Demonstration of Ecosystem Management Options (DEMO)

Project Description

As societal perceptions of the role of federal forests have changed, so have strategies for managing these forests. The DEMO experiment arose in response to a need to formally evaluate the silvicultural and ecological tradeoffs, as well as the social perceptions, of new approaches to forest management—in particular, the retention of live trees at varying levels and spatial patterns. Here we provide a brief overview of the history and evolution of the DEMO study, the experimental design, and the major areas of investigation.

History and Evolution of the DEMO Study

In the 1980s, public concern over the fate of the northern spotted owl and the loss and fragmentation of the old-growth forests on which it depends led to unprecedented interest in natural resource management in the Pacific Northwest. Fueled by intense political activism, local and regional debates gained national prominence as lawsuits initiated by environmental groups led to a series of injunctions from federal district courts that brought timber sales to a halt on lands managed by the USDA Forest Service and USDI Bureau of Land Management. In April 1993, in response to this "timber crisis," President Clinton commissioned the Forest Ecosystem Management Assessment Team (FEMAT) to formulate and assess the consequences of an array of options for managing federal forest lands within the range of the northern spotted owl. This assessment was the first attempt to develop a comprehensive plan for ecosystem management at a broad geographic scale. The Record of Decision, and the standards and guidelines associated with the resulting management plan, The Northwest Forest Plan, were published in April 1994. Green-tree or structural retention is now a standard component of harvest prescriptions on federal "matrix" lands within the range of the northern spotted owl.

As changes in federal forest management policy evolved under the paradigm of "ecosystem management," it became apparent that implementation of new approaches to management were hampered by a paucity of research and, in particular, research targeted to and integrated with management. To address these needs, an ecosystem management partnership (subsequently named New Perspectives Partners) was formed, bringing together scientists from the University of Washington, Oregon State University, the Forest Service Pacific Northwest Research Station, and the Aerial Forest Management Foundation, and resource managers from the Forest Service Pacific Northwest Region.

Working with members of Congress in 1992, the partners emphasized the need for experiments on alternative approaches to forest harvest and suggested how such studies might be implemented on federal and state lands in the Pacific Northwest. At the same time, the Douglas Project Coalition (a local group of businessmen and citizens from Douglas County, Oregon) sought funds for a large-scale study and demonstration of the biological, social, and economic consequences of diverse management strategies. In 1992, Congress allocated funds to support the establishment of silvicultural experiments in Washington and Oregon using "new forestry" and "landscape management techniques." The Forest Service was directed to conduct this work in consultation with the New Perspectives Partners and Douglas County Coalition. After considerable debate on research objectives, management needs, and experiments, a final experimental design was adopted—one that tested a broad range of retention levels (15 to 100 percent of original basal area) and two distinct spatial patterns of retention (dispersed vs. aggregated). From a larger group of potential study locations in western Oregon and Washington, eight were identified, each containing relatively homogenous stands large enough to support six, 13-ha experimental units. Six of these locations were subsequently treated.

For a discussion of the evolution and history of the DEMO study see:

Franklin, Jerry F.; Norris, Logan A.; Berg, Dean R.; Smith, Gordon R. 1999. The history of DEMO: an experiment in regeneration harvest of Northwestern forest ecosystems. Northwest Science. 73(Special Issue): 3-11.

Study Areas

To establish a broad geographic and ecological base of inference, six blocks were chosen to represent a diversity of forest types in western Oregon and Washington. Blocks encompass markedly different physical environments, mature forest structures, stand ages, and disturbance histories on the Umpqua (Oregon) and Gifford Pinchot (Washington) National Forests, and on the Department of Natural Resources' Capitol State Forest. Stands represent the western hemlock, grand fir, white fir, and silver fir zones (defined by the climax tree species). Douglas-fir dominates all sites, but associated tree species differ among blocks.

Experimental Design

The DEMO study consists of a randomized complete block design, with six, 13-ha structural-retention treatments (square or slightly rectangular in shape) replicated at each of six blocks (geographic locations). Treatments were implemented as follows:

1. 100 percent retention: no harvest (an undisturbed control used to assess responses to harvest and natural temporal variation).
2. 75 percent aggregated retention: all merchantable trees (>18 cm diameter at breast height) were removed from three circular, 1-ha (56 m radius) “gaps” (25 percent of the treatment unit); all other trees were retained.
3. 40 percent dispersed retention: dominant and co-dominant trees were retained in an even distribution throughout the treatment unit; the target basal area was that of the corresponding 40% aggregated retention unit.
4. 40 percent aggregated retention: all trees were retained within five circular, 1-ha aggregates (40 percent of the treatment unit); all merchantable trees in the surrounding matrix were harvested.
5. 15 percent dispersed retention: dominant and co-dominant trees were retained in an even distribution throughout the treatment unit; the target basal area was that of the corresponding 15% aggregated retention unit.
6. 15 percent aggregated retention: all trees were retained within two circular, 1 ha aggregates (15 percent of the treatment unit); all merchantable trees in the surrounding matrix were harvested.

Within each unit, sampling is structured around a permanent grid system (8 x 8 or 7 x 9 points at 40-m spacing). For a detailed description of the DEMO experimental design see:

Treatment Prescriptions and Implementation

By design, all harvest and postharvest prescriptions were applied consistently among the treatment units within a block. Among blocks, however, methods of harvest, slash treatment, and planting details varied as a function of topography, physical environment, and forest composition and structure. Harvests were completed in fall 1997 (3 blocks) and 1998 (3 blocks). Details on harvest prescriptions, treatment of down woody material, retention and creation of snags, and reforestation can be found in:

Areas of Research

The DEMO study address both ecological and silvicultural responses to structural-retention harvests, as well as public perceptions of the aesthetic qualities of resulting stand structures. A diversity of study organisms was chosen, including those critical to characterizing forest structure (live and dead trees) and those thought to be sensitive to retention level or pattern, including late-seral herbs and bryophytes, ectomycorrhizal fungi, arthropods, amphibians, forest-floor small mammals, arboreal rodents, and diurnal birds. Preharvest measurements were completed between 1994 and 1996, and initial postharvest measurements between 1998-2000. Although most studies were short term in nature, measurements of forest structure and composition extend through 2016.

Details on the diversity of research topics, including histories and methods sampling, publications, and data availability can be found in:

Aubry, Keith B.; Halpern, Charles B. 2020. The Demonstration of Ecosystem Management Options (DEMO) study, a long term-experiment in variable-retention harvests: rationale, experimental and sampling designs, treatment implementation, response variables, and data accessibility. Gen. Tech. Rep. PNW-GTR-978. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.136 p.