Research and Publications
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With concern over the health of aspen in the Intermountain West, public and private land managers need better guidance for evaluating aspen condition and selecting and implementing actions that will be effective in restoring aspen health. The Utah Forest Restoration Group collaboratively synthesized a step-by-step approach for aspen restoration that was applicable to western U.S. forests. In a successful case study in shared stewardship, these restoration guidelines were applied to a challenging real-world setting.
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This article analyses homeowners’ decisions to undertake fire-safe investments and create defensible space on their property using a unique dataset from 35 wildland–urban interface communities in Nevada. The dataset combines homeowner information from a mail survey with their observed fire-safe investments obtained through parcel-level hazard assessments. We find that homeowners’ self-reported mitigation expenditures are driven by their subjective beliefs about their wildfire risk, whereas observed defensible space status is driven by their costs of investment. We develop a theoretical model of a homeowner’s fire-safe investment decision that accounts for our empirical results.
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Managers can use the First Order Fire Effects Model (FOFEM) when planning prescribed burns to achieve mortality-related objectives and for creating post-fire salvage guidelines to predict which trees will die soon after fire. Of the preceding observations, 13,460 involved trees that burned twice. Researchers evaluated the post-fire tree mortality models in FOFEM for 45 species. Approximately 75% of models tested in the FOFEM had either excellent or good predictive ability. Models performed best for thick-barked conifer species. Models tend to overpredict mortality for conifers with moderate bark thickness and underpredict mortality in primarily angiosperms or thin-barked conifers. Managers who rely on these models can use the results to (1) be aware of the uncertainty and biases in model predictions and (2) choose a threshold for assigning dead and live trees that optimizes certainty in either identifying or predicting live or dead individuals.
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With remotely-sensed (Landsat) estimates of vegetation cover collected every 2–5 years from southwestern Wyoming, USA, over nearly three decades (1985–2015), we modeled changes in sagebrush cover on 375 former oil and gas well pads in response to weather and site-level conditions. We then used modeled relationships to predict recovery time across the landscape as an indicator of resilience for vegetation after well pad disturbances, where faster recovery indicates a greater capacity to recover when similarly disturbed. We found the rate of change in sagebrush cover generally increased with moisture and temperature, particularly at higher elevations. Rate of change in sagebrush cover also increased and decreased with greater percent sand and larger well pads, respectively. We predicted 21% of the landscape would recover to pre-disturbance conditions within 60 years, whereas other areas may require >100 years for recovery. These predictions and maps could inform future restoration efforts as they reflect resilience. This approach also is applicable to other disturbance types (e.g., fires and vegetation removal treatments) across landscapes, which can further improve conservation efforts by characterizing past conditions and monitoring trends in subsequent years.
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Two weed-suppressive bacteria strains of Pseudomonas fluorescens, known as ACK55 and D7, have been shown to reduce these exotic grass populations in eastern Washington, yet little is known about the efficacy of these or other weed-suppressive bacteria in other areas. Researchers tested the effects of ACK55 and D7 on Bromus tectorum both in the laboratory and at field sites in Montana and Wyoming. The bacteria strains reduced Bromus tectorum germination and root and shoot lengths in Petri-plates, but had no effect on plants during growth chamber plant-soil bioassays or field experiments. Bromus arvensis, a species similar to Bromus tectorum, was also unaffected by the weed-suppressive bacteria. Findings contribute to a growing body of evidence that the ACK55 and D7 are not reliable tools for controlling Bromus tectorum in the Northern Great Plains, Central Rocky Mountains, and elsewhere.
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We used long‐term data from the Utah Division of Wildlife Resources Range Trend Project to assess short‐term (1–4 yr post‐treatment) and long‐term (6–10 yr post‐treatment) effects of fire on vegetation cover at 16 sites relative to sage‐grouse habitat vegetation guidelines. Sagebrush cover remained low post‐fire at sites considered historically unsuitable for sage‐grouse (<10% initial sagebrush cover). In contrast, at sites that had higher (>10%) pre‐fire sagebrush cover, sagebrush cover decreased to <10% in the short‐term post‐fire, but by 6–10 yr after fire, most of these sites exhibited a recovering trajectory and two sites had recovered to >10% cover. Post‐fire sagebrush cover was positively related to elevation. Across all sites, perennial grasses and forbs increased in cover to approximately meet the habitat vegetation guidelines for sage‐grouse. Cheatgrass cover did not change in response to fire, and increased perennial grass cover appears to have played an important role in suppressing cheatgrass. Our results indicate that, while fire poses a potential risk for sage‐grouse habitat loss and degradation, burned sites do not necessarily need to be considered permanently altered, especially if they are located at higher elevation, have high sagebrush cover pre‐fire, and are reseeded with perennial grasses and forbs post‐fire. However, our results confirm that fire at more degraded sites, for example, those with <10% sagebrush cover, can result in cheatgrass‐dominated landscapes and sagebrush loss at these sites should be avoided.
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Study objectives were (1) to quantify the magnitude and direction of change in the cover of native and exotic plant functional groups in relation to their exposure to fire; (2) to relate plant community changes to their historical composition, exposure to fire, and environmental conditions; and (3) to test for consistency of trends revealed by vegetation cover data derived from field plots and Landsat images. Results suggest that burned areas historically occupied by sagebrush‐dominated plant communities may have been invaded by exotic annuals prior to burning, possibly because of prior land uses, and after burning, have now transitioned to a persistent herbaceous‐dominated state. This type of state transition has important consequences for forage quality, wildlife habitat, soil nutrients, and future disturbances, such as drought and wildfire.
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Higher tree density, more fuels, and a warmer, drier climate have caused an increase in the frequency, size, and severity of wildfires in western U.S. forests. There is an urgent need to restore forests across the western United States. To address this need, the U.S. Forest Service began the Four Forest Restoration Initiative (4FRI) to restore four national forests in Arizona. The objective of this study was to evaluate how restoration of ~400,000 ha under the 4FRI program and projected climate change would influence carbon dynamics and wildfire severity from 2010 to 2099. Specifically, we estimated forest carbon fluxes, carbon pools and wildfire severity under a moderate and fast 4FRI implementation schedule and compared those to status quo and no‐harvest scenarios using the LANDIS‐II simulation model and climate change projections.
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Erosion of soil carbon (C) and nitrogen (N) following severe wildfire may have deleterious effects on downstream resources and ecosystem recovery. Although C and N losses in combustion and runoff have been studied extensively, soil C and N transported by post-fire erosion has rarely been quantified in burned landscapes. To better understand the magnitude and temporal pattern of these losses, we analysed the C and N content of sediment collected in severely burned hillslopes and catchments across the western USA over the first 4 post-fire years.
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The South-Central Oregon Adaptation Partnership (SCOAP) was developed to identify climate change issues relevant for resource management on federal lands in south-central Oregon. This science-management partnership assessed the vulnerability of natural resources to climate change and developed adaptation options that minimize negative impacts of climate change and facilitate transition of diverse ecosystems to a warmer climate. The vulnerability assessment shows that the effects of climate change on hydrology in south-central Oregon will be highly significant. Decreased snowpack and earlier snowmelt will shift the timing and magnitude of streamflow; peak flows will be higher, and summer low flows will be lower. Projected changes in climate and hydrology will have far-reaching effects on aquatic and terrestrial ecosystems, especially as frequency of extreme climate events (drought, low snowpack) and ecological disturbances (flooding, wildfire, insect outbreaks) increase.