In a changing climate, resource management depends on anticipating changes and considering uncertainties. To facilitate effective decision making on public lands, we regionally summarized the magnitude and uncertainty of projected change in management-relevant climate variables for 332 national park units across the contiguous US. Temperature, frequency of extreme precipitation events, and drought exposure are all projected to increase within seven regions delineated in the US National Climate Assessment. In particular, the anticipated collective impacts of droughts and flooding events will lead to unique management challenges, including combinations of management actions that may seem inconsistent. Furthermore, uncertainty in the magnitude of change varied by region and climate variable considered, pointing to specific opportunities for prioritization, transferability, and innovation of climate adaptation regionally and at the park-unit scale.

In water-limited dryland ecosystems of the Western United States, climate change is intensifying the impacts of heat, drought, and wildfire. Disturbances often lead to increased abundance of invasive species, in part, because dryland restoration and rehabilitation are inhibited by limited moisture and infrequent plant recruitment events. Information on ecological resilience to disturbance (recovery potential) and resistance to invasive species can aid in addressing these challenges by informing long-term restoration and conservation planning. Here, we quantified the impacts of projected future climate on ecological resilience and invasion resistance (R&R) in the sagebrush region using novel algorithms based on ecologically relevant and climate-sensitive predictors of climate and ecological drought. We used a process-based ecohydrological model to project these predictor variables and resulting R&R indicators for two future climate scenarios and 20 climate models. Results suggested widespread future R&R decreases (24%–34% of the 1.16 million km2 study area) that are generally consistent among climate models. Variables related to rising temperatures were most strongly linked to decreases in R&R indicators. New continuous R&R indices quantified responses to climate change; particularly useful for areas without projected change in the R&R category but where R&R still may decrease, for example, some of the areas with a historically low R&R category. Additionally, we found that areas currently characterized as having high sagebrush ecological integrity had the largest areal percentage with expected declines in R&R in the future, suggesting continuing declines in sagebrush ecosystems. One limitation of these R&R projections was relatively novel future climatic conditions in particularly hot and dry areas that were underrepresented in the training data. Including more data from these areas in future updates could further improve the reliability of the projections. Overall, these projected future declines in R&R highlight a growing challenge for natural resource managers in the region, and the resulting spatially explicit datasets provide information that can improve long-term risk assessments, prioritizations, and climate adaptation efforts.

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.

Surface-water availability has major implications for the environment and society in the 21st century. With climate change, increased drought severity, and altered water and land use, future water availability is predicted to continue to decline in many areas, including much of the western United States. An understanding of where and when water will be available at multiple scales is crucial for the planning and management of wildlife health, recreation, and energy development. Currently, indices describing water presence and permanence exist for specific surface-water components (for example, streams and wetlands); however, a general surface-water permanence index that includes all major surface-water components is lacking. Developing a Surface-Water Index of Permanence can provide a reliable metric to understand future river reach- to region-scale surface-water permanence and availability and inform land management and policy decisions.

A key assumption behind many predictions of ecosystem response to climate change is that plant species will track their suitable climates through space and time. However, climate connectivity – the ability of a landscape to facilitate or impede climate-induced movement – will strongly influence how plants are able to move through the landscape. Forward-looking, climate change-informed conservation and protected area stewardship requires an understanding of climate connectivity. Several factors affect climate connectivity and plant species movements, such as the distance that needs to be traveled to track suitable climate, which may exceed the dispersal ability of many species. Additionally, land use intensity in the unprotected matrix will limit climate-induced range shifts among protected areas for some species. Exposure to increasingly dissimilar climates may also impede climate-induced range shifts. While these constraints on species range shifts are well established, they have not yet been integrated to predict species-specific range movements and identify where intervention might be necessary to facilitate climate connectivity. Building on previous research, this project will develop species-specific assessments of climate connectivity and potential range shifts for a suite of management-relevant species within the North Central Climate Adaptation Science Center's protected area network including national forests and the unprotected matrix of federal, private, and tribal lands.

Climate change, cheatgrass, and increases in wildfire frequency are significant threats to big sagebrush rangelands. Frequent fire can provide opportunities for cheatgrass, a non-native annual grass, to colonize, resulting in negative effects for native species, increases in fire risk, and potential transitions from native shrublands to non-native grasslands. We currently know little about how cheatgrass and fire will affect big sagebrush rangelands in the future. Our objective was to assess the vulnerability of big sagebrush plant communities to changes in future climate, fire, and cheatgrass to guide conservation priorities and planning efforts. This work developed maps of projected 21st century changes in the abundance of important components of big sagebrush plant communities across the region. Results from this analysis demonstrate that climate change has strong potential to exacerbate the impacts of cheatgrass and wildfire. In the absence of wildfire, projected future declines in big sagebrush are relatively modest (Palmquist et al. 2021). In contrast, the combination of climate change and wildfire results in more substantial and widespread declines in big sagebrush, including in portions of the region that have been historically resilient to cheatgrass invasion (England et al. in prep.). In addition, our results suggest a potential shift in the composition of perennial grasses in the region from dominance by cool-season grasses, to dominance to warm-season grasses (Palmquist et al. 2021). This shift would have dramatic negative impacts on the services provided by big sagebrush ecosystems, particularly wildlife habitat value and grazing utilization. These results are designed for range-wide conservation and land treatment prioritization, and are being used in a new interagency sagebrush landscape conservation framework led by the USFWS and the Western Association of Fish and Wildlife Agencies (Doherty et al. in review).