UC Santa Cruz music professor David Dunn has joined forces with two forest scientists from Northern Arizona University to combat an insect infestation that is killing millions of trees throughout the West.
They are applying the results of nearly a decade of acoustic research in an unconventional collaborative effort to stop bark beetles from tunneling through the living tissue of weakened, drought-stressed pine trees.
The trio has now received a patent for a device that uses sound as a targeted sonic weapon to disrupt the feeding, communication, reproduction, and various other essential behaviors of the insects.
Dunn explained how this research came about.
“When massive tree death started occurring in Northern New Mexico where I was living, I became curious if there were sounds associated with such a large amount of biological activity,” said Dunn.
“At that time there was still the assumption that this was the result of a local bark beetle infestation due to drought conditions. Since then, we have come to realize that this was not just a local outbreak but one of many outbreaks across all of the western states and Canadian provinces that has been driven by climate change conditions. Many scientists think that we are experiencing the largest insect infestation of North America in the fossil record of the Earth,” he added.
Dunn spent a few weeks thinking about how to listen to the interior of trees and soon came up with a simple listening device that cost less than $10 to build. Designing unique and inexpensive devices in order to listen to sound had long been a part of his artistic work.
“After making hundreds of hours of recordings inside hundreds of trees, I made a large sound composition that represented the incredible diversity of sounds made by a couple of species of bark beetles and their changing responses to the life cycle of tree hosts that they invade,” said Dunn. “This was released as a CD (The Sound of Light in Trees) that garnered a lot of attention from both the sound, art, and music community, as well as various scientists involved in bio-acoustic research.”
“After that interest emerged, I was approached by my future colleagues at Northern Arizona University who not only wanted to replicate what I had done, but to collaborate on how to push this research further. These further results led to the device and protocol that we have just patented.”
Dunn noted that it is very unusual for a scientific patent to be awarded to an artist and added that there are very few examples of concrete results from collaborations between artists and scientists.
“My contribution to the project mostly concerned the technical design aspects of the audio, electronic circuit designs, and the novel sound gathering techniques,” Dunn explained. “In a very real sense, this represented a kind of reverse "tech transfer" from the arts to the sciences. Historically, it has usually been the other way around.”
“We have now entered into a period of common interests between art and science largely driven by the commonality of digital tools,” Dunn added.
“Artists are now just as involved in designing such tools as the scientific community and often create software and instrumentation in order to facilitate their creative visions that may ultimately be of even greater value to scientific research. I think that this was one of those instances and a couple of fortuitous events conspired to allow something interesting to happen.”
Dunn observed that one important aspect of art/science collaborations is the peculiar ability of artists to trust their imagination over their rational faculty.
“Most of the best scientists I know have fantastic and expansive imaginative capacities but often have to strategically mask those skills in order to operate within disciplinary and professional constraints,” said Dunn. “I personally believe that science must be a deeply rigorous enterprise, but it is not an either/or issue. It is the balance between the rational and imaginative that will ultimately solve the most serious problems that threaten us.”
“Artists can sometimes ask the pithy or embarrassing question that needs to be asked, or cuts across disciplinary constraints, or politics, without paying a professional price. As Gregory Bateson, a former faculty member of UC Santa Cruz put it: ‘rigor alone is paralytic death, imagination alone is insanity.'"
Dunn said that he and his colleagues at Northern Arizona University — Richard Hofstetter and Reagan McGuire — hope to produce a range of products as a result of their patent to combat bark beetles, as well as other insects related to them.
He added that scaling up the device to be effective in saving large forests might be possible through the use of local wireless or FM broadcast to protect select areas of forest, depending on how cheaply they can produce an effective system that can be applied to individual trees.
“One major obstacle is the issue of how to miniaturize the analog circuits and sample playback,” said Dunn. “One of my brilliant graduate students, David Kant in music, has been working on putting all of this into digital form and has largely succeeded. If we can solve that problem and come up with viable output transducers, amplification, and solar power solutions, it's very doable.”
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.”
Dead trees in the Sequoia National Forest. (Photo: U.S. Forest Service)
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.
Replanting may be a time to give native pines a chance to regain a foothold in Sierra forests.
“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.
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.
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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/.
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.
Coyote Cacher's map shows locations of coyote encounters. Green dots are the lowest level alert, yellow indicates a pet interaction and red, the most serious, warns of an attack on a pet on a leash or person.
“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.
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
Credit: Lenya Quinn-Davidson, Fire Adapted Communities Learning Network
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.
Credit: Lenya Quinn-Davidson, Fire Adapted Communities Learning Network. Hayfork, where Lenya grew up, has been an epicenter of fire activity in recent decades. It's also been the focus of fire history studies by Alan Taylor and Carl Skinner, who co-authored this new paper.
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.
Figure 2 from Taylor et al., 2016: “Regime shifts in time series (1600-2015 CE) of Sierra Nevada fire index, summer moisture (i.e., PDSI), and summer temperature (i.e., WANT). A switch to new regime (fire or climate) is shown by a vertical line … The number of tree-ring sites recording fires in each year for the 1600-1907 CE period shown by a dashed line. The fire regime periods are indicated by color shading: 1600-1775 CE (green), 1776-1865 CE (orange), 1866-1903 CE (blue), and 1904 CE to present (pink).”
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.