- Author: Jeannette Warnert
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.
- Author: Andy Lyons
- Author: Sean Hogan
Reposted from the IGIS blog
IGIS is pleased to announce a three-day "Dronecamp" to be held July 25-27, 2017, in Davis. This bootcamp style workshop will provide "A to Z" training in using drones for research and resource management, including photogrammetry and remote sensing, safety and regulations, mission planning, flight operations (including 1/2 day of hands-on practice), data processing, analysis, and visualization. The workshop content will help participants prepare for the FAA Part 107 Remote Pilot exam. Participants will also hear about the latest technology and trends from researchers and industry representatives.
Dronecamp builds upon a series of workshops that have been developed by IGIS and Sean Hogan starting in 2016. Through these workshops and our experiences with drone research, we've learned that the ability to use mid-range drones as scientifically robust data collection platforms requires a proficiency in a diverse set of skills and knowledge that exceeds what can be covered in a traditional workshop. Dronecamp aims to cover all the bases, helping participants make a great leap forward in their own drone programs.
Dronecamp is open to all but will have a focus on applications in agriculture and natural resources. No experience is necessary. We expect interest to exceed the number of seats, so all interested participants must fill in an application before they can register. Applications are due on April 15, 2017. For further information, please visit http://igis.ucanr.edu/dronecamp/.
- Author: Pamela Kan-Rice
As urban coyote numbers rise, the animals are increasingly crossing paths with residents. There have been police reports of coyotes attacking pets and even people, but there has been no place to report casual coyote encounters. Now there is a new mobile app to help keep track of where those wily coyotes are coming into contact with people. Hikers and people walking their dogs can use Coyote Cacher, created by the University of California Agriculture and Natural Resources, to report coyote sightings.
“I'm so excited about this app because it will help us to collect better information on coyote conflict in California,” said Niamh Quinn, UC Cooperative Extension advisor, who studies human-wildlife interactions. “Coyote conflict appears to be particularly high in Southern California and it seems to be emerging in other areas. The information people provide through Coyote Cacher will help inform government agencies, wildlife researchers, park managers and residents to make better coyote management decisions.”
By reporting encounters with coyotes in their neighborhoods, residents can share information to help neighbors keep their pets and children safe.
“There is a coyote encounter map that will allow the public to keep track of what is happening in their areas,” said Quinn, who is based in Orange County.
Individuals can use the app to check a map to see locations of coyote sightings. Pet owners may decide not to let their pets out at night unsupervised in areas where coyotes have been reported.
“The app allows users to sign up for email alerts,” Quinn said. “These alerts – green, yellow and red – notify users when there is a coyote encounter reported in their zip code.”
Green is the lowest alert level and will give alerts for all coyote encounters in the user's zip code, from sightings to a person being bitten. Yellow will not alert users about sightings, but will let them know about all levels of pet interactions, including pets being chased or attacked off-leash by coyotes, and red alerts. Red is the highest alert level and allows for users to be informed only about the more serious incidents, for example, a coyote attacking a pet on a leash or biting a person.
“This app will also allow me to gather baseline information on coyote activity and the success of community hazing,” Quinn said.
Community hazing involves people shouting and waving their arms at coyotes and generally being obnoxious to make the nuisance animals afraid of humans.
“It would be great if everyone would do this when they see a coyote, but at the moment this is not really happening,” Quinn said. “Also, coyotes in Southern California appear to take a lot of risks and come in close contact with humans so community hazing may not deter them.”
More intense hazing, like shooting them with paintball guns, might be more effective techniques for government agencies to manage urban coyotes, she said.
To find out if any of these techniques work, the UC wildlife scientist would like to put collars on urban coyotes to study whether the animals move away from locations after hazing.
“We are seeking funding to collar coyotes to find out more about their activity and social structure and how they react to different types of management,” Quinn said. “We would need to figure out if the effects of the hazing are long-lasting, or if the coyotes just revert to ‘bad behavior' when the hazing is stopped.”
Although Quinn's research is focused on California, Coyote Cacher can be used anywhere in the United States. The website also offers information about urban coyotes.
Coyote Cacher can be used on a computer or on a mobile device at http://ucanr.edu/CoyoteCacher.
The Coyote Cacher app was designed by UC ANR's Informatics and Geographic Information Systems and funded by UC Cooperative Extension in Orange County.
- Author: Lenya Quinn-Davidson
Reposted with permission from the Fire Adapted Communities Learning Network
I recently found myself venting about the idea of “nature.” The concept has always bothered me. There's an inherent separatism in it—an implicit line in the sand between humans and nature, where we can and should appreciate it, but we think we aren't really part of it.
I struggle with these ideas often in my work. I've had people question the naturalness of frequently burned landscapes if they know that humans had a role in ignitions—even if human ignitions extend thousands of years into the past. The dichotomy runs deep.
So it's always refreshing to see
scientific reinforcement of what I know in my heart to be true: people are a part of the landscape—a very powerful part.
This is the theme of a recent paper by Alan Taylor, Valerie Trouet, Carl Skinner and Scott Stephens in the Proceedings of the National Academy of Sciences (PNAS). The paper looks at California's Sierra Nevada over the last 400 years, and it finds that socioecological change—human activity—has been the primary driver of changes in the region's fire regimes, more so even than climate.
The paper, which came out late last year, incorporates a unique blend of fire history and human history. The authors were able to reconstruct a 415-year fire record for the region using a combination of tree ring studies and 20th century data on annual area burned. From there, they calculated a “fire index” for every year since 1600—basically a metric that combines fire occurrence and extent, and tells us how much fire activity was going on during that time. Those indices were used to identify large-scale shifts in regional fire regimes, which the authors compared with patterns of human settlement and management, and with climate.
The authors identified four major fire regime periods since 1600, which they were able to link to patterns of human activity. The first regime shift occurred in 1776, triggering a 90-year period of enhanced fire activity. During that period, the mean fire index was almost twice what it had been before 1775. The paper shows that this regime shift was coincident with the timing of Native American contact with Spanish missionaries in the region, which occurred in 1769. It's not exactly intuitive, but the authors explain that the decimation of Native Americans—and a subsequent reduction in light burning—allowed for an increase in fuel continuity and wildfire activity during that period. This connection is further evidenced by the increased sensitivity of fire activity to climate—a relationship that was relatively weak when Native Americans were conducting widespread burning.
The second regime shift occurred in 1866, at which point fire activity dropped back to pre-1776 levels. The authors attribute this shift to major land use changes across the region—mostly associated with intensive livestock grazing, which denuded herbaceous vegetation and had notable effects on fuel continuity and fire spread. During this period, fire activity was also less sensitive to climate than it had been during the previous period because of a lack of fuels.
The third shift is the one we're all most familiar with: the beginning of the fire suppression era in the early 1900s. During the fire suppression period, in which we're still operating today, fire activity has been 4–8 times less than in any other period in recent history. Likewise, the fire-climate relationship has been weak for most of this period; the 20th century has shown increased warming trends, yet fire activity has largely been squelched by human activity. Only in recent decades have we seen a strengthening of that relationship, as a perfect storm of high fuel accumulations, longer fire seasons and drier conditions enables fires of unprecedented severity and size, appearing to override the moderating effects of human management.
My last statement should give us pause. Are we entering an era—perhaps a new fire regime period—where changes in climate are overwhelming our human capacity to influence our landscape? The work of Westerling and others (check out my first Science Tuesday blog from last February) would indicate that we're headed in that direction.
But the really valuable thing about this new paper by Taylor et al. is that it gives us a larger context to work within. Yes, recent decades have had increased fire activity and increased sensitivity to climate—we've all seen it. But let's remember that our collective frame of reference is relatively short; for most of us, our vision of what's natural or normal in terms of fire comes from the mid to late 20thcentury—the height of our fire disconnect. This paper allows us to look back and see that the human relationship to fire is enduring and powerful, and that our biggest mistake in the last century has been to deny ourselves that intimacy—to value “nature” over nurture. History tells us that we should be able to buffer climate effects, but only if we actively engage at a grand scale. I think we're ready.
Taylor, A. H., Trouet, V., Skinner, C. N., & Stephens, S. (2016). Socioecological transitions trigger fire regime shifts and modulate fire–climate interactions in the Sierra Nevada, USA, 1600–2015 CE. Proceedings of the National Academy of Sciences, 201609775.
- Author: ESPM News
In response to California's growing tree mortality crisis, the Little Hoover Commission held a public hearing on California Forest Management yesterday (January 26) at the state capital in Sacramento.
Professor Scott Stephens, a fire scientist in the department of environmental science, policy, and management, delivered the opening remarks. He provided background on the causes and magnitude of tree losses happening across the state. "Our forests are not in a resilient condition," he said. "Past management actions, including fire suppression and logging focused on large trees have produced forests today that are much more vulnerable to fire and drought-related mortality." Stephens made suggestions for legislation, policy, and forest management techniques that could help restore resilience to California's forest ecosystems and prevent future mortality crises. He also offered ideas on how the state could better work with private landowners as well as the federal government to promote healthier forests.