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Montana is rich in minerals, energy, and soils, as well as prairies, forests, mountains, rivers, lakes, fish, and wildlife. Many enterprises that drive the economy are based on natural resources, including tourism, hunting, fishing, agriculture, and energy development. The outdoor-recreation economy alone supports 64,000 Montana jobs and generates nearly \$6 billion each year in economic activity.
The contribution of science to the development and implementation of policy is typically neither direct nor transparent. In 1995, the U.S. Fish and Wildlife Service (FWS) made a decision that was unprecedented in natural resource management, turning to an unused and unproven decision process to carry out trust responsibilities mandated by an international treaty. The decision process was adopted for the establishment of annual sport hunting regulations for the most economically important duck population in North America, the 6 to 11 million mallards Anas platyrhynchos breeding in the mid-continent region of north-central United States and central Canada. The key idea underlying the adopted decision process was to formally embed within it a scientific process designed to reduce uncertainty (learn) and thus make better decisions in the future. The scientific process entails use of models to develop predictions of competing hypotheses about system response to the selected action at each decision point. These prediction not only are used to select the optimal management action, but also are compared with the subsequent estimates of system state variables, providing evidence for modifying degrees of confidence in, and hence relative influence of, these models at the next decision point. Science and learning in one step are formally and directly incorporated into the next decision, contrasting with the usual ad hoc and indirect use of scientific results in policy development and decision-making. Application of this approach over the last 20 years has led to a substantial reduction in uncertainty, as well as to an increase in transparency and defensibility of annual decisions and a decrease in the contentiousness of the decision process. As resource managers are faced with increased uncertainty associated with various components of global change, this approach provides a roadmap for the future scientific management of natural resources.
Accurate reconstructions of past environmental changes are crucial in paleoecological research and require reliable chronologies of sedimentary archives. Establishing robust age-models and obtaining the most appropriate proxies for analysis is a complex scientific endeavor, requiring extensive resources and collaboration among specialists, including radiochronologists. Radiometric dating methods, such as 210 Pb and radiocarbon ( 14 C), are frequently employed to establish chronologies in aquatic sedimentary deposits and peat bogs. In this study, we review key aspects of sampling, analysis, and the principles underlying 210 Pb and 14 C age-models, focusing on methods for developing robust joint chronologies for paleoenvironmental research. Drawing largely from the authors' experiences and group discussions during and after a scientific workshop in 2022, we discuss important considerations for site selection, sampling strategies, and radiometric dating to construct integrated 210 Pb and 14 C age-models. Using expert consensus, this group – called Paleostats – aims to provide a set of best practices for other geochronologists with this methods paper. Among our conclusions, we emphasize the importance of accounting for site-specific factors such as prior information on sedimentation rates to establish appropriate sampling and analytical strategies. The use of appropriate coring devices can minimize disturbance to sediments and ensure the core surface remains intact and preserved until sectioning. Where excess 210 Pb is expected, sectioning at intervals of ≤1 cm provides an adequate sampling resolution for 210 Pb dating. Exceptions are possible, allowing for ~2–3 cm sections in areas with confirmed high sedimentation rates (e.g., > 1 cm yr −1 ). Recovering deeper core sections for 14 C dating with sufficient overlap allows for accounting errors in depth estimates made in the field. Special attention is advised during time intervals where validation proxies, such as the human-made radionuclides 137 Cs or post-bomb 14 C, are expected, and to determine the depth of secular equilibrium between 210 Pb and 226 Ra. Radiocarbon analyses are commonly performed by accelerator mass spectrometry, and age models are constructed mainly using Bayesian statistics with Markov Chain Monte Carlo techniques (e.g., Bacon ). A Bayesian approach ( Plum ) is now available for producing 210 Pb age-models, which infers the 210 Pb ex flux, eliminates the need for selecting an equilibrium depth, and allows dating cores with incomplete 210 Pb ex inventory. Plum offers improved chronologies by integrating raw 210 Pb and 14 C data, and these age-models can be enriched with other dating methodologies, such as identifying tephras and other well-recorded historical events. Harmonized reporting would contribute to making radiometric age-models reproducible, which would benefit from an international effort. Using 210 Pb and 14 C to produce integrated age-models may yield better insights into the interplay between natural and recent anthropogenic forcings on ecosystems. This can enhance our understanding of environmental processes and their impacts on climate change, ultimately supporting science-based assessments and decisions.
The passing of seasons, as gauged by annual events or phenophases in organisms' life cycles, is arguably one of the most pervasive environmental variations on Earth. Shifts in seasonal timing, or phenology, are observed in flowering and other stages of plant development, animal migration and reproduction, hibernation, and the seasonal activity of cold-blooded animals [e.g., Schwartz , 2003; Root et al ., 2005]. As an important life history trait, phenology is an object of natural selection; depending on timescales, shifts in phenology can lead to evolutionary change. Thus, phenology is not only an indicator of pattern in environmental science, but also its variation has fitness consequences for individuals, and these can scale up to broader ecological dynamics.
Alexander Skutch hypothesized that increased parental activity can increase the risk of nest predation. We tested this hypothesis using ten open-nesting bird species in Arizona, USA. Parental activity was greater during the nestling than incubation stage because parents visited the nest frequently to feed their young during the nestling stage. However, nest predation did not generally increase with parental activity between nesting stages across the ten study species. Previous investigators have found similar results. We tested whether nest site effects might yield higher predation during incubation because the most obvious sites are depredated most rapidly. We conducted experiments using nest sites from the previous year to remove parental activity. Our results showed that nest sites have highly repeatable effects on nest predation risk; poor nest sites incurred rapid predation and caused predation rates to be greater during the incubation than nestling stage. This pattern also was exhibited in a bird species with similar (i.e. controlled) parental activity between nesting stages. Once nest site effects are taken into account, nest predation shows a strong proximate increase with parental activity during the nestling stage within and across species. Parental activity and nest sites exert antagonistic influences on current estimates of nest predation between nesting stages and both must be considered in order to understand current patterns of nest predation, which is an important source of natural selection.
No abstract available.
The fast-growing demands on this natural resource expose a need to resolve many hydrologic unknowns.
The average rate of downslope movement of rock fragments on shale hillslopes is directly proportional to the sine of the slope angle or that component of the gravitational force which acts parallel to the hillslope. The rates of surficial rock creep range from a few millimeters per year on a 3degree slope to almost 70 millimeters per year on a 40-degree slope, but these rates vary with natural variations in soil characteristics and microclimate, as well as with accidental disturbances.
There is a pressing need to monitor and understand the rapid land change happening around the world. The U.S. Geological Survey is developing a new capability, called Land Change Monitoring, Assessment, and Projection (LCMAP), to innovate the understanding of land change. This capability is the Earth Resources Observation and Science Center's foundation for an integrated U.S. Geological Survey-wide land change science framework. LCMAP supports the development of consistent data and land cover products spanning large geographic extents, over extended periods, and at a higher frequency than in the past. LCMAP provides solutions to the science and management communities’ growing need for an improved understanding of the fundamental drivers of land change, the consequences of change in human and natural systems, and feedbacks associated with land change processes.
Summary Professional Paper 1814— Studies by the U.S. Geological Survey in Alaska, Volume 15 —continues a long-running series of collected volumes of U.S. Geological Survey (USGS) scientific reports on Alaska. This series presents new and sometimes preliminary findings that are of interest to Earth and biological scientists in academia, government, and industry; to land and resource managers; and to the general public. The series covers a broad spectrum of scientific topics, from various parts of Alaska, serving to emphasize the diversity of USGS efforts to meet the Nation’s needs for Earth-science information in the State. The USGS provides reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.
The United States Northern Great Plains (NGP) has a high potential for landscape-scale conservation, but this grassland landscape is threatened by encroachment of woody species. We surveyed NGP land managers to identify patterns in, and illustrate a broad range of, individual managers' perceptions on (1) the threat of woody encroachment to grasslands they manage, and (2) what management practices they use that may influence woody encroachment in this region. In the 34 surveys returned, which came from predominantly public lands in the study area, 79% of responses reported moderate or substantial woody encroachment. Eastern redcedar ( Juniperus virginiana ) and Rocky Mountain juniper ( Juniperus scopulorum ) were the most problematic encroachers. Thirty-one survey respondents said that prescribed fire was used on the lands they manage, and 64% of these responses reported that controlling woody encroachment was a fire management objective. However, only 18% of survey respondents using prescribed fire were achieving their desired fire return interval. Most respondents reported using mechanical and/or chemical methods to control woody species. In contrast to evidence from the central and southern Great Plains, few survey respondents viewed grazing as affecting encroachment. Although the NGP public land managers we surveyed clearly recognize woody encroachment as a problem and are taking steps to address it, many feel that the rate of their management is not keeping pace with the rate of encroachment. Developing strategies for effective woody plant control in a variety of NGP management contexts requires filling ecological science gaps and overcoming societal barriers to using prescribed fire.
No abstract available.
Reconstruction of the spatial pattern of trees is important for the accurate visual display of unmapped stands. The proposed process for generating the spatial pattern is a nonsimple sequential inhibition process, with the inhibition zone proportionate to the scaled maximum crown width of an open-grown tree of the same species and same diameter at breast height as the subject tree. The results of this coordinate generation procedure are compared with mapped stem data from nine natural stands of Douglas-fir at two ages by the use of a transformed Ripley's K(d) function. The results of this comparison indicate that the proposed method, based on complete tree lists, successfully replicated the spatial patterns of the trees in all nine stands at both ages and over the range of distances examined. On the basis of these findings and the procedure's ability to model effects through time, the nonsimple sequential inhibition process has been chosen to generate tree coordinates in the VIZ4ST computer program for displaying forest stand structure in naturally regenerated young Douglas-fir stands. For. Sci.
A study involving Compound Specific Isotope Analysis (CSIA) of trichloroethene (TCE) in groundwater at the Oak Grove Village (OGV) Well Site was conducted by the U.S. Environmental Protection Agency (EPA) in 2014 in an effort to fingerprint the source(s). This technical memorandum, written as a joint effort between HydroGeoLogic, Inc. (HGL) and the U.S. Geological Survey (USGS) Central Midwest Water Science Center (Schumacher, 2019), documents the procedures and analysis of the CSIA investigation. CSIA is an analytical method that measures the isotopic ratios of naturally occurring stable isotopes in specific chemical compounds in environmental samples. CSIA using primarily the ratio of carbon 13 C/ 12 C (δ 13 C), known as 1-D CSIA, has been used for decades in evaluating degradation pathways of organic compounds, including chlorinated solvents such as TCE. Ratios of stable chlorine isotopes 37 Cl/ 35 Cl (δ 37 Cl) also have been used with carbon isotopes, collectively known as 2-D CSIA, and most recently isotopes of hydrogen 2 H/ 1 H (δ 2 H) have been added, collectively known as 3-D CSIA, in attempts to further determine source, transport, and fate of compounds such as TCE (Ertl et al., 1998; Hunkeler et al., 2011; Kuder et al., 2013; McHugh et al., 2011; Shouakar-Stash et al., 2003; EPA, 2008; and van Warmerdam et al., 1995.
Seismic hazard assessments that are based on a variety of data and the best available science, coupled with rapid synthesis of real-time information from continuous monitoring networks to guide post-earthquake response, form a solid foundation for effective earthquake loss reduction. With this in mind, the Earthquake Hazards Program (EHP) of the U.S. Geological Survey (USGS) Natural Hazards Mission Area (NHMA) engages in a variety of undertakings, both established and emergent, in order to provide high quality products that enable stakeholders to take action in advance of and in response to earthquakes. Examples include the National Seismic Hazard Model (NSHM), development of tools for improved situational awareness such as earthquake early warning (EEW) and operational earthquake forecasting (OEF), research about induced seismicity, and new efforts to advance comprehensive subduction zone science and monitoring. Geodetic observations provide unique and complementary information directly relevant to advancing many aspects of these efforts (fig. 1). EHP scientists have long leveraged geodetic data for a range of influential studies, and they continue to develop innovative observation and analysis methods that push the boundaries of the field of geodesy as applied to natural hazards research. Given the ongoing, rapid improvement in availability, variety, and precision of geodetic measurements, considering ways to fully utilize this observational resource for earthquake loss reduction is timely and essential. This report presents strategies, and the underlying scientific rationale, by which the EHP could achieve the following outcomes: The EHP is an authoritative source for the interpretation of geodetic data and its use for earthquake loss reduction throughout the United States and its territories. The USGS consistently provides timely, high quality geodetic data to stakeholders. Significant earthquakes are better characterized by incorporating geodetic data into USGS event response products and by expanded use of geodetic imaging data to assess fault rupture and source parameters. Uncertainties in the NSHM, and in regional earthquake models, are reduced by fully incorporating geodetic data into earthquake probability calculations. Geodetic networks and data are integrated into the operations and earthquake information products of the Advanced National Seismic System (ANSS). Earthquake early warnings are improved by more rapidly assessing ground displacement and the dynamic faulting process for the largest earthquakes using real-time geodetic data. Methodology for probabilistic earthquake forecasting is refined by including geodetic data when calculating evolving moment release during aftershock sequences and by better understanding the implications of transient deformation for earthquake likelihood. A geodesy program that encompasses a balanced mix of activities to sustain missioncritical capabilities, grows new competencies through the continuum of fundamental to applied research, and ensures sufficient resources for these endeavors provides a foundation by which the EHP can be a leader in the application of geodesy to earthquake science. With this in mind the following objectives provide a framework to guide EHP efforts: Fully utilize geodetic information to improve key products, such as the NSHM and EEW, and to address new ventures like the USGS Subduction Zone Science Plan. Expand the variety, accuracy, and timeliness of post-earthquake information products, such as PAGER (Prompt Assessment of Global Earthquakes for Response), through incorporation of geodetic observations. Determine if geodetic measurements of transient deformation can significantly improve estimates of earthquake probability. Maintain an observational strategy aligned with the target outcomes of this document that includes continuous monitoring, recording of ephemeral observations, focused data collection for use in research, and application-driven data processing and analysis systems. Collaborate on research, development, and operation of affordable, high-precision seafloor geodetic methods that improve earthquake forecasting and event response. Advance computational techniques and instrumentation to enable use of strategies like repeat-pass imagery and low-cost geodetic sensors for earthquake response, monitoring, and research. Engage stakeholders and collaborate with partner institutions to foster operational and research objectives and to safeguard the continued health of geodetic infrastructure upon which we mutually depend. Maintaining a vibrant internal research program provides the foundation by which the EHP can remain an effective and trusted source for earthquake science. Exploiting abundant new data sources, evaluating and assimilating the latest science, and pursuing novel avenues of investigation are means to fulfilling the EHP’s core responsibilities and realizing the important scientific advances envisioned by its scientists. Central to the success of such a research program is engaging personnel with a breadth of competencies and a willingness and ability to adapt these to the program’s evolving priorities, enabling current staff to expand their skills and responsibilities, and planning holistically to meet shared workforce needs. In parallel, collaboration with external partners to support scientific investigations that complement ongoing internal research enables the EHP to strengthen earthquake information products by incorporating alternative perspectives and approaches and to study topics and geographic regions that cannot be adequately covered internally. With commensurate support from technical staff who possess diverse skills, including engineering, information technology, and proficiency in quantitative analysis combined with basic geophysical knowledge, the EHP can achieve the geodetic outcomes identified in this document.
An eight-county area at the headwaters of the Kentucky River has been designated the Kentucky River Area Development District (KRADD) by the Appalachian Regional Commission. The objective of the project described in this report has been to provide materials to KRADD planners in a format and containing terminology usable by local people untrained in earth science. Experimental maps (not included in this report) have been prepared largely from preexisting data. Time and cost limitations required a regional analysis as well as somewhat more detailed examples of selected localities. Most of the maps produced to meet these needs show the abundance and distribution of naturally occurring materials and the areas affected by various geomorphic processes. Three types of maps, showing current land use, slope, and flood-prone areas, present both basic and derived data directly applicable to specific land-use decisions. Basic map information on quality and quantity of surface and ground water, bedrock and surficial geology, and mineral fuels can be interpreted for a wide variety of current and potential uses. Texts accompanying the maps explain bedrock control of geomorphic processes, distribution and significance of surficial deposits, and hydrologic characteristics of the intricately dissected eastern Kentucky terrain. Within this conceptual framework, geomorphic processes and the landscape may be evaluated in humanly significant terms of low to high potential risk, thereby indicating both opportunities and limitations for land use.
Introduction In 2009, the U.S. Department of the Interior (DOI) Secretary Ken Salazar established a network of eight regional Climate Science Centers (CSCs) that, along with the Landscape Conservation Cooperatives (LCCs), would help define and implement the Department's climate adaptation response. The Southeast Climate Science Center (SE CSC) was established at North Carolina State University (NCSU) in Raleigh, North Carolina, in 2010, under a 5-year cooperative agreement with the U.S. Geological Survey (USGS), to identify and address the regional challenges presented by climate change and variability in the Southeastern United States. All eight regional CSC hosts, including NCSU, were selected through a competitive process. Since its opening, the focus of the SE CSC has been on working with partners in the identification and development of research-based information that can assist managers, including cultural and natural resource managers, in adapting to global change processes, such as climate and land use change, that operate at local to global scales and affect resources important to the DOI mission. The SE CSC was organized to accomplish three goals: Provide co-produced, researched based, actionable science that supports transparent global change adaptation decisions . Convene conversations among decision makers, scientists, and managers to identify key ecosystem adaptation decisions driven by climate and land use change, the values and objectives that will be used to make decisions, and the research-based information needed to assess adaptation options . Build the capacity of natural resource professionals, university faculty, and students to understand and frame natural resource adaptation decisions and develop and use research-based information to make adaptation decisions . This report provides an overview of the SE CSC and the projects developed by the SE CSC since its inception. An important goal of this report is to provide a framework for understanding the evolution of the SE CSC science agenda, which has evolved over the first 5 years of the Center’s operation.
The increasing use of natural unsaturated zones as repositories for landfills and disposal sites for hazardous wastes (chemical and radioactive) requires a greater understanding of transport processes in the unsaturated zone. For volatile constituents an important potential transport mechanism is gaseous diffusion. Diffusion, however, cannot be treated as an independent isolated transport mechanism. A complete understanding of multicomponent gas transport in porous media (unsaturated zones) requires a knowledge of Knudsen transport, the molecular and nonequimolar components of diffusive flux, and viscous (pressure driven) flux. The constitutive equations relating these flux components are available from the “dusty gas” model of Mason et al. (1967). This review presents a brief discussion of the underlying principles and interrelationships among each of the above flux mechanisms. Some aspects of these transport mechanisms are, to our knowledge, generally unrecognized in the Earth science literature. The principles underlying the transport mechanisms are illustrated with binary systems; the constitutive equations are then cast in forms thought to be most useful for the study of natural unsaturated zones. The viscous and diffusive fluxes are coupled in the constitutive equations through the Knudsen diffusivities; a knowledge of Knudsen diffusivities is necessary to calculate the viscous component of flux and pressure gradients. The Knudsen diffusivities can be calculated from measurements of the Klinkenberg effect. Two examples are presented showing that in natural systems, very small pressure gradients (1 Pa/m or less) can produce viscous fluxes greater than or equal to diffusive fluxes and that, conversely, pressure gradients of this magnitude can be generated by diffusive processes. The example calculations show that major concentration gradients can be developed for stagnant (zero flux, nonreactive) gases. A method is presented for approximating the viscous and diffusive flux components of gases in a multicomponent system from a knowledge of the concentration profiles of stagnant gases. In subsoil environments, argon and nitrogen are considered to be stagnant gases. Fick's laws are essentially, by definition, inadequate to deal with stagnant gases. In the examples presented, the error associated with estimating the total fluxes of nonstagnant gases by Fick's law, relative to stationary coordinates, ranges from a few percent to orders of magnitude.