Synthesis / Tech Report
Wildfire across the western US has increased in size, frequency, and severity since the 1950s. These changes are closely linked with increases in temperature and an increased frequency and intensity of drought. Historically, frequent low to moderate-severity fires dominated the fire regime in many western forests, maintaining low-density forests with larger trees. A history of fire exclusion, logging activity, grazing, and invasive species has led to an uncharacteristic build-up of forest fuels in many areas, increasing the susceptibility to large-scale, high-severity wildfire. The US has a history of fire suppression efforts that has exacerbated the problem by increasing the density of trees and fuel availability, and reduced the overall area burned by wildfires to levels that are below those that occurred before the beginning of the 20th century.
The western US is also experiencing larger, more severe fires that are often near communities. In recent decades, the build-up of forest fuels, a warmer and drier climate, and expansion of the wildland-urban interface (WUI) into forested areas has changed western landscapes and increased wildfire hazard. Federal policy and management have primarily focused on fire suppression and more recently on fuels reduction on some federal lands. Forest restoration and fuels reduction projects have had positive ecological impacts; however, the pace and scale of forest treatments is not keeping up with heightened wildfire activity across the West.
This plan is intended to provide a shared vision for natural resource management and conservation in Nevada. The plan incorporates the existing “All Hands – All Lands” approach together with the recent Shared Stewardship Agreement signed by the State and Federal land management agencies in Nevada to guide the strategic direction for the management of natural resources across all lands in Nevada. To ensure this goal, NDF is asking natural resource management and conservation stakeholders and interested public to review and provide substantive comments that help advance the plan’s strategic direction.
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.
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.
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.
Springs serve an ecologically important role as perennial water sources, essential habitat for native species, and support for stream flow. Spring developments on rangelands provide water to livestock and wildlife. Thoughtful design of sustainable developments will supply water to livestock and wildlife while maintaining the intrinsic ecological functions and values of springs. This guide addresses spring development project planning as well as long-term sustainable management of springs. The objectives of spring development design are (1) to retain hydrologic conditions in the developed spring habitat that are similar to undeveloped reference habitats and (2) to create a system that is easy to install and maintain. Report presents two gravity-flow development designs that incorporate flow-splitting devices to regulate environmental flows and levels and to work in a wide range of hydrologic conditions.
This plan represents the culmination of an unprecedented four-year collaboration among state and federal agencies investigating the threats of invasive plants to the sagebrush biome. The strategic plan identifies opportunities to overcome these threats through messaging, collaboration, prioritization, data sharing and increasing capacity to effectively implement cutting-edge, scientifically based management approaches across the Western landscape.
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The primary objective of this study was to explore the application of a dynamic global vegetation model (DGVM), the Ecosystem Demography (EDv2.2), to understand vegetation dynamics and ecosystem productivity in varying climate and fire scenarios. Most vegetation models do not represent sagebrush’s physical and physiological functions. Thus, we developed a sagebrush plant functional type (PFT) to use in modeling. Associated with this, the researchers performed a series of analyses and evaluations of the sagebrush and in the context of scenarios under natural (undisturbed) and disturbed (fire) environments.
- Results indicate that a number of sagebrush parameters are most sensitive to how productive the plant is (in our model). These include specific leaf area (SLA), stomatal slope, fine root turnover rate, cuticular conductance, and maximum carboxylation rate. These findings allow future sagebrush modeling efforts to further refine these parameters in different environments.
- The researchers comparisons between model runs and field data from Reynold Creek Experimental Watershed (RCEW), show good agreement. Improvements are needed to refine the model with additional PFTs representative of a range of elevations in the Great Basin.
- The researchers fire scenario modeling suggested that fire substantially reduced shrub gross primary production (GPP) and it took several decades before it was restored to pre-fire conditions. Grass GPP, however, responded more quickly in post-fire conditions. While these processes are representative of field observations and other studies, additional PFTs and improvement in fire routines in the model will provide for a better prognosis of future ecosystem dynamics of the sagebrush-steppe.
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View the complete pinyon-juniper synthesis.
This synthesis reviews current knowledge of pinyon and juniper ecosystems, in both persistent and newly expanded woodlands, for managers, researchers, and the interested public. We draw from a large volume of research papers to centralize information on these semiarid woodlands. The first section includes a general description of both the Great Basin and northern Colorado Plateau. The ecology section covers woodland and species life histories, biology, and ecology and includes a detailed discussion of climate and the potential consequences of climate change specific to the Great Basin and Colorado Plateau. The history section discusses 20,000 years of woodland dynamics and geographic differences among woodland disturbance regimes and resilience. The ecohydrology section discusses hydrologic processes in woodlands that influence soil conservation and loss; water capture, storage, and release; and the effect that woodland structure and composition have on these processes. The final section, restoration and management, covers the history of woodland management, the different methods used, the advantages and disadvantages of different vegetation treatments, and posttreatment vegetation responses. We also discuss successes and failures and key components that determine project outcomes important for consideration when restoring ecosystem function, integrity, and resilience.
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This report is part of an ongoing process of annual monitoring. It describes current conditions but is not an analysis or a description of a change of conditions. Although annual reports were produced for the years 2016 and 2017, the 2019 report also includes information from 2018. The 2019 report shows that:
- FS projects improved habitat for sage-grouse on nearly 480,000 acres from 2016-2019.
- Fires burned approximately 260,000 acres of greater sage-grouse habitat on National Forest System lands in 2016-2019.
- Data on habitat degradation are available from 2015-2018, and cumulative anthropogenic disturbance was at 0.03% on greater sage-grouse biologically significant units.
- Greater sage-grouse numbers in western states continue to cycle and are currently within the natural range of variability.