Ecological drought impacts ecosystems across the U.S. that support a wide array of economic activity and ecosystem services. Managing drought-vulnerable natural resources is a growing challenge for federal, state and Tribal land managers.  Plant communities and animal populations are strongly linked to patterns of drought and soil moisture availability.  As a result, ecosystems may be heavily altered by future changes in precipitation and soil moisture that are driven by climate change.  Although this vulnerability is well recognized, developing accurate information about the potential consequences of climate change for ecological drought is difficult because the soil moisture conditions that plants experience are shaped by complex interactions among weather, atmospheric CO2, plants and soils. There are currently very few ecologically appropriate datasets about future drought with widespread distribution at resolutions suitable for informing natural resource decision making.  This project will meet some of those needs by simulating complex interactions that affect soil moisture availability to plants and generating user-relevant soil moisture projections.  Results will include detailed and synthesized drought information for the 21st century across the entire contiguous U.S. that are delivered via the Climate Toolbox, an established source for long-term climate projections. Data provided by this project will be useful for a wide variety of applications including scenario planning, species distribution models, and ecological drought and habitat vulnerability assessments.  

Project Overview Migratory big game species, like mule deer, are at risk due to human development and more frequent drought events that can limit access to food resources during migration. To address this, researchers supported by this North Central CASC project will collaborate with State, Tribal, and Federal agencies to examine the effectiveness of corridor conservation as a strategy to improve drought resilience for over 40 mule deer herds across Western states. Ultimately, results from this project will benefit ongoing conservation efforts by identifying what levels of development impacts the species’ ability to deal with drought. Project Summary Every year, migratory big game move across landscapes to seek out important food resources and to avoid harsh weather. Yet, the landscapes animals move through are experiencing rapid changes from human development and shifting climatic conditions, which put these ecologically and culturally important migrations at risk. Mule deer, for example, are negatively impacted by drought, which changes when and where key food resources will be available along their migration route. To conserve big game migrations, State, Tribal, and Federal agencies are working together to map and protect migration corridors. Although it is often assumed that corridor conservation should enhance the resilience of migrants to climate change, the idea remains poorly tested. This project will examine the effectiveness of corridor conservation as a drought resiliency strategy for mule deer across the West. As climate change leads to more frequent and longer drought events, it will likely become even more important for deer to freely move and access critical and limited food resources during migrations. At the same time, mule deer movements are altered by human disturbances, which can cause deer to miss out on foraging opportunities. This project will bring together data and partnerships to investigate these two threats on more than 40 mule deer herds across the West, with the aim of understanding the importance of freedom of movement in the survival and resiliency of mule deer in a changing world. Results from this project will identify the amount of human development that constrains the movements of mule deer and the impacts of diminished mobility on drought resiliency. This research links two USGS priorities – conserving big game migrations and enhancing climate resiliency – while filling important knowledge gaps needed to strategically target ongoing conservation efforts.

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.

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.

The Greater Yellowstone Area (GYA) is an iconic landscape with national parks, iconic species like grizzly bears and elk, and over 11,500 square miles of forest. While fires are a natural part of the GYA, climate change and land management legacies are increasing the frequency and size of severe fires. Climate change interacts with these fires to shift conifer forests to non-forested grassland and sagebrush ecosystems. These transformations impact species habitat, carbon storage, and other management goals on public lands. However, managing for “natural ecosystems” is not always possible in the face of climate change. The Resist-Accept-Direct framework (RAD) can help: under RAD, managers can resist change to maintain ecosystems, accept climate- and wildfire-driven ecological change, even if that means losing species habitat or ecosystem services, or direct ecosystem changes to maintain or gain key resources or services. For this project, researchers will work with managers in the GYA to implement RAD as a strategy to manage wildfires and subsequent ecosystem changes. With managers from each GYA agency researchers will identify 1) shared and unique management goals, 2) management options that can resist, accept, or direct wildfire-related ecosystem changes, and 3) ways to coordinate RAD implementation across agencies, since fires span management boundaries on the landscape This project will help managers identify and coordinate approaches to achieve their conservation goals in the context of climate change, ensuring the preservation of key species, ecosystems, and resources in the North Central CASC region’s public lands.

Prescribed burning – planned, controlled fires conducted under weather and fuel conditions designed for safety and effectiveness – is a common practice used to maintain and restore native prairies in the Northern Great Plains. However, climate change will affect the number of days in a year, and when,  suitable conditions for prescribed fires occur. For instance, warmer temperatures may shift these “good prescribed-fire days” earlier in the spring and later in the fall, but uncertainty about future climate makes it hard to predict how large shifts will be and if the number of good fire days each year will generally increase or decrease. Further, it’s hard to know whether prescribed fires will continue to achieve their goals in new conditions. This project will measure how the number and timing of good fire days has changed over the last 30 years and predict how  they will change over the next 50 years under four plausible future climate scenarios. Changes to longer-term weather patterns – in the seasons leading up to and following prescribed fires – may also change the effectiveness of the fires in achieving their goals, like reducing Kentucky bluegrass, cheatgrass, and other invasive grasses. To address this issue, the project will also use data from long-term plant monitoring programs to look for patterns in how prairie responds to prescribed fire in different seasonal and annual weather conditions. Land management agencies in the Northern Great Plains like the National Park Service, U.S. Fish and Wildlife Service, and U.S. Forest Service use prescribed fires often, so it is important for them to understand how climate change will affect the number and timing of good prescribed-fire days and fire’s effects. To that end, the ultimate goal of this project is to create a model that will help managers develop effective prescribed fire strategies for an uncertain future climate.

Invasions of exotic annual grasses (EAGs like cheatgrass have caused major losses of native shrubs and grasses  in western U.S. rangelands. They also decrease the productivity and carbon storage in these ecosystems, which is expected to create dryer soils that may cause further losses in plant productivity. This cycle is the hallmark of desertification – or, fertile lands turning into deserts. Management actions that target EAGs are one of the most widespread land management actions taken in Western U.S. rangelands, but it is unclear which specific actions can simultaneously enhance drought resilience of native plant communities and increase carbon sequestration and storage. This project aims to identify the restoration treatments that are effective in combating EAGs in western rangelands by collecting data to describe the impacts of EAGs on soil carbon and to determine when, where, and how restoration actions such as applying herbicides or planting perennial native plants affect soil carbon and drought resilience. To address a key concern of land managers, the public, and national policy-makers, project researchers will work with a team of land managers across Montana, Wyoming, and Colorado to 1) refine and confirm the suitability of sampling locations, 2) connect with private landowners and land managers to access sampling locations, 3) engage managers in the science discovery process (e.g., interpreting data results) to share ownership of the findings, and 4) co-produce translational guidance for carbon sequestration metrics and for what changes to expect  in carbon sequestration and its co-benefits following restoration to prevent or rectify EAG invasions.

In the North Central region, invasive species and climate change are intricately linked to changing fire regimes, and together, these drivers can have pronounced effects on ecosystems. When fires burn too hot or too frequently, they can prevent slow-growing native plants from regrowing. When this happens, the landscape can transform into a new type of ecosystem, such as a forest becoming a grassland. This process is known as “ecosystem transformation”. This project will explore key management priorities including native community resilience and management of invasive species, wildfire, and ecosystem change, in a collaboration of researchers working directly with land managers and other stakeholders through the North Central Regional Invasive Species and Climate Change (NC RISCC) network. The team will identify areas in the North Central region that have experienced ecological transformation due to invasive grasses and their interactions with wildfire or climate change; calculate changes in carbon storage that have accompanied these transformations; and determine areas that are vulnerable to future transformation. Researchers will also identify which management practices enhance carbon storage, a key ecosystem service that agencies want to include in management plans and strategies, yet largely have not yet done so. Through this project, managers and researchers will gain a better understanding of the processes behind ecosystem transformation, as well as the carbon consequences of these changes and the management practices that can address them. This work can be used to adapt management plans for important ecosystem services that may be agency- or organization-specific, including carbon storage, native plant diversity, and ecosystem resilience. This work is critical to addressing the interactions of climate change with both invasive grasses and wildfire, as well as identifying adaptation strategies to restore carbon in forests and shrublands across the North Central region after these disturbances.

Dry stream sections are characteristic of most prairie streams. Native fish are highly adapted to variable environments, using refuge habitats (e.g., remaining wet stream fragments) to recolonize areas after seasonal drying. However, dams and other barriers can prevent recolonization of seasonally-dry stream sections habitats known to be critical spawning and rearing areas for many species. This phenomenon will likely become more common as climate change causes increasingly severe droughts, and larger sections of streams become seasonally dry. This could lead to local loss of native prairie fishes, an already at-risk group. Fisheries managers in Wyoming and Montana have limited data on climate impacts to prairie fishes, limiting their ability to prioritize management actions. This is in part because the ecology and possible climate adaptation strategies for many prairie fishes are poorly understood. Managers also have limited time to assess the success of potential restoration actions to increase fish resilience to seasonal drying and ways to increase refuge habitat. This project aims to provide landscape-level maps and resources that will help managers prioritize where and for which species management actions, such as water and habitat conservation and restoration measures, could be most beneficial. A research team will assess which species are most sensitive to drought in addition to expanding a newly created model of streamflow permanence to map drought refuges for vulnerable species. The project will also monitor stream restoration case studies to determine if process-based restoration techniques can be used to increase streamflow permanence and connectivity. Lastly, this work will be leveraged to create a short, species-specific guide to climate adaptation techniques. This guide will help agencies, landowners, conservation districts, and public interest groups determine what can be done to benefit at-risk species in their area of interest.

The USGS National Climate Adaptation Science Center (NCASC) is currently engaged in an Ecological Drought initiative, focused on understanding the impacts of drought on natural ecosystems across the country. This project supported the Ecological Drought initiative by creating an Intermountain West Drought Social Science Synthesis Working Group. The goal of this working group was to investigate human dimensions of ecological drought across the intermountain west from a comparative, regional perspective. Throughout the Intermountain West, there has been significant investment in understanding how social factors influence manager and citizen experiences of drought in particular locations. Yet there is still a gap in knowledge of how human dimensions of drought impacts, planning, and resilience are similar and different across cases and regions. The working group engaged social scientists from federal agencies and universities to identify common trends in drought management across the Intermountain West to inform more effective drought preparedness and response across the region. Project outputs included two conference sessions, a typology manuscript to be submitted by the end of FY19, and the conceptual framing of a rapid assessment methodology that was subsequently developed into a standalone project.