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Electricity-generating wind turbines are an attractive energy source because they are renewable and produce no emissions. However, they have at least two potentially damaging ecological effects. Their rotating blades are hazardous to raptors which occasionally fly into them. And wind turbines are very noisy when active, a feature that may interfere with the lives of animals beneath them. We studied California ground squirrels (Spermophilus beecheyi) in the Altamont Pass Wind Resource Area of Northern California. These squirrels emit vocalizations that alert others to the presence of a predator, and so may be forced to compensate for turbine noise by modifying antipredator behavior. We compared the antipredator behavior...
There may be no more conspicuous example of a conflict between society and technology than a wind energy landscape. The fastest growing renewable energy resource in the world, wind energy has evoked a cool public response. Through the use of interviews, the published literature, governing legislation, and personal experience, this article examines this conflict near Palm Springs, California. Its purpose is to summarize and explain the opposition that developed there from the earliest days, what has been done to mitigate it, and how the local experience is reflected in similar developments elsewhere. This particular conflict between society and technology has the potential, with proper guidance, controls, and sensitivity,...
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This raster represents a continuous surface of sage-grouse habitat suitability index (HSI) values for Nevada during summer, which is a surrogate for habitat conditions during the sage-grouse brood-rearing period.
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Successful implementation of environmental flow projects depends on land and water managers having clear objectives and access to reliable data. This guidebook provides information on a variety of methods that can be utilized under different fiscal or temporal constraints to determine and implement appropriate environmental flow targets. Based on evidence from cases focused in the Southwestern United States and Northern Mexico, steps are suggested to help ensure maintenance of flows under uncertain future natural and socioeconomic conditions. The importance of education and engagement to increase acceptance of environmental flows based projects and gain key player and community buy in is described. Limitations on...
Land managers are responsible for developing effective strategies for conserving and restoring Great Basin ecosystems in the face of invasive species, conifer expansion, and altered fire regimes. A warming climate is magnifying the effects of these threats and adding urgency to implementation of management practices that will maintain or improve ecosystem functioning. This Factsheet Series was developed to provide land managers with brief summaries of the best available information on contemporary management issues to facilitate science delivery and foster effective management. Each peer-reviewed factsheet was developed as a collaborative effort among knowledgeable scientists and managers. The series begins with...
Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations....
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Synopsis: The goal of this study was to examine contaminant loadings associated with stormwater runoff from recently burned areas in urban fringe areas of southern California, to derive regional patterns of runoff and contaminant loadings in this context. Postfire stormwater runoff was sampled from five wildfires that each burned between 115 and 658 km2 of natural open space between 2003 and 2009. The area is characterized by classic Mediterranean climate conditions of relatively mild to cool wet winter and warm to hot dry summers. Between two and five storm events were sampled per site over the first one to two years following the fires for basic constituents, metals, nutrients, total suspended solids, and polycyclic...
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This shapefile represents habitat suitability categories (High, Moderate, Low, and Non-Habitat) derived from a composite, continuous surface of sage-grouse habitat suitability index (HSI) values for Nevada and northeastern California during summer¸ which is a surrogate for habitat conditions during the sage-grouse brood-rearing period.
There is increasing recognition that overall interactions among plant species are often the net result of both positive and negative effects. However, the positive influence of other plants has rarely been examined using detailed demographic methods, which are useful for partitioning net effects at the population level into positive and/or negative effects on individual vital rates. This study examines the influence of microhabitats created by the native shrubs Artemisia tridentata and Purshia tridentata on the demography of the invasive annual grass Bromus tectorum in the Great Basin Desert, California, USA. Shrub understory environments differed significantly from intershrub space and were characterized by higher...
Invasive annual grasses have become increasingly important components of desert vegetation in North America. They are especially problematic because they increase the extent, severity, and frequency of fire in desert shrublands that normally experience fire very rarely, or not at all. After fire, invasive grasses and forbs are often dominant and restoration methods are required to promote native plant recovery. Three treatments to control invasive annual grasses and forbs were implemented in the first 3 years following a fire in creosote bush scrub vegetation. Treatments included early season mechanical removal (raking) of all annuals, grass-specific herbicide (Fusilade II), and Fusilade II plus hand pulling of...
Abstract (from http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00196.1): In this study (Part I), the mid-twenty-first-century surface air temperature increase in the entire CMIP5 ensemble is downscaled to very high resolution (2 km) over the Los Angeles region, using a new hybrid dynamical–statistical technique. This technique combines the ability of dynamical downscaling to capture finescale dynamics with the computational savings of a statistical model to downscale multiple GCMs. First, dynamical downscaling is applied to five GCMs. Guided by an understanding of the underlying local dynamics, a simple statistical model is built relating the GCM input and the dynamically downscaled output. This statistical...
Wind erosion and aeolian transport processes are under studied compared to rainfall-induced erosion and sediment transport on burned landscapes. Post-fire wind erosion studies have predominantly focused on near-surface sediment transport and associated impacts such as on-site soil loss and site fertility. Downwind impacts, including air quality degradation and deposition of dust or contaminants, are also likely post-fire effects; however, quantitative field measurements of post-fire dust emissions are needed for assessment of these downwind risks. A wind erosion monitoring system was installed immediately following a desert sagebrush and grass wildfire in southeastern Idaho, USA to measure wind erosion from the burned...
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Synopsis: Researchers analyzed variation in crop pollination services provided by native, unmanaged, bee communities on organic and conventional farms situated along a gradient of isolation from natural habitat. Pollination services from native bees were significantly, positively related to the proportion of upland natural habitat in the vicinity of farm sites, but not to any other factor studied, including farm type, insecticide usage, field size and honeybee abundance. The scale of this relationship matched bee foraging ranges. Stability and predictability of pollination services also increased with increasing natural habitat area. This strong relationship between natural habitat area and pollination services...
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Synopsis: The individual species and aggregate community contributions of native bees to crop pollination are documented, on farms that varied both in their proximity to natural habitat and management type (organic versus conventional). On organic farms near natural habitat, we found that native bee communities could provide full pollination services even for a crop with heavy pollination requirements (e.g., watermelon, Citrullus lanatus), without the intervention of managed honey bees. Agricultural intensification diminished these pollination services by roughly 3- to 6-fold. The decline of native bee pollination services with agricultural intensification resulted in significant reductions in both diversity and...
Big sagebrush (Artemisia tridentata) is one of the most widespread and abundant plant species in the intermountain regions of western North America. This species occupies an extremely wide ecological niche ranging from the semi-arid basins to the subalpine. Within this large niche, three widespread subspecies are recognized. Montane ecoregions are occupied by subspecies vaseyana, while subspecies wyomingensis and tridentata occupy basin ecoregions. In cases of wide-ranging species with multiple subspecies, it can be more practical from the scientific and management perspective to assess the climate profiles at the subspecies level. We focus bioclimatic model efforts on subspecies wyomingensis, which is the most...
The uncertainties associated with climate-change projections for California are unlikely to disappear any time soon, and yet important long-term decisions will be needed to accommodate those potential changes. Projection uncertainties have typically been addressed by analysis of a few scenarios, chosen based on availability or to capture the extreme cases among available projections. However, by focusing on more common projections rather than the most extreme projections (using a new resampling method), new insights into current projections emerge: (1) uncertainties associated with future greenhouse-gas emissions are comparable with the differences among climate models, so that neither source of uncertainties should...
Government agencies that develop infrastructure such as roads, waterworks, and energy delivery often impact natural ecosystems, but they also have unique opportunities to contribute to the conservation of regional natural resources through compensatory mitigation. Infrastructure development requires a planning, funding, and implementation cycle that can frequently take a decade or longer, but biological mitigation is often planned and implemented late in this process, in a project-by-project piecemeal manner. By adopting early regional mitigation needs assessment and planning for habitat-level impacts from multiple infrastructure projects, agencies could secure time needed to proactively integrate these obligations...
California’s highly variable climate and growing water demands combine to pose both water-supply and flood-hazard challenges to resource managers. Recently important efforts to more fully integrate the management of floods and water resources have begun, with the aim of benefitting both sectors. California is shown here to experience unusually large variations in annual precipitation and streamflow totals relative to the rest of the US, variations which mostly reflect the unusually small average number of wet days per year needed to accumulate most of its annual precipitation totals (ranging from 5 to 15 days in California). Thus whether just a few large storms arrive or fail to arrive in California can be the difference...
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Synopsis: This study examines the influence of landscape fragmentation on trophic cascades in southern California. Results indicate that, as habitat fragmentation negatively affects the persistence of coyote populations, the abundance of smaller meso-predators increase, resulting in higher mortality rates in scrub-breeding birds. Fragment size was a strong indicator of coyote abundance, and coyote abundance was a strong indicator of bird diversity, as coyotes kept down the number of meso-predators that prey on birds. The positive effect of fragment area and the negative effect of fragment age were the strongest determinants of bird diversity in this system. Conclusions: Fragment size correlates with coyote abundance,...
Natural-resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural-resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and...
map background search result map search result map Crop pollination from native bees at risk from agricultural intensification The area requirements for an ecosystem serivce: crop pollination by native bee communities in California Stormwater contaminant loading following southern California wildfires Mesopredator release and avifaunal extinctions in a fragmented system. Summer Season Habitat Categories Shapefile Summer Season Habitat Suitability Index raster dataset Desert Flows Methodology Guidebook Crop pollination from native bees at risk from agricultural intensification The area requirements for an ecosystem serivce: crop pollination by native bee communities in California Summer Season Habitat Categories Shapefile Summer Season Habitat Suitability Index raster dataset Stormwater contaminant loading following southern California wildfires Mesopredator release and avifaunal extinctions in a fragmented system. Desert Flows Methodology Guidebook