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The changing science of forest health.

Researchers, land managers, and lawmakers are building a synergy to more efficiently address tough questions about our "unraveling" western forests.

In many western states, forest health is an immediate and growing concern to land managers and to people living in and around these forests. Trees across millions of acres in eastern Oregon and Washington have been killed by insects and disease, and similar problems exist in an area that extends east into Idaho and south into Utah, Nevada, and California.

These forests are suffering from a pattern of historic use and management that has altered the natural conditions of their ecosystems, making the forests much more susceptible to drought stresses and attacks by insects and disease. Past logging practices, combined with decades of aggressive firefighting, have changed many of these forests from open, park-like Ponderosa pine and larch stands to dense stands of true firs, Douglas-fir, and lodgepole pine. These stressed and overcrowded forests--where too many trees compete for scarce moisture and nutrients--are ripe for invasion by insects and disease. As they die in increasing numbers, the forests become tinderboxes ready to explode into disastrous wildfires.

Scientists, resource managers, and policymakers are asking how healthy conditions can be restored, how further forest decline can be prevented, and how the risk of catastrophic losses can be reduced. The questions are extremely difficult because scientists have only begun to study forest health from an ecosystem perspective--one that encompasses all the basic elements such as plants, animals, and soils, plus processes that affect forest health at various geographic scales. We do not yet have as solid a scientific basis for management actions as some people would like.

At the same time, however, we face critical problems that need to be addressed immediately: These forest systems are at high risk, as are many human values in and around them. There isn't time to generate and test hypotheses in order to find proven practices for restoring health to forest ecosystems. Instead, scientific research, new management approaches, and policymaking efforts must proceed simultaneously. This is what's happening. Although it discomforts people accustomed to more rational processes, this approach creates a synergy of its own: Scientists become more active players in the policymaking process, resource managers work more closely with scientists to begin implementing new practices, and policymakers become better versed in rapidly evolving scientific and management debates.


Last June 4, Forest Service Chief Dale Robertson directed his staff to begin implementing an ecosystem-management approach on the National Forest System. The agency has been testing ecosystem-management practices for the past three years through its New Perspectives program.

A team of scientists at the H.J. Andrews Forest Experiment Station in Oregon's Willamette National Forest is a focal point of the New Perspectives efforts. This team recently formed the Cascade Center for Ecosystem Management, through which it is mounting an ambitious effort--the Augusta Creek Landscape Project. The 19,000-acre Augusta Creek watershed is being proposed as a management area where different timber-management strategies will be developed to copy natural patterns of disturbance, particularly fire. On one part of the project area, researchers might attempt to mimic periodic medium-intensity wildfires, which burn out underbrush and kill some larger trees, through a combination of selective harvesting and prescribed burning on a 70-year rotation. On another part, they might replicate the effects of less-frequent, high-intensity fires, which burn virtually all the biomass on a site, resulting in complete stand replacement. This might be done by implementing a 400-year rotation age, and a harvest technique that would replace the entire stand while leaving biological legacies as nature would.

Conceptually, this seems fairly straightforward. However, patterns of historic fire disturbance are merely a reference point. Many other variables have to be weighed in the development of these management strategies. Most notably, the scientists will have to consider the current mix of species, the ages and structure of the late-successional forests that dominate the area, traditional timber practices, biological diversity, the carbon cycle, maintenance of cold-water flows, and the resistance of the landscape to disturbance.


Other scientists around the country are greatly expanding on the work being done at Andrews. In the Northern Region of the Forest Service, scientists and resource managers have developed an innovative approach that links the latest scientific concepts to on-the-ground management practices. Called Sustaining Ecological Systems (SES), the approach has three central features:

1) Organizing environmental analysis around ecosystem elements and processes considering landscape composition (the kinds and amounts of elements, such as plants, animals, and soils), structure (the pattern of distribution of these elements, both vertically and across the landscape), and function (the flow of species, materials, and energy across landscapes and through time).

2) Recognizing that ecosystems occur in a "nested" arrangement, one within another, and must be considered in a hierarchy of geographic scales, such as sites, stands, watersheds, river basins, and continents.

3) Considering broad temporal and spatial scales.

The critical concept of SES analysis is a comparison of current ecosystem conditions, at various geographic scales, to the range of natural variability that determined the character of the biotic communities and species native to the area. Currently, the best way to estimate "natural variability" is through a process of historical characterization, examining the records of these ecosystems and landscapes during the period from the mid-1800s to the mid-1900s, prior to extensive fire suppression and timber-harvest activities. "It is this comparison with natural variability that provides the basis for conserving biodiversity, thus maintaining the viability of most species both known and unknown," states the SES report.


Last July, a panel of resource specialists appointed by the regional forester released a report, Restoring Ecosystems in the Blue Mountains, that describes how the panel used the SES environmental-analysis approach to address the region's forest-health problems. An earlier report had found that in 1990, 53 percent (nearly two million acres) of the three national forests in the Blues--the Umatilla, Malheur, and Wallowa-Whitman--contained trees that were dead and defoliated as a result of insects and disease. Another million acres on other federal, state, and private lands were suffering the same problems.

The panel started at a broad geographic scale, recognizing the Blue Mountains as a distinct physiographic region with its own climate and topography. It divided the region into three physiographic zones: The Marine zone in the north is coolest and wettest; the Continental zone in the south is the warmest and driest; and the Mixed zone in the central Blue Mountains blends the two other climates.

Within each zone, the panel identified river basins ranging from half a million to a million acres in size. This was the scale at which the panel estimated ecosystem health. From the vast array of elements and processes that comprise an ecosystem, the panel selected nine as indicators of forest health--the same way a doctor might select heart rate, blood pressure, and body temperature as indicators of human health.

The scientists first estimated the range of natural variability for each of these elements, prior to fire exclusion and timber harvest. Then they estimated the current condition of each element. In comparing current conditions to the range of natural variability, they found that five of 19 river basins had been "pushed" far outside of their natural variability. The general conclusions were:

* Throughout the Blue Mountains, the amount of climax fir forest dominated by pine and larch is currently less than the estimated ranges of natural variability, especially in the drier southern geographic zone.

* Progressing southward through the Blues, the amount of climax fir forest composed of multiple layers of Douglas fir and true fir increases to levels that are higher than the estimated range of natural variability.

* Some of the river basins in the southern Blues have significantly higher percentages of high-density, low-vigor ponderosa and lodgepole pine than occur under "natural" conditions.

* Almost all river basins currently show higher levels of available fuels (standing dead and down material) than is natural.

* Riparian shrub cover and streambank stability are below their ranges of natural variability in most of the river basins, especially in the central and southern zones.

A key assumption of the SES ecosystem-approach is that an element or process that is outside its range of natural variability can not be sustained naturally. In other words, if an element, such as the parklike Ponderosa pine component, should diminish to a point that has never occurred naturally in that ecosystem, it is assumed that nature alone will not be able to sustain this element in the future.

Not all elements and processes have to be returned to their natural range of variability to be sustained, however. Some can be, and have been, maintained outside of their natural ranges by management activities, such as planting trees after timber harvest and restocking fish in streams. If an element is found to be outside its range, resource managers need to consider: 1) what the effects might be if they do nothing, 2) what management activities might help restore that element to its natural range, and 3) whether it's worth the cost to try to restore it to its natural range.

In weighing these questions, resource managers also need to consider which values are at risk. The panel conducted a series of interviews to better understand the concerns of various public groups and individuals related to the Blue Mountain forest-health problem. It found that most concerns fell into four areas:

* A need to reduce fuels, and thus risk of catastrophic fires, and better use of fire-management practices.

* Water-quality concerns, such as providing high-quality municipal water supplies and improving deteriorating streambanks and wetlands.

* Restoring and more sensitively managing riparian areas for water quality and to improve fish habitat.

* Timber-management practices, particularly salvage and restoration, to capture the economic value of the timber, especially dead and dying trees, but to do it in ways that help restore conditions, such as structure and composition, so that forests are better able to resist insects and disease.

Using all of this information, the panel grouped the Blue Mountain river-basin ecosystems into three categories, from most altered to least altered, and suggested the following strategies for restoring forest health:

On one extreme, river basins pushed far outside their natural range of variability pose substantial risks to terrestrial and aquatic ecosystem values. Restoration activities there should be based on an ecosystem approach, use landscape-level planning, and address values at risk and ecosystem imbalances.

In river basins not as far outside their natural range of variability, restoration activities should focus on protecting values at risk and correcting ecosystem imbalances.

On the other extreme are river basins that are near or within their naturally sustainable range. If restoration activities are necessary there, they should address site-specific conditions related to the protection of values at risk.

The panel also identified a number of long-term objectives and potential activities for restoring forest health in the Blue Mountains. The objectives corresponded closely with the concerns or values at risk, such as reducing fire risk, ensuring water quality, and restoring riparian areas. Potential activities--such as reducing fuels, establishing stand conditions to minimize insect epidemics, and restoring ponderosa pine on sites where it is well adapted--were consistent with those in earlier reports and national forest plans.

Some people find the panel's recommendations unsatisfying because they do not propose new restoration activities or any further assurance that forest health can indeed be restored. However, the report demonstrates a thoughtful, systematic approach to assessing forest health from an ecosystem perspective. This is a great step forward, and it goes about as far forward as current science will carry it in terms of understanding forest health and ecosystem management. In that, it is certainly state of the art, and a groundbreaking study.


Last June, AMERICAN FORESTS decided that the forest-health issue in the West was of significant national concern and warranted immediate policy action. Executive Vice President Neil Sampson conveyed this message to Congress in midsummer. "It's time to get beyond business as usual on many of these western forests because the risks of major environmental, economic, and social disaster are growing, and the actions being taken so far are not even beginning to keep up with the worsening situation. It's past the time for studies--it's time for action."

Sampson proposed a forest-health action program with dual focuses: first, increased effort to remove dead and dying trees, both to help make the forest more fire-resistant and to capture the short-lived value of the trees for wood processing after they have died; and second, preventive actions to make forests that are not yet dying more resistant to drought, insects, and disease. These actions include thinning and planting to begin converting to stocking levels and species mixes better adapted to their sites, reducing ladder fuels (low-level materials that allow a fire to climb), and creating structural characteristics to promote diverse habitats and other ecological values. These actions, like those recommended by the Blue Mountains panel, were not new. They addressed the forest-health problem with our best current understanding of ecosystem science and forest-management practices.

Shortly after Sampson's testimony, Congressman Larry LaRocco of Idaho and members of the House Agriculture Committee encouraged AMERICAN FORESTS to draft a bill based on an action program focused on forest-health improvement. We began working with Congressman LaRocco and his "National Forest Health Act of 1992" (H.R. 4980) to shift its focus from further study and expedited salvage sales to an ecosystem approach. We worked closely with the federal agencies to better understand the barriers to implementing ecosystem-based forest-health projects.

One key reason AMERICAN FORESTS was willing to commit substantial time and resources to this policy effort was that we sensed an unusual opportunity to define common ground between the environmental community and the forest-products industry. This notion proved to be right. When we approached them, representatives from both interests expressed a willingness to work on the issue.

Through intense negotiations in the final two weeks of the congressional session, the forest-health bill made great progress. Its substance came to incorporate key ecosystem concepts from the Blue Mountains reports. And the process by which forest-health programs and projects would be implemented was strengthened by improving scientific and public review while still providing means to expedite management activities responding to time-sensitive resource concerns.

With Sampson facilitating negotiations, the environmental and industry representatives came close to final agreement on a bill. Both interests agreed to support the bill during markup by the full Agriculture Committee on September 24, since only a few points remained to be hammered out between them. These points--primarily dealing with legal-process issues--proved too much to contend with in the remaining days of the session, so further action was not pursued. Nevertheless, environmental and industry representatives agreed that the process had been constructive and promised to continue this dialogue with the goal of achieving closer agreement on legislation by the start of the next Congress.

The forest-health issue has thus emerged as a significant concern on the congressional agenda. Through the efforts of Congressman LaRocco and other policymakers, and a commitment by AMERICAN FORESTS, we now have a bill which, by virtue of its being passed by the Agriculture Committee, has a substantial legislative record. There is also an established dialogue between the environmental community and the forest-products industry that both groups characterized as a "landmark" development, given their recent history of confrontation on virtually every other forestry issue.

AMERICAN FORESTS is committed to building on these achievements. We are working to develop even better forest-health legislation for the next session, using the best information we can obtain from scientists and resource managers--who in turn are working concurrently to address the forest-health issue on their separate but ever-more closely interwined tracks.
COPYRIGHT 1992 American Forests
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Copyright 1992, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Author:Clark, Lance
Publication:American Forests
Date:Nov 1, 1992
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