Dueling Databases: How Much Old Growth Forest Is There? It All Depends On Who You Ask, How They Map The Woods And Analyse Data, Says UW Geographer

April 08, 1997

Sometimes it becomes inevitable that people can't see the forest for the trees, particularly when a one-and-a-half-pound endangered bird and competing institutional cultures get in the way.

That seems to be case of what happened at the height of the controversy over the northern spotted owl in the late 1980s and early '90s when the U.S. Forest Service and the Wilderness Society used similar satellite technologies and came up with drastically different totals for old-growth forests in the Pacific Northwest, according to a University of Washington geographic information systems analyst.

Robert Norheim, who compared the mapping methods used by the two organizations for his master's thesis in geography and is now employed as an analyst in the university's College of Forest Resources, will outline how these groups could come up with such divergent estimates Thursday at the 13th International Symposium on Computer-Assisted Cartography in Seattle's Washington State Convention and Trade Center.

Norheim says the institutional cultures of the organizations, deadline pressures, budget restrictions, different definitions of old growth and the use of similar but different technologies all contributed to the final numbers published: 3.7 million acres of old- growth forest by the Forest Service and 2 million acres by the Wilderness Society. The intent of Norheim's research was not to rate the two mapping efforts, but rather to explain how the figures could be so different.

The two projects had their genesis in 1988 when Congress directed the forest service to map and inventory its old-growth forest on the west side of the Cascade Mountains. With hearings looming to consider endangered species status for the spotted owl, the Forest Service was given 15 months to complete its work. The Wilderness Society, not trusting the forest service to come up with accurate numbers, began its own mapping project at the same time.

Institutional cultures and agendas wound up playing key role, according to Norheim.

"The Wilderness Society's goal was not to win, but rather to cast doubt on the Forest Service's report and have it be accepted without question," he says. "The Forest Service, on the other hand, had to come up with definitive numbers. The more old growth found, the more reliable the agency's earlier estimates would appear to be and the less creditable the environmental organizations' earlier criticism would be. Also the more old growth found, the more that could be allocated between ecosystem protection and the agency's traditional timber interests."

Norheim characterizes the Forest Service as having a unique acculturation process that builds strong loyalty and includes frequent transfers that "result in employees identifying more with the agency than with their communities." He adds that despite the agency's commitment to multiple-use forests, timber harvesting has been the dominant activity since the 1950s and it responded to environmental protection for the spotted owl by denigrating it as "single use."

The Wilderness Society is an environmental organization that has focused as defender of public land and has advocated setting forest lands aside as wilderness that can't be touched. However, the society and other large environmental organizations have come under fire as being more interested in perpetuating themselves and willing to compromise than in fighting battles, he says.

Both organizations hired outsiders to conduct their mapping projects. The Forest Service employed a firm, Pacific Meridian Resources, with which it already had a relationship. The Wilderness Society used Peter Morrison, a former Forest Service ecologist.

The two projects differed from the outset, according to Norheim. The Forest Service was well funded by Congress, it purchased high-resolution satellite data and Pacific Meridian had state-of-the-art computer software and hardware. Morrison, operating with a smaller budget, worked with a patchwork of donated computer components, lesser-quality satellite imagery and a smaller staff.

The two groups also disagreed on the definition of old growth. Because all of the characteristics of old growth can't be determined by remote sensing, the first set of maps Pacific Meridian prepared were titled "Potential Old Growth Map." However, the Forest Service, says Norheim, had the word potential dropped from the maps when they were presented to Congress and the public. The Wilderness Society and Morrison muddied the situation by mapping what it called ancient forest instead of old growth. This consisted of three categories: true old growth, high-elevation ancient forest and other ancient forest.

In addition to using different technologies to analyze satellite imagery, the two projects, although ostensibly mapping the same nine forests actually did not map the same areas within those forests.

"The Forest Service mapped only those areas specified by Congress, those areas in Region Six west of the Cascade Crest, even though the spotted owl lived in neighboring forests in California and east of the Cascade Crest," says Norheim. "The Forest Service did only what it had to and no more, similar to its earlier approaches to handling the spotted owl.

"The Wilderness Society mapped areas where it felt there was unprotected old growth, including areas in California and areas east of the Cascade Crest which fell outside Region 6. Its motivation was to find unprotected old growth so it could advocate for preservation."

Norheim adds that both projects were working under severe time pressure to produce maps in time to influence the debate over endangered species status for the owl. As a result, he says Pacific Meridian used a controversial technique that tried to mimic photo-interpretation while Morrison was pressured to complete his work by the Wilderness Society and used several different techniques during various parts of his study.

"The lesson from all of this is that when you get two sets of numbers you have to see where they come from and who put them together. This is not matter of counting apples and oranges, but one of counting golden delicious and red delicious apples," he says.

For more information, contact Norheim at (206) 543-9138 or norheim@u.washington.edu.

University of Washington
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