Search Results: %252525257Bsearch_term_string%252525257D
View report.
This study showed higher levels of resilience to fire than is typically discussed in the sagebrush steppe, in part because the studied ecosystems were in good condition before the fire, but also because the longer post-fire monitoring time (17 years) may be more appropriate to capture patterns of succession in these ecosystems.
View article.
We compared vegetation recovery spanning 20 yr following prescribed fire on mid-succession and late-succession western juniper woodlands on Steens Mountain, Oregon. Our objective was to evaluate vegetation dynamics between early (first decade) and later successional (second decade) time periods after fire. The first decade after fire vegetation on burned mid-succession sites were codominated by native herbaceous perennials and sprouting shrub species and on late-succession sites vegetation was codominated by nonnative cheatgrass and snowbrush. During the second decade after fire, vegetation composition converged and both mid-succession and late-succession sites were codominated by herbaceous perennials, mountain big sagebrush, round-leaf snowberry, and snowbrush. Herbaceous and shrub vegetation composition of both burned woodland phases proved to be highly resilient to fire, the difference was that native shrub-herbaceous recovery on late-succession sites required about twice as much time as mid-succession sites. The resilience of both mid-succession and late-succession woodland sites was likely a product of ecological site characteristics (e.g., elevation and precipitation zone) that affords a competitive advantage for native perennial species over invasive annuals.
View article.
The goal of restoration actions in these communities is to control the annual grasses and promote co-occurring perennial vegetation. Indaziflam and imazapic, applied as pre-emergent herbicides, have both been used for this purpose. Indaziflam often has less than desired control in the first year but can control annual grasses for multiple years. In contrast, imazapic has effective control in the first year, but control is short-lived. Land managers have recently started tank-mixing these two herbicides to potentially alleviate their individual shortcomings and theoretically achieve more effective, long-term annual grass control. However, little is known about the effectiveness of aerially applying these herbicides together, particularly compared with just applying indaziflam, and the effects on co-occurring perennial vegetation. We investigated the effects of applying indaziflam individually and in combination with imazapic at three sites (two in Oregon and one in Washington). Applying indaziflam and imazapic in tandem provided better control of annual vegetation and promoted perennial vegetation, although site differences influenced treatment effects. Applying indaziflam individually controlled annual vegetation but did not generally generate a response from perennial vegetation. Tank-mixing indaziflam and imazapic improved first-year control compared with only applying indaziflam, but control was still better in the second year after treatment, suggesting that a greater rate of imazapic than used in this study may be needed to achieve better first-year control. The results of this study suggest that applying indaziflam and imazapic in tandem may be an effective strategy for controlling invasive annual grasses and promoting co-occurring perennial vegetation.
View article.
Behavioral responses to wildfire by sage-grouse are more flexible than has been described, and sage-grouse demonstrated resilience by rapidly adapting space use to avoid short-term consequences of catastrophic fire when high-quality habitat remained adjacent to the burn and within their seasonal range. Our results imply behavioral and fitness consequences of fire are context-dependent and likely impacted by attributes of the fire and surrounding landscape after disturbance. Furthermore, among-study differences in behavioral and fitness outcomes of sage-grouse after fire supported underappreciated predictions from both fire ecology and site fidelity theory, and suggest conditions where behavioral flexibility should be expressed, and fidelity relaxed, based on severity of disturbance, landscape context, and species mobility.
View brief.
Two studies found that planting site climate, post-planting weather, planting season, tree seed lot sources, and tree species had particularly meaningful impacts on planted tree seedling performance after fire. Although the survival monitoring data used in both studies were limited to tree seedling survival after the first growing season, survival rates for this vulnerable period were linked to longer-term survival trends.
View article.
In this study, we present a framework for forecasting large fire occurrence – an extreme value event – and evaluating measures of uncertainties that do not rely on distributional assumptions. The statistical model presented here incorporates qualitative fire danger indices along with other location and seasonal specific explanatory variables to produce maps of forecasted probability of an ignition becoming a large fire, as well as numbers of large fires with measures of uncertainties. As an example, 6 years of fire occurrence data from the Western US were used to study the utility of two fire danger indices: the 7-Day Significant Fire Potential Outlook issued by Predictive Services in the US and the National Fire Danger Rating’s Energy Release Component. This exercise highlights the potential utility of the quantitative risk index as a real-time decision support tool that can enhance managers’ abilities to discriminate among planning areas in terms of the likelihood and range of expected significant fire events.
View field guide.
** Updated 2017 ** The Fire Behavior Field Reference Guide (FBFRG) was developed as a hands-on user tool for field going Fire Behavior Analysts (FBANs), Long Term Fire Analysts (LTANs), and other fire behavior operational personnel. The FBFRG was created by the S-590 steering committee. The guide was developed by course coordinators, coaches, and field going personnel as a reference tool and look up guide for use in training and in the field by fire behavior analysts and fire managers alike.
View article.
This study used graph theory, representing priority areas as spatially distributed nodes interconnected by movement corridors, to understand the capacity of priority areas to function as connected networks in the Bi-State, Central, and Washington regions of the greater sage-grouse range. The Bi-State and Central networks were highly centralized; the dominant pathways and shortest linkages primarily connected a small number of large and centrally located priority areas. These priority areas are likely strongholds for greater sage-grouse populations and might also function as refugia and sources.
View article.
This study found that prescribed fires conducted under favorable conditions (2011) induced potentially positive bighorn responses including high survival and increased use of treated areas. Fires during drought conditions were more widespread with little vegetative response (2012) and coincided with increased bighorn mortality in spring 2013.
View article.
This study provides quantitative evidence linking long-term declines of sage-grouse to chronic effects of wildfire. Projected declines may be slowed or halted by targeting fire suppression in remaining areas of intact sagebrush with high densities of breeding sage-grouse.