In this study, we combined two actual evapotranspiration datasets (ET), one obtained from a root zone water balance model and another from an energy balance model, to partition annual ET into green (rainfall-based) and blue (surface/groundwater) water sources. Time series maps of green water ET (GWET) and blue water ET (BWET) are produced for the conterminous United States (CONUS) over 2001–2015.
Paleohydrologic records provide a valuable perspective on the variability of streamflow and hydroclimate that is critical for water resource planning and placing present day and future conditions into a long-term context. Until now, key insights gained from streamflow reconstructions in the other river basins across the Western U.S. have been lacking in the Milk and St. Mary River Basin. Here we utilize a new database of naturalized streamflow records for the Milk and St. Mary Rivers and an expanded network of tree-ring records from the region to reconstruct streamflow at eight gaging locations located in the mountains, foothills, and plains reaches of the basins. The network of streamflow reconstructions presented here were generated for use by the Bureau of Reclamation and Montana Department of Natural Resources and Conservation in the Basin Study update for the Milk and St. Mary Rivers, and provides important data resources to water managers balancing increasing water demands for hydropower, irrigation, and ecological resources with increasing drought and flood risk in the basin.
Wildfires and housing development have increased since the 1990s, presenting unique challenges for fire management. However, it is unclear how the relative influences of housing growth and changing wildfire occurrence have contributed to risk to homes. We fit a random forest using weather, land cover, topography, and past fire history to predict burn probabilities and uncertainty intervals. Then, we estimated risk at 1-km resolution and monthly intervals from 1990 through 2019 by combining predicted burn probabilities with housing density across the Southern Rocky Mountains. We used 3 scenarios to evaluate how housing growth and changes in burn probability influenced risk individually and combined (observed, 1990 housing, and 1990 weather). This data release includes python scripts used for all processing steps and a readme file describing where to acquire original datasets used by the random forest model, instructions for running the python scripts, and descriptions of outputs. Preprocessed model inputs were too large to share. However, raster layers are included for modeled burn probability and risk for the 3 scenarios.
As climate change progresses, profound environmental changes are becoming a widespread concern. A new management paradigm is developing to address this concern with a framework that encourages strategic decisions to resist, accept, or direct ecological trajectories. Effective use of the Resist-Accept-Direct (RAD) framework requires the scientific community to describe the range of plausible ecological conditions managers might face, while recognizing limits to our ability to predict precisely where or how specific climatic changes may unfold or how complex environmental systems will respond - the climatic future does not fully determine the ecological one. Recent advances have improved development and delivery of climate futures (summaries of climate conditions for each climate model projection), but approaches for creating and working with a range of ecological scenarios for each climate future do not yet exist. This project will develop potential approaches for crafting ecological scenarios, i.e., storylines designed to capture the range of plausible ecological responses to climate change. Researcher propose to synthesize and compare typical approaches for estimating ecological responses to climate change, consider extensions that allow for multiple ecological community or biome types under each climatic scenario, and develop approaches for “winnowing” a large set of plausible ecological scenarios into a workable, representative set.
Land and water managers often rely on hydrological models to make informed management decisions. Understanding water availability in streams, rivers, and reservoirs during high demand periods that coincide with seasonal low flows can affect how water managers plan for its distribution for human consumption while sustaining aquatic ecosystems. Substantial advancement in hydrological modeling has occurred in the last several decades resulting in models that range widely in complexity and outputs. However, managers can still struggle to make informed decisions with these models for a variety of reasons, including misalignments between model outputs and the specific decision they are intended to inform, limitations in the technical capabilities of managers that may not have the experience or resources to use complex or expensive models, or the limitations of the models themselves. This project will provide a state of the science on low flow hydrological modeling that can be used to address management decisions specific to low flow hydrology, drought, and impacts from climate change. Specifically, through a worshop series, this project will 1) detail the decisions that managers must make related to low flow hydrology, drought, and climate change, 2) provide an inventory of appropriate hydrological models and model output that align to case-by-case decision making, and 3) identify areas for model improvements to address gaps, limitations, and uncertainties. A synthesis that summarizes and aligns hydrological models to the appropriate management decisions is expected to support more informed decision making and better outcomes as a result of more efficient and effective model application.
As climate change looms large, the Aaniiihnen and Nakoda people of the Fort Belknap Indian Community are undertaking a climate change impact assessment in the Little Rocky Mountains to better prepare for the future. This mountain range is home to numerous food and medicinal species of cultural importance. It is critical to understand how climate change has affected and will affect availability of these species and the cultural implications for the Tribe in order to enhance food sovereignty and cultural resiliency, improve tribal health, and maintain local biodiversity. The project will assess the presence and distribution of valued species including subalpine fir, juneberry, chokecherry, and others, while engaging the community in discussions around access and community needs. Adopting a holistic approach to climate change assessment, traditional ecological knowledge and the cultural implications of climate change will be an integral and innovative aspect of the project. Community meetings, elder interviews, and youth engagement sessions will contribute to understanding the interconnected issues of protecting significant species and culture in their full complexity. Scenarios of future climate change impacts on the plant species and the community will be explored to inform planning and management decisions and the Fort Belknap Indian Community Climate Adaptation Plan.
Surface-water availability has been identified as one of the biggest issues facing society in the 21st century. Where and when water is on the landscape can have profound impacts on the economy, wildlife behavior, recreational use, industrial practices, energy development, and many other aspects of life, society, and the environment. Projections indicate that surface-water availability will be generally reduced in the future because of multiple factors including climate change, increased drought frequency and severity, and altered water and land use. Thus, it is important resource managers understand which areas are most vulnerable to reduced water availability impacts, and to what extent current conditions may change. This project aims to create an index, the Surface-Water Index of Permanence (SWIPe), to determine when and where surface water will remain permanent on the landscape. It will build on previous work looking at streamflow permanence (using the USGS PROSPER model), surface-water inundation extent (using the USGS DSWE model), and wetland extents and permanence (using remotely sensed vegetation characteristics). Outcomes of this work will deliver crucial information on where surface water is most likely to be reduced under drought conditions. The research team will also work with partners to develop index outputs that are useful for exploring current and potential future surface-water availability characteristics and how they might affect bison behavior. This information linking surface-water permanence with wildlife behavior will be critical to improving the ability to mitigate the potential effects of reduced surface-water availability for wildlife and humans.
Across the western U.S., pinyon and juniper trees are expanding into sagebrush and grassland plant communities. This vegetation change has been perceived to have a significant impact on the economic value of these grasslands, which support activities such as livestock grazing and hunting, but expanding pinyon and juniper forests may also lead to increased risk of fire. Over the past several decades pinyon-juniper forests have been removed across large areas of land to improve wildlife habitat and grazing land productivity while reducing risks of wildland fire. What isn’t known is whether these strategies are effective in reaching this goal, especially given that our future climate will likely be hotter and drier across many regions of the western U.S. This project will develop a tool that can inform management decisions on where, when, and how to prioritize pinyon-juniper treatments under a future climate that is likely to be hotter and drier. This work will be conducted primarily on the Colorado Plateau, in the states of Colorado, Utah, and Arizona. The study aims to support collaboration between resource managers and researchers to create a support tool for planning, implementing, and evaluating pinyon-juniper treatments. The research team will then guide a broader community of stakeholders in using this tool in planning future pinyon-juniper treatments under changing climate conditions.
The long-term success of management efforts in sagebrush habitats are increasingly complicated by the impacts of a changing climate throughout the western United States. These complications are most evident in the ongoing challenges of drought and altered rangeland fire regimes resulting from the establishment of nonnative annual grasses. The Integrated Rangeland Fire Management Strategy recognized these growing threats to sagebrush habitat and initiated the development of an Actionable Science Plan to help the scientific and management communities address the highest priority science needs to help improve rangeland management efficacy in the West. Since the establishment of the original Integrated Rangeland Fire Management Strategy Actionable Science Plan in 2015, a considerable amount of climate science research has focused on western rangelands. Before the identification of the next set of priorities, there needs to be an assessment of how that science addressed the initially identified set of priorities. This research project will develop a scorecard that will provide the science and management communities with a clear understanding of how well the initially identified management priorities related to climate change and adaptation have been addressed since 2015. This will provide a baseline for discussions about the actionable science needed to continue to address the issues driving the loss, degradation, and fragmentation of sagebrush habitats in the western United States. The research team will 1) host a series of stakeholder meetings with rangeland researchers and agency managers to compile a set of current science needs related to climate science, 2) refine those needs through community input, and 3) host a series of prioritization meetings with a broadened stakeholder group to identify and update high priority climate science needs around rangeland management. These will form the basis of the next Actionable Science Plan and help focus the science and management communities on funding and implementing science activities that will address these needs in the coming years.
Natural & cultural resource managers are facing a slew of new challenges for managing public lands stemming from climate change and human-driven stressors like invasive species, fragmentation, and new resource uses. In some cases, the very landscapes and species they are managing are changing in significant ways, transforming from one set of conditions to another. As a result, previously successful management strategies may become less effective, or in some cases ineffective. New and transforming conditions leave managers in a bind on how to respond to transforming public lands and natural resources. On the most basic level managers have three choices of how to respond: resist change, accept change, or direct change (RAD). These difficult decisions cannot be fully answered by scientific information. Instead, decisions are influenced by several social factors, both unique to the individual manager and from outside sources. This research project will examine how key institutional and emotional factors shape management decisions about changing resources. Four national parks that are experiencing significant ecological transformation are the focus of the analysis: Sequoia & Kings Canyon, Acadia, Glacier, and North Cascades. The team will use interviews and focus groups to study how the culture and policy of individual parks, and the psychological and emotional experiences of managers responding to landscape changes, influence decisions. This project has four main goals: 1) to increase understanding of how institutional and emotional factors influence manager decision making in the National Park Service in the face of ecological transformation, 2) to provide tailored, actionable products to park managers in each case study location to inform unit-level decisions, 3) to develop examples of how to engage Tribal Nations with ties to park lands in decisions about transforming landscapes and establish connections between parks and Tribal partners, and 4) to contribute to emerging theory on the social science of ecological transformation in public land management.