Climate Change and...
Yellow-cedar research yields prototype for climate change adaptation planning
“We just followed the most likely evidence and it turns out that climate change is a central part of cedar death.”
Land Management Implications
- Models on current and future habitat suitability for yellow-cedar can help managers integrate climate adaptation strategies into their management planning.
- Extensive areas of yellow-cedar decline occur in wilderness and other conservation areas where little management is done.
- Active management in the form of planting and selective thinning is often necessary to enhance yellow-cedar’s competitive status.
- Guidance is provided for salvage logging opportunities in areas with large concentrations of dead yellow-cedars that retain valuable wood properties long after death.
The Oak and the Reed: A Fable
Oaks and reeds have very different ways of coping with strong winds and other forces, but are also both valued resources. National Forest and Grassland managers are tasked with protecting a diverse set of resources on public lands that have a wide range of responses to their environment. This task is becoming increasingly challenging as the climate brings us stronger and more variable weather patterns. Scientists at the Grassland, Shrubland and Desert Ecosystems program (GSD) of the U.S. Forest Service are working on solutions to help land managers prepare for the different ways in which climate will affect our diverse forest and grassland resources.
One way we can use science to help management, is to predict how different species will respond to climate change – which will be like oaks and which will be like reeds. This knowledge prepares us for the future. GSD scientists created a vulnerability scoring system, SAVS, so that managers can identify which species will be more resilient or bounce back and which will be more vulnerable or topple under future climate conditions. SAVS can be useful when little information is available on a species’ climate change response or a large number of species need to be prioritized. In addition, lead author Karen Bagne notes, “this tool is not just about high or low scores but is also about a process to highlight the many ways climate affects species.” These predictions can then be used to find early actions to protect a species from an impact, such as strong winds, or improve a species ability to bounce back.
There is a lot we don’t know, but sometimes just learning what we don’t know can help. Compared to the forests many of us associate with public lands, grasslands, shrublands, and deserts receive little attention despite their high value and the greater threat from fragmentation and development. GSD scientists from six western states recently produced a comprehensive review and needs assessment on climate change issues in these important ecosystems. GSD has also taken a closer look at the Southwest and reviewed the available climate change assessments across scales and topics. Not only do these syntheses identify key climate issues and robust solutions, but they also highlight areas where more research and assessment is needed. And so the work of GSD and its partners continues.
As the winds of change intensify, we need not have a landscape comprised of only reeds if we choose. Working together, scientists and managers can develop solutions to help preserve and manage all of the resources we value.
It Takes Two
Science can provide important information for making good management choices, but only if scientists know what managers need. In an effort to improve management of the Great Plains under future climate change, scientists at GSD teamed up with grassland managers. A workshop was organized with two parts: one to communicate the latest climate change science relevant to the Great Plains and two to discuss the science needs of grassland managers. Science findings were presented via a webinar and were well received by managers as well as other scientists. During workshop discussions, it was clear, however, that much of the science information needed to take the next step and translate science findings into specific management recommendations across a wide range of fields. "Don't just tell us what is going to happen. Tell us what it means" was a common plea. Recordings of the webinar talks are available online.
Together scientists and managers can find creative ways to use available tools and find solutions that will sustain or enhance our public lands. GSD collaborated with Coronado National Forest managers and the University of Arizona to select and score 30 priority management species and used the SAVS scores (see preceding story) in conjunction with species distribution data to create a picture of vulnerability across the southeastern Arizona landscape. Vulnerability scores were integrated with spatial data to expand the scale of decision-making from a single species to a landscape. Interesting results include high vulnerability for species such as the elegant trogon (Trogon elegans) and Tarahumara frog (Rana tarahumarae), and also for upland species such as Northern gray hawk (Buteo nitidus plagiata) and Gould's wild turkey (Meleagris gallopavo mexicana).
Scientists at the Grassland, Shrubland and Desert Ecosystems Science Program (GSD) of the U.S. Forest Service Rocky Mountain Research Station continue to work on solutions to help land managers prepare for the different ways in which climate will affect our diverse forest and grassland resources.
About those involved
PAUL HENNON is a research plant pathologist with a dual appointment in the Threat Characterization and Management Program, PNW Research Station and Forest Health Protection, State and Private Forestry, Alaska Region. He earned a Ph.D. from Oregon State University in 1986. His research in southeast Alaska addresses the ecology and management of diseases and tree death, the structure of hemlock-dominated forests, and all aspects of yellow-cedar and its decline.
DAVE D’AMORE is a research soil scientist with the Land and Watershed Management Program of the PNW Research Station in Juneau, Alaska. He earned an M.S. in soil science from Oregon State University in 1994 and a Ph.D. at the University of Alaska Fairbanks in 2011. His research work concentrates on the interaction of soil biogeochemical cycles and forested ecosystems in the coastal temperate rain forests of south-eastern Alaska.
Three decades ago, a handful of researchers took on a century-old mystery. Since about 1880, swaths of yellow-cedar were dying across 600 miles of North Pacific coastal rain forest for reasons entirely unknown. At first they suspected a biotic explanation for the species’ death—a fungus, perhaps, or maybe an insect pest. But, when those investigations failed to yield a culprit, they broadened the scope of their work to draw from a range of disciplines. The outcome was not only the successful identification of the cause of yellow-cedar decline, but an interdisciplinary research approach that now holds great promise for evaluating the effects of climate change.
Pacific Northwest (PNW) Research Station pathologist Paul Hennon and soil scientist Dave D’Amore were among the first to study the decline of yellow-cedar, a culturally, economically, and ecologically valuable species. Noted for its strength and resistance to rot, yellow-cedar is coveted for a variety of uses, ranging from totem poles to building materials, so its decline was a serious cause for concern. As a graduate student in the 1980s, Hennon explored biotic cause after biotic cause—including an assortment of insects, fungi, and viruses—but was unable to generate any conclusive results.
Each round of investigation generated more questions than it answered, and so the small project steadily grew into a large research program. Ecologists, soil scientists, hydrologists, ecophysiologists, dendrochronologists, climatologists, and landscape scientists all joined in the investigation. And, when they did, the cause of yellow-cedar decline slowly came into focus.
“We were led by the clues to eventually look at other possible factors, and that was a turning point,” Hennon said. “It was never one of our goals to research climate change effects on forests. We just followed the most likely evidence and it turns out that climate change is a central part of cedar death. Before we expanded into a multidisciplinary approach, we only got so far and didn’t solve it. It was only by involving a broader team that we were able to make more progress toward understanding the cause of the decline .”
Ultimately, that interdisciplinary team found that yellow-cedar loss was the result of a complex, “perfect storm” of conditions—a warming climate, reduced snowpack, poor soil drainage, and the species’ unique shallow rooting. These factors lead to fine-root freezing, which eventually kills the trees. “The amount and duration of snow is decreasing in Alaska due to warming temperatures, and cedars provide a clear example of vegetation response to climate change,” says D’Amore.
But the scientists’ identification of the cause of widespread yellow-cedar mortality wasn’t the only important outcome of their decades-long investigation, though it was the original motivation. Their long-term, multidisciplinary approach forms the basis for a new conservation and adaptive management strategy, one whose mapping overlays topography, cedar populations, soil drainage, and snow and so enables land managers to pinpoint locations where yellow-cedar habitat is expected to be suitable or, conversely, threatened in the future. The approach brings climate change predictions squarely into management scenarios and can serve as a prototype for evaluating the effects of climate change in other parts of the country.
- Influence of forest canopy and snow on microclimate in a declining yellow-cedar forest of Southeast Alaska
- Adaptation to exploit nitrate in surface soils predisposes yellowcedar to climate change-induced decline while enhancing the survival of redcedar: a new hypothesis.
- Influence of simulated snow cover on the cold tolerance and freezing injury of yellow-cedar seedlings.
For more information:
This study was first published in BioScience: http://www.treesearch.fs.fed.us/pubs/40035
It was also highlighted in the January 2013 issue of Science Findings, a publication of the PNW Research Station. The full article written by Marie Oliver is available here in three formats: