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In this study, we use freely available, satellite remote sensing to explore changes in vegetation productivity(normalized difference vegetation index) of three distinct, low-tech, riparian and wet meadow restoration projects. Case studies are presented that range in geographic location (Colorado, Oregon, and Nevada), restoration practice (Zeedyk structures,beaver dam analogs, and grazing management), and time since implementation. Restoration practices resulted in increased vegetation productivity of up to 25% and increased annual persistence of productive vegetation. Improvements in productivity with time since restoration suggest that elevated resilience may further enhance wildlife habitat and increase forage production.Long-term, documented outcomes of conservation are rare; we hope our findings empower practitioners to further monitor and explore the use of low-tech methods for restoration of ecohydrologic processes at meaningful spatial scales.
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This study presents a method and case study to evaluate the effectiveness of restoration of riparian vegetation using a web-based cloud-computing and visualization tool (ClimateEngine.org) to access and process remote sensing and climate data. In each study area, the post-restoration NDVI-precipitation relationship was statistically distinct from the pre-restoration relationship, suggesting a change in the fundamental relationship between precipitation and NDVI resulting from stream restoration. We infer that the in-stream structures, which raised the water table in the adjacent riparian areas, provided additional water to the streamside vegetation that was not available before restoration and reduced the dependence of riparian vegetation on precipitation. This approach provides a cost-effective, quantitative method for assessing the effects of stream restoration projects on riparian vegetation.
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Low-severity wildland fires and prescribed burns have long been presumed by scientists and resource managers to be harmless to soils, but this may not be the case, new research shows. According to two new studies, low-severity burns cause damage to soil structure and organic matter in ways that are not immediately apparent after a fire.
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Through a series of examples spanning at least four research disciplines and three ranges of spatial scale, we illustrate that by precisely defining parameters in a way that holds across scales and relaxing one steady-state simplification, we begin to capture the inherent variability that has largely eluded the fire behavior community. Through exploring examples of “deep interdependence,” we make the case that fire behavior science is well equipped to launch forward into more complex lines of inquiry.
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Past and current forest management affects wildland fire smoke impacts on downwind human populations. However, mismatches between the scale of benefits and risks make it difficult to proactively manage wildland fires to promote both ecological and public health. Building on recent literature and advances in modeling smoke and health effects, we outline a framework to more directly quantify and compare smoke impacts based on emissions, dispersion, and the size and vulnerability of downwind populations across time and space. We apply the framework in a case study to demonstrate how different kinds of fires in California’s Central Sierra Nevada have resulted in very different smoke impacts.
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Using the Forest Service of the US Department of Agriculture (USDA) as a relevant test case for systemic investigation, this paper argues that fundamental changes in how the fire management community thinks about, learns from, plans for, and responds to wildland fires may be necessary. The intent is to initiate a broader dialog around the current and future state of wildland fire management.
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This paper presents a case study to demonstrate the ability of the modeling framework to capture the onset and dynamics of a post-fire dust event and then use the modeling framework to estimate particulate matter (PM) emissions from burn scars left by wildfires in U.S. western sagebrush landscapes during 2012. Modeled emissions from 1.2 million ha of burned soil totaled 32.1 Tg of dust as PM10 and 12.8 Tg as PM2.5. Despite the relatively large uncertainties in these estimates and a number of underlying assumptions, these first estimates of annual post-fire dust emissions suggest that post-fire PM emissions could substantially increase current annual PM estimates in the U.S. National Emissions Inventory during high fire activity years. Given the potential for post-fire scars to be a large source of PM, further on-site PM flux measurements are needed to improve emission parameterizations and constrain these first estimates.
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Annual growth-ring analysis was used to determine the year of establishment and the relationship between recruitment and weather events. Results indicated stand ages and locations were different (P > 0.001) among species and subspecies, and years of recruitment were strongly correlated with local and hemispheric weather patterns. Linear and multiple regressions modeled recruitment pulses for all four species. Weather-based predictor variables indicated complex interactions between recruitment and climatic controls. Pacific Decadal Oscillation index variables were prominent predictors for all four species at their associated sites. Other important local weather variables included total annual precipitation the year before recruitment, the year of recruitment, and the year following recruitment. In Nevada and the Great Basin, it is imperative that successful sagebrush seeding technologies are discovered and implemented.
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In this study, a multivariate dataset was analyzed using principal components analysis to identify “defining factors” that best explained variation among sites. Variation was primarily attributed to an inverse relationship between crested wheatgrass and sagebrush abundance (R2 = 0.69; P < 0.0001) and their affinity for either silty or sandy soil textures, respectively, as well as a negative association between crested wheatgrass abundance and species diversity (R2 = 0.67; P < 0.0001). These results do not support the assumption that crested wheatgrass seedings uniformly remain in vegetation states with low diversity and poor sagebrush reestablishment over the long term (i.e., 43 − 63 yr). We suggest that a broader interpretation of plant community dynamics is needed while avoiding generalizations of how historically seeded Wyoming big sagebrush sites will respond over time.
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In this study, exotic annual grass cover and density were greatly reduced in all treatments where perennial seedlings were planted compared with the control (no seedlings planted). Treatments including crested wheatgrass (Agropyron desertorum) generally limited annual grasses more than other treatments. Most notably, forage kochia (Bassia prostata) reduced exotic annual grasses less than crested wheatgrass and crested wheatgrass planted with forage kochia. This suggests that if forage kochia will be planted, it should be used in conjunction with perennial bunchgrasses in efforts to revegetate exotic annual grass − invaded sagebrush steppe. Established native vegetation also greatly reduced exotic annual grass reinvasion. Though some differences existed among established vegetation treatments, our study highlights that established perennial vegetation prevents redomination by invasives after exotic annual grass control.