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In this study, we used longer-term data to evaluate the relationships among soil climate conditions, perennial herbaceous cover, and cheatgrass cover following fuel management treatments across the environmental gradients that characterize sagebrush ecosystems in the Great Basin. Both prescribed fire and mechanical treatments increased soil water availability on woodland sites and perennial herbaceous cover on some woodland and sagebrush sites. Prescribed fire also slightly increased soil temperatures and especially increased cheatgrass cover compared to no treatment and mechanical treatments on most sites. Non-metric dimensional scaling ordination and decision tree partition analysis indicated that sites with warmer late springs and warmer and wetter falls had higher cover of cheatgrass. Sites with wetter winters and early springs (March-April) had higher cover of perennial herbs. Our findings suggest that site resistance to cheatgrass after fire and fuel control treatments decreases with a warmer and drier climate. This emphasizes the need for management actions to maintain and enhance perennial herb cover, such as implementing appropriate grazing management, and revegetating sites that have low abundance of perennial herbs in conjunction with fuel control treatments.
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Using epidemiology studies to understand the exposure-response relationship for PM, this study found that firefighters were at an increased risk for long-term health effects from smoke exposure. The risk for lung cancer mortality increases nearly linearly with exposures over time and is more strongly influenced by exposure duration than are the risks of death from cardiovascular or ischemic heart disease. On the other hand, the risk of cardiovascular mortality rises steeply for doses in the range we estimated for firefighter exposures but flattens out at higher exposures to PM. The data presented in this paper clearly identify the crews and activities most likely to exceed occupational exposure limits and firefighters may have a an increased health risk from smoke exposures.
Visit SageSTEP website.
SageSTEP is a long-term multidisciplinary experiment evaluating methods of sagebrush steppe restoration in the Great Basin.
You can find and access information on this project’s:
- Land management treatments
- Treatment effects on vegetation and fuels; soils and biogeochemistry; water runoff and erosion; wildlife and insects
- The economics and human perspectives of management treatments
- Association with climate change
- Research findings thus far and project future
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This brief presents the following findings:
- Overall, mulching treatments in three Colorado conifer forest types promoted denser and more diverse native understory plant communities, particularly over the longer-term.
- The positive effect of mulching on understory plants was largely driven by the response of herbaceous plants; shrubs showed little response to mulching treatments.
- Exotic plants tended to be more common in mulched stands than in untreated stands.
- While understory plants in mulched stands could be heavily suppressed in localized areas where mulch contributed to a deep forest floor, these areas were rare.
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This study quantifies the effect of seasonal reburns on woody surface fuels, forest floor fuels, and understory tree regeneration abundance in six previously thinned ponderosa pine stands in the southern Blue Mountain Ecoregion of Oregon, USA. Each stand consisted of an unburned control, and four season by reburn treatments: spring 5 yr, spring 15 yr, fall 5 yr, and fall 15 yr. All reburn treatments reduced the forest floor depth compared to those areas not burned (controls). Fall burning, regardless of frequency, generated 1000 hr fuel primarily from overstory mortality resulting from the initial entry burns and subsequent snag and branch fall. But, for the other woody fuel types, reburning had minimal impact, regardless of season or frequency. All reburn treatments reduced regeneration survival, but 5 yr fall reburning was most effective in reducing excessive conifer seedlings. Repeated spring or fall reburns following thinning will reduce forest floor depth but, to achieve low woody fuel loads and control excessive conifer regeneration, it may be necessary to conduct reburns using different timing, such as during drier periods when wildfire ignitions by lightning occurred historically.
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Targeted livestock grazing must be carefully implemented and monitored to meet fuels management objectives on an annual and long-term basis. Grazing to reduce fuels on a landscape must be both strategic and surgical. Surgical means that targeted livestock grazing will be done to the level and limited to the minimum area needed to meet fuel and landscape or project management objectives within BLM’s regulatory framework. Therefore, sound project planning is essential.
View fact sheet, pg. 54.
This fact sheet provides an overview of the immediate and short-term hydrologic impacts of fire on infiltration, runoff, and erosion by water, and of the effectiveness of various mitigation treatments in the reduction of runoff and erosion in the years following the fire.
View all topics reviewed in the Fact Sheet series.
In this webinar, Steve Knick, USGS Forest and Rangeland Ecosystem Science Center, shares his research on changes within bird communities living in ecotone regions where land management treatments have been conducted to reduce woodland expansion into sagebrush habitats.
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This paper defines the term ecological drought as an episodic deficit in water availability that drives ecosystems beyond thresholds of vulnerability, impacts ecosystem services, and triggers feedbacks in natural and/or human systems. We support this definition with a novel, integrated framework for ecological drought that is organized along two dimensions—the components of vulnerability (exposure + sensitivity/adaptive capacity) and a continuum from human to natural factors. The purpose of this framework is to help guide drought researchers and decision-makers to understand 1) the roles that both people and nature play as drivers of ecosystem vulnerability, 2) that ecological drought’s impacts are transferred to human communities via ecosystem services, and 3) these ecological and ecosystem service impacts will feed back to both natural and human systems. In addition, our framework will help identify important trade-offs and strategies for reducing the ecological drought risks facing both human and natural systems in the 21st century.
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Study results from this project suggest that treatments over a 70-year period on public lands in the southwestern United States are shifting toward restoration practices that are increasingly large, expensive, and related to fire and invasive species control.