they become large fuels on the forest floor, leading to more intense fires.”
The cost of removing the trees can be substantial. The State of California is funneling disaster relief funds through California counties, utilities are felling trees that pose a threat to power lines, and local jurisdictions are removing trees that could fall on roads and other public infrastructure. However, most tree removal is the responsibility of private landowners.
When the dead trees are gone, before considering replanting, Kocher suggests Sierra residents carefully assess what has survived.
“There is often a lot of live vegetation remaining,” Kocher said. “Make a map and mark where you find living trees and shrubs and identify them by species and size. If you have a significant number of trees left, you may not need to replant.”
Kocher suggests nurturing the remaining young trees.
“You may want to thin trees out so that available sun and soil moisture are focused on the healthiest individuals. Some watering in the summer may help counter stress caused by increased solar radiation,” she said.
If removing the dead trees leaves the landscape too bare, replanting native conifers is a good strategy. Conifers include pine, cedar and fir trees, but in California's dense forests, firs and cedars – which do well in shady conditions – are beginning to dominate. Replanting may be a time to give native pines – such as Jeffrey, ponderosa and sugar pines – a chance to recover ground.
“The fact that many pines have died does not necessarily mean they are no longer adapted to your location, even with our warming climate,” Kocher said. “There may be a few locations that are less suitable for trees that have grown there in the past, but for most areas, local growing conditions should support native conifers in the near future.”
Native plants and shrubs that died during the drought or were damaged during tree removal will likely come back on their own without replanting. Shrubs and oaks can re-sprout and native herbaceous plants generally store seed in the soil that will grow under native rainfall conditions.
Replanting of trees also gives landowners the chance to shape the landscape for best effect. Kocher offers the following recommendations on replanting trees in natural landscapes:
- Space trees at least 10 feet apart.
- Trees and flammable vegetation should be kept at least 10 feet away from the home, planted sparsely within 30 feet of the home and spaced widely enough in the 30 to 100-food zone so the crowns of the trees will not touch when they are mature. Beyond 100 feet, trees can fill into a more natural looking forest.
- Plant trees at least 10 feet from power lines.
- Do not plant trees within the road right of way to prevent interference with snow clearance, maintenance and construction projects.
- Plant pines where there is a lot of sun. Do not plant sugar pine on the driest sites.
- Avoid planting where the mature trees will block desired views.
Since 2006, a team of University of California Agriculture and Natural Resources scientists has been studying the effects of vegetation management in the Sierra Nevada forest on fire behavior, forest health, water quality and quantity, the Pacific fisher (a small mammal in the weasel family) and the California spotted owl. The researchers are writing up their final reports and seeking public feedback on their recommendations and next steps in the process.
On Wednesday, May 27, community members are invited to discuss the recommendations with the Sierra Nevada Adaptive Management Project (SNAMP) team at an all-day meeting in the Sacramento area.
“Although adaptive management as a theory of practice in resource management has been in the literature for decades, few studies have been done to truly apply theory to actual practice,” said Susie Kocher, a UC ANR Cooperative Extension forestry and natural resources advisor for the Central Sierra area.
The US Forest Service's 2004 Sierra Nevada Forest Plan Amendment calls for managing the 11 national forests in the Sierra Nevada using the best information available to protect forests and homes. SNAMP is designed to provide resource managers with research-based information for making forest management decisions.
The SNAMP meeting will be held 9 a.m. to 4 p.m. on May 27 at the Wildland Fire Training Center, 3237 Peacekeeper Way in McClellan (near McClellan Airfield outside Sacramento).
To attend, please register at http://ucanr.edu/snamp2015annualmeeting by Sunday, May 24. Registration is free.
For more information about the project, visit http://snamp.cnr.berkeley.edu. The final SNAMP report will be available for download at http://snamp.cnr.berkeley.edu/snamp-final-report. Comments will be accepted online at http://ucanr.edu/snampreportcomments until July 15.
“It is a classic disconnect,” said Susie Kocher, UC Cooperative Extension advisor in the Central Sierra office. “That's why Cooperative Extension was formed almost 100 years ago. Policymakers could see that research advances weren't being implemented on farms. The same thing has happened in natural resource management.”
For example, Kocher said, scientists have known since the 1960s that systematic fire suppression has many negative consequences, but it took a very long time to get that message into practice by agencies charged with managing wildfire.
“After the Great Burn of 1910, which killed 87 people, there was a public clamor to attack fire and treat it as an enemy,” Kocher said. “We've come a long way since then. Now land managers have a good understanding of how important it is to have low-intensity fire in Sierra forests.”
Fire agencies are now beginning to understand that they must pay attention to technology transfer. Kocher believes UC Cooperative Extension is a logical player in the process.
“Cooperative Extension is the exemplar,” Kocher said. “We try to get new and evolving understanding into the hands of people who use the information to made decisions – not just land managers, but the public and policy makers as well.”
Beginning in 2009, the federal Joint Fire Science Program created 15 regional fire science exchanges to accelerate awareness, understanding and use of wildland fire science. Scott Stephens, professor in the Department of Environmental Science, Policy and Management at UC Berkeley, leads the California consortium. Stacey S. Frederick serves as the consortium's full-time coordinator. Other UC academics involved are Kocher and Yana Valachovic, UCCE advisor in Humbolt and Del Norte counties.
Since its inception four years ago, the consortium has hosted webinars, conferences and symposia, and offered field consultations, field trips, tours, demonstrations and expertise. Another significant role of the group has been distilling academic fire science research reports into easy-to-read one-to two-page research briefs. To date, well over 100 briefs have been written by the consortium on a wide range of topics.
The California Fire Science Consortium maintains a comprehensive website that contains links to the research briefs, webinar recordings and information about upcoming events. The consortium also offers a twitter feed @cafirescience and Facebook page https://www.facebook.com/CaliforniaFireScienceConsortium and you can sign up for their monthly newsletter here.
Every year, the day after Thanksgiving, Susie Kocher bundles up her children, gathers the extended family and hikes into the Lake Tahoe Basin forest to find a Christmas tree.
“It’s my favorite part of the season,” Kocher said. “Having the fresh, living thing in the house really symbolizes the holiday. You can’t do it with a fake tree.”
Kocher, a forester and the natural resources advisor for UC Cooperative Extension in the Central Sierra, lives and works in Lake Tahoe. The Lake Tahoe Basin Management District is one of nine national forests in California, all of them in the northern part of the state, where the U.S. Forest Service allows Christmas tree cutting with a $10 permit.
Though some people mourn the death of any tree, Kocher says careful selection and removal of Christmas trees is an enchanting family tradition that enriches forest health.
“We have a lot of small trees on public lands because of fire suppression,” Kocher said. “They’re all competing with one another and many will ultimately die. A smart harvest of Christmas trees can improve the forest by helping with thinning.”
People with permits to cut down Christmas trees in national forests must follow strict guidelines. The trees must be within 10 feet of another living tree, the base of the trunk cannot be more than six inches wide and it must be cut within six inches of the ground. Some national forests limit the harvest to certain tree species.
Despite committing to these guidelines when obtaining a permit, Kocher said she has seen some Christmas tree harvesters make ill-advised choices.
“Some are too lazy to find a good tree and will cut the top off a large tree,” Kocher said. “You can be driving around and see what looks like a poor old Dr. Suess tree, which is what grows from the ugly remnant left behind in the forest.”
Such irresponsible Christmas tree cutting has led some forests to discontinue Christmas tree harvesting for personal use.
Kelly Hooten, information specialist with the Sierra National Forest, said the organization stopped issuing Christmas tree cutting permits because people would tend to cut down only healthy, strong trees.
“It’s really the sickly, Charlie Brown trees that we would prefer to thin in our forest,” Hooten said.
The El Dorado National Forest does not allow Christmas tree cutting because there are more than 30 Christmas tree farms in the vicinity where visitors can choose and cut down their own trees.
“Allowing Christmas tree cutting in forests would hurt these farmers economically,” said Lynn Wunderlich, UCCE advisor in the Central Sierra office. Many Christmas tree farmers also provide food, crafts, activities and visits with Santa.
“Families can visit the farmer year after year as their children grow, so that’s part of the experience,” Wunderlich said.
There has been ongoing debate about whether a fake tree or real tree is more environmentally friendly, but for Kocher, there is no question.
“Fresh real trees are a renewable resource, fake trees are not,” she said. “It’s an agricultural product. You can contribute to a local farmers’ income or you can help thin the forest. Picking and bringing home a fresh tree, decorating it and smelling it defines the season for me. Without it, I don’t think it would feel like Christmas.”
“The fire interval is completely out of whack compared to pre-settlement conditions,” Kocher said.
In a historical, natural and healthy fire regime, nearly half of Sierra forests would experience fire every 12 years and three-quarters would burn every 20 years. However, only 0.2 percent of Sierra forest land has burned repeatedly at least every 20 years in modern times, while 74 percent has not had a single wildfire or prescribed burn in the last 103 years.
These conclusions are part of a report Kocher produced for the Sierra Nevada Conservancy, a state agency created by the California legislature in 2004 with the understanding that the environmental, economic and social well-being of the Sierra Nevada and local communities would benefit from an organization providing strategic direction.
SNC commissioned reports about Sierra Nevada indicators, such as Demographics and the Economy, Land Conserved and Habitat, and Water and Air Quality and Climate. Kocher’s report is titled Forest Health and Carbon Storage. Future system indicator reports will cover Fire Threat and Agricultural Lands and Ranches.
Forest health is a particularly difficult indicator to frame and quantify as there is no consensus on exactly what defines forest health, Kocher writes in the introduction.
“Forest health is a concept that is commonly used but not well defined,” Kocher said. “You’d think you’d be able to answer how healthy a forest is in a straight forward way. But you have to look at stressors, the natural processes that are happening in a forest. What does the landscape look like?”
Because forest health cannot be characterized by any single, simple measure, Kocher selected three data sets to provide an indication of the health of forests in the region: fire return interval, wildfire threat to ecosystems and forest pest impact and threat. She found that fire return interval told the most provocative story.
Fire return interval tracks the frequency with which wildfire revisits the same land over and over. Kocher compared the frequency of fire return between the pre-settlement “natural” state and modern times.
The pre-settlement or “reference” fire return interval is an estimate of how often, on average, a given forest type likely burned in the three or four centuries prior to Euro-American settlement in the middle of the 19th century. As such, the reference state includes fires deliberately set by Native Americans to manage forest vegetation and wildlife.
Researchers determined fire frequency by analyzing fire scars in tree rings of live and dead trees. Results show that forested areas previously burned every 11 years on average in the warmer and drier lower elevation forests such as ponderosa pine. On the other end of the spectrum, fire occurred only every 133 years for sub-alpine forests where it takes much longer for fuels to accumulate and dry.
Fire suppression in the last 100 years has left much of the Sierra forest land vulnerable to high severity wildfire, Kocher wrote in her report. High severity wildfire across wide areas poses a threat to forest plant and animal life, to forest communities and watershed function, particularly in the northern half of the Sierra Nevada Conservancy Region.
Kocher’s report also reviewed carbon storage in Sierra Nevada forests. Since carbon in the atmosphere is leading to global climate change, there is increased interest in storing carbon in forests.
“It could be said that by suppressing fire, we have sequestered more carbon,” Kocher said. “In an overstocked forest, there are more standing trees and more fuel on the ground. Storing more carbon may help in the short run, but in the long term, your stand has a higher risk of burning up. That puts a lot of carbon into the atmosphere.”
Forest thinning improves the stability of carbon storage in the long-term. Whether it reduces the amount of carbon stored depends on what factors are taken into consideration, Kocher suggests. Part of the complexity of the equation stems from whether or not forest products removed from the forest are factored in. Most studies that account for the carbon sequestered by lumber and other products removed during thinning find that thinning both increases the quantity and stability of carbon sequestered by forests over time.