Treesearch

Predictive relationships between soil drainage and soil morphological features are essential for understanding hydromorphic processes in soils. The linkage between patterns of soil saturation, reduction, and reductimorphic soil properties has not been extensively studied in mountainous forested terrain. We measured soil saturation and reduction during a 4-yr period in three catenas of the perhumid coastal temperate rainforest of Alaska and compared these measurements to soil morphological features of Spodosols and Histosols. Soil saturation and anaerobic conditions indicated by redox...

Questions: Are exotic plant species favoured by non-native ungulate herbivores and disadvantaged by native herbivores in forested rangelands? Do the impacts of ungulates on exotic vs native plants depend on forest management activities such as prescribed fire and stand thinning? Location: Northeastern Oregon, USA. Methods: We recorded changes in richness and cover of different exotic and native plant life forms in experimental plots that were grazed only by cattle (a non-native herbivore), only by elk (a native herbivore) or not grazed by any ungulate over a 7-yr period at bothmanaged...

Climate impact studies often require the selection of a small number of climate scenarios. Ideally, a subset would have simulations that both (1) appropriately represent the range of possible futures for the variable/s most important to the impact under investigation and (2) come from global climate models (GCMs) that provide plausible results for future climate in the region of interest.We demonstrate an approach to select a subset of GCMs that incorporates both concepts and provides insights into the range of climate impacts. To represent how an ecosystem process responds to projected...

Fire incident teams depend on accurate fire diagnostics and predictive data to guide daily positioning and tactics of fire crews. Currently, the U.S. Department of Agriculture - Forest Service National Infrared Operations (NIROPs) nighttime airborne data provides daily information about the fire front and total fire affected area of priority fires to the incident teams on the ground. During the peak of the fire season, NIROPs aircraft can fly over 30 incidents per night to monitor active fires. The total flight hours performed by NIROPs aircraft have increased in the last five years,...

Studies project that a warming climate will likely increase wildfire activity in many areas (Westerling and others 2002; Flannigan and others 2005, 2009; Littell and others 2009). These analyses are often of aggregate statistics like annual area burned, which are insufficient for analyzing changes in seasonality of fire events, the temporal resolution useful for fire management and understanding what drives individual events. Stavros and others (in press, a) show that very large wildfires (VLWFs >20,234 ha ~50,000 ac) may account for only the top two percent of all fires burned in the...

The appropriate role of large airtankers (LATs) in federal fire suppression in the United States has been the source of much debate and discussion in recent years as the U.S. Forest Service (USFS) has faced impending decisions about how best to address an aging fleet of contracted aircraft. Questions of fleet efficiency are complicated by inadequacies in historical data on airtanker use. A need for improved data collection systems for LATs was a key recommendation to come from a 2013 U.S. Government Accountability Office (GAO) investigation into actions made by the USFS and the U.S....

The management of wildfire is a dynamic, complex, and fundamentally uncertain enterprise. Fire managers face uncertainties regarding fire weather and subsequent influence on fire behavior, the effects of fire on socioeconomic and ecological resources, and the efficacy of alternative suppression actions on fire outcomes. In these types of difficult decision environments, even well-trained and experienced individuals can become susceptible to cognitive limitations and decision biases, as indicated by several recent analyses of fire manager decision making. This extended abstract focuses on...

In response to federal wildfire policy changes, risk-informed decision-making by way of improved decision support, is increasingly becoming a component of managing wildfires. As fire incidents escalate in size and complexity, the Wildland Fire Decision Support System (WFDSS) provides support with different analytical tools as fire conditions change. We demonstrate the application of WFDSS information and tools to assess risk management cycle elements by using a case study wildfire from the 2013 fire season; the Gold Pan Fire, Bitterroot National Forest, Montana, USA. Examples of the...

The tree-killing mountain pine beetle (Dendroctonus ponderosae Hopkins) is an important disturbance agent of western North American forests and recent outbreaks have affected tens of millions of hectares of trees. Most western North American pines (Pinus spp.) are hosts and are successfully attacked by mountain pine beetles whereas a handful of pine species are not suitable hosts and are rarely attacked. How pioneering females locate host trees is not well understood, with prevailing theory involving random landings and/or visual cues. Here we show that female mountain pine beetles orient...

The incidence of large, costly landscape-scale fires in western North America is increasing. To combat these fires, researchers and managers have expressed increased interest in investigating the effectiveness of past, stand-replacing wildfires as bottom-up controls on fire spread and severity. Specifically, how effective are past wildfires in mitigating the behavior and effect of future fires, and for how long? Our research focused on two recent fires that encountered past wildfires but with significantly different outcomes. The 2006 Tripod Complex fires in Washington State flanked...