Treesearch

Wildland fires are globally widespread, constituting the primary forest disturbance in many ecosystems. Burn severity (fire-induced change to vegetation and soils) has short-term impacts on erosion and post-fire environments, and persistent effects on forest regeneration, making burn severity data important for managers and scientists. Analysts can create atlases of historical and recent burn severity, represented by changes in surface reflectance following fire, using satellite imagery and fire perimeters. Burn severity atlas production has been limited by diverse constraints outside the...

Multiple research and management partners collaboratively developed a multiscale approach for assessing the geomorphic sensitivity of streams and ecological resilience of riparian and meadow ecosystems in upland watersheds of the Great Basin to disturbances and management actions. The approach builds on long-term work by the partners on the responses of these systems to disturbances and management actions. At the core of the assessments is information on past and present watershed and stream channel characteristics, geomorphic and hydrologic processes, and riparian and meadow vegetation....

Increased wildfire activity combined with warm and dry post-fire conditions may undermine the mechanisms maintaining forest resilience to wildfires, potentially causing ecosystem transitions, or fire-catalyzed vegetation shifts. Stand-replacing fire is especially likely to catalyze vegetation shifts expected from climate change, by killing mature trees that are less sensitive to climate than juveniles. To understand the vulnerability of forests to fire-catalyzed vegetation shifts it is critical to identify both where fires will burn with stand-replacing severity and where climate conditions...

Increases in burned area across the western United States (US) since the mid‐1980s have been widely documented and linked partially to climate factors, yet evaluations of trends in fire severity are lacking. Here we evaluate fire severity trends and their interannual relationships to climate for western US forests from 1985 to 2017. Significant increases in annual area burned at high severity (AABhs) were observed across most ecoregions, with an overall eightfold increase in AABhs across western US forests. The relationships we identified between the annual fire severity metrics and...

Bark beetle outbreaks alter forests in many ways including stand structure, fuels and fire behavior, wildlife habitat, and aesthetic value. Less understood are the effects outbreaks have on understory vegetation, despite the importance for overstory succession, nutrient cycling, water quality, soil erosion, and wildlife. Beetle outbreaks also change forests in ways that could promote invasion by nonnative weeds, but this is rarely studied. We assessed changes in cover of understory vegetation and presence/abundance of weeds in lodgepole pine forests in Colorado, Idaho, Montana, Utah and...

Researchers are increasingly examining patterns and drivers of postfire forest recovery amid growing concern that climate change and intensifying fires will trigger ecosystem transformations. Diminished seed availability and postfire drought have emerged as key constraints on conifer recruitment. However, the spatial and temporal extent to which recurring modes of climatic variability shape patterns of postfire recovery remain largely unexplored. Here, we identify a north–south dipole in annual climatic moisture deficit anomalies across the Interior West of the US and characterize its...

Continuing long and extensive wildfire seasons in the Western US emphasize the need for better understanding of wildfire impacts including post-fire management scenarios. Advancements in our understanding of post-fire hillslope erosion and watershed response such as flooding, sediment yield, and debris flows have recently received considerable attention. The potential impacts of removing dead trees, called salvage logging, has been studied, however the use of remotely sensed imagery after salvage logging to evaluate spatial patterns and recovery is novel. The 2015 North Star Fire provided...

Despite widespread interest in white‐tailed deer (Odocoileus virginianus) in the southeastern United States, historical deer populations and densities have not been compiled into one accessible source. We digitized maps from 1950, 1970, 1982, and 2003 and reviewed literature to quantify population sizes and densities in the Southeast, although previous estimates may not be accurate. Deer population sizes declined to a minimum of <215,000 during the early 1900s. Population sizes and mean deer densities were 304,000 and 0.22 deer/km2 by 1940, 476,000 and 0.35 deer/km2 by 1950, 2.9 million to...

Why do recreational carrying capacity standards change over time? When shared evaluative standards change at a recreational destination, what are the social processes that might lead people to evaluate “how many is too many” differently over time? This study examined how 24-year changes in personal, social, and experiential characteristics of boaters at the Apostle Islands National Lakeshore were related to changes in their evaluation of encounters with other boaters. The results showed that boaters had become more tolerant of encounters over time. This normative change was associated with...

We discovered unique Douglas-fir open woodlands in the Umatilla National Forest using historical surveys. Historical ponderosa pine forests of the western United States are transitioning to denser forests comprised of a greater proportion of fire-sensitive species, including true firs. We used historical (1879 to 1887) surveys to quantify the composition and structure of the Umatilla National Forest in eastern Oregon andWashington and provided contemporary forest information for comparison. We also modeled fir and pine distributions using environmental predictors and the random forests and...