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We demonstrate the application of a scale selection approach that jointly estimates the scale of effect and the effect of sagebrush cover on trends in population size using counts from 584 sage-grouse leks in southwestern Wyoming (2003–2019) and annual estimates of sagebrush cover from a remote sensing product. From this approach, we estimated a positive effect of mean sagebrush cover with a 95% probability that the scale of effect occurred within 5.02 km of leks. In an average year, we found that lower levels of sagebrush cover within these estimated scales could support increasing trends in sage-grouse population size when populations were small, but higher levels of sagebrush cover were needed to sustain growing populations when populations were larger. With standardized monitoring and annual estimates of vegetation from remote sensing, this scale selection approach can be applied to identify relevant scales for other populations, species, and biological responses such as demography and movement.
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Within a common garden, 69 populations from diverse seed sources and 13 taxonomic varieties were evaluated for 17 phenological, morphological, and production traits in 2016 and 2017. Analyses of variance showed taxonomic varieties and seed source locations differed for all plant traits. Linear correlation revealed source locations with warmer mean temperature and more precipitation generally had later phenology, larger umbels, more leaf area, higher leaf dry weight, and more seed and shoot dry weight production. Canonical correlation strongly linked seed source climates at source locations with plant traits evaluated in the common garden, suggesting climate-driven adaptive evolution. Canonical variates 1 and 2, explaining 60% of the variation, were used to develop regression models that predicted their values from climate variables across the study area. Using geographic information technology these were mapped into 12 seed zones representing 1.31 million km2 in the Western United States. These zones were designed to provide guidance to practitioners when sourcing sulfur-flower buckwheat for restoration projects. We expect this methodology can be successfully applied to other species to develop seed zones based on adaptive evolution.
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Here, we examine recent (2010–2020) trends in human migration across the US in relation to features of the natural landscape and climate, as well as frequencies of various natural hazards. Controlling for socioeconomic and environmental factors, we found that people have moved away from areas most affected by heat waves and hurricanes, but toward areas most affected by wildfires. This relationship may suggest that, for many, the dangers of wildfires do not yet outweigh the perceived benefits of life in fire-prone areas. We also found that people have been moving toward metropolitan areas with relatively hot summers, a dangerous public health trend if mean and maximum temperatures continue to rise, as projected in most climate scenarios. These results have implications for policymakers and planners as they prepare strategies to mitigate climate change and natural hazards in areas attracting migrants.
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In a 16-year study, Rocky Mountain Research Station Research Ecologist Sharon Hood and her colleagues assessed three types of radial thinning to determine whether they would improve the growth and survival of sugar pines, a species of white pine, in southwest Oregon on sites located in the Umpqua National Forest and Bureau of Land Management Roseburg District. In addition to evaluating a control group, the researchers examined three kinds of treatments in which trees and shrubs were removed around sugar pines to 3 m (10 ft); 7.6 m (25 ft), while retaining large trees with diameters greater than 64 cm (2 ft); or 7.6 m (25 ft). Though some of the radial thinning strategies seemed promising at the 9-year mark, the radial thinning did not improve sugar pine survival at the end of the study (year 16), as compared to the control group. The extended (7.6 m) radial thinning with complete tree removal treatment did increase tree growth for sugar pine that survived, but the level of tree mortality was similar regardless of whether trees had radial thinning or not. Most tree mortality was due to the native mountain pine beetle.
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Fuel treatments can substantially reduce smoke emission from subsequent wildfires and if located in consideration of meteorological patterns, these fuel treatments can reduce ambient concentrations of PM2.5.
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We found widespread increases in cover and production of annual grasses and forbs, declines in herbaceous perennial cover, and expansion of trees. Cover and production of annual plants now exceed that of perennials on > 21 million ha of BLM rangeland, marking a fundamental shift in the ecology of these lands. This trend was most dramatic in the Western Cold Desert of Nevada and parts of surrounding states where aboveground production of annuals has more than tripled. Trends in annuals were negatively correlated with trends in bare ground but not with trends in perennials, suggesting that annuals are filling in bare ground rather than displacing perennials. Tree cover increased in half of ecoregions affecting some 44 million ha and underscoring the threat of woodland expansion for western rangelands. A multiscale variance partitioning analysis found that trends often varied the most at the finest spatial scale. This result reinforces the need to combine plot-level field data with moderate-resolution remote sensing to accurately quantify vegetation changes in heterogeneous rangelands. The long-term changes in vegetation on public rangelands argue for a more hands-on approach to management, emphasizing preventative treatment and restoration to preserve rangeland habitat and functioning. Our work shows the power of new remote-sensing tools for monitoring public rangelands and developing effective strategies for adaptive management and conservation.
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This study calculated fire history metrics from the Landsat Burned Area Product (1984–2020) across the conterminous U.S. (CONUS) including (1) fire frequency, (2) time since last burn (TSLB), (3) year of last burn, (4) longest fire-free interval, (5) average fire interval length, and (6) contemporary fire return interval (cFRI).
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Clearly there is broad consensus that society should manage wildlands to avoid severe wildfire impacts. But how else should a society invest in risk reduction? What are the primary drivers of risk? Where are the dominant impacts we are trying to avoid? What are our primary objectives in managing wildfire? How do we create social change to meet those objectives? These are serious questions that we often get wrong because of our laser focus on public lands forests.
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Evaluating the cumulative ability of fuel treatments to change landscape patterns of fire behavior and effects is challenging. By quantifying fire hazard, followed by evaluating outcomes of wildfires on environmental and ecological indicators and social values, it becomes possible to assess how individual fuel treatments placed within the context of a fuel management regime are effective based on desired conditions that address management objectives. This conceptual framework offers a much-needed middle-ground planning, monitoring, and reporting approach between overly simplistic annual reporting summaries of the area treated, number of fires, and burned area and detailed fire simulation modeling outcomes by putting individual treatments and fires in the context of current and desired vegetative conditions and social values. Our fuel treatment effectiveness framework examines the state of fuels through the lens of fire hazard and connects fuels to subsequent fire behavior and effects over time and space. The framework provides a way to focus regional and national fuel management planning efforts toward creating fuel management regimes that increase social and ecological resilience from wildfire.
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This analysis reveals that investing in collaborative capacity to advance agency-agency partnerships and public engagement might not slow down mitigation, but rather enable agencies to “go slow to go fast” by building the support and mechanisms necessary to increase the pace and scale of mitigation work. Reframing the wildfire problem through a careful analysis of competing frames and the underlying assumptions that privilege particular solutions can reveal a broader suite of solutions that address the range of key barriers.