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Pacific Northwest Research Station

Science Findings

PNW Science Findings communicates science to people who make and influence decisions about managing land in the Pacific Northwest. This signature product from the Pacific Northwest Research Station was initiated in 1998 and is published 9 to 12 times per year.

Science Delivery - Science Findings

Volunteers plant a tree in Portland, Oregon. In an urban setting, trees can improve the aesthetics of a neighborhood; they are also associated with improving the public health outcomes of residents. Photo courtesy of Friends of Trees.
Exposure to urban trees is associated with improved public health outcomes, including healthier infant birth weights, fewer symptoms of attention-deficit hyperactivity disorder, and decreased cardiovascular mortality. Conversely, tree loss is linked to increased rates of cardiovascular disease and higher mortality. Could this mean that trees save lives?…
Standing dead Douglas-fire trees.
Defoliating insects inflict costly damage to forests, sometimes at landscape scales. Outbreaks of the native Douglas-fir tussock moth (Orgyia pseudotsugata) occur every 5 to 10 years in the western United States and southern British Columbia. The larvae feed on the needles of Douglas-fir, grand fir, or white fir trees. If the defoliation becomes severe…
Four people holding nets and other electrofishing equipment walk in a stream.
The fisheries and aquatic sciences confront complex challenges in the overexploitation and degradation of aquatic-riparian ecosystems world-wide. Although the field comprises diverse natural resources available to diverse groups, changing the human face of its workforce so that it closely reflects everyone who depends on those resources has been slow.…
Two people hike across high-elevation meadow.
Invasive annual grasses have long been known to increase wildfire danger in shrublands and woodlands of the American West. Ventenata (Ventenata dubia) is one such grass. First reported in North America in 1952 in Washington state, it is now expanding into previously invasion- resistant forest landscapes. Unlike cheatgrass, another invasive grass, ventenata…
Group of workers wearing chest waders install a beaver dam analog in Bridge Creek, Oregon.
Recruiting beavers—or building structures that mimic beaver dams—is an increasingly popular method for restoring streams and floodplains in the American West. Doing so can boost the growth of vegetation for cattle forage and improve habitat for fish and wildlife.But with a nature-based solution for stream restoration, anything can happen.Gordon Grant and…
New housing development near Corvallis, Oregon. As urban and suburban areas expand, forest and agricultural land is often developed for housing. Both Oregon and Washington passed land-use legislation that attempts to restrict such development. USDA Forest Service photo by Jeff Kline.
Anecdotal evidence and some previous studies suggest that as development approaches private forest land, there’s a decline in commercial timber management of those forests. At the request of Gary Lettman, then a principal forest economist with the Oregon Department of Forestry, Jeff Kline and Andrew Gray, researchers with the USDA Forest Service…
Scenic image of small tree-covered islands in Thorne Bay, Alaska.
The coastal zone of southeast Alaska contains thousands of rivers that drain into the Gulf of Alaska. This is the wettest and most topographically varied region in North America. The deluge of freshwater plays a critical role in supporting the Gulf of Alaska’s terrestrial and aquatic ecosystems as well as regional economies. However, the amount, timing,…
Worker wearing hardhat cuts wood with portable sawmill.
The USDA Forest Service has long worked with international partners. In that tradition, the Forest Service and Mpingo Conservation & Development Initiative (MCDI) launched a partnership to support community forestry in Tanzania. Starting in 2017, Susan Charnley and Greg Frey, researchers with the Forest Service’s Pacific Northwest Research Station and…
Orthotrichum lyellii.
Concerned about air quality in southcentral Seattle’s Duwamish Valley, community leaders collaborated with USDA Forest Service Pacific Northwest (PNW) Research Station to implement a study similar to one in Portland, Oregon, in 2015 that found that urban tree moss indicated the presence of airborne toxic metals.Together, PNW Research Station scientists and…
Measuring discharge. Photo by USFS.
When the fall rains begin, the water volume in coastal streams in the Pacific Northwest increases, allowing coho salmon (Oncorhynchus kisutch) to move upstream and spawn. The common wisdom for many years has been that this increase in stream discharge is the main trigger that signals it’s time for coho to begin their migration, build their redds (nests),…
FIA crews at work.
The USDA Forest Service uses many forms of technology to manage 193 million acres that comprise the National Forest System: handheld data-entry devices and satellites; modeling software and LiDAR (light detection and ranging) remote sensing; and desktop computers and servers. Collectively, these technologies power the models that create the maps land…
Klawock Totum park. Photo by Ali Freibott, USFS.
Large western redcedar (Thuja plicata) and yellow-cedar (Callitropsis nootkatensis) trees have been prominent in many Tlingit, Haida, and Tsimshian Alaska Native traditions for 5,000 years. Today, these southeast Alaska tribes harvest logs from their historical territories within the Tongass National Forest. Cedars that are more than 450 years old provide logs for totem poles and canoes as well…
Streams, Chugach AK.
The Earth’s climate is warming most rapidly in the high latitudes of the polar and subpolar regions. Winter temperatures, in particular, are increasing.This trend is being observed in Alaska’s Copper River Delta, where scientists Steve Wondzell, Gordon Reeves, and Luca Adelfio conducted a multiyear study on the effects of changing stream temperatures on…
Mount Hood National Forest.
In the United States, the forest products industry loses an estimated $500 million to $1 billion annually to illegal logging. Once illegally harvested wood is removed from the forest, it’s difficult for USDA Forest Service law enforcement to prove beyond a reasonable doubt that the wood was illegally harvested. The use of DNA is a recent development that…
A playground in Portland, Oregon. Novel research by USDA Forest Service scientists and researchers in New Zealand found a correlation between greater exposure to plant diversity and reduced risk of childhood asthma and acute lymphoblastic leukemia. USDA Forest Service photo.
Mammals, including humans, have evolved in concert with the world of microbes. From birth to childhood and throughout adult life, the human immune system is shaped by exposure to microbes. Global loss of biodiversity is a pressing ecological concern, and scientists have begun to study whether reduced contact with the natural world adversely affects the…
Brooke Penaluna, a research fisheries biologist with the Pacific Northwest Research Station, collects a water sample from Oak Creek in western Oregon. Environmental DNA is extracted from samples and analyzed in a lab to determine the species that live in and around the stream. Photo courtesy of Ivan Arismendi.
Streams and rivers are a rich repository of minute traces of genetic material from all organisms that live in or near the water, from the tiniest microbes to fish, mammals, and trees. This environmental DNA (eDNA) can tell a detailed story about the life within and around the waterbody.Brooke Penaluna and Richard Cronn, scientists with USDA Forest Service…
A small portion of the Mendocino National Forest, California, that burned during the 2018 Mendocino Complex. Photo by Morris Johnson, USDA Forest Service.
Every summer, wildfires burn thousands of acres of forests in the American West. After the fire, forest managers must decide what to do next: Leave the postfire landscape to recover naturally? Harvest some of the burned trees for timber? What combination of management actions is most likely to reduce the severity of a repeat wildfire and to make the…
Researcher Dan Mikowski uses a laser range finder to determine specific distance between traps for red turpentine beetles at a wildfire site in central Oregon. USDA Forest Service photo by Rick Kelsey.
The red turpentine beetle (Dendroctonus valens) is native to North America and attacks stressed, dying, or recently dead pine trees, especially fire-injured ponderosa pine. State and federal agencies use baited traps to detect, monitor, and manage populations of native and nonnative insect species. Trapping efforts are labor intensive, and the lures…
Northern spotted owl habitat in an Oregon coastal forest. Photo by David Patte, U.S. Fish and Wildlife Service.
Northern spotted owl (Strix occidentalis caurina), a species listed under the Endangered Species Act, have been monitored for nearly three decades using callback surveys and mark-and-recapture methods. Callback surveys can result in negative effects on the owl yet are widely used on federal, state, and private forest land prior to activities that range…
Drained reservoir with mountains in the background.
Dams and the reservoirs they create are notorious for disrupting the migration of salmon, both when they travel downstream as juveniles and when they return to spawn years later as adults.In an effort to improve downstream salmon migration, the U.S. Army Corps of Engineers in 2011 began yearly, short-term draining of Fall Creek Reservoir located on a…
Grass burning beneath a canopy of trees.
In 1994, an executive order on environmental justice directed federal agencies to identify and address any disproportionately high adverse effects their actions and policies may have on the health and environment of minority and low-income populations.Until recently, a suitable procedure did not exist for assessing natural resource management activities…
Two recreational vehicles in the forest with two cars in the foreground.
Homelessness is often associated with urban areas, yet since the Great Depression, national forests have served as a refuge for individuals and families. In recent years, more people are living on the national forests and grasslands, whether by choice or because of economic circumstances. Unfortunately, the presence of nonrecreational campers affects the…
Pile of logs on the bank of a river.
Salmon and steelhead habitat restoration projects in the Pacific Northwest have frequently relied on the use of engineered logjams—logs that are cabled together and placed in rivers to create pools where young salmon can live and grow in their first year before migrating to the ocean. Monitoring programs that rely on fish counts have shown that these human…
Salmon swimming underwater.
Adult salmon sense when the time is right to leave the ocean and head for fresh water to spawn. But how do they know this? And how will climate change affect this cycle? Rebecca Flitcroft, a research fish biologist with the USDA Forest Service, Pacific Northwest Research Station, and colleagues took a closer look at the connection between migration…
Aerial view of dense tree canopy.
Brown root rot (caused by Phellinus noxius) and myrtle rust (caused by Austropuccinia psidii) are natural disturbances in their native tropical and subtropical forest ecosystems. A tree infected with either fungal pathogen becomes unhealthy and likely dies, sometimes within 3 months. These pathogens are threatening forest ecosystems around the world as…
Line of people hiking on a trail.
More people visit public lands for recreation than for any other reason, which makes providing opportunities for sustainable recreation a key service that national forests can provide. Recreation managers, however, frequently lack basic information on the amount and extent of recreation use. Traditional approaches that rely on visitor traffic counts and in…
Group of people wearing hardhats standing in the forest.
Across the American West, forests have diverse owners and are managed for different goals. But when wildfire ignites on one parcel—whether managed by the USDA Forest Service, a corporation, a tribe, or a family forest land owner—all neighbors are at risk. Fire doesn’t respect property boundaries.For the past decade, the Forest Service has been promoting an…
Rows of planted trees in a field.
The 741 million acres of forestland in the United States play a role in mitigating the effects of climate change by sequestering nearly 16 percent of the atmospheric carbon dioxide emissions produced annually in our country. Reducing the conversion of forestland to other uses and planting even more trees, whether through afforestation or reforestation…
A sign stating "Douglas Fir Heredity Study" with a trees in the background.
One of the first forest genetics studies in the United States launched in 1912 in the Pacific Northwest. Researchers at that time gathered Douglas-fir seeds from various locations in Oregon and Washington, raised the seedlings in a nursery, then transplanted them to places other than where the seeds originated.The results had wide-ranging impact, revealing…
Salmon swimming underwater.
Forests provide a suite of goods and services that are vital to human health and livelihoods. Studies of ecosystem services, which frequently attempt to place a monetary value on forest processes and organisms, can help inform management decisions by providing a baseline for discussing the costs and benefits of different management options.A recent study…
Forest of tree trunks.
Wildfires were a frequent source of disturbance in forests of the Western United States prior to Euro-American settlement. Following a series of catastrophic wildfires in the Northern Rockies in 1910, the U.S. Forest Service adopted a broad wildfire suppression policy that has resulted in forests thick with small trees. These crowded trees compete for…
Photo of a stream flowing into the ocean.
Municipal water managers need to know if water will be reliably available from watersheds. Civil engineers need to calculate stream discharge to construct bridges to withstand 100-year floods. A hypothesis proposed in 1997 by Gordon Grant, a research hydrologist with the USDA Forest Service Pacific Northwest Research Station, underlies a method for getting…
Herd of elk with forest in the background.
Elk are an iconic species in the Pacific Northwest. The animals are valued as a cultural resource by American Indian tribes, and elk viewing and hunting bring economic and social benefits to many rural communities. Elk forage on grasses, shrubs, and other early-seral vegetation. As timber harvests have declined on federal land in the region over the past…
Aerial view of forests in Alaska.
In interior Alaska’s 115 million acres of boreal forest, white and black spruce are the dominant tree species. Climate models suggest that the region is becoming warmer and drier, resulting in declining growth of black and white spruce, according to some researchers. These drier conditions also may lead to greater risk of stand-replacing wildfires,…
River with a beaver dam in the center constructed with sticks.
Beavers have become a source of inspiration for public and private land managers over the past decade. Beaver dams can help control flooding, raise groundwater levels, and improve surface water flows. Some land managers are now designing stream restoration projects that mimic the way beaver dams shape river ecosystems. Beaver-related restoration may even…
A river and the surrounding banks.
Climate change poses a clear danger to salmon and steelhead in the Columbia River basin. Rising water temperatures increasingly limit their ability to migrate, spawn, and successfully produce the next generation of fish.Steve Wondzell, a research ecologist with the USDA Forest Service’s Pacific Northwest Research Station, conducted a study on the upper…
Line of firefighters walking down a hill towards a plume of smoke.
Accurate predictions of how weather may affect a wildfire’s behavior are needed to protect crews on the line and efficiently allocate firefighting resources. Since 1988, fire meteorologists have used a tool called the Haines Index to predict days when the weather will exacerbate a wildfire. Although the Haines Index is widely believed to have value, it…
Wildland firefighter stands next to burning grass with trees in the background.
After a more than a century of fighting to keep fire out of forests, reintroducing it is now an important management goal. Yet changes over the past century have left prescribed burning with a big job to do. Development, wildfire suppression, rising global temperatures, extended droughts, exotic species invasions, and longer fire seasons add complexity to…
Dense forest with vegetation in the foreground.
Forests are considered a natural solution for mitigating climate change because they absorb and store atmospheric carbon. With Alaska boasting 129 million acres of forest, this state can play a crucial role as a carbon sink for the United States. Until recently, the volume of carbon stored in Alaska’s forests was unknown, as was their future carbon…
Small fish swimming underwater.
For decades, federal, state, and nonprofit organizations have been working to restore freshwater habitat for Oregon coastal coho salmon (Oncorhynchus kisutch), a species listed as threatened under the federal Endangered Species Act. Much of the restoration, however, has been done without directly considering the availability and connectivity of seasonally…
Lizard standing on a rock.
Resource managers are under increasing pressure to prioritize conservation efforts by assessing climate risk for numerous species. Amphibians, fish, and reptiles are particularly vulnerable to habitat alteration and climate change, yet many species fly under the conservation radar due to lack of basic information.Dede Olson, a research ecologist with the…
Expansive plains with mountains in the background.
Since the 1930s, the United States Forest Service Forest Inventory and Analysis (FIA) program has inventoried the nation’s forests to produce “The Nation’s Forest Census.” This census provides valuable snapshots of forests in the lower 48 states, Hawaii, southeast Alaska, and the U.S.-affiliated Pacific Islands. Although select areas of interior…
Tidal flats with forest and mountains in the background.
The shoreline in southeast Alaska is changing. In many places, the shoreline is rising as glaciers melt and the land rebounds; elsewhere, rising sea levels are submerging the current shoreline. These changes are altering coastal habitats and subsistence resources on which many rural Alaska Native communities rely in southeast Alaska.Forest Service…
Field of plants with yellow flowers.
In the Pacific Northwest, clearcutting is the preferred method for harvesting wood products from Douglas-fir plantations because it’s economical and mimics a large-scale disturbance. Following a clearcut, Douglas-fir seedlings are planted throughout the recovering native plant community. Yet the newly planted seedlings and native plants aren’t the only…
Elk standing next to trees wearing collar.
Recreating on public land is increasingly popular in the Pacific Northwest. Recreation management requires balancing opportunities for people to enjoy the outdoors with mitigating the effects on wildlife and other natural resources. Recreation and wildlife managers grappling with these issues asked Forest Service scientists to quantify the impacts of…
Reservoir of water with mountains in the background.
The Mount St. Helens eruption on May 18, 1980, fundamentally transformed the surrounding landscape. The eruption triggered geophysical processes that are still unfolding. A debris avalanche caused by the eruption, for example, blocked the outlet from Spirit Lake. To prevent the rising lake level from breaching the blockage and potentially flooding…
Person wearing hardhat in the forest standing next to buckets.
Foresters have long known that trees under stress from fire injury are vulnerable to bark beetle attacks. Rick Kelsey and Doug Westlind, researchers with the Pacific Northwest Research Station, have developed a new mechanistic model to explain how physiological changes cause heat stress in woody tissues exposed to sublethal fire temperatures and produce a…
Young female cones of Douglas-fir tree.
To successfully reproduce, conifers must have impeccable timing—opening their female cones to receive pollen from the male cones of nearby trees. This timing is a response to temperature and other environmental cues. It is to the tree’s advantage to flower when risk of damaging frost is low, but early enough in the spring to take full advantage of the…
Pine martin wearing a collar standing on a branch.
The Pacific marten once ranged throughout coastal forests of the Pacific Northwest, but by the late 1940s, it was thought to be extinct. In 1996, however, a population was found in northern California. This member of the mustelid family, which includes weasels and fishers, depends on diverse, mixed-conifer forests with a dense understory of salal and other…
A roughskin newt standing in moss.
As central components of food webs worldwide, amphibians provide vital ecosystem services. The continental United States alone has 230 amphibian species and is the world hotspot for salamander species. However, this amphibian biodiversity is threatened by Batrachochytrium salamandrivorans (Bsal), a fungal pathogen native to Asia that spread to Europe and…
An egg in a nest.
The marbled murrelet (Brachyramphus marmoratus) is a threatened coastal bird that feeds on fish and nests in old-growth forests. In northwest Washington, murrelet populations are declining despite protections provided by the Northwest Forest Plan.Wildlife biologists Martin Raphael and Tom Bloxton, with the USDA Forest Service Pacific Northwest Research…
Person wearing a hardhat kneels in a stream to collect a water sample.
The forested watersheds of the Pacific Northwest can sequester a significant amount of atmospheric carbon dioxide (CO2), making them valuable carbon sinks for offsetting the carbon emissions that are contributing to global changes in the climate. However, as trees are storing carbon, water is leaching it from the soil. Some of the carbon is captured by…
Standing dead trees after a wildland fire.
Wildfires consume existing forest fuels but also leave behind dead shrubs and trees that become fuel to future wildfires. Harvesting firekilled trees is sometimes proposed as an economical approach for reducing future fuels and wildfire severity. Postfire logging, however, is controversial. Some question its fuel reduction benefits and its ecological…
Aerial view of planted rows of trees.
Diameter growth is seasonal in Douglasfir, the evergreen tree found in much of western Washington, Oregon, and northern California. Initiation and cessation of diameter growth are both triggered by environmental cues. The tree responds to these cues to improve its chances of growing under favorable conditions. As environmental conditions change, however,…
Drone flying with forest in the background.
Accurate measurements of natural resources are a prerequisite for resource assessment. Demetrios Gatziolis, a scientist with the USDA Forest Service Pacific Northwest Research Station, and his colleagues with Washington State University developed and tested protocols for using structure-from-motion photogrammetry to obtain data that can be used to…
Three people walking down a path next to a meadow of flowers.
Millions of people head to federal lands every year for recreation—891 million visits in 2016 alone. These visits have significant economic implications, not only for restaurants, resorts, outfitters, and other businesses near recreation sites, but also for the people actually participating in outdoor recreation.Scientists Eric White and Jeff Kline,…
Logs laying on the ground in the woods.
Although burned trees are the most visible damage following a wildfire, a forest’s soil can also be damaged. The heat generated by a wildfire can alter the soil’s physical properties and kill the fungi and bacteria that are responsible for nutrient cycling and other ecosystem services. What isn’t well understood is the extent of the heating within the soil…
Aerial view of a river with an island in the center covered in trees.
Increasing the population of spring Chinook salmon and summer steelhead in Washington state’s Methow River is a goal of the Upper Columbia Spring Chinook Salmon and Steelhead Recovery Plan. Spring Chinook salmon and summer steelhead are listed as endangered and threatened, respectively, under the Endangered Species Act.Installing logjams and reconnecting…
Map of Portland with highways.
Air quality is a critical issue affecting the health of billions of people worldwide, yet often little is known about what is in the air we breathe. To reduce air pollution’s health impacts, pollution sources must first be reliably identified. Otherwise, it is impossible to design and effectively enforce environmental standards. However, urban networks of…
Four people stand around a map on a table.
Resource managers have long mapped biophysical forest data. Often lacking, however, is relevant social science data for understanding the variety of human needs a given landscape fulfills.For nearly a decade, Lee Cerveny has been exploring how to provide this data on public lands around the Pacific Northwest. Cerveny is a research social scientist with the…
Pedestrians move along a sidewalk on rollerblades, on foot, and on a wheelchair.
A balanced diet and regular exercise are fundamental for good health, and a daily dose of nature may be equally important. Nearly 40 years of research has demonstrated that “metro nature”—nature found in urban environments, such as parks or tree-lined streets—provides positive and measurable health benefits and improves people’s quality of life.A research…
Large trees in a forest with dense understory vegetation.
With the passage of the Multiple Use Sustained Yield Act of 1960, the U.S. Forest Service has managed its 193 million acres of forest and grassland for multiple uses, including timber, watersheds, and wildlife. Using today’s terminology, some of these purposes are considered ecosystem services, which encompass a breadth of benefits provided by forests,…
Person typing on laptop next to stream.
Water temperature drives the complex food web of a river network. Aquatic organisms hatch, feed, and reproduce in thermal niches within the tributaries and mainstem that comprise the river network. Changes in water temperature can synchronize or asynchronize the timing of their life stages throughout the year. The water temperature fluctuates over time and…
Group of people wearing hardhats standing on a gravel road.
Interest in landscape-scale approaches to fire management and forest restoration is growing with the realization that these approaches are critical to maintaining healthy forests and protecting nearby communities. However, coordinated planning and action across multiple ownerships have been elusive because of differing goals and forest management styles…
Woodpecker on the side of a tree.
Woodpeckers and other cavity-excavating birds worldwide are keystone species. These birds excavate their nests out of solid wood, and because their nests are often well protected against predators and the environment, other species use and compete for their old, vacant nests. The presence of cavity-excavating birds in forests has far-reaching effects on…
Pile of logs in the middle of a rocky stream.
In the Pacific Northwest, native salmon and trout are some of the toughest survivors on the block. Over time, these fish have evolved behavioral adaptations to natural disturbances, and they rely on these disturbances to deliver coarse sediment and wood that become complex stream habitat. Powerful disturbances such as wildfire, postfire landslides, and…
Aerial view of houses and neighborhoods with a plume of smoke rising on the horizon.
Landscape exposure to multiple stressors can pose risks to human health, biodiversity, and ecosystem services. Attempts to study, control, or mitigate these stressors can strain public and private budgets. An interdisciplinary team of Pacific Northwest Research Station and Oregon State University scientists created maps of the conterminous United States…
Plains in the tundra.
Alaska’s Arctic tundra is one of the most rapidly warming regions in the world. For years, scientists have been working to interpret the effects of its changing climate and determine what these changes may mean for the rest of the planet. Coarse-scale satellite imagery of much of this region shows the tundra is becoming greener. This has been widely…
Forest with large diameter tree trunks.
As a signatory to the United Nations Framework Convention on Climate Change, the United States annually compiles a report on the nation’s carbon flux—the amount of carbon emitted into the atmosphere compared to the amount stored by terrestrial landscapes. Forests store vast amounts of carbon, but it’s not fully understood how a forest’s storage capacity…
People wearing hardhats pushing wheelbarrows in the forest.
Societies use biologically active chemicals as medicines and pesticides to protect human and agricultural health. But widespread use of synthetic compounds raises concerns about their safety, and resistance development in targeted pests.To find safer alternatives, scientists turned to native plants and trees in Pacific Northwest forests using multiyear…
Photo of a river with a dam being removed.
In recent decades, dam removal has emerged as a viable national and international strategy for river restoration. According to American Rivers, a river conservation organization, more than 1,100 dams have been removed in the United States in the past 40 years, and more than half of these were demolished in the past decade. This trend is likely to continue…
Two martens on a log with forest in the background.
Martens are small forest carnivores associated with dense, mature forests. These important indicators of a forest’s biodiversity are vulnerable to management activities that open the forest canopy or remove downed debris. Many fuel reduction treatment do just that: dense stands of trees are thinned to minimize fire hazard and future fire severity. Until…
Rocky stream with pieces of string stretch across at regular intervals.
Land use and climate change are two key factors with the potential to affect stream conditions and fish habitat. Since the 1950s, Washington and Oregon have required forest practices designed to mitigate the effects of timber harvest on streams and fish. Yet questions remain about the extent to which these practices are effective. Add in the effects of…
Purple flowers growing on rocky ground.
Mount St. Helens’ explosive eruption on May 18, 1980, was a pivotal moment in the field of disturbance ecology. The subsequent sustained, integrated research effort has shaped the development of volcano ecology, an emerging field of focused research. Excessive heat, burial, and impact force are some of the disturbance mechanisms following an eruption. They…
House and truck in the foreground with a plume of smoke rising from the forest in the background.
Effectively addressing wildfire risk to communities on large multi-owner landscapes requires an understanding of the biophysical factors that influence risk, such as fuel loads, topography, and weather, and social factors such as the capacity and willingness for communities to engage in fire-mitigation activities. Biophysical and social processes often are…
Group of people wearing hardhats standing in a circle in a grassy meadow.
Since 1960, the Forest Service has been guided by the multiple-use concept, which recognizes five major uses for public lands—timber, water, range, recreation, and fish and wildlife habitat—and mandates that all five should be equally considered in management plans. In recent decades, however, it has become evident that people also value many other…
Photo of water flowing from the ground into a natural pool.
Much of the water supply in the Pacific Northwest originates in national forests. It sustains the region’s aquatic ecosystems, agriculture, hydroelectric power, and community water supplies.Understanding how climate change will affect water supply is one of the most pressing issues of our time. Substantial changes are projected in the types of…
Aerial photograph of forests and drained lakes in the Arctic.
Higher global temperatures are changing ecosystems in the Arctic. They are becoming greener as the climate and land become more hospitable to taller vegetation. Scientists predict that woody vegetation in the Arctic will increase by more than 50 percent, and half of all vegetated areas will shift to types more suited to the higher temperatures and changing…
Sign in a field that states "Ranchers feed families, provide wildlife habitat and preserve open space."
Sustainable working landscapes are critical to the conservation of biodiversity in the American West and its cultures of rural ranching and forestry. Given the West's patchwork of public, private, and tribal lands, perhaps the best way to conserve biodiversity and ecosystem function on a large scale is through a process of collaborative conservation. These…
Field of grass with trees in the background.
Earth's climate is changing, as evidenced by warming temperatures, increased temperature variability, fluctuating precipitation patterns, and climate-related environmental disturbances. And with considerable uncertainty about the future, Forest Service land managers are now considering climate change adaptation in their planning efforts. They want…
Graphic that depicts timing of budburst by 2080 for Western hemlock, Western redcedar, and Pacific madrone.
Trees bursting forth with new leaves signal the arrival of spring. Budburst for most temperate tree species occurs after a tree has been exposed to a sufficient number of chilling and forcing hours over the winter. Waiting until these chilling and forcing hours have accumulated is a survival mechanism.If a tree bursts bud prematurely, delicate tissue may…
Forest of spruce trees with a waterbody in the background.
The Chugach and Tongass National Forests are changing, possibly in response to global warming. Forested areas within Alaska's temperate rain forests are creeping into areas that were previously too cold or too wet. These forests are also becoming denser. As biomass increases, the amount of carbon stored in the forest also increases.Tara Barrett, a research…
Person carrying clipboard stands in a grassy field.
National forests and grasslands are home to a diverse array of wildlife. To keep tabs on the general viability and wellbeing of these inhabitants, land managers need practical, defensible monitoring protocols. Population monitoring is one method. Another is habitat monitoring, which provides critical information about the quantity and quality of key…
A shovel full of gray and brown soil.
New research reveals how topography, soil temperature, and subtle shifts in soil drainage are key drivers in ecosystem function in the coastal temperate rain forests of southeast Alaska and British Columbia. These studies, by Dave D'Amore and his colleagues, provide a better understanding of the influence of soil hydrology on dissolved organic carbon…
Rows of metal dishes containing Douglas-fir twigs.
Douglas-fir is an iconic tree in the Pacific Northwest. Although individual trees may appear to be identical, genetic differences within each tree have resulted from adaptation to the local environment. These genetic differences over time have resulted in differences among populations that are important to the species' survival and growth in changing…
Forest with vegetated understory and small stream.
Since the Northwest Forest Plan implemented riparian buffers along non-fish bearing streams in 1994, there have been questions about how wide those buffers need to be to protect aquatic and riparian resources from upland forest management activities. The Density Management and Riparian Buffer Study of western Oregon, also initiated in 1994, examines the…
Two fish swimming underwater above a rocky substrate.
Steelhead are the sea-going form of Oncorhynchus mykiss. Rainbow trout, also O. mykiss, remain in freshwater. Each form, or life-history, can produce offspring of the other, but the mechanism for this and potential effects that climate change may have on the species are poorly understood.Forest Service scientist Gordie Reeves, along with…
Person walks through meadow using herbicide sprayer.
Herbicides are primarily used for protecting agricultural crops from weeds and controlling vegetation competition in newly planted forest stands. Yet for over 40 years, they have also proven useful in controlling invasive plant species in natural areas. Nonnative invasive plant species, if not controlled, can displace native species and disrupt an…
A tree-lined stream drains into a pool of water.
Even while emissions are in decline, sulfur released into the air primarily by coal- and oil-burning power plants continues to acidify streams in the eastern United States, stressing vegetation and harming aquatic life. Watersheds rich in base cations—nutrients that attract and bind acidic molecules—naturally buffer streams against acidification. These…
Hand holding up woodchips.
The elevated intensity of wildfire seasons in the American West combined with political, environmental, and economic issues surrounding the use of coal and oil are spurring a growing interest in the use of woody biomass as a fuel for heating and electrical generation.David Nicholls, a forest products technologist at the Alaska Wood Utilization Research and…
Person wearing hardhat kneels to collect a sample next to a scorched tree.
Stress in trees is caused by disturbances such as fire, flood, disease, or insect infestations. A single stressor may not be enough to kill a tree, but a combination can be deadly.Tree tissues produce and accumulate ethanol in response to many stressors. Ethanol provides the stressed tissues with an emergency energy source when their normal source of…
Barn in a meadow with a hill in the background.
Developing forest lands and agricultural lands for other uses has wide-ranging implications. Land development can affect production from forest and agricultural lands, wildlife habitat quality, the spread of invasive species, water quality, wildfire control, and infrastructure costs. In its attempts to mitigate these effects, Oregon implemented statewide…
Grass, with forests and mountains in the background.
Seed zones and seed transfer guidelines describe where plants are most likely to thrive. Scientists with the Forest Service and Agricultural Research Service undertook a 9-year project to build empirical seed zones for bluebunch wheatgrass, a foundational native grass throughout the West. The research will help the Forest Service and Bureau of Land…
Closeup of beetle standing on tree.
In the last decade, pine forests throughout much of the western United States have been ravaged by the mountain pine beetle (Dendroctonus ponderosae). This bark beetle is native to the United States and has been responsible for massive tree kills in the past. The current outbreak, however, has been notably severe and wide ranging and the effects have been…
Person standing next to tall shrubs.
Bohemian knotweed spreads aggressively along rivers. This invasive weed chokes waterways, displaces native plants, erodes riverbanks, and keeps tree seedlings from growing. Communities in the Pacific Northwest spend millions of dollars to eradicate it on the assumption that it harms fish habitats.But knotweed is difficult to kill. It takes years of…
Person writes on a tree stump with a marker.
Until recently, scientific understanding of the history and ecology of the Pacific Northwest's mixed-conifer forests east of the Cascade Range was minimal. As a result, forest managers have had limited ability to restore the health of publicly owned forests that show signs of acute stress caused by insects, disease, grazing, logging, and wildfire.A recent…
Three people standing with tree branch.
Swiss needle cast is caused by a fungus native to the Pacific Northwest. Its host is Douglas-fir, an iconic evergreen tree in the region. The fungus does not kill its host, but it adversely affects the tree's growth. The fungal fruiting bodies block the stomata, small openings on the underside of the needle where carbon dioxide, water vapor, and other…
Two people holding a bottle and a pump collecting scientific data.
Nitrogen is an element essential to plant growth and ecosystem productivity. Excess nitrogen, however, is a common water pollutant. It can lead to algal blooms that deplete the water's dissolved oxygen, creating "dead zones" devoid of fish and aquatic insects.Previous research showed that the subsurface area of a stream, known as the hyporheic zone,…
Person wearing hardhat standing in the forest.
The Forest Vegetation Simulator (FVS) is a widely used computer model that projects forest growth and predicts the effects of disturbances such as fire, insects, harvests, or disease. Land managers often use these projections to decide among silvicultural options and estimate the potential effects of these options on forest conditions. Despite FVS's…
Aerial view of a home surrounded by forest.
Large wildfires in the United States pose significant challenges to fire management agencies charged with protecting lives, property, and natural resources. A vigorous initial response to a wildfire, a process referred to as "initial attack," can greatly reduce the likelihood of the fire becoming larger and causing substantial damage.Successful initial…
Closeup of five minnows laid in a row.
Salmon evolved in natural river systems, where temperatures fluctuate daily, weekly, seasonally, and all along a stream’s path—from the mountains to the sea. Climate change and human activities alter this natural variability. Dams, for example, tend to reduce thermal fluctuations.Currently, scientists gauge habitat suitability for aquatic species by…
Graphic depicting shaded areas showing treatment areas from low to high, and topography.
Human settlement and land management have radically altered the composition and structure of eastern Washington forests. Restoring high-functioning landscapes and habitat patterns have broad implications for the future sustainability of native species, ecosystem services, and ecosystem processes. Many land managers and scientists have turned their…
Shaded forest understory.
The floor of a Douglas-fir forest may be rich in organic matter, but nutrients essential to plant growth are locked within the decomposing needles, leaves, and fallen wood. Before nitrogen, phosphorus, and other nutrients can be cycled back through the forest system, they need to be further broken down into forms accessible to plants. Understanding how…
A fisher standing on a log.
Martens, sables, and fishers are midsized carnivores belonging to the genus Martes. Their silky coats have been valued in the fur trade for centuries, which has contributed to a marked decline in their numbers. Pacific Northwest Martes species depend on structurally complex forested ecosystems and specific climatic conditions for their…
Map overlaid on photo of water in the foreground, with meadow and trees in the background.
The catastrophic fires and tragic losses during the 2013 fire season have resulted in many discussions about fire management policies aimed at protecting communities and restoring fire-resilient forests from the growing incidence of severe wildfires. Forest Service scientist Alan Ager has been exploring how concepts in spatial ecology and operations…
People walking along paved path bordered by trees and light poles.
Humans have intuitively understood the value of trees to their physical and mental health since the beginning of recorded time. A scientist with the Pacific Northwest Research Station wondered if such a link could be scientifically validated. His research team took advantage of an infestation of emerald ash borer, an invasive pest that kills ash trees, to…
Bird sitting in a nest on a tree.
In 1992, the marbled murrelet population in the Pacific Northwest was listed as threatened under the federal Endangered Species Act, along with the northern spotted owl and Pacific salmon. These designations were embodied in the 1994 Northwest Forest Plan, which takes an ecosystem approach to managing about 25 million acres of federal lands, with a goal of…
Frog sitting in the grass.
The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), causes the infectious disease chytridiomycosis, which has triggered massive die-offs and extinctions of amphibians around the world. The disease, identified in 1998, is a significant contributor to the global amphibian biodiversity crisis, and no clear means of arresting its spread has…
Forest of coniferous trees extending off into the distance.
As forest carbon offset projects become more popular, professional foresters are providing their expertise to support them. But when several members of the Society of American Foresters questioned the science and assumptions used to design the projects, the organization decided to convene a task force to examine whether these projects can provide the…
Two people with forest in the background.
The fire-prone landscapes of the West include both public and private lands. Wildfire burns indiscriminately across property boundaries, which means that the way potential fuels are managed on one piece of property can affect wildfire risk on neighboring lands. Paige Fischer and Susan Charnley, social scientists with the Pacific Northwest Research Station…
Hand holding a mushroom in the forest.
Soil health is fundamental to ecosystem health. Disturbances such as fire and timber harvesting can affect the abundance, activity, and composition of soil microbial communities and thus affect soil productivity. In response to forest managers, scientists with the Pacific Northwest Research Station compared health and productivity indicators between soils…
Two people wearing hardhats standing in the forest.
Longleaf pine (Pinus palustris) savannas of the southeastern United States contain some of the world’s most diverse plant communities, along with a unique complement of wildlife. Their traditionally open canopy structure and rich understory of grasses and herbs were critical to their vigor. However, a long history of land-use practices such as logging,…
Graphic depicting a plane flying over trees collecting Light Detecting and Ranging Data (LIDAR).
Light detection and ranging (LiDAR), also known as airborne laser scanning, is a rapidly emerging technology for remote sensing. Used to help map, monitor, and assess natural resources, LiDAR data were first embraced by forestry professionals in Scandinavia as a tool for conducting forest inventories in the mid to late 1990s. Thus early LiDAR theory and…
Trees with blue sky in the background.
Yellow-cedar has been dying across 600 miles of North Pacific coastal rain forest—from Alaska to British Columbia—since about 1880. Thirty years ago, a small group of pathologists began investigating possible biotic causes of the decline. When no biotic cause could be found, the scope broadened into a research program that eventually encompassed the fields…
Tops of coniferous trees with clouds and mountains in the background.
Climate change is altering growing conditions in the temperate rain forest region that extends from northern California to the Gulf of Alaska. Longer, warmer growing seasons are generally increasing the overall potential for forest growth in the region. However, species differ in their ability to adapt to changing conditions. For example, researchers with…
Three people stand next to vegetation.
National forest managers are charged with tackling the effects of climate change on the natural resources under their care. The Forest Service National Roadmap for Responding to Climate Change and the Climate Change Performance Scorecard require managers to make significant progress in addressing climate change by 2015. To help land managers meet this…
Person standing in front of an enormous western redcedar trunk.
People have long valued mature western redcedar for its strong, lightweight wood that is rot-resistant. The species has cultural importance for Northwest tribes who use the tree’s bark and roots as well as the wood. Redcedar is very shade-tolerant and is often found in the understory and midstory of Pacific Northwest forests. It is also very adaptable and…
Three people kneeling to place plastic square on the ground to assess vegetation.
Leafy spurge is an invasive weed that has appeared along streams throughout much of the country. Riparian ecosystems are particularly sensitive areas that can be threatened by nonnative invasive species. These areas also can be damaged by herbicides commonly used in uplands to control invasive plants. In a collaborative effort by the U.S. Forest Service,…
Researcher places a square of plastic piping on the ground.
The logging debris that remains after timber harvest traditionally has been seen as a nuisance. It can make subsequent tree planting more difficult and become fuel for wildfire. It is commonly piled, burned, or taken off site. Logging debris, however, contains significant amounts of carbon and nitrogen—elements critical to soil productivity. Its physical…
Wetland extending off into the distance, with forested hills in the background.
Establishing markets for ecosystem services—the benefits that nature provides, such as clean air, water, and wildlife habitat—has gained traction in some circles as a way to finance the conservation of these public goods. Market influences on supply and demand work in tandem to encourage ecosystem protection. Jeff Kline and Trista Patterson, scientists with the Pacific Northwest (PNW) Research…
Small spruce tree next to a measuring stick.
Alaska's boreal forest have experienced unprecedented levels of disturbance. Fire is becoming more frequent and burning larger areas compared to the 1960s and 1970s. In the mid 1990s, insect outbreaks reached epidemic proportions. During the same period, timber harvesting increased to meet demand for logs no longer coming from the Pacific Northwest forest…
A sage-grouse standing in a meadow.
Populations of greater sage-grouse have declined dramatically across their North American range for many decades in response to harmful effects of a plethora of human activities and land uses, prompting legal actions to protect the species under the Endangered Species Act (ESA). To evaluate the impacts of land-uses and habitat changes on sage-grouse,…
Two cows standing next to a road.
Scientists have had little information about how prescribed fire and cattle grazing—common practices in many Western ponderosa pine forests—affects plant abundance and reproduction in the forest understory. Pacific Northwest Research Station scientists began to explore how these practices affect vegetation in a five-year study of postfire vegetation in…
Two deer standing in the snow in the forest.
Mule deer populations in central Oregon are in decline, largely because of habitat loss. Several factors are likely contributors. Encroaching juniper and invasive cheatgrass are replacing deer forage with high nutritional value, such as bitterbrush and sagebrush. Fire suppression and reduced timber harvests mean fewer acres of early successional forest,…
Aerial view of a stream draining into the ocean.
Exploring relationships between landscape characteristics and rivers is an emerging field, enabled by the proliferation of satellite date, advances in statistical analysis, and increased emphasis on large-scale monitoring. Landscapes features such as road networks, underlying geology, and human developments, determine the characteristics of the rivers…
Burned and partially burned trees.
The 1994 Northwest Forest Plan (NWFP) established a common management approach across federal land within the range of the northern spotted owl. It also established a monitoring framework to track, among other things, the plan’s effectiveness at maintaining and restoring late-successional and old-growth forests.Station scientists Janet Ohmann and Warren…
House with trees in the foreground.
 City dwellers can find many reasons to value neighborhood trees. The urban greenery provides relief from the built environment that many find appealing. In fact, a previous study found that a tree in front of a home increased that home's sales price by more than $7,000. Two new studies explore the measurable effects that urban trees and green spaces…
Coastal tailed frog sitting on the ground.
Climate variation exacerbates threats to amphibians such as disease and habitat loss. Yet, by and large existing species- and land-management plans give little if any consideration to climate impacts. Moreover, many management actions that do address emerging climate patterns have yet to be evaluated for feasibility and effectiveness. To help address these…
Researchers standing near trees with clipboards and measuring sticks.
The massive volcanic eruption of Mount St. Helens 31 years ago provided the perfect backdrop for studying the earliest stages of forest development. Immediately after the eruption, some areas of the blast area were devoid of life. On other parts of the volcanic landscape, many species survived, although their numbers were greatly reduced. Reassembly began…
Crew member wearing hardhat piles tree branches.
Federal policies direct public-land managers to reduce wildfire risks for urban areas close to wildlands, while broader agency goals call for landscape restoration to create fire-resilient forests. This study used wildfires simulation modeling to examine the tradeoffs between focusing fuel reduction efforts on a wildland-urban interface (WUI) in Oregon’s…
Aerial photo of a gravel bar on the Clackamas River in Oregon.
Thermal pollution in rivers can be caused by dams, logging, municipal wastewater treatment, and other human activities. High water temperatures stress ecosystems, kill fish, and promote disease and parasites, and so dam operators, timber companies, and municipalities are held responsible for thermal loading caused by their operations. These entities are…
North American red fox with trees in the background.
The red fox is one of the most widespread and adaptable mammals on Earth. In the American West, however, there are populations of native red foxes that occur only in alpine and subalpine habitats, which may be at risk from human-caused and natural pressures. One potential threat is global climate change, which is likely to reduce both the amount and…
Hummingbird feeding its young in a nest camouflaged with lichen.
In Pacific Northwest forests, lichens provide essential winter forage for deer and elk and also nesting materials and habitat for rodents, birds, and invertebrates. Although lichens are often the first organisms to populate a landscape and many species can survive in the most barren environments, lichens with the greatest ecological value tend to be the…
Researcher holding a Clark's nutcracker.
Whitebark pine inhabits some of the most pristine high-elevation areas of the West. Despite being protected from direct human influence, the tree is declining from indirect effects of fire suppression and climate change. As a keystone species, its decline has widespread ramifications. Successful restoration requires understanding the behavioral ecology of…
Cover of Science Findings depicting a group of people standing in a meadow with trees in the background.
Regulation alone cannot solve complex ecological problems on private lands that are managed for diverse uses. Executing coordinated restoration projects at the watershed scale is only possible with the cooperation and commitment of all stakeholders. Locally organized, nonregulatory watershed councils have proven to be a powerful method of engaging citizens…
Two people examine rows of tree seedlings.
The timing of spring budburst in woody plants impacts not only the subsequent seasonal growth for individual trees, but also their associated biological community. As winter and spring temperatures have warmed under the changing climate, in many species budburst has been happening earlier in the year. Understanding the long-term effects of this shift and…
Hillslopes covered with trees.
Land use change is a key part of global change. Deforestation, urban sprawl, agriculture, and other human influences have substantially altered natural ecosystems and fragmented the global landscape. Slowing down deforestation and afforesting environmentally sensitive agricultural land are important steps for mitigating climate change. Because no policy…
A single-family home with a white picket fence and a for sale sign in the yard.
For urban dwellers, trees soften a city’s hard edges and surfaces, shade homes and streets, enhance neighborhood beauty, filter the air, mitigate storm runoff, and absorb carbon dioxide. Trees may even reduce crime and improve human health. However, these benefits have not been well quantified, making it difficult for urban planners and property owners to…
Burned tree trunks in a forest after experiencing a wildfire.
A network of late-successional forest reserves is central to the Northwest Forest Plan, the guiding vision for managing federal forests in Washington, Oregon, and northern California within the range of the northern spotted owl. These reserves were created to maintain older forest structure as habitat for the northern spotted owl, marbled murrelet, and…
Researcher wearing hardhat kneels on the ground in a burned forest.
Soil exposed to prolonged intense heat during a wildfire turns a distinctive red color. The heat volatilizes soil nutrients and kills subterranean microbial communities. Patches of severely burned red soil are found most frequently in areas that were heavily covered with down, dead wood before the fire. It has long been thought that exposure to such heat…
Field with a grid of planted oak tree seedlings.
The decline of oak woodlands is an urgent conservation challenge in the Pacific Northwest. Prior to settlement by Euro-Americans, prairies, oak-dominated savannas, and oak woodlands were abundant in the low-lying areas of the region. Now it’s estimated that 1 to 5 percent of that native oak savanna remains. The rest has been supplanted by pastures, fields…
Aerial view of forest and streams.
Acre for acre, streams of the coastal temperate rain forest along the Gulf of Alaska export 36 times as much dissolved organic carbon as the world average. Rain and snow are the great connectors, tightly linking aquatic and terrestrial systems of this region. The freshwater that flushes over and through the forest floor leaches carbon and other nutrients…
Researcher wearing hardhat kneels down to clear vegetation away from a tree seedling.
Interactions among plant species and their growth patterns help shape a forest. Various management practices can enhance forest complexity and in return yield benefits that include enhanced growth of desired species, slowing the spread of root disease, and improved wildlife habitat.Based on science by Timothy B. Harrington, Warren DevineCitationParks,…
Salamander standing on a rock.
Many forest-dwelling species rely on both terrestrial and aquatic habitat for their survival. These species, including rare and little-understood amphibians and arthropods, live in and around headwater streams and disperse overland to neighboring headwater streams. Forest management policies that rely on riparian buffer strips and structurebased management…
Graphic that depicts how the shape of a watershed determines the sources and timing of runoff that govern stream flow.
New technology has given scientists the means to probe the hidden world of belowground hydrology. Steve Wondzell with the Pacific Northwest Research Station and his colleagues conducted several experiments in Montana’s Tenderfoot Creek Experimental Forest and Oregon’s H.J. Andrews Experimental Forest to determine which factors control the timing and…
Graphic depicting a forest food web.
Soil organisms play essential roles in forest health, and truffle fungi are one of the more fascinating groups of these important organisms. After 40 years of specimen collection and study, scientists with Pacific Northwest Research Station have published a report documenting how truffle fungi affect tree survival and growth, perform valuable functions in…
Machine in the forest cutting down and moving trees.
Increasingly large and severe wildfires threaten millions of forested acres throughout the West. Under certain conditions, mechanical thinning can address these hazardous conditions while providing opportunities to create renewable energy and reduce our carbon footprint but how do land managers decide whether thinning is a good idea? How do they decide…
Person standing in front of enormous tree trunk.
Forests significantly influence the global carbon budget: they store massive amounts of carbon in their wood and soil, they sequester atmospheric carbon as they grow, and they emit carbon as a greenhouse gas when harvested or converted to another use. These factors make forest conservation and management important components of most strategies for adapting…
Group of researchers standing in Amazon Creek collecting water samples.
Excess nitrogen stemming from human activities is a common water pollutant. Fertilizer runoff, sewage, and fossil fuel emission all contain nitrogen that often ends in streams, rivers, and ultimately the ocean. Research has found that more nitrogen enters a river system than can be accounted for at its mouth, indicating that instream processing is…
Wolverine climbs a tree at night.
The wolverine is one of the rarest and least-known mammals in North America. A lack of understanding regarding its historical distribution in the contiguous United States and its broad-scale habitat needs has hampered conservation efforts. Using a suite of research methods, including the assemblage of historical data on wolverine occurrence, analyses of…
Landscape with meadow in the foreground and forested hills in the background.
Oregon’s land use planning program has protected an estimated 1.2 million acres of forest and agricultural land from development since its inception in 1973. As a result, these resource lands continue to provide forest products and food as well as another unexpected benefit: carbon storage. By keeping forests as forests, land use planning capitalizes on…
Researcher with hardhat uses measuring tape to check the diameter of a tree trunk.
Can management of 40- to 80-year- old forests on the Olympic Peninsula accelerate the development of stand structures and plant and animal communities associated with much older forests? The Olympic Habitat Development Study, a cooperative project between the Pacific Northwest Research Station and the Olympic National Forest, began in 1994 to examine this…
Water flows through a gap in an earthen embankment created by adjacent machinery.
Removing dams that are outdated, unsafe, or pose significant economic or environmental costs has emerged in the last 10 years as a major river restoration strategy. The removal of the 45-foot-high Marmot Dam on the Sandy River in 2007 resulted in the biggest sediment release accompanying any dam removal to date. It also provided an unprecedented…
Grove of tall trees with a car in the foreground.
How should old-growth forests be managed? Should they be managed? Stakeholders with differing values and agendas have debated these questions for years. Over time, the debate has evolved: now there is greater awareness about the complexity of old-growth ecosystems and different ways humans value them. A scientist at the Pacific Northwest Research Station…
Pileated woodpecker standing on tree next to nest cavity.
The pileated woodpecker is a species of conservation concern and a keystone species in mature and old forests of the Pacific Northwest. In the Blue Mountains of northeast Oregon, researchers from the PNW Research Station in La Grande, Oregon, studied the effects of natural and human-caused disturbance on pileated populations and their habitat over a period…
Hand holding a Van Dyke’s salamander.
Most ecosystems contain a few common species and many rare ones. By virtue of being rare, these species are often poorly understood and difficult to manage. Scientists at the PNW Research Station have recently published a landmark book that chronicles what is known and what they've recently learned about conserving cryptic biodiversity. For the past decade…
Two researchers wearing hardhats stand in a field littered with woody debris.
In 1999, the Fall River Long-Term Site Productivity study began in coastal Washington to investigate how intensive management practices affect soil processes and forest productivity. By comparing conventional harvests to more intensive wood removal treatments, researchers are answering long-standing questions about how residual organic matter influences…
Mechanical thinning underway in a forest.
Frequent, low-intensity fires were historically a common feature in many dry forests of the United States. Today, largely owing to fire exclusion and past management practices, many of these fire-dependent forests contain significantly more small trees and fewer large trees than occurred under the natural fire regime. These altered conditions increase the…
Four people sit on logs in the forest.
Over the past 7 years, a strong collaboration has emerged between the H.J. Andrews Experimental Forest ecosystem research group and the Spring Creek Project for Ideas, Nature, and the Written Word, an independently funded program for nature writing based in the Department of Philosophy, Oregon State University. The program is called Long-Term Ecological…
Machinery transports downed trees and branches.
The fire hazard in many western forests is unacceptably high, posing risks to human health and property, wildlife habitat, and air and water quality. Cost is an inhibiting factor for reducing hazardous fuel, given the amount of acreage needing treatment. Thinning overly dense forests is one way to reduce fuel loads. Much of the product removed during these…
Artwork depicting birds in a forest.
Although prescribed fire is increasingly being used in ponderosa pine forests as a management tool to reduce the risk of future high-severity wildfire, its effects on wildlife habitat have rarely been examined. The Birds and Burns Network was created to assist managers in planning prescribed fire projects that will reduce fuels and enhance bird habitat.…
Person wearing hardhat walking through forest with sparsely vegetated understory.
The threat from wildland fire continues to grow across many regions of the Western United States. Drought, urbanization, and a buildup of fuels over the last century have contributed to increasing wildfire risk to property and highly valued natural resources. Fuel treatments, including thinning overly dense forests to reduce fuel and lower fire risk, have…
A debris flow with piles of logs.
Not all landslides are created equal. Some have the potential to run out to streams and others do not. Some are likely to simplify and damage stream habitat, and others can be important sources of gravel and large wood, fundamental components of habitat complexity for salmon and other stream inhabitants. Forest managers want to avoid negative consequences…
Aerial view of marine aquaculture pens.
Commercial farming of Atlantic salmon in marine net-pens has become a booming industry. At present, approximately 130 salmon farms exist along the Pacific coast of North America. Most of these farms are in cold marine bays within British Columbia, where farmed salmon have become the province’s most valuable agricultural export. Each year, thousands of…
Stream covered with fallen trees.
Although stream protection has become a central tenet of forest management in the Pacific Northwest, it is often only the larger, fish-bearing streams that are afforded the strongest safeguards. Yet, even without fish, headwater streams and riparian areas are hotspots of biodiversity, and they are the source of much of the water, gravel, and nutrients that…
Grassy meadow with scattered trees and mountains in the background.
Oregon white oak savanna and woodland habitat in the Pacific Northwest has declined to less than 10 percent of its former range, and much of what remains is of poor quality. In addition to urbanization and agricultural development, habitat is being lost to conifers that have invaded oak areas, which were once maintained through frequent burning by Native…
A young lava flow.
Late summer streamflow in western and central Oregon and northern California is almost exclusively due to immense groundwater storage in the Cascade Range. The volume of water stored in permeable lava flows in the Cascades is seven times that stored as snow. Nonetheless, until recently, virtually all examinations of streamflow trends under future climates…
Aerial view of experimental forest treatments.
In response to societal concerns about clearcutting in the Pacific Northwest, structural or green-tree retention is now an integral part of harvest prescriptions on federal lands. However, the benefits of different levels or patterns of retention for the ecological, microclimatic, and aesthetic attributes of resulting forest stands remain speculative.…
Street with stores along one side and mountains in the background.
The Northwest Forest Plan (the Plan) was designed to balance protection of older forest ecosystems with mitigation of impacts on rural communities and economies. It was implemented by using an adaptive management approach that featured an interagency monitoring program. This program included socioeconomic monitoring—the systematic observation and…
A meadow with islands of coniferous trees.
Mountain meadows in the Pacific Northwest are patches of remarkable biological diversity. Lush, forb-, grass-, and shrub-dominated communities attract rich assemblages of arthropods, support diverse communities of birds, and provide habitat for small mammals and other wildlife. Recent encroachment by conifers has reduced the extent and ecological integrity…
Yellow-cedar forest in decline.
For more than a century, yellow-cedar has been inexplicably dying throughout the northern coastal rain forests of the Pacific Northwest. Yellow-cedar mortality has been mapped on more than a half million acres in southeastern Alaska, yet until recently the cause of death was a stubborn mystery. Researchers are hopeful, after several decades of…
A small tributary creek showing bank erosion and channel incision.
How do you project the effects of management decisions made today on future conditions of riparian forests, stream habitat, and fish abundance in the streams and rivers of the interior Columbia Basin? Researchers at PNW Research Station have developed some novel analytical tools to help answer this question. Their work is part of the Interior Northwest…
Sagebrush ecosystem with mountains in the background.
Sagebrush habitats are declining rapidly across western North America, with over 350 associated plant and animal species at risk of local or regional extirpation. The sagebrush ecosystem is one of the largest in the United States, and it is vulnerable to a litany of threats. Chief among them is invasion of cheatgrass into the understory, followed by high-…
Hands holding a marbled murrelet.
The marbled murrelet is a small diving seabird that occupies coastal waters from Alaska to central California. Murrelets have a unique nesting strategy that requires them to commute tens of miles inland, where they use large mossy branches on older conifers as platforms to balance their solitary egg. Populations have been declining for decades as the…
Trees in a partially harvested forest.
Change is the only constant in forest ecosystems. Quantifying regional-scale forest change is increasingly done with remote sensing, which relies on data sent from digital camera-like sensors mounted to Earth-orbiting satellites. Through remote sensing, changes in forests can be studied comprehensively and uniformly across time and space.CitationThompson,…
New home under construction with forest in the background.
Changing patterns of land use are at the heart of many environmental concerns regarding U.S. forest lands. Of all the human impacts to forests, development is one of the most significant because of the severity and permanency of the change. Concern about the effects of development on America’s forests has risen sharply since the 1990s, when the conversion…
Landscape of forest, water, and mountains in Alaska.
The condition of aquatic habitat and the health of aquatic species, particularly salmon, are a significant concern in the Pacific Northwest. Land management agencies use fish and riparian guidelines intended to maintain or improve aquatic habitat. Gauging whether or not those guidelines are effectively meeting their objectives requires careful monitoring…
A cartoon dragon made of debris flow with cartoon people fleeing.
Conservation measures for aquatic species throughout the Pacific Northwest rely heavily on maintaining forested riparian zones. A key rationale for this strategy is that the presence of standing and downed trees next to streams will provide a continuous source of wood, which is an important structural component of aquatic habitat. Yet little is known about…
Forested landscape with mountains in the background.
Some federal forest managers working in late-successional reserves find themselves in a potential no-win situation. The Northwest Forest Plan requires that the reserves be protected from large-scale natural and human disturbances while simultaneously maintaining older forest habitat. This is a challenge for managers working in drier reserves, where forest…
Group of people walking through the forest.
The Pacific Northwest is one of the world’s major timber-producing regions, and its capacity to produce wood on a sustained-yield basis is widely recognized. Nonetheless, there has been increasing public interest in assuring that forests are being sustainably managed, as well as a desire by landowners to demonstrate their commitment to responsible…
Close-up of a standing dead tree.
Decayed wood plays many critical roles in forest ecosystems. Standing dead trees, called snags, provide habitat for a suite of wildlife, including several species of birds, insects, bats, and other mammals. Down wood provides wildlife habitat and performs ecosystem services such as releasing humus, nitrogen, and phosphorus into the forest soil, storing…
Close-up of growing mushrooms.
A century of fire suppression has resulted in dense fuel loads within the dry pine forests of eastern Oregon . To alleviate the risk of stand-replacing wildfire, forest managers are using prescribed fire and thinning treatments. Until recently, the impact of these fuel treatments on soil productivity has been largely unknown. Such information is essential…
Small tree with a clipboard next to it.
In the mid-1990s, forest managers on the Malheur National Forest were concerned about their prescribed fire program. Although they have only a few weeks of acceptable conditions available in the spring and fall, they were worried that spring-season prescribed burning might be exacerbating black stain root disease and having negative effects on understory…
Close-up of a flying squirrel.
A century of effective fire suppression has radically transformed many forested landscapes on the east side of the Cascades. Managers of dry forests critically need information to help plan for and implement forest restoration . Management priorities include the stabilization of fire regimes and the maintenance of habitat for the northern spotted owl and…
Trucks traveling down a highway in a snowy landscape.
Millions of miles of highway crisscross the United States . Highways fragment the landscape, affecting the distribution of animal populations and limiting the ability of individuals to disperse between those populations. Moreover, animal-vehicle collisions are a serious hazard to wildlife, not to mention people.Researchers at the PNW Research Station in…
Foggy forest of coniferous trees.
In response to the highly uncertain outcomes inherent in forest management, “options forestry” has been introduced as a novel approach that includes an honest appraisal of uncertainties and learning as a specific objective. The strategy is unique in that it uses a variety of management pathways, all designed to reach the same goal, and structures them in a…
Group of people having a discussion outdoors.
Conserving biodiversity in the Oregon Coast Range requires tradeoffs. Policymakers must consider both the costs and benefits of new conservation programs. During this appraisal process, the costs, in terms of economic activity forgone, are often easier to quantify than the benefits. We all know that biodiversity is valuable, but how does its value compare…
Landscape of forested and logged areas.
Policies to achieve biodiversity goals have been implemented across many different forest ownerships in the last 10 years. Surprisingly, little research has been done to examine how well those policies might achieve their goals, how they might change landscapes in the future, and how the policies affecting different owners add up to a total picture of…
Oak woodlands and alpine meadows.
Nineteen scientists from leading research institutes in the United States collaborated to estimate how California’s environment and economy would respond to global climate change. A scientist from the PNW Research Station led efforts to estimate effects on vegetation, carbon, and fire.To quantify the range of the possible effects of climate change over the…
Landscape view of forested hills.
There is little question that global warming would increase the risk of wildfires by drying out vegetation and stirring the winds that spread fire. Until recently, however, land managers were unable to formulate appropriate responses because the spatial scales of predictions were far too coarse. Current research being done at the PNW Research Station in…
Rocky stream in the forest.
Water temperature influences virtually every biotic component of stream ecosystems. Not surprisingly, increased summer temperatures in streams with coldwater species of fish such as salmon and trout have become a topic of concern regionally and internationally. Although stream temperature has been studied for many years, controversy continues over the…
Rapids in a stream with adjacent banks.
Decisionmakers concerned with Pacific salmon and trout have, out of necessity, relied on limited, site-scale information when planning and evaluating efforts to protect or restore freshwater habitat. To help broaden the context of conservation approaches, scientists in the Coastal Landscape Analysis and Modeling Study (CLAMS) have developed tools that characterize the species-specific potential…
A dam in a river with water flowing over the top.
About 75,000 irrigation, flood control, and hydropower dams in the United States are aging, deteriorating, or have outlived their useful lives and purposes. Not surprisingly, dam removal is emerging as both a challenge and opportunity for river management and research. Scientists at the PNW Research Station in Corvallis, Oregon, are using scale models and…
Two fisher kits.
Overtrapping of fishers in the early 1900s, combined with widespread habitat loss from clearcut logging, has resulted in the extirpation of this forest-dwelling carnivore throughout much of its former range in the Western United States. Poor dispersal abilities, low-density populations, and low reproductive rates all hinder the recovery of this little-…
Person walks through a field of tall grass with scattered trees.
Over the past two decades, unprecedented levels of disturbance have occurred in the white spruce forests of Alaska. Spruce bark beetles, fires, and timber harvests have left millions of acres of dead spruce with little spruce regeneration. To assist public and private landowners, Pacific Northwest Research (PNW) Station scientists are testing various…
House in rural location surrounded by trees.
How population growth and development affect forests is a shared concern among forest managers, policymakers, land use planners, and fish and wildlife specialists. Of particular interest is the "wildland-urban interface." It is characterized by expansion of residential and other developed land uses onto forest landscapes in a manner that threatens the…
Two people with sledgehammers pound in a shallow well.
The flow of a mountain stream is difficult to follow, especially when it weaves in and out of the channel, flowing through streambanks and seeping through the streambed. Flowing belowground, the stream water mixes with ground water in the riparian aquifer before reemerging in the channel, sometime later and somewhere further downstream. Underground, the…
Two people wearing hard hats kneeling to rake the ground.
The web of life that exists below ground and out of sight may be the final frontier for forest ecologists. Among the many unknowns in this realm are the thousands of species of so-called ectomycorrhizal fungi, those fungi that have mutual-need associations with both trees and mammals.The richness and diversity of ectomycorrhizal fungi species contribute…
Western tanager bird standing on the ground.
Controversy over timber harvesting continues, and public perception of timber harvest has become increasingly important in the debate over land management decisions. However, forest management alternatives are often framed in terms to which the public cannot easily relate, such as "millions of board feet", or terms that trigger a preconceived negative…
Person holding large caliper leans against tree.
In 1910, Thornton T. Munger, the first director of the PNW Research Station, established the first forested permanent study plot in the Pacific Northwest. He recognized that long-term field observation was the only approach that could provide real data on forest dynamics, which occur over time scales longer than human lifespans.For the next 80 years,…
Mountainous landscape with logging roads, land slides, and soil disturbance.
Interactions among forests, forestry, and water remain a critical aspect of Forest Service land stewardship. Small, experimental watershed studies managed by Forest Service Research and Development have a long history of advancing science and management and have resulted in a rich collection of long-term data. Early work addressed effects of forestry…
Three people stand next to stream gauging station.
Interactions among forests, forestry, and water remain a critical aspect of Forest Service land stewardship. Small, experimental watershed studies managed by Forest Service Research and Development have a long history of advancing science and management and have resulted in a rich collection of long-term data. Early work addressed effects of forestry…
Hands holding a red tree vole.
When the Northwest Forest Plan became law via the record of decision in 1994, it contained an unprecedented provision for conducting regionwide surveys of poorly known and usually ignored taxa, such as fungi, mollusks, lichens, and mosses. The purpose was to enhance the very limited understanding of persistence issues for these taxa and, thereafter, to…
A northern flying squirrel.
Tree squirrels in the Pacific Northwest are part of a keystone complex that includes ectomycorrhizal fungi, Douglas-fir, and spotted owls. All three squirrel species—the northern flying squirrel, the Douglas' squirrel, and the Townsend’s squirrel—consume truffles produced by fungal partners of important tree species. The squirrels then spread the spores of…
Diagram depicting how smectitic clays accumulated in the Detroit Reservoir and were delivered to downstream sources.
In the Pacific Northwest, several recent and dramatic "muddy waters" events have created major problems for water utilities. Resulting from floods and measures to retrofit dams to reduce impacts on temperature, these events also have focused public and scientific attention on interactions among dams, forest-land use, and municipal water supplies. Far from…
Coniferous forest with dead tree branches in the foreground.
Swiss needle cast (SNC), the yellowing disease of Douglas-fir evident in many parts of Pacific Northwest Coast Range forests, is caused by a fungus endemic to the region. The disease apparently caused no significant widespread injury until the 1970s, when Christmas tree growers began to report needle loss. Since the late 1980s, SNC has become increasingly…
Pileated woodpeckers and tree nest.
Prior to 1994, the pileated woodpecker was a management indicator species (MIS) of mature and old-growth forest conditions on 16 of 19 national forests in the Pacific Northwest Region. This status required each of those national forests to establish pileated woodpecker habitat areas that included tracts of mature and old-growth forest with minimum…
Two researchers collecting measurements in the forest.
In order to address policy issues relating to biodiversity, productivity, and sustainability, we need detailed understanding of forest vegetation at broad geographic and time scales. Most existing maps developed from satellite imagery describe only general characteristics of the upper canopy. Detailed vegetation data are available from regional grids of…
Homes constructed adjacent to forests.
In making choices about how to manage the country’s wealth of forest land, stakeholders including U.S. taxpayers—have many choices, all of them with ripple effects that extend far beyond the immediate stands of trees. In the Pacific Northwest, as elsewhere, biophysical, ecological, and socioeconomic factors combine to influence the areas of forest cover…
Decaying stump covered in vegetation in the forest.
How do we promote resistance to disturbance, resilience when disturbance does occur, and forest health in general when forests and landscapes are actively managed for a variety values? How do we manage for sustainability when humans and their consumption patterns are munching up the earth at alarming rates? How do we move beyond the now-controversial ideas…
Water flowing through a rocky stream.
Buffers along streams cover a tremendous proportion of the land base in the forested systems of the western Pacific Northwest. These buffers were designated primarily to conserve and restore habitat for salmon and trout, but conservation of habitat for a number of other organisms also has been implicit in their design. Recent research evaluated the…
Forested landscape from elevated vantage point.
Genetic resource management has historically called for altering the genetic structure of plant populations through selection for traits of interest such as rapid growth. Although this is still a principal component of tree breeding programs in the Pacific Northwest, managing genetic resources now also brings a clear focus on retaining a broad diversity…
Northern flying squirrel.
Forest management throughout the world is producing simplified forests. There is growing concern that these forests maintain neither complete vertebrate communities nor conditions favorable to maintenance of genetic diversity of those vertebrate populations that do find habitat in simply structured stands. Genetics is increasingly being used as a basis for…
Researcher wearing hard hat kneels to measure moss on a tree.
Wild harvest of nontimber forest products (NTFP) contributes to an international commercial trade in plant material—thought to be thousands of tons of raw product valued at billions of dollars. From 1991 through 1998, international trade in pharmaceutical plants alone was valued at over $1 billion, with the United States second only to China in value of export (United Nations Statistics Division…
Geology as destiny: cold waters run deep in western Oregon.
The summer of 2001 brought the second-worst drought on record in Oregon, resulting in historically low streamflows and reservoir levels, stressed aquatic ecosystems, and even dramatic confrontations between irrigators and federal resource agencies in the Klamath basin. These events underscore the critical and growing importance of water availability and…
A stand of trees after being thinned.
Thinning is one of our most important ways to influence tree and stand development. The objectives may include increasing the volume, size, and quality of wood produced from a forest and developing particular stand structures and characteristics for other values, such as wildlife or aesthetics.The Levels-of-Growing-Stock (LOGS) Cooperative was initiated in…
Forest after a wildfire.
Public debate on postfire logging has intensified in recent years, particularly since passage of the "salvage rider" in 1995, directing accelerated harvest of dead trees in the western United States.Supporters of postfires logging argue that it is part of a suite of restoration techniques, and that removal of timber means reduction of fuels for future…
Researcher examines fire scar dates on a stump.
It is widely accepted that wildfire has been part of the Douglas-fir region for millennia, but the variations across space and time in frequency, severity, pattern, and influence of native people are poorly understood. With wildfire raging every summer across parts of the West, interest is growing in the roles of fire in ecosystems, the possible use of…
Graphic depicting simulated changes in vegetation through time.
Developing sustainable forestry practices requires a perspective that encompasses whole and large landscapes, and a broad view of time and geographic space. However, understanding and visualizing the effects of different forest policies on ecological and socioeconomic conditions at such scales is a major challenge.Until recently, we lacked the conceptual…
Is carbon storage enough? Can plants adapt? New questions in climate change research
As it becomes increasingly apparent that human activities are partly responsible for global warming, the focus of climate change research is shifting from the churning out of assessments to the pursuit of science that can test the robustness of existing models. The questions now being addressed are becoming more challenging: Can water-use efficiency of…
A one-half acre gap in tree canopy.
When large trees die, individually or in clumps, gaps are opened in the forest canopy. A shifting mosaic of patches, from small single-tree gaps to very large gaps caused by wildlife, is a natural part of the development of composition and structure in mature forests. Gaps increase the diversity of forests across the landscape and present local…
Decaying logs on the ground in the forest.
Dead wood is a crucial component of healthy, biologically diverse forests. Yet basic information about the distribution and characteristics of snags and down trees in forest of the Pacific Northwest is lacking. Such information is needed to assess wildlife habitat, carbon stores, fuel conditions, and site productivity. Current guidelines for dead wood…
Trees in a forested wetland.
The question has risen over whether forested wetlands in southeast Alaska are suitable for sustainable timber production. A significant factor limiting forest productivity in this region is excess soil moisture. Very little is known about the soil conditions that influence tree growth on forested wetlands. A research study was completed to provide…
Map depicting the range of Forest - Tundra, Lichen Woodland, and Closed Forest in North America.
Only a small boby of research addresses the impacts of timber harvesting in the boreal forest of Alaska. The two projects described here began in 1970 and 1980 to develop more reliable methods of regenerating white spruce—the main commercial species in interior Alaska—from seed, and quantifying vegetation and soil responses.A "by-product" of timber harvest…
A gray jay standing on a nest with eggs.
Future choices in managing federal and private forest lands in the Pacific Northwest, particularly for commodity production, are partly dependent on how the threatened marbled murrelet responds to the Northwest Forest Plan. Is the plan functioning for this elusive species, and are populations stabilized or increasing?Because the murrelet forages at sea but…
Close-up of English ivy.
Settlement of the Pacific Northwest by immigrants from the Eastern United States changed the composition of lowland landscapes from dominance by forests and prairie to dominance by cities, suburbs, agriculture, and transportation infrastructure. Historical disturbance regimes imposed by nature and by indigenous people were disrupted. In the uplands, timber…
Two storage tanks with a building between them.
Changing natural resource policies and new ecosystem management strategies affect the people of the Pacific Northwest. But in what context are these changes happening? How can we measure them? And how are they related to economic and community development activities?When the Northwest Forest Plan was implemented, it included the Northwest Economic…
Dense stand of ponderosa pine forest.
Well-intentioned fire suppression efforts during the last 80 to 100 years have altered the structure of low-elevation forests in the interior Northwest. Historically, nondestructive, frequent, low-intensity fires have given way to larger, infrequent, severe, high-intensity fires. Because of altered fire behavior, forests now have increased fuel, and…
Close-up of a chanterelle mushroom.
the "survey and manage" requirement of the Northwest Forest Plan is a challenge for land managers strapped for time and funds to implement it and for environmentalists concerned about its implementation. Its single species management approach raises some interesting questions.What makes these species rare to begin with? And why have they survived? On the…
Close-up of a northern pocket gopher.
When Mount St. Helens blew in 1980 it took with it some old ideas that have surprised scientists over the intervening 20 years. Traditional wisdom about ecological succession, survival, and disturbance regimes was moved aside by discoveries of the power of time and chance as environmental agents. Theories about recovery and restoration also have been…
Forest covered landscape elevated in topography.
Key to the long-term success of implementing the Northwest Forest Plan (NWFP) is adaptive management—the idea of treating management policies as experiments, learning from them, and using them as a basis for changes and adjustments. Although much of the NWFP involves standards and guides that prescribe future management, and restrictive allocations such as…
Stream with vegetated banks.
Over the years, scientists have published many results from studies about the importance of habitat such as woody debris for supporting fish populations. They also have learned much about the ways in which land management activities can enhance or degrade such habitat. They know much less, however, about the food half of this foo-and-shelter equation.In…
Landscape with rows of plants and a building.
The United States is expected to add around 120 million, an additional 40 percent, to its population in the next 50 years and personal incomes are generally projected to rise. This will inevitably intensify land use pressures. Between 1992 and 1997, USDA's National Resource Inventory estimated that 2.2 million acres of rural land were developed each year,…
People wearing hard hats standing in a field of downed trees.
Mandates to harvest, beetle infestations, log export restrictions, pulp mill closures, high transportation costs, ecological versus economic effects--the litany of challenges in the Alaska timber markets is sufficient to stymie land and timber managers. For decades, they have had to confront and make decisions about these conflicting issues without…
Close-up of an American marten.
Biodiversity has at last become a familiar term outside of scientific circles. Ways of measuring it and mapping it are advancing and becoming more complex, but ways of deciding how to conserve it remain mixed at best, and the resources available to manage dimishing biodiversity are themselves scarce. One significant problem is that policy decisions are…
Two people holding a basket of matsutake mushrooms.
Recreational and tribal use of mushrooms has been historically important, and during the last two decades, commercial demand for mushrooms has burgeoned. A large nontimber forest product market in the Pacific Northwest is for various species of wild edible mushrooms. Many of these species grow symbiotically with forest trees by forming nutrient exchange…
Trees and mossy logs in a forest.
Managing whole ecosystem is a concept gaining considerable acceptance among forest managers throughout the Northwest, but it does not have a clear or simple definition. Terminology and definitions can be confusing.Forests are complex places, formed by complex processes, and the moment we try to simplify, we are likely to damage the healthy functioning of…
Groups of people in a room sitting at round tables.
Traditional scientific assessments have limitations in providing full understanding of the potential impacts forest management has on communities. Much of the knowledge communities have of themselves is inaccessible to quantitative methods but can be provided through participatory processes, or what is termed "civic science." Self-assessment by communities…
Rapid river flowing through expansive landscape.
In the next few decades, hundreds of private dams will be relicensed by the Federal Energy Regulatory Commission. Many of them are on or influence Forest Service lands. Relicensing requires rigorous technical assessments of the effects of dams on critical resources, including channels, aquatic habitat, water quality, and recreation. Dams differ widely in…
Group of people having a discussion in the outdoors.
Bioregional assessments to deal with critical, even crisis, natural resource issues have emerged as important meeting grounds of science, management, and policy across the United States. They are placing heavy demands on science, scientists, and science organizations to compile, synthesize, and produce data, for policy decisions. There is no blueprint for…
Planted row crops with single-family homes in the background.
A concern among land managers is land use. Who is using the land? What is it being used for? Is the amount of farm and forest land lost to development really increasing? Research forester and economist Jeff Kline and research forester Ralph Alig at the PNW Research Station are conducting studies to answer questions about land development in western Oregon…
Logged field with a pen under construction in the center.
Many elk populations in the Northwest are declining (20 to 40 percent or more). Why? Nobody really knows. But the situation calls for a more explicit understanding of the influence of habitat management on elk herd demography and productivity. John Cook and Larry Irwin, scientists with the National Council of the Paper Industry for Air and Stream…
A clearcut forest.
What are the best alternatives for easing conflict among aesthetics, economic values, and sustained wood production of responsible timber harvesting? How can forest managers craft options across a landscape for a mix of values and forest conditions? In part, with an understanding of the interactions of sustained timber production, wildlife habitat, and…
Marten looking out from hollow log.
Twenty years after publication of a report on wildlife habitat in managed east-side forests, Pacific Northwest Research Station scientists Evelyn Bull, Catherine Parks, and Torolf Torgersen, are updating that report and discovering that the current direction for providing wildlife habitat on public forest lands does not reflect findings from research since…
A bear walking along rocky ground.
This issue of Science Findings examines the results of a study designed to provide a broad array of silvicultural options for land managers. Pacific Northwest Research Station scientist Mike McClellan is leading the study and has found that timber harvesting by using alternatives to clearcutting is viable in the current marketplace and technically feasible…
Group of people with forested mountainous landscape in the background.
What lessons does historical disturbance hold for the management of future landscapes? Fred Swanson, a researcher at the Pacific Northwest Research Station and John Cissel, research liaison for the Willamette NF, are members of a team of scientists and land managers who are examining the way we think about and manage landscapes.The team found that past…
Group of cattle drinking at a water trough.
Grazing and how it impacts the landscape is a concern for public and private land managers. This issue of "Science Findings" examines the issue of cattle and grazing and provides some background, perspective, and research results on various grazing systems. Researchers Jim McIver, of the Forest Service's Blue Mountains Natural Resources Institute, and Mike…
Forest after thinning.
Ecosystem function—the internal dynamics of a forest—is now recognized as a crucial component to forest health and biological diversity.Pacific Northwest Research Station scientist Andy Carey and others propose that the presence of small critters can be a measure of a forest's health. His research also shows that thinning, rather than legacy retention,…
Aerial view of a forested landscape and waterbody.
This issue of "Science Findings" focuses on remote sensing research and how it can be used to assess a landscape. The work of PNW Research Station scientists Tom Spies and Warren Cohen and their use of satellite technology in developing the coastal landscape analysis and modeling study (CLAMS) is featured. The CLAMS study area includes more than 5 million…
Flooded area with partially submerged trees and recreational vehicles.
Global warming: Is it real or not? Ron Neilson, PNW Research Station bioclimatologist, has been studying the phenomena for about 25 years. He also is the lead author on one of three models in the world designed to track climate-driven vegetation change patterns on the planet.Neilson's findings, featured in this issue of "Science Findings," may be able to…
Bald eagle holding a carcass in its beak.
This issue of "Science Findings" focuses on ecologist Mary Willson's research in Alaska that has revealed anadromous fish to be "cornerstone species." A cornerstone species provides a resource base to support much of an ecosystem. Anadromous fish, in this case, have been found support much of the Pacific coastal ecosystem. Key findings of Willson's team…
Two people selling chanterelle mushrooms and a counter.
Commercial, recreational, and subsistence harvesting of chanterelle mushrooms in Washington's Olympic Peninsula has long been an issue for managers and harvesters alike. What guidelines should be used to manage nontimber products?Is there concern about possible increased commercial harvesting? Pacific Northwest Research Station scientist Leon Liegel and…
Group of people holding clipboards while having a discussion outside.
Adaptive management. What is it and how can it help us learn? Bernard Bormann, a PNW Research Station scientist, is leading a study on the subject. He defines the term this way: the management of complex natural systems by building on common sense and learning from experience. Experience can often mean change. The challenge of implementing adaptive…
Cougar standing with front paws on a stump.
How can we maintain biodiversity as human population levels continue to increase at a rapid rate? This issue of Science Findings focuses on southern California, one of the richest areas of biodiversity in the country, and home of 1.5 million people. Pacific Northwest Research scientist Ross Kiester, in conjunction with a cooperative research agreement with…
Forest that mostly lacks understory vegetation.
A project in western Washington tries to mimic natural disturbance to create forest structure similar to late-seral stages. A model was developed to identify pathways to achieve this structure with four indices: capacity to support vertebrate diversity, forest floor function, ecological productivity based on tree-using rodents, and production of deer and elk.The study found that maximizing…
Person carrying basket filled with wood on their back.
In a unique effort to compare and contrast differing views on future supply and demand for wood, a study found that demand for wood will increase, but there is no evidence of a crisis at the world scale. Opportunities to increase wood production, however, are limited and trade-offs among competing uses of forests are inevitable. A complex of factors…
Forest with reduced wood fuel in the understory.
Adaptive management is a fusion of science and management used to improve and care for natural resources. This issue of "Science Findings" centers on how this type of management is used to tame wildfire incidents in northeastern Oregon's Blue Mountain range.The following article considers how adaptive management is being used by the La Grande, Oregon-based…
Men standing next to a train car.
As part of the Interior Columbia Basin Ecosystem Management Project, 198 small communities were assessed for their ability to deal with change and the characteristics that contribute to this ability. Scientists conducted on-the-ground studies and had communities assess themselves.The data revealed complex differences, patterns, and underlying relationships…
Landscape of forest, meadows, hills and mountains.
Examining biophysical and social conditions, trends, and opportunities, the Columbia basin assessment draws a composite picture of the basin with two integrated measures: ecological integrity (the presence and functioning of ecological components and processes) and socioeconomic resiliency (the social and economic adaptability of a geographic area to…
Dense forest of small-diameter trees.
Big shifts have been made over the last decade in how society thinks forest lands should be managed. Forest policy has subsequently changed. Land managers now grapple with how to make society's intentions work in the forests of today.This issue of PNW Science Findings presents the Colville study's examination of the vast forests of small-diameter wood in…
A northern spotted owl perched on a tree branch.
The information we bring to the table is usually complex. The April issue of Science Findings illustrates this complexity. Scientific inquiry about an individual species and its habitat requires modeling, assumptions, and time. Uncertainty remains after studies are done. Once policy is made, implementation continues to build new understanding, which may…
Steep hillslope after a landslide.
This issue examines research the Station has been conducting on how catastrophic disturbances affect fish habitat. Whereas our February issue discussed the physical dynamics of a flood on a landscape, here we expand to major disturbances in general while narrowing in a fish habitat still at a landscape scale.Our work in this area is unfolding new knowledge…
Aerial view of flooded area.
In our first issue, we describe research that reflects our responsiveness to natural events and our ability to address issues over time. Floods can bring tragedy in the wake of their destruction. Floods also are a natural process that has shaped our landscapes. We hope that our scientific information helps people make wise choices that influence floods…
Last updated August 4, 2023
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