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.

Range-wide occupancy trends for the Mojave desert tortoise (Gopherus agassizii) by Amanda M. Kissel, Bryan Wallace, Jessie Anderson, Brett G. Dickson, Kristen Van Neste, Vincent Landau, Roy C. Averill-Murray, Linda J. Alison, and Amy Fesnock. In Ecosphere, 14, 1. April 2023.

Data from long-term monitoring programs, such as the US Fish and Wildlife Service (USFWS) line distance sampling (LDS) program for Mojave desert tortoises (Gopherus agassizii), are increasingly being used in new ways to elucidate trends in population dynamics. We used the USFWS LDS data in a novel way to generate range-wide predictions of occupancy, colonization, and local extinction rates from 2001 to 2018. We developed a dynamic occupancy model to answer fundamental questions posed by Bureau of Land Management personnel regarding how G. agassizii are distributed across the landscape over space and time. We transformed the LDS data into detection/nondetection data and constructed a Bayesian dynamic occupancy model using several time-varying (e.g., temperature, precipitation, normalized difference vegetation index, fire, and a proxy for invasive grasses) and static covariates (e.g., soil properties, topography, distance to roads, distance to urban areas) hypothesized to influence G. agassizii occupancy dynamics. We estimated that over the entire time series (2001–2018) the probability of G. agassizii occupancy is declining in over one quarter (26%) of the range, largely in the northeastern part of the range, but that from 2011 to 2018, 77% of the range has a declining trend. Drawing on these model outputs, we developed an interactive, web-based tool for exploring trends in dynamic occupancy across the species range, allowing users to focus on areas of management interest or concern.(Available to BLM employees)

Using Public Litigation Records To Identify Priority Science Needs For Managing Public Lands by Alison C. Foster, Sarah K. Carter, Travis S. Haby, Leigh D. Espy, and Malia K. Burton. In Ecology and Society, 28, 1. March 2023.

Relevant science is essential for effective natural resource decision making, including on public lands managed by the United States Department of the Interior (DOI) Bureau of Land Management (BLM), that cover 1/10th of the United States. Most of the BLM’s management decisions require analyses under the National Environmental Policy Act, and the use of science in these decisions is often challenged. Using coproduction, we assembled an interagency team of scientists and resource managers to develop a method for using public litigation to identify priority science needs for the BLM. We searched publicly available case documents finalized from 2015–2019 in Wyoming, Colorado, Utah, and New Mexico within federal courts and the DOI Office of Hearings and Appeals, and identified 108 case documents that involved challenges to the BLM’s use of science. We retained 48 case documents that contained at least one challenge about the BLM’s use of science for a specific resource. We categorized all challenges in each case document according to the proposed action, affected resource, type of science challenged (data about resources, science relevant to potential impacts, methods for analyzing potential impacts, and mitigation actions), and specific nature of the challenge (e.g., challenging direct effects analysis). We identified priority science needs based on the frequency of challenges, the number of states where similar challenges occurred, whether the BLM lost the challenge, and whether the case was remanded. Top needs related to oil and gas development actions and included science about effects on air quality and climate, water, and socioeconomics; data for air quality and climate; and methods for analyzing potential impacts to cultural resources and air quality and climate. The BLM can use this information to prioritize actions (e.g., funding new research or science syntheses) to strengthen its science foundation for decision-making.(Available to BLM employees)

Monitoring Grazing Use: Strategies for Leveraging Technology and Adapting to Variability by Andrew R. Kleinhesse, Emily J. Kachergis, Sarah E. McCord, Justin Shirley, Nicole R. Hupp, Jennifer Walker, John C. Carlson, Scott L. Morford, Matthew O. Jones, Joseph T. Smith, Brady W. Allred, David E. Naugle. In Rangeland Ecology and Management, 87, 1-12. March 2023. 

The US Bureau of Land Management (BLM) manages nearly 1 million km2 of public lands that support recreation, livestock production, and wildlife habitat. Monitoring the condition of vegetation on these lands is crucial for sound management but has historically been difficult to do at scale. Here we used newly developed remote-sensing tools to conduct an unprecedented assessment of trends in vegetation cover and production for all BLM rangelands from 1991 to 2020. We found widespread increases in cover and production of annual grasses and forbs, declines in herbaceous perennial cover, and expansion of trees. Cover and production of annual plants now exceed that of perennials on > 21 million ha of BLM rangeland, marking a fundamental shift in the ecology of these lands. This trend was most dramatic in the Western Cold Desert of Nevada and parts of surrounding states where aboveground production of annuals has more than tripled. Trends in annuals were negatively correlated with trends in bare ground but not with trends in perennials, suggesting that annuals are filling in bare ground rather than displacing perennials. Tree cover increased in half of ecoregions affecting some 44 million ha and underscoring the threat of woodland expansion for western rangelands. A multiscale variance partitioning analysis found that trends often varied the most at the finest spatial scale. This result reinforces the need to combine plot-level field data with moderate-resolution remote sensing to accurately quantify vegetation changes in heterogeneous rangelands. The long-term changes in vegetation on public rangelands argue for a more hands-on approach to management, emphasizing preventative treatment and restoration to preserve rangeland habitat and functioning. Our work shows the power of new remote-sensing tools for monitoring public rangelands and developing effective strategies for adaptive management and conservation.(Available to BLM employees)

Long-Term Trends in Vegetation on Bureau of Land Management Rangelands in the Western United States by Vincent Jansen, Alexander C.E. Traynor, Jason W. Karl, Nika Lepak, James Sprinkle. In Rangelands, 44(1), 64-77. February 2022.

During grazing permit renewals, the Bureau of Land Management assesses land health using indicators typically measured using field-based data collected from individual sites within grazing allotments. However, agency guidance suggests assessments be completed at larger spatial scales. We explored how the current generation of remotely sensed data products could be used to quantify aspects of land health at watershed scales in Colorado to provide broad spatial and temporal context for the land health assessment process. We found multiple indicators could be quantified using these data products and were relevant to land health standards. Within focal watersheds, bare ground cover decreased over the past 30 years, while annual herbaceous cover has increased over the last 10 years. Vegetation productivity was variable over time, but interannual fluctuations were consistent across watersheds. Remotely sensed data products can help resource managers understand how current conditions relate to broad spatial and temporal trends in the region and could provide another line of evidence for the land health assessment process. They may also identify target areas where management strategies, such as eradication of invasive annual grasses, should be focused, and could help resource managers communicate complex issues to the public. (Available to BLM employees)

Adaptive Monitoring for Multiscale Land Management: Lessons Learned from the Assessment, Inventory, and Monitoring (AIM) Principles by Emily Kachergis, Scott W. Miller, Sarah E. McCord, Melissa Dickard, Shannon Savage, Lindsay V. Reynolds, Nika Lepak, Chris Dietrich, Adam Green, Aleta Nafus, Karen Prentice, Zoe Davidson (Authors are all BLM). In Rangelands, 44(1), 50-63. February 2022.

Land management and natural resource decisions play an increasingly crucial role amidst many simultaneous changes occurring on rangelands globally. Ongoing changes include 1) intensifying and diversifying land uses; 2) expectations of multiple ecosystem services from rangelands; 3) multiscale management objectives; and 4) novel weather, climate, and disturbance patterns and species assemblages. Traditionally, managers attempt to match monitoring efforts to individual issues or management questions on a case-by-case basis to guide rangeland management. Although this approach may provide high-quality data to answer a specific question in an area, it is not robust to the spectrum of changes that land managers are experiencing and it results in inconsistent monitoring efforts across landscapes and land uses. In contrast, rangeland monitoring information is most valuable when collected consistently, through long-term efforts addressing multiple objectives and different scales of land management decisions. This information empowers decision-makers to man- age change through adaptive land management. The challenge is to create a flexible, multiscale monitoring program that is both feasible to implement at broad scales and responsive to local-scale management questions. In addition, the program must overcome the significant institutional hurdles to establishing and sustaining monitoring, and adapt through time as new information emerges and questions change (“adaptive monitoring”). (Available to BLM employees)