Treesearch

The wildfires that burned in the Northern Rockies region of the USA during the 2017 fire season provided an opportunity to evaluate the suitability of using broadscale and temporally limited infrared data on hot spot locations to determine the influence of several environmental variables on spotting distance. Specifically, correlations between the maximum observed spot fire distance for each unique combination of fire and day and geo-referenced environmental data on wind speed, vegetation, and terrain, along with specific fire characteristics (size, fire perimeter shape, and growth), were...

Remotely sensed radiation, attractive for its spatial and temporal coverage, offers a means of inferring energy deposition in fires (e.g. on soils, fuels and tree stems) but coordinated remote and in situ (in-flame) measurements are lacking. We relate remotely sensed measurements of fire radiative energy density (FRED) from nadir (overhead) radiometers on towers and the Wildfire Airborne Sensor Program (WASP) infrared camera on a piloted, fixed-wing aircraft to energy incident on in situ, horizontally oriented, wide-angle total flux sensors positioned,0.5 m above ground level. Measurements...

The fates of native bee communities in the Great Basin sagebrush steppe are linked with the susceptibilities of their floral hosts to increasingly frequent wildfires. Postfire survival and subsequent flowering of six prevalent perennial wildflowers representing five families were quantified across a range of realistic fire severities created using a calibrated propane burn barrel. Five burn prescriptions of varying intensity and duration were applied to cultivated rows of basalt milkvetch (Astragalus filipes Torr. ex A. Gray), Blue Mountain prairie clover (Dalea ornata Eaton & J. Wright),...

US public land management agencies are faced with multiple, often conflicting objectives to meet management targets and produce a wide range of ecosystem services expected from public lands. One example is managing the growing wildfire risk to human and ecological values while meeting programmatic harvest targets for economic outputs mandated in agency budgets. Studies examining strategic management tradeoffs on federal lands and program efficiencies are rare. In this study we used the 79 western US national forests to examine tradeoffs between forest management scenarios targeting...

Risk management typologies and their resulting archetypes can structure the many social and biophysical drivers of community wildfire risk into a set number of strategies to build community resilience. Existing typologies omit key factors that determine the scale and mechanism by which exposure from large wildfires occur. These factors are particularly important for land managing agencies like the US Forest Service, which must weigh community wildfire exposure against other management priorities. We analyze community wildfire exposure from national forests by associating conditions that...

Outdoor recreation is increasingly recognized to impact nature and wildlife, yet few studies have examined recreation within large natural landscapes that are critical habitat to some of our most rare and potentially disturbance-sensitive species. Over six winters (2010-2015) and four study areas (> 1.1 million ha) in Idaho,Wyoming, and Montana, we studied the responses of wolverines (Gulo gulo) to backcountry winter recreation. We fit Global Positioning System (GPS) collars to 24 individual wolverines and acquired > 54,000 GPS locations over 39 animal-years during winter (January-April)....

A major task for researchers in the twenty-first century is to predict how climate-mediated stressors such as wildfires may affect biodiversity under climate change. Previous model predictions typically did not address non-stationarity in climate-fire relationships across time and space. In this study, we applied spatially-explicit non-stationary area burned projection models to evaluate recent and future climate-driven trends in area burned across the ranges of three spotted owl subspecies in the western United States. We also used high-severity fire probability models to evaluate the...

Context: Habitat loss and fragmentation are the most pressing threats to biodiversity, yet assessing their impacts across broad landscapes is challenging. Information on habitat suitability is sometimes available in the form of a resource selection function model developed from a different geographical area, but its applicability is unknown until tested. Objectives: We used the Mexican spotted owl as a case study to demonstrate how models developed from different geographic areas affect our predictions for habitat suitability, landscape resistance, and connectivity. We identified the most...

Background: Historical forests (circa 1799 to 1846) of Indiana were predominantly composed of American beech (25% of all trees) and upland oaks (27% of all trees). I compared historical forest composition, using studies of smaller areas to approximate composition for uncommon species or genera (< 4.5% of all trees) and forest types, to current forest composition and forest types in Indiana. I also compiled published historical density estimates from small studies and estimated current density for the state. Results: Current forests are diverse with an even composition of many eastern...

Occupancy-based surveys are increasingly used to monitor wildlife populations because they can be more cost-effective than abundance surveys and because they may track multiple species, simultaneously. The design of these multi-species occupancy surveys affects statistical power to detect trends in occupancy because individual species vary in resource selection, detection probability, and rarity. We tested for differences in the ability of a large-scale monitoring program to detect changes in single-species occupancy of 13 medium–large mammal species captured on n = 183 cameras systematical...