Treesearch

In 2002 much of the Front Range of the Rocky Mountains in Colorado was rich in dry vegetation as a result of fire exclusion and the droughty conditions that prevailed in recent years. These dry and heavy fuel loadings were continuous along the South Platte River corridor located between Denver and Colorado Springs on the Front Range. These topographic and fuel conditions combined with a dry and windy weather system centered over eastern Washington to produce ideal burning conditions. The start of the Hayman Fire was timed and located perfectly to take advantage of these conditions resulting...

The role played by the fuel conditions within the Hayman Fire severity was complex and does not lend itself to a single conclusion or simple summary. Uncertainties in the original treatment prescription, its implementation, discerning the coverage, extent, and condition at the time of the fire made it difficult for us to clearly determine treatment effects and relate them to treatment type or amount. Available fire documentation such as the fire growth and severity maps compiled by the fire management and BAER (Burned Area Emergency Rehabilitation) teams were immensely helpful, but they...

Biomass burning is a major source of many atmospheric trace gases and aerosol particles (Crutzen and Andreae 1990). These compounds and particulates affect public health, regional air quality, air chemistry, and global climate. It is difficult to assess quantitatively the impact wildfires have on the environment because of the uncertainty in determining the size of burned areas and the amount of emitted pollutants and greenhouse gases. However, they can be estimated using data gathered daily from burned areas by MODIS satellite, experimental results of aboveground biomass burning, and the...

The Hayman Fire in June 2002 was heavily influenced by antecedent regional weather conditions, culminating in a series of daily weather events that aligned to produce widely varying fire behavior. This review of weather conditions associated with the Hayman Fire consists of two parts: 1) A brief overview of prior conditions as described by a regional climate review and assessment of the state of the fuels as described by the National Fire Danger Rating System; 2) a more detailed daily discussion of the synoptic scale and local meteorological conditions affecting the fire.

The potential of forest soils to sequester carbon (C) depends on many biotic and abiotic variables, such as: forest type, stand age and structure, root activity and turnover, temperature and moisture conditions, and soil physical, chemical, and biological properties (Birdsey and Lewis, Chapter 2; Johnson and Kern, Chapter 4; Pregitzer, Chapter 6; Morris and Paul, Chapter 7). Of increasing interest to U.S. and global soil C sequestration scenarios is the impact various forest management practices, such as harvesting, site preparation, reforestation, drainage, and fertilization, have on soil...

This study presents in situ soil temperature measurements at 5-6 depths and heat flux measurements at 2-5 depths obtained during the fall/winter of 2001/ 2002 at seven controlled (surface) fires within a ponderosa pine forest site at the Manitou Experimental Forest in central Colorado. Six of these burns included three different (low, medium, and high) fuel loadings under both a closed-canopy forested site and an open forest with a grassy meadow understory. The fuel loading for the seventh burn was a conical pile of slash about 6 m in height and 9 m in diameter and was intended to duplicate...

Natural and prescribed fires play an important role in managing and maintaining most ecosystems in the western United States. The high soil temperatures associated with fire influence forests and their ability to regenerate after a fire by altering soil properties and soil chemistry and by killing microbes, plant roots, and seeds. Because prescribed fire is frequently used to reduce surface fuels, it is important to know how fuel conditions, soil moisture, and soil properties interact to determine the soil temperatures, the depth of the soil thermal pulse, and the response of the soil...

Wood has been falling into rivers for millions of years, resulting in both local effects on channel processes and integrated influences on channel form and dynamics over a wide range of spatial and temporal scales. Effects of stable pieces of wood on local channel hydraulics and sediment transport can influence rates of bank erosion, create pools, or initiate sediment deposition and bar formation. At larger spatial scales, changes in the supply of large wood can trigger changes in both river-reach morphology and the interaction between a river and its floodplain. Over long time scales,...

Tree-ring records were used to reconstruct spatial and temporal patterns of western spruce budworm (Choristoneura occidentalis Freeman) outbreaks in mixed conifer forests of southern Colorado. Reconstructions in 11 host stands showed a regionally synchronous pattern of at least 14 outbreaks during the past 350 years. Intervals between outbreaks were highly variable within stands, but at the regional scale outbreak intervals were more consistent. Spectral analyses of regional outbreak time series confirmed periodicities at about 25, 37, and 83 years. Comparison with an independent drought...

The use of native plants for rehabilitation after wildfires and restoration of disturbed wildlands is being encouraged by various BLM programs, initiatives, and policies. This project integrates several proposals previously prepared by Idaho, Utah, and Nevada BLM to increase native plant production and use within the Great Basin, utilizing an applied science approach in a collaborative project. Although southeastern Oregon was not involved in the organizing this project, the development of native plant materials described in this proposal will also have direct application in that area....