Treesearch

The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial. Southern California’s wildfires can be partitioned by meteorology: fires typically occur either during Santa Ana winds (SA fires) in October through April, or warm and dry periods in June through September (non-SA fires). Previous work...

The Interior West Forest Inventory and Analysis Unit (IWFIA) will soon transition from a regional system to a national FIA system for compiling estimates of forest growth, removals, and mortality. The national system requires regional diameter-growth models to estimate diameters on trees in situations where the initial or terminal diameter is not known at the beginning or end of a measurement interval. Examples of such trees are those classified as alive at the beginning of the measurement interval and subsequently died (mortality) or have been harvested (removal). Only single-stem growth...

Habitat disturbance events are critical to ecological systems in which some bird species have become specialized. The vegetation community, reduced competition, ability to avoid predators, nest site characteristics, and forage opportunities within a disturbed ecosystem are all aspects that make it desirable for selection by particular species (Svardson 1949, Cody 1981, Martin 1998). Specifically, avian species rely on the forest conditions created by fire, insects, and disease (Brawn et al. 2001, Hunter et al. 2001, Devictor et al. 2008). In the Black Hills National Forest (BHNF) of South...

Wildfires present a complex applied risk management environment, but relatively little attention has been paid to behavioral and cognitive responses to risk among public agency wildfire managers. This study investigates responses to risk, including probability weighting and risk aversion, in a wildfire management context using a survey-based experiment administered to federal wildfire managers. Respondents were presented with a multi-attribute lottery-choice experiment where each lottery is defined by three outcome attributes: expenditures for fire suppression, damage to private property,...

For nearly a decade, the USFS FIA, NASA, and the University of Maryland have collaborated on the NASA/NACP funded North American Forest Dynamics (NAFD) project, and developed new approaches for annual mapping of CONUS forest dynamics (1984-2011). Building on this foundation of empirical research and results, the collaboration will continue with a new Carbon Cycle Science Synthesis Research effort to improve the spatial and temporal estimation of forest related carbon emissions. This newly funded study will 1) produce annual age and biomass maps and 2) use these national products to advance...

The Southern Plains region contributes significantly to the Nation’s wheat and beef production. Winter wheat is the principal annual crop, with much of it serving dual-use as a cool-season annual forage in addition to grain production. Cattle are raised on extensive pasture and rangelands across the region. Agricultural production and farm income in the Southern Plains are sensitive to weather variability. For example, the severe 2010/2011 drought resulted in the loss of billions of dollars in the agriculture sector. Agricultural losses were estimated to exceed $1.7 billion in Oklahoma and...

Aboveground net primary production provides valuable information on wildlife habitat, fire fuel loads, and forage availability. Aboveground net primary production in herbaceous plant communities is typically measured by clipping aboveground biomass. However, the high costs associated with physically harvesting plant biomass may prevent collecting sufficient data to account for natural spatial and temporal variability of vegetation at a landscape scale. Various double-sampling techniques have been developed to increase sample size while reducing cost. We applied a biomass estimation...

We examine 31 years (1982-2012) of temperature, precipitation and natural wildfire occurrence data for Federal and Tribal lands to determine landscape-scale patterns of drought and fire on the southern and central High Plains of the western United States. The High Plains states of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming have been in the midst of ongoing extreme drought, experiencing below normal precipitation and above normal temperatures for the past several years. Climate change is predicted to have multiple effects on fire regimes. Longer...

We studied elk (Cervus canadensis nelsoni) parturition sites at coarse (314-km2 and 7-km2) and fine (0.2-ha) scales in the Black Hills, South Dakota, 2011-2013, following a period of population decline and poor calf recruitment. Our objective was to test whether female elk selected parturition sites across spatial scales in association with forage, terrain ruggedness, road density, or hiding and security cover. At coarse scales in forests and grasslands, female elk selected sites in areas with greater proportions of vegetation communities that provided forage (56-74% of area) and more...

Patterns of reproductive output in blackbrush did not track current growing season precipitation, but instead were regulated by prior-year weather cues. The strength of the response to the masting cue depended on habitat quality, with higher mean reproductive output, shorter intervals between years of high seed production, and lower CVp at more favorable sites. Wind pollination efficiency was demonstrated to be an important evolutionary driver of masting in blackbrush, and satiation of heteromyid seed predator-dispersers was supported as an evolutionary driver based on earlier studies.