Research Database
Displaying 81 - 91 of 91
Natural tree regeneration and coarse woody debris dynamics after a forest fire in the Western Cascade range
Year: 2013
We monitored coarse woody debris dynamics and natural tree regeneration over a 14-year period after the 1991 Warner Creek Fire, a 3631-ha (8,972-ac) mixed severity fire in the western Cascade Range of Oregon. Rates for tree mortality in the fire, postfire mortality, snag fall, and snag fragmentation all showed distinct patterns by tree diameter and species, with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) more likely to survive a fire, and to remain standing as a snag, than other common tree species. Natural seedling regeneration was abundant, rapid, and highly variable in space.…
Publication Type: Report
Surface fuel treatments in young, regenerating stands affect wildfire severity in a mixed conifer forest, eastside Cascade Range, Washington, USA
Year: 2012
Previous studies have debated the flammability of young regenerating stands, especially those in a matrix of mature forest, and no consensus has emerged as to whether young stands are inherently prone to high severity wildfire. This topic has recently been addressed using spatial imagery, and weak inferences were made given the scale mismatch between the coarse resolution of spatial imagery and the fine resolution of mechanisms driving fire severity. We collected empirical stand and fire-severity data from 44 regenerating stands that are interspersed in mature, mid-elevation forests in the…
Publication Type: Journal Article
Development of Risk Matrices for Evaluating Climatic Change Responses of Forested Habitats
Year: 2012
We present an approach to assess and compare risk from climate change among multiple species through a risk matrix, in which managers can quickly prioritize for species that need to have strategies developed, evaluated further, or watched. We base the matrix upon earlier work towards the National Climate Assessment for potential damage to infrastructures from climate change. Risk is defined here as the product of the likelihood of an event occurring and the consequences or impact of that event. In the context of species habitats, the likelihood component is related to the potential changes in…
Publication Type: Journal Article
Drought-Driven Disturbance History Characterizes a Southern Rocky Mountain Subalpine Forest
Year: 2012
The view that subalpine forest vegetation dynamics in western North America are "driven" by a particular disturbance type (i.e. fire) has shaped our understanding of their disturbance regimes. In the wake of a recent (1990s) landscape-extent spruce beetle (Dendroctonus rufipennis Kirby) outbreak in the southern Rocky Mountains, we re-examined the temporal continuity in disturbance types and interactions and the possible role of drought on their occurrence by reconstructing antecedent disturbances for 11 sites across the Markagunt Plateau, southern Utah, USA. Multiple consistent lines of…
Publication Type: Journal Article
Effects of Ungulate Herbivory on Aspen, Cottonwood, and Willow Development Under Forest Fuels Treatment Regimes
Year: 2012
Herbivory by domestic and wild ungulates can dramatically affect vegetation structure, composition and dynamics in nearly every terrestrial ecosystem of the world. These effects are of particular concern in forests of western North America, where intensive herbivory by native and domestic ungulates has the potential to substantially reduce or eliminate deciduous, highly palatable species of aspen (Populus tremuloides), cottonwood (Populus trichocarpa), and willow (Salix spp.). In turn, differential herbivory pressure may favor greater establishment of unpalatable conifers that serve as ladder…
Publication Type: Journal Article
The Use of Seedbed Modifications and Wood Chips to Accelerate Restoration of Well Pad Sites in Western Colorado, USA
Year: 2012
Semiarid ecosystems of Western North America are experiencing a boom in natural gas development. However, these systems are slow to recover from the disturbances created. The purpose of this study was to develop improved restoration techniques on natural gas well pads in Western Colorado. This study examined effects and interactions of seedbed modifications, soil amendments, seed mixtures, and seeding methods. The experiment was conducted in pinyon-juniper and semidesert shrub plant communities on five natural gas well pads beginning in 2006. Soil and plant cover data were collected to assess…
Publication Type: Journal Article
Vegetation recovery after fire in the Klamath-Siskiyou region, southern Oregon
Year: 2011
This overview is intended to facilitate decisions regarding forest regeneration in the Klamath-Siskiyou Ecoregion. It summarizes the results of several scientific investigations that took place in the ecoregion. Some of the research occurred in areas without post-fire management, and other research occurred in moderately or intensively managed areas. Some of the research also occurred immediately after a wildfire, and other work occurred several decades later.
Publication Type: Report
Effectiveness of post-fire seeding at the Fitzner-Eberhardt Arid Land Ecology Reserve, Washington
Year: 2011
In August 2007, the Milepost 17 and Wautoma fires burned a combined total of 77,349 acres (31,302 hectares) of the Fitzner-Eberhardt Arid Land Ecology Reserve (ALE), part of the Hanford Reach National Monument administered by the U.S. Fish and Wildlife Service (USFWS) Mid-Columbia National Wildlife Refuge. In 2008, the USFWS implemented a series of seeding and herbicide treatments to mitigate potential negative consequences of these fires, including mortality of native vegetation, invasion of Bromus tectorum (cheatgrass), and soil erosion. Treatments included combinations of seeding (drill…
Publication Type: Report
Forest ecosystems, disturbance, and climatic change in Washington State, USA
Year: 2010
Climatic change is likely to affect Pacific Northwest (PNW) forests in several important ways. In this paper, we address the role of climate in four forest ecosystem processes and project the effects of future climatic change on these processes across Washington State. First, we relate Douglas-fir growth to climatic limitation and suggest that where Douglas-fir is currently water-limited, growth is likely to decline due to increased summer water deficit. Second, we use existing analyses of climatic controls on tree species biogeography to demonstrate that by the mid twenty-first century,…
Publication Type: Journal Article
Response of antelope bitterbrush to repeated prescribed burning in Central Oregon ponderosa pine forests
Year: 2009
Antelope bitterbrush is a dominant shrub in many interior ponderosa pine forests in the western United States. How it responds to prescribed fire is not well understood, yet is of considerable concern to wildlife and fire managers alike given its importance as a browse species and as a ladder fuel in these fire-prone forests. We quantified bitterbrush cover, density, and biomass in response to repeated burning in thinned ponderosa pine forests. Low- to moderate-intensity spring burning killed the majority of bitterbrush plants on replicate plots. Moderately rapid recovery of bitterbrush…
Publication Type: Journal Article
Synthesis of Knowledge on the Effects of Fire and Thinning Treatments on Understory Vegetation in U.S. Dry Forests
Year: 2009
The results of this synthesis illustrate several important lessons. First, current forest structure is the result of decades of fire-suppression activities, and so restoration will require multiple treatments to bring forests to within the range of historic variation. Second, while the treatments discussed in this document generally increased native plant responses, the same treatments also increased exotic plant response. Therefore, to avoid spread of exotic plant species, it is important to consider the context of the treatment area, (e.g., nearby roads, wildland urban interface, previous…
Publication Type: Report