Research and Publications
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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
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View fact sheet on pinyon-juniper ecohydrology
View fact sheet on pinyon-juniper management and restoration
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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We analyzed the relationship between predicted housing exposure to wildfire and local self-assessment of community competence to mitigate wildfire risks in 60 communities in the western US. Results generally demonstrate that (1) the number of sources of wildfire risk influences local housing exposure to wildfire, and (2) perceived community-competence is associated with predicted exposure to wildfire. We suggest that investments in ongoing updates to community risk planning and efforts to build multi-jurisdictional risk management networks may help to leverage existing capacity, especially in moderate capacity communities. The analysis improves the social-ecological understanding of wildfire risks and highlights potential causal linkages between community capacity and wildfire exposure.
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Using a sample of 722 large fires from the western United States, we observe whether a fire interacted with a previous fire, the percent area of fires burned by previous fires, and the percent perimeter overlap with previous fires. Fires that interact with previous fires are likely to be larger and have lower total expenditures on average. Conditional on a fire encountering a previous fire, a greater extent of interaction with previous fires is associated with reduced fire size but higher expenditures, although the expenditure effect is small and imprecisely estimated. Subsequent analysis suggests that fires that interact with previous fires may be systematically different from other fires along several dimensions. We do not find evidence that interactions with previous fires reduce suppression expenditures for subsequent fires. Results suggest that previous fires may allow suppression opportunities that otherwise might not exist, possibly reducing fire size but increasing total expenditures.
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It is sometimes assumed the sparse and low statured vegetation in arid systems would limit the effectiveness of two remote-sensing derived indices of burn severity: the difference Normalised Burn Ratio (dNBR) and relativised difference Normalised Burn Ratio (RdNBR). We compared the relationship that dNBR, RdNBR and a ground-based index of burn severity (the Composite Burn Index, CBI) had with woody cover and woody density 1 year after burning in five fires that occurred in the Mojave Desert during 2005. Statistically, dNBR and RdNBR were both effective measures of severity in all three elevation zones; woody cover and density had steep exponential declines as the values of each remote-sensing index increased. We found though that dNBR was more ecologically interpretable than RdNBR and will likely be of most relevance in the Mojave Desert.
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A new study shows burned leaf litter and other biomaterials can leach these molecules—called pyrogenic carbon—into fresh water where they react with sunlight. That means pyrogenic carbon in our waterways could degrade into carbon dioxide faster than previously suggested, providing an unexpected source of this greenhouse gas to the atmosphere, according to the researchers.
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This study presents a novel risk-science approach that aligns wildfire response decisions, mitigation opportunities, and land management objectives by consciously integrating social, ecological and fire management system needs. We use fire-prone landscapes of the US Pacific Northwest as our study area, and report on and describe how three complementary risk-based analytic tools—quantitative wildfire risk assessment, mapping of suppression difficulty, and atlases of potential control locations—can form the foundation for adaptive governance in fire management. Together, these tools integrate wildfire risk with fire management difficulties and opportunities, providing a more complete picture of the wildfire risk management challenge. Leveraging recent and ongoing experience integrating local experiential knowledge with these tools, we provide examples and discuss how these geospatial datasets create a risk-based planning structure that spans multiple spatial scales and uses.
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Modelling the spatial prioritization of fuel treatments and their net effect on values at risk is an important area for applied work as economic damages from wildfire continue to grow. We model and demonstrate a cost-effective fuel treatment planning algorithm using two ecosystem services as benefits for which fuel treatments are prioritized. We create a surface of expected fuel treatment costs to incorporate the heterogeneity in factors affecting the revenue and costs of fuel treatments, and then prioritize treatments based on a cost-effectiveness ratio to maximize the averted loss of ecosystem services from fire. We compare treatment scenarios that employ cost-effectiveness with those that do not, and use common tools and models in a case study of the Sisters Ranger District on the Deschutes National Forest in central Oregon.
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Recent debate over the efficiency of flood irrigation and resulting transition to other “more efficient” types of irrigation has put many of the working wet meadows sustained by flood irrigation at risk. As the sustainability of these landscapes is primarily dependent on ranchers’ management decisions, we sought to gain a deeper understanding of factors influencing ranchers who flood irrigate and how these factors interrelate.
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In common gardens at two sites over two years differences in both ploidy type and genetic variation within ploidy were observed in phenology, morphology, and production traits on 57 octoploid and 52 tetraploid basin wildrye from the Intermountain West. Octoploids had larger leaves, longer culms, and greater crown circumference than tetraploids but the numerical ranges of plant traits and their source climates overlapped between ploidy types. Still, among populations octoploids often had greater genetic variation for traits and occupied more diverse climates than tetraploids. The link between genetic traits and seed source climates suggests climate driven natural selection and adaptive evolution in basin wildrye. The more diverse climates occupied by octoploids and higher trait variation suggests a higher capacity for ecological differentiation than tetraploids in the Intermountain West.