Managing forests for non-timber objectives such as habitat for threatened or endangered species, water quality, recreational opportunities, aesthetic features, and other outputs need not preclude production of wood products. In fact, removal of some trees is often necessary to accomplish these non-timber objectives. In the Western United States, Federal, State and private land managers often consider management strategies that help maintain healthy ecosystems and restore damaged ones. Management strategies for federal land are now developed at the landscape level and stand level actions are linked to the landscape strategy. Development of proposed actions often includes input from a host of interest groups and requires balancing management objectives with political realities. Much of the wood removed during the resulting treatments is from small-diameter trees (10 to 18 cm dbh). Although the costs of removing it are high, the wood quality (suitability for an intended use) is often good and pilot studies suggest this resource is suitable for many traditional and non-traditional products. This paper summarizes results of multidisciplinary work coordinated by the Ecologically Sustainable Production of Forest Resources team at the USDA Forest Service, PNW Research Station. The ESP teams focus is to investigate the technical and economic feasibility of utilizing wood removals to help finance ecosystem management activities. This work helps federal and other land managers understand forest management effects on wood quality and the importance of marketing timber in ways that most effectively capture its economic value while accomplishing desired ecological objectives by its removal.
The Ecologically Sustainable Production of Forest Resources (ESP) team (formerly the Timber Quality Research team), at the USDA Forest Service, PNW Research Station in Portland, Oregon, has conducted research on the quantity, quality (suitability for an intended use), and value of forest products since the early 1960s. The ESP team is part of the Social and Economic Values (SEV) program, which conducts research on forest economics, management, and utilization. The ESP teams research often includes evaluation of the financial or economic feasibility of individual silvicultural treatments and entire management regimes. Since 1993, this team has participated in several studies aimed at answering questions about the costs associated with management activities intended to restore or maintain ecological function of forests in the Western United States (1, 2, 3, 4). This work, in conjunction with efforts by other groups at the PNW Research Station (5, 6), the USDA Forest Products Laboratory (FPL, 7), and universities (8, 9, 10), has improved our understanding of the types of management activities that are financially viable. Other researchers in the Western United States have also contributed to this rapid increase in information (c.f. 4, 11) as has practical experience gained by public and private landowners as they begin to implement more ecologically based management systems (12, 13).
One of the challenges associated with implementing ecosystem management regimes has to do with performing landscape level analyses with sufficient rigor to allow policy makers to understand implications of alternatives and make reasonable choices. The concept of landscape level planning on National Forests is not new. Forest plans required under the National Forest Management Act of 1976 (NFMA) were an early attempt at developing a comprehensive plan for large land areas. These plans tended to view stands as the basic management unit in the context of the portion of the forest as a whole that was "suitable" for management under a particular land allocation. They were also discrete in the sense that they did not account for interactions among adjacent owners or organizational units, even when those units might be other national forests or federal agencies. While effective for some purposes, these plans did not provide for the survival of widely dispersed plant and animal species that were dependent on specific forest conditions at a broad geographic scale, nor did they account for the actions of multiple landowners. Recognition of these shortcomings, often through court orders, led to inclusion of larger land areas, multiple management agencies or owners, and a greater recognition of recent scientific information in the planning process. A major change is that the watershed is now viewed as the basic management unit and ideally actions are planned with an understanding of how management activities in adjacent watersheds, regardless of ownership, interact with each other. This process usually involves a science based ecological and social assessment for large land areas (c.f., 14, 15). An environmental impact statement (c.f., 16) and eventually a record of decision that modifies existing plans for federal land (c.f. 17), follow the assessment. These and other policy changes combined with changes in behavior by state and private landowners are altering the nature of the resource available for processing in the West.
At a smaller scale, the USDA Forest Service has been experimenting with landscape level planning and the process of gathering public input. One way this has occurred is through the network of Adaptive Management Areas (AMAs) created under the Northwest Forest Plan for the Recovery of the Northern Spotted Owl (NWFP, 17). In one example, the staff of the Cispus AMA on the Gifford Pinchot National Forest in Washington state held a series of "Collaborative Learning" workshops (18) intended to gather public input to develop a landscape design, and ultimately a management guide, for this 57,900 hectare area (19). After two years of planning and public input, a set of alternative landscape designs was proposed. One known as the "conservation alternative" was developed and eventually adopted. This alternative evolved after extensive input from several environmental groups, the USDI Fish and Wildlife Service, the Environmental Protection Agency, and the USDA Forest Service. Normally, Forest Service line officers such as District Rangers, Forest Supervisors, or Regional Foresters make selections of management alternatives developed by Forest Service staff. In this case, the selection was made by the Southwest Washington Provincial Advisory Committee (PAC) and Provincial Interagency Executive Committee (PIEC). These groups were created under the NWFP (17) and consist of citizens and local federal land management and regulatory agency officials. The PAC provides advice to federal officials who serve on the PIEC and have decision-making authority under the National Environmental Policy Act of 1969 (NEPA).
The method used to both develop and select the landscape design for Cispus AMA Guide was a major departure from the way the Forest Service routinely uses public input and selects management options. For legal reasons this selection was not a formal decision as defined under the NEPA but it will have a major influence on the way the Forest Service manages this portion of the Gifford Pinchot National Forest. This guide calls for the use of active management to test innovative approaches at the stand, landscape, and watershed level to integrate timber production with maintenance of late-successional forests, healthy riparian zones, and high quality recreation (19).
In a second example, staff from the Central Cascades Adaptive Management Area on the Willamette National Forest worked with scientists from the PNW Research Station and Oregon State University to develop a disturbance based management plan for a 22,500 hectare area. This plan was approved through the NEPA process and is intended to achieve the Aquatic Conservation Strategy defined in the NWFP (17) without the extensive network of riparian buffers outlined in the NWFP (20). Riparian buffers typically occupy about 25% of the land area and create problems in operating on the land between them. One feature of the Central Cascades plan is easier access of more land. This easier access is not, however, necessarily coupled with the ability to remove more wood and further analysis is needed to understand the economic tradeoffs between the two alternatives.
There are many other examples of landscape level analyses that involve cooperation between land managers, scientists, and the public to bring state-of-the-art scientific information into practical use and provide a larger role for the public. In just a few years, these methods of planning have become common in the Western US. As more expertise is gained, the scope and complexity of these analyses will likely increase. At present, many scientists from disciplines such as silviculture, wood utilization, and economics use projections based on empirical or process based models. Ecologists and wildlife biologists are typically more comfortable in describing outcomes in terms of areas of habitat or conditions favorable to subject species or management objectives rather than development of production functions for given species or guilds. Over time, better methods will be developed to merge these different types of analyses to produce more quantitative descriptions of outcomes.
The ESP team has traditionally conducted research designed to provide product quantity, quality and value information at the tree or stand level. One major challenge for this team during the 1990s has been to find ways to make meaningful contributions to land managers as they turn to a more holistic approach to forest management. We have accomplished this by forming partnerships with groups of scientists and managers who have a vision of the ecological objectives associated with management activities but an incomplete understanding of the factors that will make these activities financially or economically viable. Often the only funding source available to finance a management action is a timber sale. We seek to develop methods managers can use to gather technical information needed to evaluate some of the costs and potential revenues associated with implementation of these sales.
The ESP team has become involved in the landscape level planning process through cooperative research with the University of Washington using the Landscape Management System (LMS) developed by the Landscape Management project in the Universitys Silviculture Laboratory (21). This is a map based spatially explicit system that relies heavily on site level information as input data. Since the outputs of the model are spatially explicit, they appeal to land managers responsible for a specific area who want to analyze specific alternatives. Analytical projects are underway to provide quantification of timber outputs, timber value and costs associated with implementing management actions under the landscape design for the Cispus AMA and the Central Cascades AMA. These analyses will also provide information on a number of other factors ranging from risk of fire and windthrow to habitat for specified plants or animals. Pil Sun Park from the University of Washington is conducting the work on the CISPUS AMA and Glenn Christensen, a member of the ESP team, is conducting the wood production and economic analysis for the Central Cascades AMA. These projects are in the early stages but already the work on the Cispus AMA has provided information on potential windthrow and fire risk.
The intensity of input data required for running LMS makes it most useful for detailed analysis of areas up to 20,000 hectares but cumbersome for large areas used in regional analyses since they must be subdivided for analysis. The ESP team is also developing methods to incorporate wood quality, quantity, and value into larger landscape analyses that may be "cell" based. That is, they group all areas with like characteristics into one cell then perform composite analyses on that grouping. This method is used in the analysis for the Timber Assessment (15) for the Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974.
Jim Stevens, from the ESP team, is developing methods to synthesize data from the more than 100 species specific wood product recovery studies conducted by the ESP team over the past 35 years. These synthesized data will be used to develop species specific quality and value inputs for a region wide analysis of the economic, social, and ecological implications of the NWFP on Western Washington, Oregon, and the portions of California within the range of the Northern Spotted Owl. This broader scale analysis is led by the Social and Economic Values (SEV) program at the PNW Research Station of which the ESP team is a sub-unit.
The ESP team also contributes to the implementation of ecosystem management by increasing the understanding of the costs incurred and potential revenues from harvesting small diameter timber. Many of the areas identified as needing treatments to maintain or restore ecosystem function include large numbers of small diameter trees (often in the 10 to 18 cm diameter at breast height range). In Western Washington and Oregon, these trees are mainly young Douglas-fir (Psuedotsuga menziesii) and western hemlock (Tsuga heterophylla) in plantations or dense stands that developed after clear cutting. In the Interior West, there is more species diversity and small trees are often older. They typically regenerated after intense fires or are ingrowth forming a dense understory that developed under mature stands of ponderosa pine (Pinus ponderosa) or other species as a result of fire suppression.
The difference in quality between these small trees and the larger trees traditionally processed in the West depends on their source. Plantation-grown trees tend to be younger and, therefore, contain more juvenile wood. Depending on the species, this might mean more warp in lumber or inferior mechanical properties. Trees of equivalent size from fire origin or suppressed stands tend to be older, with proportionally less juvenile wood. Generally, they have wood quality similar to the larger trees traditional processed in the region.
A recent analysis of options designed to change the developmental trajectories of young Douglas-fir plantations on federal land (2) suggested that a wide range in quality could be obtained depending on when and how thinnings are implemented. In young Douglas-fir stands very early heavy thinnings created large diameter trees with large branches, high juvenile wood content, and subsequently low quality. If less intense thinnings were used, in slightly older stands, similar diameter trees could be grown in about the same time, but they would have much smaller branches and less juvenile wood. This latter method results in better quality without substantially different stand structural characteristics or habitat value for a number of small mammals and birds. Better quality gives manufacturers more processing options for a wider range of products.
The ESP team has participated in several efforts to characterize the product yields and quality of the small diameter trees found in the Inland West. Willits and others (3, 22) reported on the volume recovery and grade yield for dimension lumber manufactured from small-diameter Douglas-fir, western larch (Larix occidentalis), and lodgepole pine (Pinus contorta var latifolia) and veneer from Douglas-fir, western larch, lodgepole pine, white fir (Abies concolor), and ponderosa pine. Erickson (23) also collected data on mechanical properties of lumber from small-diameter lodgepole pine, Douglas-fir, grand fir (Abies grandis), and ponderosa pine. For all of these species and products, with the exception of ponderosa pine, wood from small-diameter stands had satisfactory mechanical properties for structural uses, including high-value engineered wood products.
The results for ponderosa pine are not particularly surprising since this species is known to have lower structural properties than many other softwoods (24) and although it is used for commodity lumber it is not generally selected for more demanding structural uses such as engineered wood products. Ponderosa pine has traditionally been used for appearance grade lumber, i.e. Selects, Finish, and Factory grades. Future work will evaluate small diameter ponderosa pine for these products.
Eini Lowell, from the ESP team, has initiated a cooperative project with Oregon State University to evaluate the potential for cut stock recovery from lumber sawn from small trees (25). Analysis of 5 cm thick dimension lumber and 2.5 cm thick boards from Douglas-fir, western larch, and lodgepole pine suggests that the best improvement in value is obtained when cut stock is produced from the middle level grades. Attempts to use secondary manufacturing to improve value in the low and high-grade pieces were not successful.
Olson (26) investigated quality of composite products manufactured from Douglas-fir, western larch, and lodgepole pine. Products included laminated veneer lumber, particleboard and oriented strand board. Properties for all products were within the range that would be acceptable for their manufacture on a commercial scale. Similar results were found for kraft and mechanical pulps produced from Douglas-fir, western larch, and lodgepole pine (27). In most cases, pulps produced from small-diameter trees of these species are similar to the traditional resource. The differences that did exist were relatively minor.
These results suggest that for the most species the wood quality of small-diameter stems removed during treatments to restore or maintain ecosystem function is not an issue for utilization. The exception is ponderosa pine and analysis like the one performed for other species by Lowell and Funck (25) may show that small trees from this species will be suitable for appearance grade products. Analysis of the use of small diameter ponderosa pine for pulp would also be desirable.
Analysis of harvesting costs and lumber values from small diameter trees showed that cost of implementing the types of thinning operations prescribed under ecosystem management was expensive using harvester-forwarder systems and was closely related to piece size (1). The results showed that revenues from lumber are also closely tied to piece size. Further work funded by the ESP team and the FPL under Leonard Johnson at the University of Idaho (10, 28, 29) examined ways to reduce costs by pre-bunching trees along skid trails.
Even with these improvements in productivity, the costs associated with thinnings designed to restore or maintain ecosystem function are generally high. This makes the cost to the mill of much of the wood removed under ecosystem management treatments expensive compared to raw materials available from other sources. Fiedler and others (11, 30) have suggested that one of the best ways to reduce these costs is to carefully choose areas for treatment where use of less expensive harvesting systems is feasible and allow the removal of a few larger trees. They argue that by focusing on these types of stands first, natural mortality and growth will change conditions in some of the more expensive to treat stands allowing less costly operations in the decades to come.
It is well known that recovery of wood products is closely related to diameter (31). An analysis estimating gross product value for lumber, veneer, and chips using data collected in the studies conducted over the past few years by the ESP team (3, 22) and information provided by equipment manufacturers on the efficiency of state-of-the-art wood processing equipment, demonstrated the close relationship between piece size and value (Figure 1; 32). A recent analysis of the return on investment for modern random length dimension sawmills and stud mills reached similar conclusions (33).
These results demonstrate that even though the quality of wood from small-diameter trees is good, the costs associated with removing these trees from the forest and processing them into products is high. Although the search for new higher value products may help to some degree to offset these costs, adopting administrative measures and technologies to lower forest operations costs is also important. Tools to help managers understand costs and select options that are financially viable, such as the Financial Evaluation of Ecosystem Management Activities (FEEMA) software developed by Fight (5, 6) are useful in setting these priorities.
Large numbers of dead trees exist on the western landscape. Disease, insect attack, and fire have contributed to the mortality. In many situations dead trees are seen as performing a valuable ecological function but in some, their removal may set the stage for creating desired conditions at the stand, watershed, or larger scales. The ESP team has maintained a continuing research program on the utilization of dead timber. Lowell and others (34) have recently reviewed this and other literature on dead timber but some general observations are worth repeating here. The most important finding is that the physical characteristics of trees change after their death. Changes in quality occur at different rates for different species and environmental conditions. Quality is also somewhat dependent on the cause death.
As a general rule, value recovery declines more quickly than volume recovery in dead timber and small or exposed timber deteriorates faster than larger or protected trees (34, 35, 36, 37, 38, 39 40). Stain, weather check, rot, and, in burnt timber, char are the primary value reducing factors. The quality of the trees at the time of death also helps to determine the rate of value loss. For example, blowndown old-growth trees with substantial amounts clear wood will lose value more quickly than similar size young-growth trees even if they deteriorate at the same rate. This happens because deterioration proceeds from the outside of the tree where the clear wood is located. In young-growth little or no clear wood was present at the time of death so only structural lumber or veneer is lost. In old-growth trees the lost volume contains high value clear wood (39). As a result, it is important to understand the type, size, and condition of dead trees when scheduling salvage operations after a large event that may have killed stands with varying characteristics.
Federal land managers in the Western United States are developing effective methods to gather public input on proposed management actions that allow citizens a much greater voice in shaping those actions. At the same time, the use of recent scientific information in the analysis and design of landscape level management plans is increasing. The removal of wood or other forest resources can play a role in decreasing the cost of management activities designed to restore or maintain ecosystem function even when wood production is not the primary objective of the activity. Much of the wood removed during these treatments will, however, be from small-diameter trees. Harvesting and processing costs for this material are high but quality is often as good or better than the traditional resource. Dead timber may also make up an important component of materials removed to restore or maintain ecosystem function. Characteristics of this material will change over time at rates depending on species, size, age, and environmental factors. In many cases, covering at least some of the costs associated with implementation of ecosystem management treatments should be possible by selling the wood removed but careful planning will be necessary to achieve this goal.
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Contact: R. James Barbour, USDA Forest Service, PNW Research Station, P.O. Box 3890, Portland, OR 97208-3890