Treesearch

An often-overheard phrase, "there is no future without smoke," describes fire, and associated smoke, as an ecological process inextricably tied to Western forests. While fire can provide many benefits such as reducing fuels and renewing forests, smoke from fires poses a serious challenge to public health, land managers, and air quality regulators. So, can we reduce these challenges?Spanish version: https://research.fs.usda.gov/treesearch/67848

Climate change affects populations over broad geographic ranges due to spatially autocorrelated abiotic conditions known as the Moran effect. However, populations do not always respond to broad-scale environmental changes synchronously across a landscape. We combined multiple datasets for a retrospective analysis of time-series count data (5–28 annual samples per segment) at 144 stream segments dispersed over nearly 1,000 linear kilometers of range to characterize the population structure and scale of spatial synchrony across the southern native range of a coldwater stream fish (brook...

On Earth Day, 2022, the White House issued an executive order requiring federal agencies to inventory the mature and old-growth forests on Federal lands, to complete this inventory within a year of the order, and to make it available to the public. This order extended from the 2021 Bipartisan Infrastructure Law (i.e., the Infrastructure Investment and Jobs Act 2021), which invested $5.5 billion over 5 years to address some of the USDA Forest Service’s most pressing issues, including the increased risk of wildland fire, ecosystem restoration, and the conservation of old-growth forests. To...

Contrary to broad perceptions, high mountain streams are warming more slowly than low-elevation streams and rivers. Studies by Rocky Mountain Research Station (RMRS) scientists and their collaborators show that they will sustain populations of cold-water species, including fish such as threatened bull trout and cutthroat trout, even as the climate warms. This is also good news for other animals dependent on cold-water systems, including birds such as the American dipper and harlequin duck, mammals such as river otters, and insects such as stone flies and mayflies, which are critical to...

In the westernmost Canadian province of British Columbia, fishers (Pekania pennanti) occur in low-elevation forested ecosystems in the central and northern portions of the province, with several substantial mountain ranges and rivers bisecting this distribution. The effect of these geographic features on gene flow and population structuring is unknown and may contribute to fishers differentiating into 2 or more populations within the province. To better understand population structuring within the range of fishers in British Columbia, we collected tissue samples from 491 fishers from...

Background: Wildfire is a major proximate cause of historical and ongoing losses of intact big sagebrush (Artemisia tridentata Nutt.) plant communities and declines in sagebrush obligate wildlife species. In recent decades, fire return intervals have shortened and area burned has increased in some areas, and habitat degradation is occurring where post-fire re-establishment of sagebrush is hindered by invasive annual grasses. In coming decades, the changing climate may accelerate these wildfire and invasive feedbacks, although projecting future wildfire dynamics requires a better understandi...

Soil organic matter decomposition and its interactions with climate depend on whether the organic matter is associated with soil minerals. However, data limitations have hindered global-scale analyses of mineral-associated and particulate soil organic carbon pools and their benchmarking in Earth system models used to estimate carbon cycle-climate feedbacks. Here we analyse observationally derived global estimates of soil carbon pools to quantify their relative proportions and compute their climatological temperature sensitivities as the decline in carbon with increasing temperature. We...

Surface mining may be humanity’s most tangible impact on Earth’s surface and will become more prevalent as the energy transition progresses. Prediction of post-mining landscape change can help mitigate environmental damage, but requires understanding how mining changes geomorphic processes and variables. Here we investigate surface mining’s complex influence on surface processes in a case study of mountaintop removal/valley fill (MTR/VF) coal mining in the Appalachian Coalfields, USA. The future of MTR/VF landscapes is unclear because mining’s effects on geomorphic processes are poorly...

Infrequent, large-magnitude discharge (>10 6 m 3/s) outburst floods - megafloods - can play a major role in landscape evolution. Prehistoric glacial lake outburst megafloods transported and deposited large boulders (≥4 m), yet few studies consider their potential lasting impact on river processes and form. We use a numerical model, constrained by observed boulder size distributions, to investigate the fluvial response to boulder deposition by megaflooding in the Yarlung-Siang River, eastern Himalaya. Results show that boulder deposition changes local channel steepness (ksn) up to ∼180%...

Erosion following human disturbance threatens ecosystem health and inhibits effective land use. Mountaintop removal/valley fill (MTR/VF) mined landscapes of the Appalachian Coalfields region, USA, provide a unique opportunity to quantify the geomorphic trajectory of disturbed lands. Here we assess how MTR/VF-induced changes to topography and vegetation influence spatiotemporal erosion patterns in five mined watersheds. We use landscape evolution models starting from pre- and post-MTR/VF topographic data to isolate the influence of mining-induced topographic change. We then constrain ranges...