Skip to main content
Advanced Search

Filters: Tags: {"type":"Drought, Fire and Extreme Weather","name":"fire"} (X) > Types: Citation (X)

41 results (55ms)   

View Results as: JSON ATOM CSV
Abstract (from http://www.bioone.org/doi/abs/10.3417/2017006): The Earth system is undergoing rapid, profound anthropogenic change. The primary axes of change include not only the climate system, but also the spread of invasive species, altered biogeochemical and hydrological cycles, modified disturbance regimes, and land degradation and conversion. These factors are influencing the distribution of species and the structure and function of ecosystems worldwide, interacting with climatic stressors that may preclude the persistence of many current species distributions and communities. Ecological disturbances such as wildfires and insect outbreaks can interact with climate variability to precipitate abrupt change...
Abstract (from SpringerOpen): Wildfires in the Pacific Northwest (Washington, Oregon, Idaho, and western Montana, USA) have been immense in recent years, capturing the attention of resource managers, fire scientists, and the general public. This paper synthesizes understanding of the potential effects of changing climate and fire regimes on Pacific Northwest forests, including effects on disturbance and stress interactions, forest structure and composition, and post-fire ecological processes. We frame this information in a risk assessment context, and conclude with management implications and future research needs. Large and severe fires in the Pacific Northwest are associated with warm and dry conditions, and such...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/gdj3.47/abstract): Two datasets of soil temperature observations collected at Norman, Oklahoma, USA, were analysed to study horizontal and vertical variability in their observations. The first dataset comprised 15-min resolution soil temperature observations from 20 September 2011 to 18 November 2013 in seven plots across a 10-m transect. In each plot, sensors were located at depths of 5, 10, and 30 cm. All seven plots observed fairly consistent maximum soil temperature observations during the spring, fall, and winter months. Starting in late May, the observed spread in soil temperatures across the 10-m transect increased significantly until August when the...
A warming climate, fire exclusion, and land cover changes are altering the conditions that produced historical fire regimes and facilitating increased recent wildfire activity in the northwestern United States. Understanding the impacts of changing fire regimes on forest recruitment and succession, species distributions, carbon cycling, and ecosystem services is critical, but challenging across broad spatial scales. One important and understudied aspect of fire regimes is the unburned area within fire perimeters; these areas can function as fire refugia across the landscape during and after wildfire by providing habitat and seed sources. With increasing fire activity, there is speculation that fire intensity and...
Wildfire refugia are forest patches that are minimally-impacted by fire and provide critical habitats for fire-sensitive species and seed sources for post-fire forest regeneration. Wildfire refugia are relatively understudied, particularly concerning the impacts of subsequent fires on existing refugia. We opportunistically re-visited 122 sites classified in 1994 for a prior fire refugia study, which were burned by two wildfires in 2012 in the Cascade mountains of central Washington, USA. We evaluated the fire effects for historically persistent fire refugia and compared them to the surrounding non-refugial forest matrix. Of 122 total refugial (43 plots) and non-refugial (79 plots) sites sampled following the 2012...
Abstract (from Remote Sensing in Ecology and Conservation): The use of unmanned aerial vehicles (UAVs) to map and monitor the environment has increased sharply in the last few years. Many individuals and organizations have purchased consumer‐grade UAVs, and commonly acquire aerial photographs to map land cover. The resulting ultra‐high‐resolution (sub‐decimeter‐resolution) imagery has high information content, but automating the extraction of this information to create accurate, wall‐to‐wall land‐cover maps is quite difficult. We introduce image‐processing workflows that are based on open‐source software and can be used to create land‐cover maps from ultra‐high‐resolution aerial imagery. We compared four machine‐learning...
Cheatgrass (Bromus tectorum) has increased the extent and frequency of fire and negatively affected native plant and animal species across the Intermountain West (USA). However, the strengths of association between cheatgrass occurrence or abundance and fire, livestock grazing, and precipitation are not well understood. We used 14 years of data from 417 sites across 10,000 km(2) in the central Great Basin to assess the effects of the foregoing predictors on cheatgrass occurrence and prevalence (i.e., given occurrence, the proportion of measurements in which the species was detected). We implemented hierarchical Bayesian models and considered covariates for which > 0.90 or < 0.10 of the posterior predictive mass...
Abstract (from http://www.hydrol-earth-syst-sci.net/21/1/2017/): The phase of precipitation when it reaches the ground is a first-order driver of hydrologic processes in a watershed. The presence of snow, rain, or mixed-phase precipitation affects the initial and boundary conditions that drive hydrological models. Despite their foundational importance to terrestrial hydrology, typical phase partitioning methods (PPMs) specify the phase based on near-surface air temperature only. Our review conveys the diversity of tools available for PPMs in hydrological modeling and the advancements needed to improve predictions in complex terrain with large spatiotemporal variations in precipitation phase. Initially, we review...
Abstract (from http://www.bioone.org/doi/abs/10.3955/046.089.0305): It is hypothesized that climate impacts forest mosaics through dynamic ecological processes such as wildfires. However, climate-fire research has primarily focused on understanding drivers of fire frequency and area burned, largely due to scale mismatches and limited data availability. Recent datasets, however, allow for the investigation of climate influences on ecological patch metrics across broad regions independent of area burned and at finer scale. One area of particular interest is the distribution of fire refugia within wildfire perimeters. Although much recent research emphasis has been placed on high-severity patches within wildfires,...
Abstract (from http://www.sciencedirect.com/science/article/pii/S0378112716308532): Across the western United States, the three primary drivers of tree mortality and carbon balance are bark beetles, timber harvest, and wildfire. While these agents of forest change frequently overlap, uncertainty remains regarding their interactions and influence on specific subsequent fire effects such as change in canopy cover. Acquisition of pre- and post-fire Light Detection and Ranging (LiDAR) data on the 2012 Pole Creek Fire in central Oregon provided an opportunity to isolate and quantify fire effects coincident with specific agents of change. This study characterizes the influence of pre-fire mountain pine beetle (MPB; Dendroctonus...
Abstract (from http://iopscience.iop.org/article/10.1088/1748-9326/aa6f94/meta): High temperatures and severe drought contributed to extensive tree mortality from fires and bark beetles during the 2000s in parts of the western continental United States. Several states in this region have greenhouse gas (GHG) emission targets and would benefit from information on the amount of carbon stored in tree biomass killed by disturbance. We quantified mean annual tree mortality from fires, bark beetles, and timber harvest from 2003–2012 for each state in this region. We estimated tree mortality from fires and beetles using tree aboveground carbon (AGC) stock and disturbance data sets derived largely from remote sensing. We...
This fact sheet was prepared by Jessica Halofsky, David Peterson and Brian Harvey, University of Washington, School of Environmental and Forest Sciences. Editorial assistance from Patti Loesche and Darcy Widmayer. Funding for this work provided by the U.S. Department of the Interior, Northwest Climate Adaptation Science Center. This fact sheets goes with the following synthesis paper: https://doi.org/10.1186/s42408-019-0062-8.
Abstract (from http://link.springer.com/article/10.1007/s11258-016-0568-y): Resprouting is a key functional trait for species in disturbance prone environments. In many semi-arid environments, woody plants face both fire and drought as recurring disturbances. Past work has demonstrated that oaks inhabiting sky-island forests of the northern Sierra Madre Oriental have differing microhabitat preferences and heavy stem dieback occured during the historic 2011 drought indicating potential xylem failure. These oak species, representing two sections within the genus, are all post-fire resprouters: they can resprout from underground storage organs when fire kills above ground tissue. Resprouts provide an opportunity to...
Abstract (from ScienceDirect): Altered climate and changing fire regimes are synergistically impacting forest communities globally, resulting in deviations from historical norms and creation of novel successional dynamics. These changes are particularly important when considering the stability of a keystone species such as quaking aspen (Populus tremuloides Michx.), which contributes critical ecosystem services across its broad North American range. As a relatively drought intolerant species, projected changes of altered precipitation timing, amount, and type (e.g. snow or rain) may influence aspen response to fire, especially in moisture-limited and winter precipitation-dominated portions of its range. Aspen is...
thumbnail
Field measurements, daily meteorological inputs, and previously validated iSnobal simulations were used to run and inform the biogeochemical models Biome-BGC and Biome-BGC MuSo at three aspen stands in the Reynolds Creek Experimental Watershed. iSnobal simulations of snow redistribution were used to modify measured precipitation values to account for the redistribution of snow. Biome-BGC simulations were run under historical conditions (1984-2015) assuming both a uniform and redistributed snow layer. Biome-BGC MuSo simulations were run under historical (1996-2015) and future climate scenarios (2046-2065) and account for the redistribution of snow. Biogeochemical simulation data sets include input files used to run...
thumbnail
Composite Burn Index (CBI) Plot Data from 2015 field campiagn. These data are used in the detection of unburned areas using Landsat imagery, see for more info: Meddens, A. J., C. A. Kolden, and J. A. Lutz. 2016. Detecting unburned areas within wildfire perimeters using Landsat and ancillary data across the northwestern United States. Remote Sensing of Environment 186:275-285. Note that the data are entered into the jFiremon database management tool and outputted as a Microsoft Access database. Most plot locations are recorded in the UTM_zone11 with NAD83 datum, although some are recorded in zone 10. See spreadsheets for more info. A total of 380 plots were recorded.
Abstract (from esa): Western U.S. wildfire area burned has increased dramatically over the last half‐century. How contemporary extent and severity of wildfires compare to the pre‐settlement patterns to which ecosystems are adapted is debated. We compared large wildfires in Pacific Northwest forests from 1984 to 2015 to modeled historic fire regimes. Despite late twentieth‐century increases in area burned, we show that Pacific Northwest forests have experienced an order of magnitude less fire over 32 yr than expected under historic fire regimes. Within fires that have burned, severity distributions are disconnected from historical references. From 1984 to 2015, 1.6 M ha burned; this is 13.3–18.9 M ha less than expected....
Abstract (from http://www.sciencedirect.com/science/article/pii/S0034425716305016): Measuring post-fire effects at landscape scales is critical to an ecological understanding of wildfire effects. Predominantly this is accomplished with either multi-spectral remote sensing data or through ground-based field sampling plots. While these methods are important, field data is usually limited to opportunistic post-fire observations, and spectral data often lacks validation with specific variables of change. Additional uncertainty remains regarding how best to account for environmental variables influencing fire effects (e.g., weather) for which observational data cannot easily be acquired, and whether pre-fire agents of...
Aspen forests are “biological hotspots” in the western United States that support numerous wildlife species. Aspen ecosystems are also economically and socially important, providing high quality forage for livestock and game species (e.g. elk), as well as drawing tourists and improving local economies. Aspen ecosystems are in decline across portions of the western U.S., which is thought to be partly due to drought, and recent research suggests that future climate projected for the western U.S. will be even less capable of supporting aspen. We used different research methods to investigate key controls on aspen growth and survivability in the northern Great Basin and central Rockies. Specifically, we projected the...
map background search result map search result map Field measurements, biogeochemical model input files, climate data, and simulation output for aspen sites in the Reynolds Creek Experimental Watershed, ID, USA (1984-2015). Composite Burn Index (CBI) Plot Data from 2015 field campaign Composite Burn Index (CBI) Plot Data from 2015 field campaign Field measurements, biogeochemical model input files, climate data, and simulation output for aspen sites in the Reynolds Creek Experimental Watershed, ID, USA (1984-2015).