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.
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)
Integrating multiple indices of habitat quality to inform habitat management for a sagebrush indicator species by Megan C. Milligan, Peter S. Coates, Shawn T. O'Neil, Brianne E. Brussee, Michael P. Chenaille, Derek A. Friend, Kathleen Steele, Justin R. Small, Timothy S. Bowden (BLM), Arlene D. Kosic, Katherine Miller, Michael L. Casazza. In Ecological Informatics, Volume 90, December 2025.
Robust science is needed to inform natural resource management and policy decisions. Predictive species habitat maps are frequently employed in conservation decision-making but are often based on a single metric representing habitat quality. We outlined a framework that combines multiple spatially explicit indices of potential habitat quality that could be used to identify and prioritize habitat management areas, using the greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) as an example species. Due to large-scale changes in sagebrush ecosystems, sage-grouse have suffered significant population declines in recent decades and have become key to land management plans throughout the western United States, where comprehensive habitat maps are crucial to effective conservation efforts. We evaluated habitat selection and survival patterns of sage-grouse across six distinct annual life stages and seasons to generate predictive habitat map surfaces, mapped the distribution of current occupancy, and combined maps of potential selection and survival patterns with space use and occupancy indices to delineate example habitat management categories. Our approach facilitates identification of priority areas to target for habitat preservation and areas where anthropogenic impacts could occur with likely minimal impact to the species. Overall, by combining indices representing selection, survival, and current occupancy, we provide a framework to allow for a flexible and targeted management approach that could be adapted to a wide variety of species. (Open Access)
A New Marine Vertebrate Assemblage from the Upper Cretaceous Lincoln Limestone, Comanche National Grassland, Southeastern Colorado, USA, with Comments on the Vertebrate Assemblages at or Near the Contact between the Graneros Shale and Greenhorn Limestone in Colorado, Kansas, and Nebraska by Kenshu Shimada, Patrick B. Gonzales, Michael J. Everhart, Gregory A. Liggett (BLM), Denny J. Martin, Bruce A. Schumacher. In Transactions of the Kansas Academy of Science, Volume 128, Issue 3-4, December 2025.
The Lincoln Limestone Member of the Greenhorn Limestone is an Upper Cretaceous sedimentary rock unit formed in the North American Western Interior Seaway during the Cenomanian Stage. Here we report a new Lincoln Limestone fossil vertebrate assemblage from the Comanche National Grassland in southeastern Colorado, USA. The fossil assemblage consists of at least 22 taxa, comprising minimally 11 chondrichthyans, 10 osteichthyans, and one squamate reptile. The new fossil assemblage is compared with other chronologically similar (i.e. putatively late middle-early late Cenomanian) vertebrate assemblages in Colorado, Kansas, and Nebraska, with a revised comparative taxonomic list of those assemblages. Examining stratigraphically well-constrained fossil assemblages shows differing environments and habitat preferences across the Western Interior Seaway. Deeper water localities (Colorado) versus localities nearer to the eastern shoreline (Nebraska) exhibit variation in lithologic and taxonomic compositions due to sea level change through time and space. (Available to BLM employees)
Environmental Characteristics Linked to Successful Introductions of a Rare Wetland Grass (Pleuropogon oregonus) by Stella M. Copeland, Erik P. Hamerlynck, Brandon J. Palmer, Sara I. Sternick, Collin W. Williams, Calla R. Hagle, Carter G. Crouch. In Natural Areas Journal Volume 45, Issue 4, October 2025.
Rare plant conservation often includes introductions via outplantings or seedings, yet these efforts are often unsuccessful. This study leveraged experimental plantings in a successful introduction program to assess environmental characteristics associated with outplanting success (survival, abundance, growth) for a rare grass species, Pleuropogon oregonus (Oregon semaphoregrass), in a large wetland site in eastern Oregon. The study evaluated associations between success and environmental variables suggested by previous observations including soil moisture metrics (based on volumetric water content), light competition (leaf area index), and surface cover with 4 y of transplants. We additionally tested for potential species indicators of successful planting locations. We found that lower survival and abundance of first year plantings were associated with greater light competition. Growing season drought (minimum soil moisture) was nonlinearly related to survival and abundance suggesting that higher moisture conditions can sometimes be favorable. However, prolonged growing season soil moisture (days) was slightly associated with lower survival and abundance. Bare ground cover was positively associated with first year abundance, but was not related to survival. Yearly growth rate was not associated with any environmental variables. Meadow foxtail (Alopecurus pratensis), a common introduced grass also found in natural populations, was an indicator of first year failure. Our results suggest that outplanting efforts for this species should select areas with lower light competition and at least seasonally dry soils for increased initial success. Further research is needed to identify environmental characteristics favoring long-term introduction success, as factors associated with survival were not strongly related to population growth. (Available to BLM employees)
Ferruginous Hawk nest site selection, success, and productivity: Implications for mitigating the effects of natural gas development by Sarah Ramirez, Bryan Bedrosian, Dale Woolwine (BLM), Liba Pejchar. In Biological Conservation, Volume 310, October 2025.
When encroaching development threatens habitat loss for wildlife species, it is crucial to understand the important relationships between wildlife and their environment to best inform mitigation efforts. We investigated factors associated with nest site selection, success, and productivity in a species of conservation concern, the Ferruginous Hawk (Buteo regalis), in a relatively remote landscape prior to planned natural gas development. We used a long-term dataset (2009–2023) and a resource selection function framework to evaluate how nest site selection was influenced by habitat characteristics. We further used generalized linear mixed models to evaluate whether these factors were associated with nest success and productivity. The study area consisted of 1.16 % existing development, yet Ferruginous Hawks selected nest sites in open space developed landcover (cleared vegetation with a singular structure). Nests on anthropogenic structures also had lower nest success and productivity compared to other substrates, suggesting that even very low levels of development can result in an ecological trap. Additionally, Ferruginous Hawks had higher reproductive success farther from secondary roads but showed a complex relationship with proximity to producing natural gas wells. Reproductive success was positively associated with natural covariates, such as terrain ruggedness and grassland landcover, that could serve as a proxy for prey availability. Evaluating factors contributing to nesting demographics prior to the onset of energy development is vital to prevent the local extinction of species that are particularly sensitive to land use change. (Available to BLM employees)
Ecological niche modeling and potential dispersal of emerald ash borer in the Pacific Northwest by Gengping Zhu, Max Ragozzino, Mark Cody Holthouse, Mattthew Mills, Jessica L. Celis (BLM), Stacy Johnson (BLM), and David W. Crowder. In Journal of Economic Entomology, Volume 118, Issue 5, July 2025.
The emerald ash borer, Agrilus planipennis Fairmire (Coleoptera: Buprestidae), is a notorious invasive pest that can devastate ash trees, Fraxinus spp. L., and embedded communities. While emerald ash borer is established in eastern North America, it was recently detected in Forest Grove, Oregon and in Vancouver, British Columbia, raising concerns that it may spread across the Pacific Northwest riparian ecosystems dominated by ash. A quarantine zone has been established in Oregon, but future mitigation depends on assessing the spread to new regions. Here, we used habitat suitability models and dispersal simulations to predict the potential spread of emerald ash borer. Specifically, we compared climate spaces occupied by Oregon and British Columbia populations with other native and introduced populations, and then used habitat suitability models and dispersal simulations to predict future distributions. We show that the newly established Oregon and British Columbia populations currently occupy relatively narrow climate niche, and many suitable niche spaces are unoccupied in the Pacific Northwest, indicating potential for range expansion. We also show there are vast areas of suitable habitat that extend south of the present quarantine zone throughout inland western Oregon and north into Washington. In Vancouver, the most suitable habitat was found along the Fraser River, where emerald ash borer could disperse inland. Dispersal models suggest that, without intervention, emerald ash borer could disperse into Washington within 2 yr, throughout western Oregon in 15 yr, and reach California in 20 yr. Our work supports intensive quarantine efforts for emerald ash borer and identifies areas where monitoring and management efforts should focus. (Open Access)