Research and Publications
The Northeastern California Plateaus Bioregion Science Synthesis reviews literature relevant to the ecology and management of the Great Basin ecosystems and dry pine forests of the Lassen and Modoc National Forests. Critical factors on these national forests are reduced water availability—expected to become more challenging as levels and patterns of precipitation and temperature change under climate variability—coupled with a high proportion of rangeland and open woodland whose vegetation community is influenced by grazing of livestock and wild animal populations. Conifer encroachment of rangelands and the densification of woodlands, a result of fire suppression, impact wildlife communities that rely on open woodlands and other habitats characterized by having overstories of low density. Sagebrush habitat, in particular, is threatened by fragmentation and conversion. Socioeconomic changes in the region include a transition in the economic base from extraction to that of consumption of amenity values, and the resulting fragmentation of landownership. The local human population is expected to continue its trend of decline, but increased pressure by recreationists from nearby expanding urban areas is forcing land managers to consider increasingly complex situations or actions integrating social, ecological, and economic factors. Indigenous peoples are assuming a greater role in the management of their lands. Finally, disturbance patterns, such as nonhistorical fire frequency and intensity levels, novel combinations of climate patterns, and the pervasive pressure of nonnative invasive species could result in future ecosystems different than those today, presenting additional managerial challenges. This synthesis is intended to serve as a science-based foundation that supports management of Northeastern California forests, woodlands, and rangelands.
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This California Fire Regime Ecoregion classification map (i.e., using clustered driver variability layers) aims to devise a fire regime classification that better aligns with ecosystem types.
This brief aims to clarify basic liability laws in California, using state law and case examples to further the collective understanding and comfort around prescribed fire liability.
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In this second phase of the research, we conducted in-depth case studies of federal land management units that were actively working to increase their application of prescribed fire. We selected four case studies based on interviewee recommendations from our first round of interviews. These cases were: the San Juan National Forest (Colorado), the BLM Socorro Field Office/Cibola National Forest (New Mexico), the Sierra National Forest (California), and the Rogue-River Siskiyou National Forest (Oregon), with a focus on the Ashland Forest Resiliency Project in the Siskiyou Mountains Ranger District. For each case study, we conducted between 11 and 17 interviews with Forest Service or BLM staff members and key external partners. In total, 53 interviews were conducted with 62 interviewees for this phase of the project. Interviews focused on the nature of the prescribed fire program on the unit, key partners, primary challenges, and strategies and opportunities for increasing use of prescribed fire.
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Collectively, these studies show that the Weed-Suppressive Bacteria P. flourescens — strains ACK55, D7, and MB906 — are not likely to be effective in controlling invasive exotic grasses in western U.S. rangelands. There were no negative effects to exotic annual grasses, perennial bunchgrasses, or total community cover within three or four years of treatment when WSB was applied in the field alone or in combination with herbicides. It is possible that new formulations or application techniques could lead to more consistent, desired effects; however the studies described above tested three strains across a wide range of conditions, and yet no consistent effects were observed.
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Two of the principal functional groups of the understory vegetation (grasses and forbs) respond positively to tree removal by any means, with grasses—both annual and perennial—showing the greatest increases to both burning and cutting over the ten-year time period. This was an expected result, because it was assumed that understory species were significantly suppressed prior to treatment by pinyon and juniper trees on the landscape as a result of competition for resources, principally water (but possibly also light). If the hypothesis of competition for water were true, then we would expect to also see an increase in water resources in the soil after trees were removed, mirroring the response in the understory vegetation.
Prescribed fire and mow treatments maintained fire behavior below this threshold for extreme fire behavior, and in early years even kept it within the 4 ft control mark. Control and tebuthiuron treatments can be expected to have fire behavior that is more difficult to control.
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Numerical weather prediction (NWP) models can produce high-resolution forecasts of gust front conditions, and identifying these conditions from the model outputs may provide enhanced fire weather guidance. Abrupt changes in wind direction and speed can dramatically impact wildfire development and spread. Most importantly, such changes can pose significant problems to firefighting efforts and have resulted in a number of fire fatalities over the years. Frequent causes of such wind shifts are thunderstorm and convective system outflows, known as gust fronts, and the identification and prediction of these present critical challenges for fire weather forecasters. Anticipating and warning of these phenomena in wildland fire situations thus represent opportunities for enhancing the safety of incident personnel and the effectiveness of the firefighting operations. With these considerations we have developed a software tool to identify and depict convective outflow boundaries in high-resolution numerical weather prediction (NWP) models to provide guidance for fire weather forecasting.
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This study evaluated the potential for climate change and drought to reduce or eliminate isolated aspen communities in southwestern Idaho. We used a landscape simulation model integrated with inputs from an empirically derived biogeochemical model of growth, and a species distribution model of regeneration to forecast how changes in climate, declining snowpack, and competition with a conifer species is likely to affect aspen occupancy over the next 85-years. We found that simulated reductions in snowpack depth (and associated increases in climatic water deficit) caused a reduction in aspen persistence; aspen occupancy was reduced under all high emissions climate scenarios. Douglas-fir (Pseudotsuga menziesii) occupancy also declined under all future climates. Aspen regeneration declined over the course of all simulations, with an ensemble ratio of mortality/establishment increasing over the course of both low and high emissions climate scenarios. Climate-induced mortality of aspen clones increased in frequency under all climate scenarios and, under the most severe emissions scenarios, contributed to a substantial decline of aspen cover. Our research suggests that snowbanks will become an important determinant of long-term persistence of aspen under changing climate in the region.
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This study applied a remote sensing change detection approach to map reductions in pinyon-juniper cover across the sage-grouse range and developed a method for rapidly updating maps of canopy cover. We found total conifer reduction over the past several years (2011−2013 to 2015−2017) amounted to 1.6% of the area supporting tree cover within our study area, which is likely just keeping pace with estimates of expansion. Two-thirds of conifer reduction was attributed to active management (1.04% of the treed area) while wildfire accounted for one-third of all estimated conifer reduction in the region (0.56% of the treed area). Results also illustrate the breadth of this management effort—crossing ownership, agency, and state boundaries.
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Since the mid-1800s pinyon-juniper (PJ) woodlands have been encroaching into sagebrush-steppe shrublands and grasslands such that they now comprise 40% of the total forest and woodland area of the Intermountain West of the United States. More recently, PJ ecosystems in select areas have experienced dramatic reductions in area and biomass due to extreme drought, wildfire, and management. Due to the vast area of PJ ecosystems, tracking these changes in woodland tree cover is essential for understanding their consequences for carbon accounting efforts, as well as ecosystem structure and functioning. Here we present a carbon monitoring, reporting, and verification (MRV) system for characterizing total aboveground biomass stocks and flux of PJ ecosystems across the Great Basin.