Geology topics

Sarah K. Carter

Publications and source records attributed to Sarah K. Carter.

At least 19 recordsLinked to original sources

USGS2026

Colocating artificial intelligence data centers with energy infrastructure on Federal public lands—A science synthesis and spatial analysis to inform decision making

Executive Summary Artificial intelligence (AI) is rapidly transforming industries and economies, creating an urgent need to strategically plan for the energy and infrastructure required to support increasing AI use. U.S. Federal agencies and bureaus have been directed to explore ways to accelerate permitting, development, and deployment of energy resources and AI technologies, including encouraging the colocation of energy infrastructure and data centers. To inform these initiatives, this report synthesizes relevant scientific information and presents a spatial analysis of existing energy infrastructure and data centers on or near U.S. Federal public lands managed by the Bureau of Land Management (BLM). The purpose of this science synthesis and spatial analysis is to provide the BLM with foundational information for considering potential colocation of data centers with energy infrastructure on Federal public lands to support evidence-based decisions. Additionally, this report provides insight into current (2025) and potential future energy demands by providing projections of a range of potential future environmental conditions relevant to maintaining industry-recommended cooling temperature standards necessary for efficient data center operations. As a part of this effort, a rapid response literature review was conducted of the best available science on the topic of data center development and energy infrastructure in July–August 2025, supplemented by additional resources recommended by U.S. Federal agency and bureau subject matter experts (hereafter experts; including the U.S. Department of Energy National Laboratory of the Rockies) and peer reviewers. To better understand current conditions relevant to AI data center development, a spatial analysis was conducted across Alaska and 11 States in the Western United States, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming, all of which contain extensive BLM-managed surface lands (hereafter referred to as “BLM lands”) that could be considered for the colocation of energy infrastructure and AI data centers. This effort identified BLM lands within 10 miles of existing transmission lines, consistent with methods used in previous BLM programmatic environmental impact statements. This report describes the types of data centers operating within the United States, which vary in ownership, size, technology, and proximity to end users. This report then outlines the primary considerations of data center development, including reliable energy supply, natural resources (such as water availability to support cooling requirements), and relevant policy and regulatory considerations. Energy supply considerations are pivotal for data center operation. Between 2014 and 2018, data centers in the United States accounted for nearly 2 percent of the Nation’s total electricity consumption, and data center energy consumption is projected to increase from 2 to 6.7–12 percent of total U.S. electricity use by 2028. These energy requirements necessitate careful consideration of energy supply when considering potentially suitable locations for data center development. Experts anticipate that an increase in renewable energy generation will likely support most potential future power demand needs, including for data centers, followed by increases in natural gas, nuclear, and geothermal energy production. Additional capacity in the form of battery storage will likely not generate electricity, but may improve the reliability and flexibility of supply, helping to ensure that growing data center loads can be met. However, the U.S. Department of Energy estimates that the United States will need, on average, 57 percent more energy transmission infrastructure by 2035 to account for the growing power demand introduced by development such as data centers. Cooling server equipment in data centers requires large amounts of electricity and water, and this demand can be exacerbated by hot and humid conditions. Energy efficient water-based cooling technologies may reduce electricity consumption onsite but require more water consumption. This additional water demand has the potential to increase water stress and competition with other users. As such, developing data centers will likely need a thorough assessment of current and potential future water availability, as well as consideration of how water demand may change across other sectors. Data center development involves policy and regulatory considerations, as projects must undergo environmental review and authorization processes that can take 18–24 months. Coordinating these environmental reviews and authorizations with other energy development projects, such as building new transmission lines, may cause additional delays. Recent efforts by the U.S. Department of Energy and U.S. Department of the Interior aim to expedite environmental reviews and authorizations and improve coordination across agencies. The spatial analysis identified 771 existing AI data centers and more than 3,300 power plants. The spatial analysis found that 6 percent of AI data centers and 22 percent of power plants in the Western United States were on or within 1 mile of BLM lands, and California had the largest number of facilities. Most existing AI data centers were near high-voltage transmission lines and close to power plants, supporting efficient energy delivery. More than 90,000,000 acres of BLM lands were within 10 miles of existing high-voltage transmission lines, representing 38 percent of BLM lands in the study area. Available transmission infrastructure and the overlap with BLM lands varied by State, and Alaska had limited overlap compared to the rest of the Western United States. To operate most efficiently, data center temperatures must be at or below 80.6 degrees Fahrenheit. This analysis of future temperature and precipitation projections indicated increasing cooling demands for data centers, particularly in Arizona, California, and Nevada, where rising temperatures are expected to increase energy and operational costs while potentially stressing current regional electrical grid infrastructure. This report highlights relevant energy supply, natural resources, and regulatory considerations for data center development on BLM lands. This report does not provide a comprehensive ecological, regulatory, land suitability, or permitting analysis. The factors described here are contextual considerations only and are not intended to identify, rank, quantify, or recommend optimal areas for data center colocation. This spatial analysis focused solely on energy considerations relevant to data centers and did not consider water availability, critical habitats, BLM National Conservation Lands, areas of cultural or historical significance, and other sensitive resources. These topics are recognized as critical but were not within the scope of this science synthesis and spatial analysis.

Scientific Investigations Report↗

USGS2026

Science strategy for Cotoni-Coast Dairies, an onshore unit of the California Coastal National Monument

This science strategy describes the scientific mission of the unit, science previously conducted on or near the unit, and the partners who have given considerable effort to produce this science. Further, it identifies priority science needs, outlines the unit’s plan to meet those science needs in coordination with partners, shares scientific protocols for conducting new research, and identifies systems of communication to help ensure science information generated from this research is shared throughout BLM, with partners, and with the public. These components of the science strategy are intended to help achieve the fundamental goals of the effort: to support and expand partnerships while identifying priority science information needs of unit staff and partners and clearly outlining pathways for conducting, communicating, and applying that science.

California↗

USGS2026

Cumulative effects analysis to inform public land management in the United States: Key characteristics and legal challenges

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.

Alaska, Colorado↗

USGS2025

A habitat suitability model for testing and refining the range of Zuni fleabane, a threatened plant species

Land managers and conservation practitioners need practical tools to protect rare species in light of rapidly changing climate and land use patterns. Habitat suitability models are tools that can inform multiple-use land management decisions and target conservation actions. The narrow endemic Zuni fleabane Erigeron rhizomatus occurs on lands managed for multiple uses and was listed as threatened under the US Endangered Species Act in 1985 due to the main threat of surface mining. Despite intermittent surveys in recent decades, managers still do not have a comprehensive understanding of suitable habitat characteristics or the geographic extent of suitable habitat across its range. We developed and field-validated a habitat suitability model for Zuni fleabane using an iterative, ensemble approach. We tested the null hypothesis that the model would not identify major new populations outside the known range but rather assist in refining the boundaries of known suitable habitat. We also set out to improve our understanding of biotic and abiotic characteristics that define suitable habitat across geographically distant metapopulations. Our model identified areas with low, medium, high, and very high probability of containing suitable habitat. We identified a new metapopulation beyond the 3 known (disproving our null hypothesis), as well as additional suitable habitat within the previously known regions. This model predicts where Zuni fleabane habitat likely occurs and may help land managers and conservation practitioners identify new populations, survey habitat at fine scales, avoid impacts from multiple-use management activities, and recover this threatened species.

Arizona, New Mexico↗

USGS2025

Potential risks of vegetation treatments to introduce and increase invasive annual grasses in rangelands of Montana, North Dakota, and South Dakota— A science synthesis to inform National Environmental Policy Act analyses

The U.S. Geological Survey is working with Federal land management agencies to develop a series of planned structured science syntheses to support environmental effects analyses that agencies conduct under the National Environmental Policy Act (NEPA). This report synthesizes science information relevant to environmental effects analyses concerned with potential increases in the distribution and abundance of invasive annual grasses (IAGs) from proposed vegetation treatments for habitat restoration. The focal environments for this synthesis are rangelands in the intermontane valleys of Montana and the northern Great Plains of Montana, North Dakota, and South Dakota. The synthesis is organized to align with the standard elements of NEPA analyses and provides information on relevant scientific studies, data availability, analysis methods, and mitigation measures. We found that the likelihood of increasing IAGs from vegetation treatments depends on treatment type and environmental context. In sagebrush ecosystems of the focal region, prescribed fire often reduces or does not increase IAGs. Treatments that cause soil disturbances, such as mechanical removals of sagebrush or firebreak constructions, are more likely to increase IAGs than other treatments. Herbicides applied to reduce sagebrush cover have not increased the proportion of IAGs in the plant community. Temperature and precipitation have been strong factors in determining IAG responses to vegetation treatments in sagebrush ecosystems of the focal region, where more precipitation in spring and summer likely provides a competitive edge to native, perennial grasses more than winter annual grasses like Bromus tectorum L. (cheatgrass). In grasslands, prescribed fire often reduces IAGs, but effects depend on the abundance of native species and are often short lived. Mowing can increase or decrease IAGs in grassland ecosystems. Grassland site conditions, such as southeast-facing slopes, sandier or rockier sites, or lower native species cover or richness affect the likelihood of invasion by annual grasses. Maintaining adequate cover of perennial vegetation creates rangelands that are resistant and resilient to annual grass invasions. Managers can minimize invasion potential by focusing on treatment type, placement, and seasonal timing. Herbicides also can provide effective mitigation, especially in combination with other controls such as prescribed fire or grazing. This report can be incorporated by reference in NEPA documentation, included in a project record, or provide a general reference for understanding and identifying literature about increases in IAGs associated with vegetation treatments in rangelands in this focal region.

Montana, North Dakota, South Dakota↗

USGS2025

Scientific opportunities in the National Landscape Conservation System

The National Landscape Conservation System consists of unique and beautiful places across America’s landscapes where identified resources and values are protected and science is highlighted. The mission of the National Landscape Conservation System (NLCS), which is managed by the Bureau of Land Management and is often referred to as the agency’s National Conservation Lands, is to conserve, protect, and restore nationally significant landscapes for their cultural, ecological, and scientific values. This clear inclusion of science in the NLCS mission sets the stage for individual units to serve as places of learning, teaching, discovery, and innovation. Science is an integral part of managing the National Conservation Lands, and science conducted within and across the more than 900 units that make up the NLCS can inform and influence conservation and public land management well beyond its boundaries. Here, we highlight seven core aspects of National Conservation Lands that present valuable science opportunities: (1) the scientific values for which individual units are designated; (2) the many other resources, objects, and values within units; (3) the value of units as “control” sites for understanding the effects of activities such as mineral extraction that commonly occur elsewhere on multiple-use public lands but are often prohibited within National Conservation Lands; (4) the value of units for studying the effects of activities such as recreation that regularly occur and may be intensified on National Conservation Lands; (5) the high visibility of units, which draws strong interest and engagement from scientists, partners, and the public; (6) the functioning of the units as a network managed for a common purpose, which provides an opportunity to explore cross-cutting science questions across widely varying contexts and geographies; and (7) the opportunities units provide to promote and apply Indigenous Knowledge to scientific research to manage natural and cultural resources. Because of all of these characteristics, National Conservation Lands can serve as hubs for basic and applied science that can inform management of all public lands and resources into the future. We highlight these science opportunities through examples from existing units and suggest two actions that could help further science activities and impact on National Conservation Lands.

Parks Stewardship Forum↗

USGS2025

Climate consideration in environmental effects analyses on federal public lands in the United States

Effects of a changing climate, including drought, wildfire, and invasive species encroachment, are evident on public lands across the United States. Decision making on Federal public lands requires analyses under the National Environmental Policy Act (NEPA), and there are guidelines for considering climate in NEPA analyses. To better understand how climate most recently has been considered, we analyzed a stratified random sample of 130 environmental assessments (EAs) completed by the Bureau of Land Management (BLM) from 2021 to 2023 across the contiguous United States. We assessed whether EAs considered (1) potential effects of the proposed action on climate (2) potential climate effects on the proposed action, and (3) potential climate effects on resources of concern. We also identified whether EAs included data and science about climate or greenhouse gas emissions, and which datasets and documents were cited. We used two approaches: automated keyword searches and document analysis. Thirty-seven percent of EAs considered the potential effects of the proposed action on climate, 8% considered the potential effects of climate on the proposed action, and 4% of individual resource analyses considered the potential effects of climate on the resource. EAs in the ‘oil and gas development,’ ‘renewable energy,’ and ‘forestry and timber management’ proposed action categories most frequently considered the potential effects of climate and used climate data and science. Our findings suggest an opportunity for scientists to work more closely with public land managers to identify available data and science for considering climate in environmental effects analyses and to provide science delivery mechanisms that can facilitate the consideration and use of climate science in decision making.

Environmental Management↗

USGS2025

Effects of nonmotorized recreation on ungulates in the western United States—A science synthesis to inform National Environmental Policy Act analyses

The U.S. Geological Survey is working with Federal land management agencies to develop a series of science syntheses to support National Environmental Policy Act (NEPA) analyses. This report synthesizes science information about the potential effects of nonmotorized recreation on ungulates in the western United States. We conducted a structured literature search to find published science, data, and analysis methods about the characteristics of nonmotorized recreation, ungulate exposure and response to nonmotorized recreation, and approaches to mitigate negative effects of nonmotorized recreation on ungulates. The sections of the report align with standard elements of the NEPA analysis process. We found that timing, intensity, duration, and spatial distribution of nonmotorized recreation are important factors to understand when assessing effects of recreation on ungulates. Several aspects of ungulate biology, which vary by species, population, and individual, affect ungulate susceptibility to effects from recreation, including diet, migration and movement, and seasonal biology. Techniques for assessing effects include basic spatial analyses based on buffers around trails and recreation sites and more technical analytical methods based on displacement or avoidance of recreation sites. Options for mitigating negative effects of nonmotorized recreation on ungulates include timing and type-of-use restrictions, recreator education, and project design features to avoid human-ungulate conflicts. Public land managers can use this report by incorporating it by reference in NEPA analyses or as a general reference to find literature or identify gaps in the literature about the effects of noise from nonmotorized recreation on ungulates.

Scientific Investigations Report↗

USGS2025

Mapping predicted ecological states at landscape scales using remote sensing data and machine learning

Dryland ecosystems, covering 45% of the Earth's land and supporting over one-third of the global population, face significant threats from land degradation and ecological state change. Managing these ecosystems is complex, and science-based frameworks like Ecological Site Descriptions and state-and-transition models are essential tools for guiding decisions to support ecological health while maintaining stakeholder values such as grazing, wildlife, and recreation. However, alignment of these frameworks with smaller scale soil survey maps limits their applicability to broader ecological processes. Here, we extend these frameworks to larger landscapes with a machine learning approach that integrates large-scale, high-resolution vegetation data with identified ecological states from a data-driven state-and-transition model developed for a landscape-scale Ecological Site Group. A “global” model, which used combined inputs from multiple remotely sensed datasets, outperformed individual dataset models based on evaluation with independent data. Ecological state maps generated through this approach broaden the utility of state-and-transition models across Ecological Site Groups, providing a more spatially robust tool for land management at watershed and larger landscape scales. These methods, and the associated ecological state maps, can help meet critical needs for improved land condition assessments that support development of resource management plans and help identify priority areas for restoration and conservation.

Arizona, Colorado, New Mexico, Utah, Wyoming↗

USGS2025

Exploring the science and data foundation for Federal public lands decisions

Public lands provide diverse resources, values, and services worldwide. Laws and policies typically require consideration of science in public lands decisions, and resource managers are committed to science-informed decision-making. However, it can be challenging for managers to use, and document the use of, science and data in their decisions. To better understand science and data use in Federal public lands decisions in the United States, we assessed the number, type, and age of documents cited in 70 Environmental Assessments (EAs) completed by the Bureau of Land Management (BLM) in Colorado from 2015–2019. We focused on the BLM, as they manage the largest area of public lands in the United States. We selected Colorado as our study area, as actions proposed on BLM lands in Colorado are representative of those across the nation. Fifty percent of citations were categorized as science and 23% as data. EAs contained an average of 17 citations (range 0–111), with documents analyzing effects of oil and gas development and recreation actions including the highest and lowest mean number of citations (41 and 6, respectively). Of individual resource analysis sections within EAs, 24% contained ≥1 science citation and 21% contained ≥1 data citation. Journal articles were the most cited type of document (26% of citations) followed by non-BLM inventories (13%). Forty-seven percent of citations were relatively recent (2010 or later); the oldest citation was from 1927. Commonly analyzed resources with the highest mean number of citations were socioeconomics, mineral resources, and noise. Fourteen of 33 commonly analyzed resources included <1 citation on average. Actions and resources with no or few citations represent opportunities for strengthening the transparent use of science and data in public lands decision-making.

Colorado↗

USGS2024

Identifying priority science information needs for managing public lands

Public lands worldwide provide diverse resources, uses, and values, ranging from wilderness to extractive uses. Decision-making on public lands is complex as a result and is required by law to be informed by science. However, public land managers may not always have the science they need. We developed a methodology for identifying priority science needs for public land management agencies. We relied on two core data sources: environmental effects analyses conducted for agency decisions and legal challenges to those decisions. We considered needs in four categories: data, science, methods, and mitigation measures. We classified topics as primary science needs when (1) the topic was analyzed frequently in agency environmental analyses, (2) our metric of quality/defensibility was low or mitigation measures were frequently included for the topic, and (3) the agency was challenged on its use of science for the topic. We applied our methodology to the Bureau of Land Management—the largest public land manager in the United States—in Colorado, a state with abundant and diverse public lands. Primary identified needs were data on vegetation; science about effects of oil and gas development and livestock grazing on multiple resources, including terrestrial wildlife; methods for analyzing environmental effects for many topics; and mitigation measures for protecting vegetation, soils, water quality, and archaeological and historic resources. Science needs often reflect needs for facilitating and supporting the use of existing science in agency decision-making. Our method can be applied across agencies, geographies, and timeframes to help strengthen science use in public lands decision-making.

Environmental Management↗

USGS2024

Effects of noise from oil and gas development on raptors and songbirds—A science synthesis to inform National Environmental Policy Act analyses

The U.S. Geological Survey is working with Federal land management agencies to develop a series of science syntheses to support environmental effects analyses that agencies conduct to comply with the National Environmental Policy Act (NEPA). This report synthesizes science information about the potential effects of noise from oil and gas development on North American raptors, songbirds, and other small avian species. We conducted a structured search of published scientific literature to find information about noise levels produced during oil and gas development, methods for analyzing sound propagation, the effects of noise on avian species, and measures to reduce noise emissions. We follow the organization first established in U.S. Geological Survey Scientific Investigations Report 2023-5114, in which the report sections align with standard elements of NEPA analyses. We found that oil and gas development is a common source of human-caused noise on public lands and includes noise sources such as heavy construction and drilling machinery, long-term production machinery, truck traffic, and aircraft. Common techniques for predicting potential noise include field data collection using a sound level meter, inference from previously published data, and sound propagation modeling. The effects of human-caused noise on songbirds are well researched, whereas, among raptors, only owl species have been well-studied in relation to noise. Several studies have established that noise can reduce owl hunting success because many owl species are heavily reliant on hearing prey when hunting. The effects of noise on songbirds depend on several factors. Typically, birds that rely on vocal communication for mating, predator detection, and spatial orientation, and that are less able to adjust the frequencies of their vocalizations, are more vulnerable to behavioral changes and decreased fitness in noisy areas. Techniques suggested in the literature for reducing noise emissions include artificial sound barriers, seasonal and daily timing restrictions, traffic control measures, and siting infrastructure to take advantage of natural sound barriers. Public land managers can use this report by incorporating it by reference in NEPA documentation, as supplemental information, or as a general reference to find literature or identify gaps in the literature about the effects of noise from oil and gas development on raptors and songbirds.

Scientific Investigations Report↗

USGS2024

Structured science syntheses to inform decision making on Federal public lands

The U.S. Geological Survey, Bureau of Land Management, and U.S. Fish and Wildlife Service partnered to develop a new type of science product: the structured science synthesis. Structured science syntheses are peer-reviewed reports that synthesize science information about a priority resource management issue on public lands. Structured science syntheses are developed explicitly to facilitate the application of science to decision making. Key characteristics of structured science syntheses include that they are coproduced with resource managers, developed using clear, repeatable methods and designed for ease of use. The syntheses include different types of science information needed for analyses completed under the National Environmental Policy Act.

Fact Sheet↗

USGS2024

Modeling rare plant habitat together with public land managers using an iterative, coproduced process to inform decision-making on multiple-use public lands

Public lands across the United States are managed for multiple uses, resources, and values ranging from energy development to rare plant conservation. Intensified energy development and other land use changes across the Southwestern United States have increased the need for proactive management to mitigate impacts to rare plants. Habitat suitability models can inform decision-making and lead to more effective conservation of rare plants and their habitats, but high-quality models that are suited for use at local scales are lacking for many species. Our team of scientists and managers developed ensembles of habitat suitability models for five rare plant species in New Mexico using a coproduced, iterative framework complemented by comprehensive ground truthing and tailoring of products for use in public land decisions. Our process resulted in substantial differences from initial models through changes to environmental predictors, species occurrence and background data, and development of new species-specific predictors. Involving species experts and end users in model development can strengthen the process and resulting model and build understanding and trust in final products. Both factors can promote use of models to inform public land permitting and planning decisions that may affect rare plants, including by guiding development away from highly suitable habitats.

Colorado, New Mexico↗

USGS2024

Accuracy, accessibility, and institutional capacity shape the utility of habitat models for managing and conserving rare plants on western public lands

Public lands are often managed for multiple uses ranging from energy development to rare plant conservation. Habitat models can help land managers assess and mitigate potential effects of projects on rare plants, but it is unclear how models are currently being used. Our goal was to better understand how staff in the Bureau of Land Management currently use habitat models to inform their decisions, and perceived challenges and benefits associated with that use. We first examined litigation documents to determine whether the agency has been challenged on its use of data for rare plants and found no relevant legal challenges. Second, we analyzed model use in National Environmental Policy Act (NEPA) documents and found no clear citations of habitat models. Finally, we conducted interviews with agency staff who analyze potential effects of proposed actions on rare plants in NEPA documents. The primary challenges interviewees faced in using models related to data organization and access, model quality and accuracy, and institutional capacity. Interviewees believed models could be used more to inform decisions and actions to conserve rare plants and rare plant habitat on public lands and recommended improving staff access to models, creating models for additional species, and addressing staffing limitations.

Arizona, California, Colorado, New Mexico, Utah, W↗

USGS2024

Effects of culverts on habitat connectivity in streams—A science synthesis to inform National Environmental Policy Act analyses

The U.S. Geological Survey is working with Federal land management agencies to develop a series of science syntheses to support environmental effects analyses that agencies conduct to comply with the National Environmental Policy Act (NEPA). This report synthesizes science information about the potential effects of culverts on stream connectivity and subsequent effects on fish. We conducted a structured search of published scientific literature to find information about (1) culvert design, installation, and degradation; (2) methods for analyzing culvert condition and quantifying stream connectivity; and (3) the effects of changes to stream connectivity on freshwater fish. We follow the organization first established in U.S. Geological Survey Scientific Investigations Report 2023-5114, in which the report sections align with standard elements of NEPA analyses. We found that, while the effects of dams on stream biota are well documented, smaller barriers at road crossings, like culverts, are prevalent and collectively have a substantial effect on habitat connectivity. Individual culverts differ in the degree to which they impede the movement of aquatic organisms, and we documented methods to assess and estimate the permeability of a culvert, or the ability of aquatic organisms to pass through it. Finally, we outlined methods for using culvert location and permeability information to quantify connectivity in a watershed based on the Dendritic Connectivity Index. Studies have shown that channel constriction, perched outlets, and extreme flow velocities are some of the characteristics of culverts that may hinder aquatic organism passage. Culverts can serve as daily and seasonal barriers to fish, disrupting access to habitat and essential resources like cold water or overwintering refuges. Reduced connectivity can have population-level effects, leading to lower fish species richness and abundance in affected watersheds. Public land managers can use this report by incorporating it by reference in NEPA documentation, as supplemental information, or as a general reference for literature about the effects of culverts on stream connectivity and freshwater fish.

Scientific Investigations Report↗

USGS2024

A habitat suitability model for testing and refining the range of Zuni fleabane, a threatened plant species

Land managers and conservation practitioners need practical tools to protect rare species in light of rapidly changing climate and land use patterns. Habitat suitability models are tools that can inform multiple-use land management decisions and target conservation actions. The narrow endemic Zuni fleabane, Erigeron rhizomatus, occurs on lands managed for multiple uses and was listed as threatened under the Endangered Species Act in 1985 due to the main threat of surface mining. Despite intermittent surveys in recent decades, managers still do not have a comprehensive understanding of suitable habitat characteristics or the geographic extent of suitable habitat across its range. We developed and field-validated a habitat suitability model for Zuni fleabane using an iterative, ensemble approach. We tested the null hypothesis that the model would not identify major new populations outside the known range but rather assist in refining the boundaries of known suitable habitat. We also set out to improve our understanding of biotic and abiotic characteristics that define suitable habitat across geographically distant metapopulations. Our model identified areas with low, medium, high, and very high probability of containing suitable habitat. We identified a new metapopulation beyond the three known (disproving our null hypothesis) as well as additional suitable habitat within the previously known regions. This model predicts where Zuni fleabane habitat likely occurs and may help land managers and conservation practitioners identify new populations, survey habitat at fine scales, avoid impacts from multiple-use management activities, and recover this threatened species.

EcoEvoRxiv↗

USGS2023

Annotated bibliography of scientific research on greater sage-grouse published from October 2019 to July 2022

Integrating recent scientific knowledge into management decisions supports effective natural resource management and can lead to better resource outcomes. However, finding and accessing scientific knowledge can be time consuming and costly. To assist in this process, the U.S. Geological Survey (USGS) created a series of annotated bibliographies on topics of management concern for western lands. Previously published reports introduced a methodology for preparing annotated bibliographies to facilitate integration of recent, peer-reviewed science into resource management decisions. Therefore, relevant text from those efforts is reproduced here and built on to incorporate new information. The greater sage-grouse (Centrocercus urophasianus; hereafter “GRSG”) has been a focus of scientific investigation and management action for the past two decades. The 2015 U.S. Fish and Wildlife Service listing determination of “not warranted” under the Endangered Species Act was in part a result of a large-scale collaborative effort to develop strategies to conserve GRSG populations and their habitat and to reduce threats to both. New scientific information augments existing knowledge and can help inform updates or modifications to existing plans for managing GRSG and sagebrush ecosystems. However, the sheer number of scientific publications can be a challenge for managers tasked with evaluating and determining the need for potential updates to existing planning documents. To assist in this process, the USGS has reviewed and summarized the scientific literature published since January 1, 2015. Our most recent GRSG literature summary was published in 2020 (Carter and others, 2020) and included products published through October 2, 2019. Here, we consider products published between October 2, 2019, and July 21, 2022. We compiled and summarized peer-reviewed journal articles, data products, and formal technical reports (such as U.S. Department of Agriculture Forest Service General Technical Reports and USGS Open-File Reports) on greater sage-grouse. We first systematically searched three reference databases and three government databases using the search phrase “greater sage-grouse.” We refined the initial list of products by removing (1) duplicates, (2) publications not published as research, data products, or scientific review articles in peer-reviewed journals or as formal technical reports, and (3) products for which greater sage-grouse was not a research focus or the study did not present new data or findings about greater sage-grouse. We summarized each product using a consistent structure (background, objectives, methods, location, findings, and implications) and identified management topics addressed by each product; for example, species and population characteristics. We also identified projects that provided new geospatial data. The review process for this annotated bibliography included two initial internal colleague reviews of each summary, requesting input on each summary from an author of the original publication, and formal peer review. Our initial searches resulted in 221 total products, of which 147 met our criteria for inclusion. Across products summarized in the annotated bibliography, broad-scale habitat characteristics, behavior or demographics, site-scale habitat characteristics, habitat selection, and population estimates or targets were the most commonly addressed management topics. The online version of this bibliography, which will be available on the Science for Resource Managers tool ( https://apps.usgs.gov/science-for-resource-managers ), will be searchable by topic, location, and year, and will include links to each original publication. The studies compiled and summarized here may inform planning and management actions that seek to maintain and restore sagebrush landscapes and GRSG populations across the GRSG range.

Open-File Report↗