Research and Publications
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This study found that more than 20 years were required for adaptive differences to emerge among 13 populations of Wyoming big sagebrush grown in common gardens.
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Discussions of successes, struggles, and failures with partner-specific tools are vital to the successful implementation of “translational ecology” a formal term for biological conservation partnerships.
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Collaborative forest management efforts often encounter challenges related to process and stakeholder relationships. To address these challenges, groups may employ the services of coordinators and facilitators who perform a range of tasks in support of the collaborative. We sought to understand differences between facilitation and coordination in terms of trust creation and maintenance. We conducted case studies in four collaborative groups, one with a facilitator and three with coordinators. We highlight the trust-building practices unique to the facilitator and discuss the potential implications for future collaborative groups.
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This document was prepared to help scientists and the public, both of whom may not be familiar with bee taxonomy, learn how to practically identify bees in sagebrush steppe and shrubland habitats in southwest Idaho. We provide information to identify bees to the level of family and genus. A tentative list of the bee genera captured at sites used for insect community studies is included.
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Ephemeral snowpacks, or those that persist for < 60 continuous days, are challenging to observe and model because snow accumulation and ablation occur during the same season. This has left ephemeral snow understudied, despite its widespread extent. Using 328 site years from the Great Basin, we show that ephemeral snowmelt causes a 70-days-earlier soil moisture response than seasonal snowmelt. In addition, deep soil moisture response was more variable in areas with seasonal snowmelt. To understand Great Basin snow distribution, we used MODIS and Snow Data Assimilation System (SNODAS) data to map snow extent. Estimates of maximum continuous snow cover duration from SNODAS consistently overestimated MODIS observations by >25 days in the lowest (<1500 m) and highest (>2500 m) elevations. During this time period snowpack was highly variable. The maximum seasonal snow cover during water years 2005–2014 was 64 % in 2010 and at a minimum of 24 % in 2014. We found that elevation had a strong control on snow ephemerality, and nearly all snowpacks over 2500 m were seasonal except those on south-facing slopes. Additionally, we used SNODAS-derived estimates of solid and liquid precipitation, melt, sublimation, and blowing snow sublimation to define snow ephemerality mechanisms. In warm years, the Great Basin shifts to ephemerally dominant as the rain–snow transition increases in elevation. Given that snow ephemerality is expected to increase as a consequence of climate change, physics-based modeling is needed that can account for the complex energetics of shallow snowpacks in complex terrain. These modeling efforts will need to be supported by field observations of mass and energy and linked to finer remote sensing snow products in order to track ephemeral snow dynamics.
Here, we ask how mean climate and climate variation at individual sites and across a species’ range affect the specialist-generalist spectrum of germination strategies exhibited by 10 arid land forbs. We investigated these relationships using climate data for the western United States, occurrence records from herbaria, and germination trials with field-collected seeds, and predicted that generalist strategies would be most common in species that experience a high degree of climate variation or occur over a wide range of conditions. We used two metrics to describe variation in germination strategies: (a) selectivity (did seeds require specific cues to germinate?) and (b) population-level variation (did populations differ in their responses to germination cues?) in germination displayed by each species. Species exhibited distinct germination strategies, with some species demonstrating as much among-population variation as we observed among species. Modeling efforts suggested that generalist strategies evolve in response to higher spatial variation in actual evapotranspiration at a local scale and in available water in the spring and annual precipitation at a range-wide scale. Describing the conditions that lead to variation in early life-history traits is important for understanding the evolution of diversity in natural systems, as well as the possible responses of individual species to global climate change.
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The historical management of agroecological systems, such as California’s rangelands, have received criticism for a singular focus on agricultural production goals, while society has shifting expectations to the supply of multiple ecosystem services from these working landscapes. The sustainability and the multiple benefits derived from these complex social-ecological systems is increasingly threatened by weed invasion, extreme disturbance, urban development, and the impacts of a rapidly changing and increasingly variable climate. California’s grasslands, oak savannas, and oak woodlands are among the most invaded ecosystems in the world. Weed eradication efforts are rarely combined with seeding on these landscapes despite support for the inclusion of the practice in a weed management program. Depending on seed mix choice, cost and long-term uncertainty, especially for native seed, is an impediment to adoption by land managers. We investigated four seeding mixes (forage annual, native perennial, exotic perennial, and exotic-native perennial) to evaluate how these treatments resist rein-vasion and support the delivery of simultaneous multiple ecosystem services (invasion resistance, native richness, nitrogen fixing plants, pollinator food sources, plant community diversity, forage quality, and productivity). We found the increase of exotic and native perennial cover will drive resistance to an invading weedy summer flowering forb Centaurea solstitialis but provides a mixed response to resisting invasive annual grasses. The resistance to invasion is coupled with little tradeoff in forage productivity and quality and gains in plant diversity and native cover.
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This study tested the effects of different levels of functional diversity (planting grasses and shrubs together, vs. planting shrubs alone), seed source (cultivars, local or distant wild-collections), and irrigation regime (spring or fall and spring) on restoration outcomes. In the higher fertility field, increasing functional diversity appeared to have a neutral to competitive effect. After declines in shrub densities after irrigation ceased, these effects did not persist. Grasses initially suppressed or had a neutral effect on weeds relative to an unseeded control, but had neutral or facilitative effects on weeds relative to shrub-only seeding. Initially, commercial grasses were either equivalent to or outperformed wild-collected grasses, but after irrigation ceased, commercial grasses were outperformed by wild-collected grasses in the higher fertility field. Local shrubs initially outperformed distant shrubs, but this effect did not persist. Fall and spring irrigation combined with local shrubs and wild-collected grasses was the most successful strategy in the higher fertility field, while in the lower fertility field, irrigation timing had fewer effects. Superior shrub emergence and higher grass persistence indicated that the use of wild and local seed sources is generally warranted, whereas the effects of functional diversity and irrigation regime were context-dependent. A bet-hedging approach that uses a variety of strategies may maximize the chances of restoration success.
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This study evaluated the influence of preestablished plant species distance, direction, and identity on antelope bitterbrush (Purshia tridentata Pursh) seedling establishment and biomass production. Antelope bitterbrush seeds were planted 10- and 20-cm away from the base of three preestablished plant species. Sowing antelope bitterbrush seeds 20-cm away from preestablished plant bases yielded 1.59 times greater seedling establishment than seeds sown 10-cm away, suggesting that established plants interfere with bitterbrush recruitment. Antelope bitterbrush seedling survival after 2 y of growth was greater than 96% for all treatments, suggesting that early growth phases were the primary bottlenecks to establishment. Antelope bitterbrush forage production decreased with proximity to preestablished plants. After 2 y of growth, antelope bitterbrush biomass was almost 3 times greater for plants grown without preestablished plant neighbors or with a preestablished grass (Elymus elymoides Raf.) than with preestablished forb species (Dalea candida Michx. ex Willd. or Gaillardia aristata Pursh). Inoculating preestablished plants with soil from native sites or arbuscular mycorrhizal fungi did not influence antelope bitterbrush establishment or growth. We suggest that plant trait complementarity and spatial relationships can be used to design seeding strategies to increase antelope bitterbrush establishment and forage production.
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In his October 26, 2017 commentary in these pages, Dr. Tom Zimmerman highlights a number of ongoing and future challenges faced by wildland fire management. To address these challenges he also identifies an important role for science and in particular management-relevant wildland fire research. Here, we first briefly elaborate on Dr. Zimmerman’s challenges and how they relate to new opportunities for the role of science. Second, we focus on three additional institutional or “cultural” barriers or divides that should be acknowledged and addressed when forging a path forward for wildland fire research and its necessary companion: science delivery. As commenters on these matters, we represent only a small portion—even within the federal wildland fire science community—of those responsible for or interested in the funding, execution, and delivery of actionable science to end users. Nevertheless, we represent key programs with specific missions to serve federal wildland fire-related management and policy information needs.