A Fine-Scale Understanding of Sagebrush Islands to Improve Restoration Outcomes in the Intermountain West

In the Intermountain West, rapid expansion of non-native grasses, primarily cheatgrass, has created a repeating cycle where cheatgrass easily ignites and after a fire, more cheatgrass establishes in the burned area, leading to more fire, and more cheatgrass. The primary method to prevent further fires is to plant grass and shrub seeds after a fire because they can deter cheatgrass from establishing and reduce the chance of fire. However, this approach does not always work. There is a need and interest in alternative ways to establish native grasses and forbs. Sagebrush, the dominant shrub of lower-elevation regions of the Intermountain West, may act as a nurse plant: a plant that alters the environment around itself in a way that is beneficial to other plants. Capitalizing on the attributes that make sagebrush nurse plants, like shade and higher soil moisture, may help the establishment of grasses and forbs before a fire occurs, increasing the likelihood that cheatgrass will not dominate that system. While the area around nurse plants generally is thought of as a favorable place for grasses and forbs to grow, that may not always be the case. There may be minimal differences in the microenvironment between the canopy and interspace and there can be competition under the canopy between newly established plants and other vegetation that is already present. I found that the sagebrush canopy influenced the survival of two native wildflower species, Munro’s globemallow and common yarrow, when they were transplanted as seedlings, but survival of two native transplanted grass species, bluebunch wheatgrass and squirreltail, was unaffected by the sagebrush canopy. However, when those same grasses were planted as seeds, if the seeds emerged, their emergence was highest near the canopy. Some of the attributes that make the canopy a “good” place for grasses and wildflowers to grow extend into the interspace, making the interspace potentially similarly “good.” I found that bluebunch wheatgrass and globemallow were shade tolerant and grew in ways that may allow them to be competitive under the canopy and persist in the interspaces, outside of what is generally considered a “good” nurse shrub microenvironment

Collaborative Knowledge Braiding for Restoration: Assessing Climate Change Risks and Adaptation Options at Wuda Ogwa in Southeastern Idaho, United States

The restoration of culturally significant landscapes poses formidable challenges given more than 160 years of settler-colonial land use change and a rapidly changing climate. A novel approach to these challenges braids Indigenous and western scientific knowledge. This case study braids Indigenous plant knowledge, species distribution models (SDMs), and climate models to inform restoration of the Bear River Massacre site in Idaho, now stewarded by the Northwestern Band of the Shoshone Nation. MaxEnt SDMs were used to project the future spatial distribution of culturally significant plant species under medium (SSP2-4.5) and high (SSP5-8.5) emissions scenarios. These results support Tribal revegetation priorities and approaches, identified by tradeoffs between each species\u27 current and future suitability. This research contributes to a knowledge-braiding approach to the analysis of climate risks, vulnerabilities, and restoration possibilities for Indigenous-led restoration projects by using the Wuda Ogwa ecological restoration site as a case study

Addressing Barriers to Proactive Restoration of At-Risk Sagebrush Communities: A Causal Layered Analysis

Restoration success in degraded rangelands often depends on a site\u27s resilience to disturbance and resistance to invasive plants. Because it is more difficult to restore plant communities after they are dominated by invasive species, a potential approach is proactive restoration in sites at risk of crossing degradation thresholds (e.g. initiating restoration prior to invasive grass dominance). When developing a new restoration approach, it is important to consider operational feasibility, including social, budgetary, and environmental factors. Accordingly, we studied influences within land management agencies on the adoption of a specific proactive restoration approach: out-planting native grass and forb seedlings into sagebrush stands before they are dominated by cheatgrass (Bromus tectorum). Managers from federal and state land management agencies across the Great Basin, U.S.A, were interviewed regarding perceived feasibility of these practices. Twelve in-depth interviews were conducted, and responses were analyzed using a qualitative method, causal layered analysis, not previously applied in a land management context. In the most superficial (litany) layer, cost and scale were prominent. The next (systemic) layer was framed by policy and bureaucracy limitations as well as technical barriers to implementation. In the third (worldview) layer, lack of a proactive management tradition within agencies represented a principal barrier. In the deepest (myth/metaphor) layer, the central belief is that human intervention should be used to protect ecosystem services only after they are disrupted due to human activity. Based on the different obstacles found at each level, we suggest ways to overcome the barriers detected

Resolving and Predicting Neighborhood Vulnerability to Urban Heat and Air Pollution: Insights From a Pilot Project of Community Science

Abstract Urban heat and air pollution, two environmental threats to urban residents, are studied via a community science project in Los Angeles, CA, USA. The data collected, for the first time, by community members, reveal the significance of both the large spatiotemporal variations of and the covariations between 2 m air temperature (2mT) and ozone (O3) concentration within the (4 km) neighborhood scale. This neighborhood variation was not exhibited in either daily satellite observations or operational model predictions, which makes the assessment of community health risks a challenge. Overall, the 2mT is much better predicted than O3 by the weather and research forecast model with atmospheric chemistry (WRF‐Chem). For O3, diurnal variation is better predicted by WRF‐Chem than spatial variation (i.e., underestimated by 50%). However, both WRF‐chem and the surface observation show the overall consistency in describing statistically significant covariations between O3 and 2mT. In contrast, satellite‐based land surface temperature at 1 km resolution is insufficient to capture air temperature variations at the neighborhood scale. Community engagement is augmented with interactive maps and apps that show the predictions in near real time and reveals the potential of green canopy to reduce air temperature and ozone; but different tree types and sizes may lead to different impacts on air temperature, which is not resolved by the WRF‐Chem. These findings highlight the need for community science engagement to reveal otherwise impossible insights for models, observations, and real‐time dissemination to understand, predict, and ultimately mitigate, urban neighborhood vulnerability to heat and air pollution