Treesearch

Before European settlement of the interior west of the United States, coniferous forests of this region were influenced by many disturbance regimes, primarily fires, insects, diseases, and herbivory, which maintained a diversity of successional stages and vegetative types across landscapes. Activities after settlement, such as fire suppression, grazing, and logging significantly altered these disturbance regimes. As a result, forest structure and species composition have departed from historical conditions on many landscapes and this has led to increased forest densities, forest type...

Pinyon-juniper woodlands occur in 10 states and cover large areas in many of them. These woodlands can be dominated by several species of pinyon pine (Pinus spp. L.) and juniper (Juniperus spp. L.) (Lanner 1975; Mitchell and Roberts 1999; West 1999a). A considerable amount of information is available on the expansion of the woodlands that has occurred over large parts of the geographic ranges of the tree species involved (Miller and Tausch 2001). In southern Utah, the woodlands contain Utah juniper (Juniperus osteosperma), singleleaf pinyon (Pinus monophylla), and two-needled pinyon (Pinus...

Quaking aspen (Populus tremuloides Michx.) is the most widely distributed broadleaf tree in North American (Little 1971; Sargent 1890). Aspen forests occur from Labrador on the east coast to Alaska in the north to Mexico in the south. In its eastern range, aspen is relatively continuously distributed. In the western United States, however, it occurs on the more suitable sites on mountains and high plateaus (Jones 1985). On xeric sites, it is found primarily in riparian zones. Most western aspen occur on public lands and exist as pure clones, successional to conifer, or as small-scattered...

Many areas throughout the United States are facing the triple threat of increasing fire severity, residential growth in areas prone to wildland fire, and suppression costs and losses. In addition, substantial changes are occurring in the way we plan and implement management on federal lands relative to use of wildland fire, prescribed fire, and mechanical fuel management. Past emphasis in fire management has been on wildfire suppression and prescribed fire in support of other resources such as hazard reduction and site preparation in harvested areas and wildlife habitat improvement....

This document provides managers with a literature synthesis of the historical conditions, current conditions, fire regime condition classes (FRCC), and recommended treatments for the major ecosystems in southern Utah. Sections are by ecosystems and include: 1) coniferous forests (ponderosa pine, mixed conifer, and Engelmann spruce-subalpine fir), 2) aspen, 3) pinyon-juniper, 4) big and black sagebrush, and 5) desert shrubs (creosotebush, blackbrush, and interior chaparral). Southern Utah is at the ecological crossroads for much of the western United States. It contains steep environmental...

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were monitored for 4 years following three wildfires. Logistic regression analyses were used to develop models predicting the probability of attack by Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins, 1905) and the probability of Douglas-fir mortality within 4 years following fire. Percent crown volume scorched (crown scorch), cambium injury, diameter at breast height (DBH), and stand density index for Douglas-fir were most important for predicting Douglas-fir beetle attacks. A nonlinear relationship between crown scorch and cambium...

North American sagebrush steppe communities have been transformed by the introduction of invasive annual grasses and subsequent increase in fire size and frequency. We examined the effects of wildfires and environmental conditions on the ability of rush skeletonweed (Chondrilla juncea L.), a perennial Eurasian composite, to invade degraded sagebrush steppe communities, largely dominated by cheatgrass (Bromus tectorum L.). Recruitment of rush skeletonweed from seed and root buds was investigated on 11 burned and unburned plot pairs on Idaho's Snake River Plain following summer 2003 wildfires...

In an innovative effort, the USDA Forest Service is planning to reduce the long-term threat of catastrophic wildfires by inaugurating a series of forest thinnings for bioenergy. The start-up project is in the Nutrioso area of the Alpine Ranger District, Apache-Sitgreaves National Forest. ''The Nutrioso Wildland/Urban Interface Fuels Reduction Project'', under the authority of the Healthy Forest Restoration Act of 2003, addresses the existing condition of the forest, defines the desired condition of the forest, and proposes actions that will result in a healthier forest and a reduced risk...

Climate plays a central role in shaping fire regimes over long time scales and in generating short-term weather that drives fire events. Recent research suggests that the increasing numbers of large and severe wildfires, lengthened wildfire seasons, and increased area burned are, in part, related to shifts in climate. The historical fire regimes in many ecosystems have been disrupted. Efforts to restore ecosystem structure and integrity are facing both a changed fuel load condition and a changing climate. The San Diego Declaration on Climate Change and Fire Management attempted to consolida...

This paper offers an analysis of the strengths, weaknesses, opportunities, and threats in the risk management process, decision support systems (DSSs), and other types of decisionmaking, including recognition primed decisionmaking, bricolage with the goal of improving DSSs and decisionmaking. DSSs may be thought of as any technology or knowledge that is used as an aid in decisionmaking. Many types of risk management processes and DSSs exist in wildland fire, wildland fire, and prescribed fire at the tactical, operational, and strategic levels. In the wildland fire community, DSSs exist as...