Chad S. Boyd’s research while affiliated with Oregon Department of Agriculture and other places

Understanding how climate change will contribute to ongoing declines in sagebrush ecological integrity is critical for informing natural resource management, yet complicated by interactions with wildfire and biological invasions. We assessed potential future changes in sagebrush ecological integrity under a range of scenarios using an individual plant-based simulation model, integrated with remotely sensed estimates of current sagebrush ecological integrity. The simulation model allowed us to estimate how climate change, wildfire, and invasive annuals interact to alter the potential abundance of key plant functional types that influence sagebrush ecological integrity: sagebrush, perennial grasses, and annual grasses. Our results suggest that climate driven reductions in sagebrush ecological integrity may occur over broader areas than increases in sagebrush ecological integrity. Declines in sagebrush ecological integrity were most likely in hot and dry regions while increases were more likely in cool and wet regions. The most common projected transitions of sagebrush ecological integrity classes were declines from Core Sagebrush Area to Growth Opportunity Area and from Growth Opportunity Area to Other Rangeland Area. Responses varied considerably across projections from different global climate models, highlighting the importance of climate uncertainty. However, our projections tended to be robust in areas that currently have the highest sagebrush ecological integrity. Our results provide a long-term perspective on the vulnerability of sagebrush ecosystems to climate change and may inform geographic prioritization of conservation and restoration investments. The results also suggest that ongoing threats, such as the continued invasion by annual grasses and increased wildfire frequency, are likely to be amplified by climate change, and imply that the current imbalance between capacity for conservation to address threats to sagebrush will grow as the climate warms.

Rangeland carbon is often conceptualized similarly to intensively managed agricultural lands, in that we need to sequester and store more carbon. Unlike intensively managed agricultural lands, rangeland soils cannot sequester more carbon due to pedogenic and climatic limitations that influence plant community and microbial community dynamics. This requires a new paradigm for rangeland carbon that focuses on maintaining carbon security following disturbances like fire and plant community conversions (e.g., annual grasslands and conifer woodlands). To attain this, we propose the creation of a Carbon Security Index (CSI). CSI is a unitless, scalable value that can be used to compare carbon security across range-land sites and over time and incorporates a plant fractional cover ratio, resistance and resilience, and wildfire probability. Using the Great Basin as a case study, we found that CSI decreased by 53% basin wide from 1989 to 2020. Using the Sagebrush Conservation Design's sagebrush ecological integrity categories across the Great Basin, we found that CSI in "core" areas remained relatively unchanged between 1998 and 2020 (decreased by 1%), whereas "growth opportunity" areas CSI began to change (decreased by 13%) and "other rangeland" areas CSI decreased by 67%. We found that CSI was able to act as an indicator for determining when carbon security would decrease several years prior to a wildfire disturbance, which then rapidly reduced CSI. Finally, we created a carbon security management map to help prioritize potential management for achieving greatest carbon security and locations for restoration. These results show that CSI provides landowners and land managers an opportunity to assess how secure their carbon is on the land and help them prioritize areas for restoration.

This special issue of Rangeland Ecology and Management is dedicated to applying the Sagebrush Conservation Design (SCD) to improve conservation outcomes across the sagebrush biome in the face of pervasive ecosystem threats. This special issue provides new science and real-world examples of how we can implement the SCD to save a biome. The SCD is a tool to identify intact sagebrush areas and address the largest threats to the ecosystem. The SCD focuses on first protecting intact and functioning sagebrush ecosystems, called Core Sagebrush Areas, then works outward toward more degraded areas (i.e., “Defend the Core”). The premise behind the Defend the Core approach is simple: focus resources first on preventative actions that retain ecosystem services in Core Sagebrush Areas because they are more cost-effective and more likely to be successful. The opening article of this special issue creates a foundation for the 19 following papers, providing a coherent path for implementing the SCD. The overarching themes are: 1) Business-As-Usual Won't Save the Sagebrush Sea, 2) Better Spatial Targeting Can Improve Outcomes, 3) Conservation Planning is Needed to Develop Realistic Business Plans, 4) Targeted Ecosystem Management: Monitoring Shows Managing for Sagebrush Ecological Integrity is Working, 5) Maintaining Sagebrush Ecological Integrity is Ecologically Relevant, and 6) There is Only Hope if We Manage Change. The collective articles show that there is no shared plan to save the biome, yet a business plan for the biome could ensure realistic goals. The sagebrush biome still has vast expanses of open spaces with high ecological integrity at a scale that is rare in other ecological systems within the lower 48 states. If we focus on the common ground of the main drivers of ecosystem change, implementing the SCD and Defending the Core are viable strategies to help save a biome.

In the last 20 years, the North American sagebrush biome has lost over 500 000 ha of intact and largely intact sagebrush plant communities on an annual basis. Much of this loss has been associated with expansion and infilling of invasive annual grasses (IAGs). These species are highly competitive against native perennial grasses in disturbed environments, and create fuel conditions that increase both the likelihood of fire ignition and the ease of wildfire spread across large landscapes. Given the current rate of IAG expansion in both burned and unburned rangelands, we propose a range-wide paradigm shift from op-portunistic and reactive management, to a framework that spatially prioritizes maintenance of largely intact, uninvaded areas and improvement of invaded habitats in strategic locations. We created a framework accompanied by biome-wide priority maps using geospatial overlays that target areas to MAINTAIN large, uninvaded areas as natural resource anchors through activities to prevent IAGs, IMPROVE areas where management success in restoring large, intact landscapes is most likely, and CONTAIN IAG infestations where necessary. We then offer three case studies to illustrate the use of these concepts and map products at multiple scales. Our map products operate at the biome scale using regional data sources and additional data sources will be needed to inform local conservation planning. However, the basic strategic management principles of (1) maintaining the intact and uninvaded areas that we can least afford to lose to IAGs, (2) improving areas where we have a reasonable likelihood of restoration success, and (3) containing problems where we must, are timely, relevant, and scalable from the biome to local levels. Published by Elsevier Inc. on behalf of The Society for Range Management. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)