Climate Change and...

Mendocino National Forest Case Study

Alder Springs Fuel Reduction Stewardship Project: Assessing Potential Climate Change Benefits From Forest Management

In Brief

What: A fuel reduction project under a stewardship contract with an added research component examining how forest management may mitigate climate change. This is a joint project between the Mendocino National Forest and the Pacific Southwest Research Station

Where: The wildland urban interface around the community of Alder Springs in the Grindstone Ranger District on the Mendocino National Forest in northern California.

Why: (1) The fuel reduction treatments are expected to restore ecosystem health and reduce fire hazard in areas considered at high risk for catastrophic wildfire within a wildland urban interface. (2) The project is an opportunity to validate research models that test whether forest management can mitigate effects of climate change by reducing greenhouse gases from wildfire. (3) The project will demonstrate and evaluate potential market opportunities for carbon sequestration and carbon offsets.


• Field crews conducted pretreatment inventory of forest conditions fall 2007.

• Five types of fuel reduction treatments were applied within study area.

• Biomass from the thinning treatments was transported to two power plants where it was used to generate electricity.

• Field crews completed posttreatment inventory of forest conditions summer 2008.

Next step: Researchers will analyze pre- and posttreatment data to determine the immediate carbon impact of the treatment and determine how much carbon is available to burn from different sources such as trees, understory vegetation, and dead wood. This input will be given to fire modelers so they can model different fire behaviors. Preliminary results are expected fall 2008.


The Alder Springs project on the Grindstone Ranger District of the Mendocino National Forest (NF) is reducing hazardous fuels while addressing a set of research questions involving carbon emissions, carbon markets, and biomass energy production (fig. 1). The project is being conducted through a partnership among the Mendocino NF, Pacific Southwest Research Station (PSW), Winrock International Institute for Agricultural Development, Wheelabrator Technologies, Inc., and State of California. Roughly 3660 acres were inventoried and then treated to reduce fire hazard in fall 2007 and spring 2008. Field crews followed up with posttreatment inventories in summer 2008. After analyzing the pre- and posttreatment data, researchers hope to have a better understanding of how public forest management may contribute to mitigating global climate change by reducing greenhouse gas emissions and increasing carbon sequestration. The research will also examine how treatments could increase carbon market opportunities.

Historical evidence indicates that every 8 to 15 years, low-intensity fires burned through the Alder Springs project area. Fire suppression beginning in the early 1900s interrupted these fire intervals, and a large wildfire has not occurred since 1922. Since then, dense vegetation has grown up, and dead wood and other potential fuel have accumulated, greatly increasing the fire hazard.

Project location in the Mendocino National Forest.

Figure 1—Project location in the Mendocino National Forest.


Several reasons exist for reducing the fire hazard in this area. One is to reduce risk to human life and property. The Alder Springs project area is located within in a wildland-urban interface (WUI). Given the topography, access, and weather patterns of the area, fuel reduction treatments that will slow the spread and length of flames are needed so that in the event of wildfire, residents can be safely evacuated and fire crews deployed.

A second reason for reducing fire hazard is to minimize the release of carbon and other greenhouse gases during a wildfire. There are three ways in which fuel reduction projects can reduce greenhouse gas emissions:

1. Thinning forests improves forest health, and healthy forests absorb more carbon dioxide (CO2) from the atmosphere.
2. Thinned forests decrease fire risk and so have the potential to reduce greenhouse gas emissions from catastrophic wildfires.
3. Biomass from thinning projects can replace nonrenewable fossil fuels used to produce energy, potentially reducing fossil fuel carbon emissions.


Growing interest in carbon management, renewable energy production, and the magnitude of national forest lands in need of fuel reduction treatments all point to the timeliness of the project. The Alder Springs fuels reduction project was developed under the Healthy Forests Initiative and stewardship contracting authorities. Future stewardship contracts may be enhanced by integrating revenue from timber, carbon credits, bioenergy, and other ecosystem services.

The research component of this project will do the following:

• Quantify the effects of treating forest fuels at biomass facilities. This practice may decrease greenhouse gas emissions by reducing the severity and corresponding carbon loss of wildland fires, increasing carbon sequestration in treated stands, and displacing greenhouse gas emissions from fossil-fuel-based electricity generation or transport fuels.

• Develop a classification system for the costs and potential value of stewardship projects. The Alder Springs Project will be used as a test case to develop a GIS-based model in which timber, carbon, and biomass values potentially influence treatment site selection among the forest’s managed areas in need of treatment.

• Provide project design protocols managers can use to incorporate potential carbon credits. Researchers will provide tools that can identify carbon and bioenergy benefits, and potentially real revenue.

• Provide a framework for reporting the sale of carbon credits from fuels reduction work. This fosters confidence that reducing national forest fuels creates offsets comparable to planting trees, reducing power plant emissions, or increasing renewable energy capacity.

• Analyze the impact of bioenergy trends on the price of biomass and carbon. Managers are better able to ensure predictable supplies if they know how renewable energy portfolio standards, government incentives for alternative fuels, and higher natural gas prices will affect markets.

If the research demonstrates a net carbon benefit, a key goal of this project will be to determine whether additional financial incentives exist for forest management projects.
If carbon credits can be gained from forest management, they may provide market incentives that would allow the Forest Service to treat more acres, improving forest health and reducing the threat of wildfire. Carbon credit trading markets already exist in Europe and Asia, and markets are beginning to take shape within the United States.

Although biomass from forest management projects already has some economic value for energy production, that value often is not enough to recover the costs of the fuels treatment. If a net carbon benefit is shown to exist then carbon credit trading may have the potential to increase the number of forest health projects that the Forest Service can offer.

This project and the associated research are important first steps toward understanding how public forest management might contribute to mitigating global climate change. Although research models already suggest that there are likely climate change benefits to be gained from forest management, this is the first time those models are being integrated on an actual forest management project.

Project Basics

Five types of fuel reduction treatment were used in the project area (table 1). The goal was to reduce the intensity of wildfire and provide a foothold for future suppression activities.

Table 1—Alder Springs fuel reduction treatments

Helitorch burning
Precommercial thinning
Understory burn (not included in other units)
Commercial thin
Roadside thin
Total acres

Treatment Descriptions

Helitorch burning consists of dropping gelled gasoline from helicopters through a helitorch. This treatment was used in chaparral fields and patches of knobcone pines (Pinus attenuata Lemm.).

In the units slated for precommercial thinning, most of the trees have less than a 10-inch diameter at breast height (DBH). All conifer trees were thinned to an approximate 20-foot spacing, leaving the largest and healthiest trees on site. All brush and conifers smaller than 4 inches DBH were removed and chipped for biomass unless needed to retain proper spacing. The residual biomass from the thinnings was used to the extent that the market allowed. Otherwise, prescribed fire, or mechanical or handpiling treatments were used to reduce this potential fuel. Biomass has been estimated at approximately 5 tons per acre in these units for a total of 2,270 tons.

Understory burning treatments place a low-intensity fire in a timbered stand to reduce surface and ladder fuels. It reduces the live understory vegetation that allows wildfire to move into the crowns of understory trees. Prescriptions were designed to reduce mortality of commercial-size trees and to retain a desired number of snags and down logs for wildlife habitat. Underburning will likely be needed every 3 to 9 years to maintain the integrity of the fuel treatment unit.

In the units slated for commercial thins, both overstory trees (greater than 8 inches DBH) and understory trees (less than 8 inches DBH) were removed to reduce stand density. Overstory trees were thinned to a 24- to 35-foot spacing, leaving the largest, healthiest trees on site to create a fire resistant stand structure. Brush of all sizes and conifers that were between 4 inches and 8 inches DBH were removed and chipped for biomass, unless they were needed to maintain proper spacing in areas that did not contain larger trees. Biomass was used to the extent that the market allowed. Otherwise, prescribed fire, or mechanical or handpiling treatments were used to reduce potential fuel. Biomass has been estimated at approximately 3 tons per acre in these units for a total of 1,530 tons. Approximately 2.7 million board feet of commercial timber volume were generated (figs. 2 and 3).

The roadside thinning was designed to increase firefighter safety by reducing the potential for hot embers from burning logs and trees to loft over the roadway and ignite. This treatment also removed snags that easily burn and might have fallen on workers in the area.

Thinning a dense stand is one way to reduce fire hazard.

Figure 2—Thinning a dense stand is one way to reduce fire hazard.

Figure 3—A thinned stand in the Alder Springs project area.


Work began on this project in fall 2007. Field crews from Winrock International measured 200 plots in the project area, recording pretreatment conditions. Fuel treatments were applied in fall 2007 and spring 2008 by Sierra Pacific Industries. Given the favorable market conditions for biomass, the contractor exercised the option to thin an additional 75 acres. The biomass has been transported in chipped form to two power plants, the Wheelabrator-Shasta plant in Anderson, California, and the Pacific Oroville Power Inc. plant in Oroville, California (fig. 4). Winrock field crews remeasured the 200 study plots to document posttreatment conditions during June and July 2008.

Researchers will analyze the pre- and posttreatment data during summer 2008. This information will be used to quantify greenhouse gas emission reductions and carbon sequestration resulting from fuel treatments. Preliminary results may be available as soon as fall 2008.

Biomass from some of the fuel reduction treatments was used to generate electricity (photo by Steve Jolly).

Figure 4—Biomass from some of the fuel reduction treatments was used to generate electricity (photo by Steve Jolly).

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