Treesearch

Monitoring ruffed grouse (Bonasa umbellus) in the Black Hills National Forest is a priority for forest managers due to the bird's status as the management indicator species for quaking aspen (Populus tremuloides) and its value to hunters and other recreational groups. We conducted drumming surveys, estimated occupancy, and assessed the influence of sampling and site variables to determine benchmark levels of precision for ruffed grouse occupancy and detection probability estimates. Using these estimates and simulations, we developed a monitoring protocol for ruffed grouse in the Black...

Recent large-scale, severe wildfires in the western United States have prompted extensive mechanical fuel treatment programs to reduce potential wildfire size and severity. Fuel reduction prescriptions typically target non-merchantable material so approaches to mechanically treat and distribute residue on site are becoming increasingly common. We examined how mulch treatments alter the distribution of woody material by size class by comparing paired mulched and untreated sites in lodgepole pine (Pinus contorta), mixed conifer, ponderosa pine (Pinus ponderosa), and pinyon pine/juniper...

The Water Erosion Prediction Project (WEPP) model is a process-based, continuous-simulation, watershed hydrology and erosion model. It is an important tool for water erosion simulation owing to its unique functionality in representing diverse landuse and management conditions. Its applicability is limited to relatively small watersheds since its current version does not simulate flow in permanent channels. In this study we developed a channel-routing module to simulate water flow in a permanent channel network. The module can utilize two methods: numerical kinematic-wave method and...

In mid-February 2006, windstorms in Arizona, Utah, and western Colorado generated a dust cloud that distributed a layer of dust across the surface of the snowpack throughout much of the Colorado Rockies; it remained visible throughout the winter. We compared the chemical composition of snowfall and snowpack collected during and after the dust deposition event with pre-event snow at 17 sites extending from central Colorado into southern Wyoming. The chemistry of dustevent snowfall and the post-event snowpack were compared to long-term wetfall precipitation and snowpack chemistry at the...

Biomass fires can significantly degrade regional air quality. Plume rise height is one of the critical factors determining the impact of fire emissions on air quality. Plume rise models are used to prescribe the vertical distribution of fire emissions which are critical input for smoke dispersion and air quality models. The poor state of model evaluation is due in large part to a lack of appropriate observational datasets. We have initiated a research project to address this critical observation gap. A ground-based, mobile elastic scanning lidar (light detection and ranging) instrument and...

A ground-based scanning lidar was utilized with a set of airborne instruments to acquire measurements of smoke plume dynamics, smoke aerosol distribution and chemical composition in the vicinity of active wildfires in the western U.S. A new retrieval technique was used for processing lidar multiangle measurements. The technique determines the location of atmospheric heterogeneity versus height, which is retrieved from the entire vertical scan taken from a selected azimuthal direction. The vertical profiles of smoke plumes derived from heterogeneity events detected from lidar are consistent...

Data-processing techniques for the scanning lidar data are considered that allow determining the upper and lower boundaries of the smoke plume or smoke layering in the vicinity of wildfires. The task is fulfilled by utilizing the Atmospheric Heterogeneity Height Indicator (AHHI). The AHHI is a histogram, which shows a number of heterogeneity events defined by scanning lidar at the consecutive height intervals in a heterogeneous atmosphere. Different variants of creating the AAHI plots for investigating the atmospheres contaminated with the smoke plume are considered. Because the boundaries...

Smoke emitted by prescribed and wild fires can make a substantial contribution to ambient aerosol (McMeeking et al. 2006; Park et al. 2007; Spracklen et al. 2007). Approaches to investigate these contributions have used a variety of different chemical smoke markers, including levoglucosan, produced by thermal degradation of cellulose, and water-soluble potassium (Andreae 1983; Engling et al. 2006; Hays et al. 2002; Simoneit 2002;Ward et al. 2006). Filter sampling is commonly employed to measure smoke markers in ambient and source samples; however, these time-integrated measurements limit...

We report the direct observation of laboratory production of spherical, carbonaceous particles - "tar balls" - from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Angstrom coefficients (AAC) indicate that a class of light absorbing organic carbon (OC) with wavelength dependent imaginary part of its refractive index - optically defined as "brown carbon" - is an important component of tar balls. The spectrum of the imaginary parts of their complex refractive indices can be described with a Lorentzian-like model...

The Water Erosion Prediction Project Climate Assessment Tool (WEPPCAT) was developed to be an easy-to-use, web-based erosion model that allows users to adjust climate inputs for user-specified climate scenarios. WEPPCAT allows the user to modify monthly mean climate parameters, including maximum and minimum temperatures, number of wet days, precipitation, and precipitation intensity (change in heavy precipitation events) in order to assess changes in surface runoff and soil erosion. In addition, the model allows the user to assess the impacts of a variety of land management alternatives...