Treesearch

Background: Drought, human disturbance, and invasive species are reshaping disturbance regimes and increasing the scale, severity, and frequency of wildfire in many ecosystems around the globe, including the sagebrush steppe of western North America. Recent studies suggested greater sage-grouse (Centrocercus urophasianus) adhere to strong site fidelity in the aftermath of wildfire, remaining inside fire perimeters for nesting and brood rearing despite negative consequences for survival and reproduction. Sage-grouse in Idaho exhibited context-dependent changes to space use after a large,...

Many territorial species use vocalizations as a primary form of territory defense, and the areas actively defended do not necessarily correspond with an individual's home range. As passive acoustic monitoring becomes a primary population assessment method for soniferous species, often in combination with occupancy modeling, effective conservation will require more detailed information on species-specific space use to refine interpretation. Northern spotted owls (Strix occidentalis caurina) actively vocalize during the breeding season, but interpreting acoustic data is complicated by...

Large-scale hydrologic models are increasingly being developed for operational use in the forecasting and planning of water resources. However, the predictive strength of such models depends on how well they resolve various functions of catchment hydrology, which are influenced by gradients in climate, topography, soils, and land use. Most assessments of hydrologic model uncertainty have been limited to traditional statistical methods. Here, we present a proof-of-concept approach that uses interpretable machine learning techniques to provide post hoc assessment of model sensitivity and...

The Spotted Turtle (Clemmys guttata) is a small freshwater turtle that is currently under review for federal listing under the U.S. Endangered Species Act. Recent distributional models suggest that Spotted Turtles potentially occur in the eastern panhandle, northcentral, and northern panhandle regions of West Virginia, with previous survey efforts documenting the species at three wetlands in the eastern panhandle. We sampled 62 sites across 41 unique wetlands in West Virginia to assess the contemporary region-scale distribution and identify occupied wetlands. We used the results of these...

Long-term survival of a conservation-reliant species requires understanding the impact of threats on population growth rate and the management actions that can help mitigate these threats. We used a threat assessment with expert-elicited estimates to determine the relative effect of each stage-specific threat on the population growth rate of the wood turtle Glyptemys insculpta. In addition, we offered potential management actions that could mitigate these threats and examined the relative cost and benefit of each. The experts responded that predators had the largest effect on hatchling and...

In late June 2021, multiple days of record-breaking heat caused an unprecedented amount of foliage death in the forests of the Pacific Northwest, USA. Portions of tree canopies with healthy green foliage prior to the heat changed to red or orange shortly after the event. The change in foliage color could be readily seen in satellite imagery and was corroborated as foliar death (heat scorch) by aerial surveys and extensive observations on the ground. To better understand the patterns and processes driving foliar death, we used satellite imagery to identify 293,546 ha of forest, or ~4.7% of...

Increasing wildfire activity in mesic, temperate Pacific Northwest forests west of the Cascade Range crest has stimulated interest in understanding whether alternative forest management practices could reduce risk of stand-replacing fire. To explore how management can enhance fire resistance in these forests and assess tradeoffs among resistance enhancement, carbon sequestration and storage, and economic returns, we conducted 40-year simulations of stand development with BioSum, a framework for conducting landscape analysis with the Forest Vegetation Simulator (FVS), utilizing a statistical...

Increasing wildfire activity and uncharacteristically severe fires in fire-prone forests have intensified longstanding tensions between biodiversity conservation and wildfire risk reduction. In the Pacific Northwest, USA, fire exclusion has been practiced for over a century, driven largely by the perception of wildfire as a destructive force to be minimized. Over the past 35 years, northern spotted owl (Strix occidentalis caurina) conservation has emphasized the protection of closed-canopy, structurally complex, older forests, which are habitat conditions associated with long-term populatio...

Planting a mixture of species during reforestation is of increasing interest, underlying a need to quantify the long-term effects of mixtures on stand development for a wide array of species. Here we report on ∼40 year response of three dual species mixture trials at a moderate quality site in Washington, USA where coast Douglas-fir (DF, Pseudotsuga menziesii var. menziesii) was grown at 3 m spacing in a 50:50 mix with either western hemlock (WH, Tsuga heterophylla), noble fir (NF, Abies procera) or western white pine (WWP, Pinus monticola). Stand metrics were compared for each trial...

Nonnative carp were spotted nearly 75 years ago in eastern Oregon’s Malheur Lake and have subsequently fully colonized the lake and surrounding wetlands, compromising water quality and the growth of native aquatic vegetation eaten by resident and migratory waterfowl. Eradication efforts have proven challenging; only a few carp are needed for the population to rebound. Managers at Malheur Lake are not alone in dealing with this invasive fish; aquatic managers elsewhere in the country face similar issues. Following a Carp Control Workshop in 2010, Jason Dunham, a researcher with the U.S....