BLM Library Science Spotlight
The Department of the Interior bases its decisions on the best available science (DOI Secretarial Order 3369). Bureau of Land Management employees actively participate in this process by regularly contributing new science to their fields. This page features current science being published by BLM authors, or supported by BLM expertise and resources.
Access to these articles is limited to BLM employees unless they are noted as Open Access.
Whitebark pine growth dynamics reflect diverse responses to climate and patterns related to bark beetle-caused mortality by Hannah R. Alverson (BLM) Diana L. Six. In Forest Ecology and Management, Volume 619, November 2026, 124056.
In order to conserve high-elevation forest ecosystems, we must understand how cold-adapted tree species respond to climatic shifts and biotic disturbances. We examined growth rates and climatic sensitivities of whitebark pine (Pinus albicaulis) across arid and mesic sites and evaluated their association with mortality caused by mountain pine beetle (Dendroctonus ponderosae). We assessed whether populations were energy- or water-limited, whether recent warming has shifted these limitations, and if shifts corresponded with beetle outbreaks. We also investigated if growth rate and climate sensitivity influenced tree survival. Historically, whitebark pine populations were primarily energy-limited, with growth increasing when warming began around 1940. A transition toward moisture limitation emerged only at the warmest mesic site as warming intensified and droughts became hotter in the 2000s. Contrary to expectations, beetle outbreaks occurred only at cooler arid sites, where trees showed positive growth responses to warmer temperatures, even during drought, while no outbreaks developed at mesic sites where growth declined during hot drought. Trees that survived outbreaks differed in growth from those that were killed, but whether surviving trees grew faster or slower varied among populations. Trees killed by beetles were no more or less sensitive to climate than survivors prior to the outbreak. These results suggest that for now, negative effects on growth due to a warming climate may be limited to warmer sites but that as temperature and growth rates increase and increase water demand, negative effects will become more widespread. Our findings challenge assumptions derived from lower-elevation moisture-limited forests and suggest that there are fundamentally different mechanisms governing beetle outbreaks in energy-limited whitebark pine ecosystems.
Field-based soil characterization in AIM monitoring: A case study of reliability challenges in North‑Central Montana. Hunter S. Stier , Michael Borgreen (BLM), Heather Nenninger (BLM), Anthony S. Hartshorn, Lance B. McNew. In Rangelands, Available online 18 July 2026. Contact the BLM Library for access.
Accurate soil assessments are essential for identifying ecological sites, which underpin effective rangeland monitoring and management decisions. Our study found poor agreement between two field crews and laboratory measurements of soil texture, with discrepancies contributing to misclassification of ecological sites. Over 80% of ecological site classifications differed between two trained field crews, highlighting challenges in standardizing field-based protocols. Some soil properties, like effervescence and structure, showed higher interrater reliability, suggesting a potential for more consistent field evaluation. Improving technician training, incorporating calibration with lab data, and refining plot-characterization strategies could enhance the accuracy and reliability of ecological site assessments across rangelands.
Nest Site Selection of American Goshawks in the Southern Rocky Mountains by Derek Schleicher (BLM), David Mcnitt (BLM), Claire Varian-Ramos, and Nate Bickford. In The Southwestern Naturalist, Volume 70, Issue 3, July 2026, pages 1-14.
In western U.S. forests, public land agencies must balance conserving wildlife while managing for wildfire mitigation, forest health, and the creation of forest products. Large-scale forest disturbance, including forestry treatments, wildfires, and insects and pathogens, can have mixed impacts on wildlife. These processes can have negative effects on wildlife habitat, particularly for species like the American Goshawk (Astur atricapillus), which prefer high canopy cover and complex forest structures. In the southern Rocky Mountains, years of fire suppression and various disturbance types have degraded goshawk nesting habitats. Thus, the species' habitat needs make it vulnerable to forest disturbance that impact critical nesting conditions. From 2022-2024, we assessed how forest disturbance, forest structure and composition, and other environmental factors influenced goshawk nest site selection (area within 30 meters of nest), selection within nesting home ranges in southern Colorado in a use versus availability framework. We used a resource selection function (RSF) with known nesting locations and systematic sampling points within their nesting home range. We found that goshawks selected nest sites in relatively high-elevation forests with dense canopies, on south and east-facing slopes, and a high terrain wetness index. These findings suggest land managers in southern Colorado should retain moderate-to-dense canopy cover, prioritize protection of mid-elevation, east-facing, and moisture-rich forest stands, and carefully plan fuel treatments to avoid high-quality nesting sites.
Extensive Use of Agricultural and Conservation Fields by Male Greater Sage-Grouse in Washington State by Peter J. Olsoy, Michael A. Schroeder, Michael Atamian, Jason Lowe (BLM), Daniel H. Thornton. In Rangeland Ecology & Management, Volume 106, May 2026, pages 70-77.
Greater sage-grouse (Centrocercus urophasianus) have declined across much of their range, including extirpation of many populations at the range edge. Along the northwestern range edge in Washington state, sage-grouse populations must persist within a landscape that contains heavily fragmented sagebrush habitat surrounded by a matrix of agricultural fields. Recently, two of the Washington populations were extirpated and two others declined sharply, highlighting the need to better understand how resident populations have adapted to a fragmented agriculture-dominated landscape to aid management decisions. We analyzed GPS collar data from 24 male sage-grouse in Washington to assess habitat selection. Sage-grouse used shrub-steppe more than any other landcover class, but less than it was available on the landscape, suggesting not all shrub-steppe is of equal quality for sage-grouse. Notably, sage-grouse utilized both agricultural and conservation fields (i.e., Conservation Reserve Program (CRP) and State Acres for Wildlife Enhancement [SAFE]) more than they were available across the landscape, but that use varied seasonally with the most use occurring in the lekking and summer seasons. Use of fallow fields peaked between June and August, while winter wheat fields were primarily used from August to October, suggesting these fields were supplying important supplemental resources during those times (e.g., wheat kernels after harvest). Sage-grouse tended to stay closer to the edge of agricultural fields and nearer to shrub-steppe than random locations, indicating that the complex mosaic of landcover types on the landscape may aid persistence. These results highlight the need for nuanced land management for sage-grouse in Washington. Importantly, this confirms the need to maintain CRP and SAFE fields in Washington to slow population declines. Open Access.
Ice patterns and trends of Teshekpuk Lake: Alaska’s longest seasonally ice-covered freshwater system by Christopher D. Arp, Allen C. Bondurant, Katie A. Drew (BLM), and Mary E. Szatkowski (BLM). In Arctic Science, Volume 12, March 2026, p 1-17.
At 850 km2, freshwater Teshekpuk Lake stands out among abundant thermokarst lakes of the Arctic Coastal Plain of northern Alaska. Its size, latitude, and proximity to the Beaufort Sea coast make long (>9 months) seasonal ice cover its dominant regime, which may play an essential role in the region’s habitat. Despite these important characteristics related to ice cover, little scientific attention has been given to this lentic system. Here, we present field and remote sensing data documenting ice-cover patterns and trends on this very large Arctic lake. Most striking is the lake’s historically short open-water season, which we estimate only lasted 59 days in 1979 and has progressively gotten longer due to both earlier ice-out (4 days per decade) and later freeze-up (3 days per decade). Observation-informed maximum ice thickness has averaged 1.7 m over the last 49 years, ranging between 1.2 m in 2019 and 2.3 m in 1976. Extensive ice thickness and snow depth surveys conducted in April 2024 using ice-penetrating radar and unmanned aerial vehicle imaging are helping us understand surface patterns across this massive lake in relation to winter wind fetch, pressure ridges, and bathymetry. This study provides the first comprehensive analysis of Teshekpuk Lake’s ice conditions and dynamics. Open Access.
Cumulative effects analysis to inform public land management in the United States: Key characteristics and legal challenges by Tait K. Rutherford, Tim O. Hammond (BLM), Alison C. Foster, Megan A. Gilbert (BLM), Travis S. Haby (BLM), Richard J. Lehrter (BLM), Jennifer K. Meineke, Ella M. Samuel, Sarah K. Carter. In Environmental Impact Assessment Review, Volume 117, March 2026, 108158.
Considering potential cumulative effects of proposed actions is fundamental to environmental impact analysis. However, cumulative effects analyses historically are not robust, especially for site-specific decisions. We sought to identify opportunities to strengthen cumulative effects analysis in a large United States public land management agency, the Bureau of Land Management (BLM). We asked 1) how cumulative effects analyses were legally challenged, 2) how site-specific cumulative effects analyses aligned with policy and compared to the broader-scale analyses to which they tiered, and 3) whether characteristics of cumulative effects analyses varied with category of proposed action, type of resource, or agency office. We used thematic analysis to assess litigation and appeals case documents finalized from 2010 to 2020 and a set of document analysis questions to assess National Environmental Policy Act (NEPA) analyses for BLM decisions completed prior to 2020 in Alaska and Colorado. We found that legal challenges related to cumulative effects focused on absence of cumulative effects analysis. In NEPA analyses, cumulative effects were frequently considered, but elements recommended in policy, such as citations, methods, and scope, were rarely included. These elements were present more often in the broader analyses to which site-specific analyses tiered. Many elements of cumulative effects analyses varied by proposed action and BLM office, and analyses of potential cumulative effects on air quality were consistently more detailed than for other resources. Our results suggest that many problems that historically plagued cumulative effects analysis persist. Advances in methods, training, and guidance could strengthen the defensibility of NEPA analyses. (Open Access)
An inland arctic biface production site in the Northern Brooks Range (Alaska, USA) by Noah Steuri, Crystal L. Glasburn (BLM), Albert Hafner, Joshua D. Reuther, and Gino Caspari. In Quaternary International, Volume 766, March 2026, 110256.
This paper presents initial results from an exploratory ground survey and test excavation conducted near Galbraith Lake in the Atigun Valley of Alaska's central Brooks Range. Combining pedestrian survey with UAV-based aerial reconnaissance, the study aimed to identify prehistoric campsites and assess site formation processes in this inland Arctic landscape. A limited test excavation at site PSM-077 revealed a lithic assemblage dominated by bifaces and debitage, consistent with on-site lithic reduction activities during the early-to-middle Holocene. Although stratigraphic integrity has been affected by periglacial processes, two radiocarbon dates indicate episodes of site use at approximately 10,500–10,250 and 4800–4500 cal BP. These ages, together with the characteristics of the lithic assemblage, suggest anthropogenic activity potentially involving both American Paleoarctic and Northern Archaic traditions. These findings highlight the long-term use of strategic locations along inland corridors by Arctic hunter- gatherers over several millennia and underscore the importance of continued research in the interior of northern Alaska. Future work integrating landscape-based survey methods, lithic analysis, radiocarbon data, and Indigenous knowledge offers a promising avenue for refining interpretations of human-environment interactions among prehistoric hunter-gatherers in the Brooks Range. (Open Access)
Invasion resistance varies by fuel break type in sagebrush ecosystems by Austin L. Nash, Brianne E. Brussee, Cali L. Weise, Douglas J. Shinneman, Susan K. McIlroy, Sarah C. Webster, Steven R. Mathews, Seth J. Dettenmaier, Lea A. Condon, Michele R. Crist (BLM), Cameron L. Aldridge, Julie A. Heinrichs, Mark A. Ricca, Shawn T. O’Neil & Peter S. Coates. In Fire Ecology, March 2026, p 47.
Wildfire is an increasingly important driver of changes within sagebrush (Artemisia spp. L.) ecosystems of the western USA, often resulting in increased spread of exotic annual grasses, such as cheatgrass (Bromus tectorum L.), and subsequent losses of native vegetation and wildlife habitat. Fuel breaks— areas of land treated to reduce or redistribute fuel loads — are widely implemented to help prevent the spread of wildfires and provide areas to facilitate firefighting efforts. However, localized installation and maintenance of fuel breaks directly reduce or remove vegetation and may propagate the spread of exotic annual grasses into fuel break boundaries and surrounding areas, inadvertently weakening ecological resilience to disturbance. To investigate if exotic annual grass cover was associated with mowed or green strip fuel breaks across the sagebrush biome, we combined multiple data sources and methodologies. We used targeted field surveys and land-management agency monitoring data within a space-for-time substitution framework coupled with a progressive-change before-after control-impact (PC BACI) study design using historical remotely sensed vegetation cover data which allowed us to account for potential confounding effects of roads on annual grass cover. (Open Access)
Lentic Riparian Meadows May Be Critical for Monitoring Trends for Grazing by Sabrina McCue (BLM), Sherman Swanson, Jacob Burdick. In Rangelands, Volume 48, Issue 1, February 2026, p 23-32.
Lentic riparian meadows provide essential habitat for many wildlife species, including sage-grouse that rely on stored soil water for green forbs in dry summers. Proper riparian functioning-condition assessment is the first step in integrated riparian management, because many riparian areas are at risk of incision and dehydration. Free-roaming horses were as much as or more attracted to riparian areas than cattle during the summer growing season. Combined use was impairing riparian functions and dehydrating and shrinking meadows. The grazing-response index compared grazing effects by focusing on the opportunity to grow or regrow when not being grazed as well as on the frequency and intensity of grazing. Our results suggest the need for movement of livestock to result in less stress and more recovery by monitoring actual use, including when and where grazing occurs. Adjusting horse numbers to achieve appropriate management levels is essential to meet the land’s health standards focused on watershed riparian functions. In many locations, quantitatively monitoring trends in lentic riparian areas will help to adjust appropriate management levels. Dominance of riparian stabilizers along the greenline or in the vegetated drainageway should be the key indicator focusing the objective. (Available to BLM employees)
Extensive Use of Agricultural and Conservation Fields by Male Greater Sage-Grouse in Washington State by Peter J. Olsoy, Michael A. Schroeder, Michael Atamian, Jason Lowe (BLM), Daniel H. Thornton. In Rangeland Ecology & Management, Volume 106, February 2026, pg 70-77.
Greater sage-grouse (Centrocercus urophasianus) have declined across much of their range, including extirpation of many populations at the range edge. Along the northwestern range edge in Washington state, sage-grouse populations must persist within a landscape that contains heavily fragmented sagebrush habitat surrounded by a matrix of agricultural fields. Recently, two of the Washington populations were extirpated and two others declined sharply, highlighting the need to better understand how resident populations have adapted to a fragmented agriculture-dominated landscape to aid management decisions. We analyzed GPS collar data from 24 male sage-grouse in Washington to assess habitat selection. Sage-grouse used shrub-steppe more than any other landcover class, but less than it was available on the landscape, suggesting not all shrub-steppe is of equal quality for sage-grouse. Notably, sage-grouse utilized both agricultural and conservation fields (i.e., Conservation Reserve Program (CRP) and State Acres for Wildlife Enhancement [SAFE]) more than they were available across the landscape, but that use varied seasonally with the most use occurring in the lekking and summer seasons. Use of fallow fields peaked between June and August, while winter wheat fields were primarily used from August to October, suggesting these fields were supplying important supplemental resources during those times (e.g., wheat kernels after harvest). Sage-grouse tended to stay closer to the edge of agricultural fields and nearer to shrub-steppe than random locations, indicating that the complex mosaic of landcover types on the landscape may aid persistence. These results highlight the need for nuanced land management for sage-grouse in Washington. Importantly, this confirms the need to maintain CRP and SAFE fields in Washington to slow population declines. (Open Access)