Treesearch

Managers are interested in the dynamics of down woody material because of its role as a fuel component, a feature of wildlife habitat, a carbon pool, and other characteristics. We analyzed nearly 9,000 plots from the Interior West, spanning the range from sparse juniper and mesquite woodland to dense spruce-fir forests, in order to characterize down woody material as it relates to stand and site factors. Average abundance of down woody material increases predictably with climatic factors, as measured by several parameters, and with stand age. However, the patterns of abundance with stand...

We document high rates of triploidy in aspen (Populus tremuloides) across the western USA (up to 69% of genets), and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species), climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a...

We have developed a density management diagram (DMD) for even-aged mixed-conifer stands in the Sierra Nevada Mountains using forest inventory and analysis (FIA) data. Analysis plots were drawn from FIA plots in California, southern Oregon, and western Nevada which included those conifer species associated with the mixed-conifer forest type. A total of 204 plots met the selection criteria for analysis, which were for even-agedness and species composition. Even-agedness was characterized by a ratio between two calculations of stand density index. Species composition included admixtures of...

Major habitat and community types in northern Utah were compared with plant alliances and associations that were derived from fidelity- and diagnostic-species classification concepts. Each of these classification approaches was associated with important environmental factors. Within a 20,000-ha watershed, 103 forest ecosystems were described by physiographic features, e.g., elevation, slope aspect, soil physical and chemical properties and a complete listing of vascular plant species. Multivariate statistics were used to analyze complex datasets that included 34 environmental factors and...

Quaking aspen (Populus tremuloides Michx.) is a critical species that supports wildlife and livestock, watershed function, the forest products industry, landscape diversity, and recreation opportunities in the Interior West (Bartos and Campbell 1998). Studies have indicated that changes in fire regimes, an increase in herbivore presence in young aspen stands, and recent drought episodes have been the main factors for increased mortality rates in aspen stands (Deblander et al. 2010). Forest Inventory and Analysis (FIA) plot data are a consistent source of ground-based information that if...

Regional precipitation patterns may have influenced the spatial variability of tree mortality during the recent mountain pine beetle (Dendroctonus ponderosa) (MPB) outbreak in the western United States. Data from the Forest Inventory and Analysis (FIA) Program show that the outbreak was especially severe in the state of Colorado where over 10 million lodgepole pines (Pinus contorta Dougl. Ex Loud.) succumbed to MPB between 2002 and 2009. Aerial detection maps of MPB-related mortality show that the infestation was initially widespread and evenly distributed throughout the range of lodgepole...

Trends in U.S. forest biomass and carbon are assessed using Forest Inventory and Analysis (FIA) data relative to baseline assessments from the 1990s. The integrity of baseline data varies by state and depends largely on the comparability of periodic versus annual forest inventory data. In most states in the Interior West FIA region, the periodic inventory's sample design, plot configuration, estimation procedures, and definitions were different from those for the annual inventory, which are nationally consistent. Direct comparisons of periodic versus annual inventory data are therefore...

Between 2000 and 2010 the US Forest Service and the Department of the Interior experienced 82 wildland fire fatalities. Our most recent organizational focus has been to eliminate fatalities. The chief of the USFS, in a letter to all employees, asked us to "suspend disbelief" with regard to the concept of a "zero fatality organization". This plea came while some field personnel argued that there was no way to eliminate fatalities without eliminating risk.

While several studies have examined the relevance of the HRO paradigm for fire management, no known empirical studies exist. In late 2007, in collaboration with researchers at the University of Michigan, we embarked on an exploration of the nature and extent of HRO practices in the US fire community. One of the primary questions was: How do HRO practices vary across the federal fire community? We sought to understand how commonly the theorized principles of HRO were practiced, and the degree to which these were associated with other aspects of organizational culture and crew social...

This dissertation project used a two-study mixed methods approach, examining the communicative accomplishment of safety from two perspectives: high reliability organizing (Weick, Sutcliffe, & Obstfeld 1999), and safety climate (Zohar 1980). In Study One, 27 firefighters from two functionally similar wildland firefighting crews were interviewed about their crew-level interactions for implementing safety rules and tasks. Findings revealed that the two crews differed in their communicative interactions related to three specific routines: planning, use of safety rules, and authority. The crews...