Wildfire: carbon threat heats up.Virtually all the studies of trees, forests, and greenhouse gas greenhouse gas
Any of the atmospheric gases that contribute to the greenhouse effect.
greenhouse gas emissions have focused on two topics - mitigation and adaptation. In plain terms, that means: How can we grow more trees and forests so we can store more carbon and reduce fossil fuel fossil fuel: see energy, sources of; fuel.
Any of a class of materials of biologic origin occurring within the Earth's crust that can be used as a source of energy. Fossil fuels include coal, petroleum, and natural gas. use, and how will we need to manage forests differently if climate change becomes a reality? In some parts of the world there is a third challenge, one we have only recently begun to consider: forests already heavily loaded - or overloaded - with carbon. If not managed differently, those forests inevitably will burn, recycling that carbon.
This is the situation over millions of acres in the western United States Noun 1. western United States - the region of the United States lying to the west of the Mississippi River
Santa Fe Trail - a trail that extends from Missouri to New Mexico; an important route for settlers moving west in the 19th century , mainly in forests that developed in the presence of frequent, low-intensity wildfires. For example, ponderosa pine ponderosa pine
pinusponderosa. was estimated to occupy about 28 million acres in 1992. Historical wildfire frequencies in the five- to 20-year range kept out small trees, brush, and prevented encroachment by other species such as firs. The early western pioneers found many open, savannah-type stands composed of a few large trees per acre and a grassy forest floor.
A century or more of fire suppression caused the forest to change significantly. Tree counts of less than 100 per acre have soared to 500 or more, even as high as 1,200 in some places. Fir thickets have moved in under the large pines, forming a continuous fuel ladder A fuel ladder is a firefighting term for live or dead vegetation that allows a fire to climb up from the forest floor into the tree canopy. Common fuel ladders include tall grasses, shrubs, and tree branches, both living and dead. that reaches from the ground into the canopy. This virtually guarantees that any ignition will turn into a hot, lethal crown fire.
AMERICAN FORESTS' Forest Policy Center has been studying the implications of this dangerous wildfire condition in cooperation with the Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and for the past two years. The study has focused on the Boise National Forest The Boise National Forest is a US national forest located north and east of the city of Boise, Idaho. It is about 2,612,000 acres (10,570 km²) in size, ranging in elevation from 2,600 to 9,800 feet (800 to 3000 m). , where since 1989 AMERICAN FORESTS, the USDA USDA,
n.pr See United States Department of Agriculture. Forest Service, the state of Idaho, University of Idaho, University of, mainly at Moscow; land-grant and state supported; coeducational; chartered and opened 1889. Among its facilities are the Water and Energy Resources Institute and the Forest, Wildlife and Range Experiment Station. Idaho, and Boise Cascade have been researching forest health conditions. With assistance from Leon Neuenschwander of the University of Idaho The university was formed by the territorial legislature of Idaho on January 30, 1889, and opened its doors on October 3, 1892 with an initial class of 40 students. The first graduating class in 1896 contained two men and two women. , the Boise has developed a state-of-the-art Geographic Information System geographic information system (GIS)
Computerized system that relates and displays data collected from a geographic entity in the form of a map. The ability of GIS to overlay existing data with new information and display it in colour on a computer screen is used primarily to (GIS) that illustrates hazard and risk conditions facing the forest. Neil Sampson of AMERICAN FORESTS and Neuenschwander have used that model to test possible C[O.sub.2] emissions from the Boise's ponderosa pine forests and evaluate how much a forest-treatment program could affect future emissions.
That model shows an alarming almost 1.2 million acres of the 2.6-million acre forest at risk of major wildfire. The model is based on 1992 satellite imagery that shows that of 378 sub-watersheds in the forest, 152 are ponderosa pine forests with high fuel loadings and a past history of ignitions from lightning or human causes. Adding to that concern is the fact that, over the past 10 years, once a wildfire on the Boise reaches 100 acres in size, it has a 22 percent chance of exceeding 5,000 acres. Using this data, wildfires are expected to affect about 7.5 percent of the at-risk forest annually, an estimate borne out by events since 1992.
The research team then developed estimates of the potential impacts of different land-treatment strategies. Each featured a prescribed fire, given the team's belief that a major management goal is to reintroduce fire to the forest to restore essential and historic ecosystem functions. Most sites will require some kind of fuel reduction, thinning, or mechanical wood removal before they are considered safe to burn. The economic impact of each strategy was estimated, including both wildfire suppression costs, treatment costs, and possible recovery of merchantable Salable; of quality and type ordinarily acceptable among vendors and buyers.
An item is deemed merchantable if it is reasonably fit for the ordinary purposes for which such products are manufactured and sold. For example, soap is merchantable if it cleans. timber in the treatment process.
Four treatment options were compared to the option of doing nothing at all: 1. Treat 30,000 acres yearly with no strategic selection; 2. Treat 30,000 acres yearly using a strategy that would treat the highest-risk areas first and those that would intercept large fires and help break up large areas of dangerous fuel conditions; 3. Treat 10,000 acres yearly with strategic selection; 4. Treat 50,000 acres with strategic selection.
Preliminary results indicate that an aggressive forest-health treatment can reduce the Boise's C[O.sub.2] emissions by an average 2 million-3 million tons yearly over the next 20 years [ILLUSTRATION FOR FIGURE 1 OMITTED]. The team also decided it was critical to develop a strategy that treats the worst areas first, saving millions in wildfire costs and losses and cutting air pollution from fire by 30 to 50 percent. Landscape diversity, as shown by Figure 2, would improve dramatically. This diversity, which provides the best possibility of protecting biodiversity, would occur in options 2, 3 and 4, which provide for a mixture of forest structures and ages within the ponderosa pine system. On a variety of measures ranging from climate change to local economics, treating these forests seems like a sensible strategy.