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May 27, 1996
Kieran Suckling
Southwest Center for Biological Diversity



The definition of healthy, natural forests has long been a matter of academic and management debate in the Southwest. That debate will surely continue. As we enter one of the driest summers and biggest fire seasons in recent history, however, the media will increasingly be called upon to make judgements, and politicians will propose political "solutions" to stop the fires.

The 60,000 acre Four Peaks Wilderness Fire on the Tonto National Forest is a case in point. Secretary of the Interior Bruce Babbitt helped firefighters battle the blaze on the ground to promote prescribed fire. Senator Jon Kyl editorialized about the loss of "towering pines" while misquoting a scientific researcher in order to further his agenda of increased logging. Arizona Governor Fife Symington flew over the fire, also calling for more logging and fewer environmental restrictions. Fortunately, it was pointed out to the Governor that the Four Peaks Fire was primarily in desert chaparral, and that neither it, nor another large fire on the Coronado National Forest have any relation to a federal court order barring logging in big timber forests.

Historically, politicians have used the emotional turmoil of large wildfire seasons, to rush through national fire policy. In the past, that meant stronger and ultimately disastrous laws to prevent forest fires. The republican Congress is already using this summer's fires to call for increased logging and exemptions from environmental laws. Senator Pete Domenici is co-sponsoring a national bill. Senator Jon Kyl is circulating a Southwest specific bill. By removing dense as well as dead trees, both politicians argue, the risk of fire will be lessened.

We now know with devastating certainty that past mandates to eradicate fire in the U.S. National Forests was a disaster. Today's large fires are partially a result of that policy. There is every indication, that mandating more logging will be equally disastrous.

The political effort to push through emergency logging to improve "forest health" will largely focus on media images. The quality of the coverage, the questions asked and not asked, will greatly influence the public's understanding and its ability to participate in a national debate in an informed manner.


The timber industry and the Forest Service like to state that pre-European forests were "open and parklike," whereas modern forests have many more trees and are denser by orders of magnitude. The greater density is attributed to fire suppression. Misguided efforts of the past to suppress every fire, resulted in more small trees surviving because they did not burn. Modern dense forests, it is said, are more prone to catastrophic fire, insect infestation, and mistletoe outbreaks. Thinning and prescribed burning are recommended as tools to reduce fuel loads, fuel ladders, inter-tree competition for water and light, and spread of mistletoe. All of this is presented as improving "forest health."


Timber industry and Forest Service discussions of "forest health" focus almost exclusively on tree sizes, tree densities and tree predators (fire, insects and mistletoe). This is because they are in the business of growing timber and selling trees. But forests are far more than trees, especially ponderosa pine forests in which grass is as much a keystone component as the trees. Forests are also creeks, wildflowers, native fish, soils, predators, fungi, songbirds, and shrubs. Their absence from the "forest health" discussion is very telling since the decline of native fish, songbirds, riparian areas, native grasses, native herbs, and large predators is well documented. It is evident that "forest health" is not about holistic ecosystem restoration, it is about producing a steady supply of trees for industrial use.

The Forest Service's recent Environmental Impact Statement on the effects of amending all eleven Southwest Forest Plans is a good example. The alternative developed by the timber industry and deemed to best provide for "forest health" by the U.S. Forest Service, is projected to cause declines in northern goshawks, sharp-shinned hawks, Mexican spotted owls, flammulated owls, southwestern willow flycatchers, and sensitive aquatic species (USFS 1995). This is not what ecologists call a healthy ecosystem.

Ecologists at Northern Arizona University (Kolb et al. 1994) distinguish "ecosystem health" from "forest health." The latter is usually a utilitarian concept tied to a resource production goal. The former considers the full range of native species and ecological processes. It seeks to restore ecosystems in their full complexity.


"Open and park-like" is the favored timber industry description of pre-European settlement forests. While such descriptions were used, early explorers and foresters also spoke of "dense, shady" forests. I will elaborate on dense forests below. First, however, let's consider what "open and park-like" meant to European-American explorers some 100 years ago. It did not mean lacking in trees. The first explorers and foresters came from the Eastern Seaboard and the Pacific Northwest where truly dense, wet, forests of hardwood, fir and cedar predominated. By comparison, the Southwest's forest were "open and park-like," but they certainly were not the "savannas" that the timber industry and some segments of the Forest Service would have the media believe.

The Beale Expedition of 1858

Beale's crossing of the Mogollon Plateau resulted in the most often quoted description "proving" the scarcity of trees in pre-European settlement pine forests:

"We came to a glorious forest of lofty pines, through which we have travelled ten miles. The country was beautifully undulating, and although we usually associate the idea of barrenness with the pine regions, it was not so in this instance, every foot being covered with the finest grass, and beautiful broad grassy vales extended in every direction. The forest was perfectly open and unencumbered with brush wood, so that the traveling was excellent."

Historians (Smith 1991) have determined that this description was written on Beale's second day in the ponderosa pine forest of the Coconino National Forest, at an elevation of 6,100 feet where sparse pines intermingle with juniper grasslands. Two days later, he would ascend to 7,400 feet, the heart of pine country. The forest there was "black with heavy timber...a heavy forest of pine...in the highest sense, sylvan." Though his low elevation description is continually presented as "the state of the forest," his complete journal contains a 2:1 ratio of densely timbered images to open forest images (Montiak 1996). These, however, are not often cited.

The Lang and Stewart Survey of 1909

The first timber survey of the Kaibab National Forest on the north rim of the Grand Canyon was conducted by D.M. Lang and S.S. Stewart in 1909. They subjectively described ponderosa pine as growing "mostly in open park-like stands or even isolated in character." Quantifying the "average" ponderosa pine stand, however, they found that it had 150 trees per acre, 107 of which are less than 6" dbh. There is no contradiction here, an acre with 150 ponderosa pine trees is open and park-like. In protected areas like Fire Point and Powell Plateau, visitors to the North Rim still enjoy picnicking and hiking in such forests to this day.

Lang and Stewart warn that forest conditions are extremely variable, and that great care should be taken not to confound conditions in one area with those in another. Their photographs are a good indication. Ponderosa forests at lower elevations mixing into pinyon and juniper are very open, those at higher elevations are much denser.

Other Early Expeditions

Dutton's (1882) description of the Kaibab Plateau having a "succession of parks and glades, dreamy avenues of grass and flowers winding between sylvan walls," corresponds well with the later assessment of Lang and Stewart. It also matches descriptions of the White Mountains in eastern of Arizona: "dense forests alternating between well watered glades" (Rothrock 1873) and large prairies "enclosed all around by dark woods" (Molhaussen 1858). All are accounts not of very open forests, but of numerous openings within dense forests.


Numerous early photographs of southwestern forests show magnificent dense pine forests at elevations of 7,000 ft and above, and open pine forests transitioning into woodlands or grasslands at lower elevations. A late photograph from the ponderosa pine belt of southern Washington state is also telling. Taken by B.I.A. Forester, Harold Weaver in 1961, it shows a shady ponderosa pine forest of dense trees. The caption reads: "The open parklike appearance still prevails on limited portions of the ponderosa pine forest in the upper Klickitat drainage. Ground cover consists principally of pinegrass. Almost all of Cedar Valley once looked like this" (Weaver 1961). Photographs of an "open and parklike" forest in central Washington state had 134 trees per acre (Rummell 1951).

Logging Interest Interpretations

In an interview with the New York Times on May 5, 1996, Forest Service spokesman, Mike Fitzpatrick said that before fire suppression, ponderosa pine forests had only 8 to 10 trees per acre. Now, he says, there are "hundreds" of "sickly" trees per acre creating fuel ladders up into the canopy of larger trees. This is the myth of the "savannah" so often repeated by the timber industry and the Forest Service. In reality, there is only one reference to savannah in the early literature (Beale 1859 in Ashworth 1991), and that was clearly in reference to a treeless plane.

Forest Service "research" on pre-European forest conditions is similarly exaggerated. Two recent studies, Changes in Southwestern Forests: Stewardship Implications (Johnson 1995) and Fire and Forest Health: Southwestern Region (Moody et al. 1992) uncritically cite references to open forests, but entirely fail to cite or discuss references to dense forests.


The number of trees per acre is highly variably, depending upon slope, aspect, elevation, temperature, humidity, soil conditions, co- dominant species, etc. Also important is the methodology used to count trees. Early foresters rarely counted small trees. On the Kaibab National Forest, for example, Lang and Stewart (1909) only estimated the volume of trees over 18 inches dbh. This is because early surveys were concerned with logging opportunities, and early loggers rarely cut trees smaller than 18 inches dbh (see below). Since most trees in a forest are generally small trees (>12" dbh), early counts typically excluded most of the trees in the forest. Without explaining this, the timber industry and the Forest Service routinely compare early surveys with modern surveys which count every tree above 2". This is like comparing apples and oranges. It results in misleading and greatly exaggerated descriptions of vastly denser modern forests.

Since the vast majority of trees in modern forests are in categories not even counted in most early studies (i.e. are under 11" dbh, see Johnson 1995), quantitative comparison of tree numbers is somewhat speculative. Prior to livestock grazing, logging and fire suppression ponderosa pine forests had between 20 and 450 trees per acre depending upon a host of factors affecting growing conditions (see Table 1). In 1986, the average number of trees per acre in all forest types (pine and fir) was 294 (Johnson 1995). Consideration of tree size ratios and 100% tree sampling, suggests that on the average modern pine forests are two to four times as dense as pre- European forests, not 10 to 20 times. Local site conditions, however, vary tremendously, some are indeed very dense, others are not.


Timber interests talk almost exclusively about the increase in numbers of small trees. They rarely discuss the near disappearance of large trees. U.S. Forest Service inventories in 1962 and 1986 record a dramatic decline in numbers of big trees (Choate 1966, Spencer 1966, Conner et al. 1990, Van Hooser et al. 1992). Thirty one percent of all trees over 29" dbh were cut down, forty eight percent of all trees over 39" were cut down

(Woolsey 1911, Lang and Stewart 1909, Cooper 1960, Pearson 1950, Rummell 1951)
Sitgreaves National Forest Maximum volume 31 > 4" dbh
Coconino National Forest Maximum volume
Average volume
Average volume
Average trees/acre, well watered, frequently very dense
> 10" dbh
> 9" dbh
> 12" dbh
> 6" dbh
> 6" dbh
South Kaibab

North Kaibab

Kaibab Plateau
Maximum volume
Average volume
Average volume
Average trees/acre, southeast exposure, dry soils, rather open
Average trees/acre
Average trees/acre

> 16" dbh
> 12" dbh
> 6" dbh
> 6" dbh

Prescott National Forest Average trees/acre, open & dry situation 28 > 4" dbh
Santa Fe National Forest Maximum volume 36 > 4" dbh
Carson National Forest Maximum volume
Maximum volume
> 7" dbh
> 4" dbh
Cibola National Forest Maximum volume 23 > 4" dbh
Alamo National Forest Maximum volume 47 > 4" dbh
Gila National Forest Fully stocked
Fully stocked
Maximum volume
> 4" dbh
> 4" dbh
> 4" dbh
Maylay Gap, Mescalero Reservation Open and parklike 317 1 - 14" dbh
Central Washington Open and parklike 134 all

That's just in one 25 year period. Intensive logging in the preceding seven decades and between 1986 and 1996 has reduced the Southwest's old growth by about 88%. Ponderosa pine old growth, formerly the most common and most commercially valuable old growth, has decline by about 98%. The majority of existing old growth is in the relatively small portion of the landscape covered by mixed-conifer forests. It has survived because of the listing of Mexican spotted owl as a threatened species under the Endangered Species Act and attempts to list the northern goshawk as well The owl, in fact, was listed primarily because the Forest Service planed to liquidate the mixed-conifer old growth after it realized that there were not enough large pines to sustain the big tree timber industry (USFWS 1993).

The Forest Service uses a remarkable accounting method to assert that the number of "large trees remained virtually unchanged" between 1962 and 1986 (Johnson 1995). This outrageous conclusion is made possible by defining a "large tree" to be 17" dbh or larger. A 17" tree, however, is not large, it is smaller than average. The average ponderosa pine on the Gila and Coconino National Forests in 1905 was 19.3" Rixon 1905, Lieberg et al. 1905). The average Douglas-fir was 23" dbh. The average pine on the Apache National Forest was 18" dbh, while trees on the Kaibab National Forest were so large that trees under 18" dbh were not measured (Plumer 1904, Lang and Stewart 1909). Trees on the San Carlos Reservation were not even considered merchantable timber if not over 24" dbh in 1910 (August and Gomez 1984).

In the early 1900's, "mature" ponderosa pines were defined as 200 years old, 300 year old trees were considered "veterans." Today, the Forest Service defines 100 year old trees "old growth."

By 1962, when the Forest Service began region- wide surveys, the forests were already highly degraded, the very largest trees being already logged off. The rule of early forestry was to exclusively and rapidly cut all the largest trees (Drake 1910, Woolsey 1911, Moore 1912). The large trees were eulogized as far back as 1891:

"What was the forest primeval at one time has since been raided by the rapacious forces of commerce, and at one point, Flagstaff, favorably located in the timber belt, has since been established by the Ayers-Riorda saw and planing mill, equipped with every modern appliance for the destruction of these old giants whose heads had nodded on the breezes of centuries...I cannot repress a sentiment of regret that the demands of civilization have caused the denudation of so many square miles of our forests" (Bourke 1891).

Noting that much of the Coconino National had already been cut over by 1949, Long Valley District Ranger James Egan still maintained that "to cut over the remaining area of virgin forest as fast as is economically feasible is good forestry" (Eagan 1949). This was done with such dedication that by the 1970's Forest Service researchers warned that "Continuing the present removal rate would require heavy cutting of small diameter trees as old growth is liquidated...The present level of sawtimber cut cannot be maintained" (USFS 1977). By the late 1980's large ponderosa pine timber had largely run out. The Lakeside District on the Apache- Sitgreaves National Forest had no old growth remaining at all. Pressure was still being applied, however, to produce more volume. The District Ranger complained that the volume just did not exist, that forest indicator species were declining, and that there would be nothing left for the future (Collins 1989). The search for more big trees led out of the cutover ponderosa pine forest, into the mixed-conifer forest, and eventually to the listing of the Mexican spotted owl as a threatened species.

A review of Forest Service environmental assessments on the Gila and Apache-Sitgreaves National Forests revealed that even under a generous definition, only 12% of the landscape is in an old growth state today, with only 2% being old growth ponderosa pine (Suckling 1995).


"The acquisition of horses by Native Americans in the 1700's and resulting environmental impacts was but a small prelude to the hundreds of thousands of domestic livestock brought by the early Euro-American settlers in the mid- to late- 1800's (Irwin et. al 1993). The rapid increase in domestic animal numbers was tantamount to a population explosion of an introduced species with no population control" (Covington et. al 1994).

Native grasses are keystone species in Ponderosa pine ecosystems. They prevent erosion, facilitate water infiltration, provide wildlife habitat, control fire movement, and prevent excessive numbers of trees from becoming established. Severe overgrazing of the forest is one of the most critical threats to forest health (Belsky and Blumenthal 1995, Morgan and Suckling 1995). Turn of the century foresters noted severe overgrazing had already resulted in erosion, flooding, and large denuded areas (Rixon 1904, Leiberg et al. 1905). One noted that overgrazing resulted in the 60 species of native grass being eventually replaced by exotic weedy plants (Plummer 1904).

By the 1920's it was evident that the removal of grass had resulted in a marked decrease in forest fire frequency, and increased shrub and tree numbers (Leopold 1924). Under natural conditions, grass is the primary medium through which forest fires ignite and spread. Removing grass densities resulted in greatly decreased incidence of fire. The lack of fire, in turn, led to more pine seedlings surviving and growing into poles. The arrival of cattle in the Southwest has been closely correlated with declining fire frequency- long before fire suppression policies or even the creation of the Forest Service (Savage and Swetnam 1990). Proposed changes in fire suppression and prescribed burn policies (USDI/USDA 1995) therefore, are unlikely to be successful unless overgrazing is simultaneously reduced.

Fire kills already established pine seedlings. Dense grass cover, however, prevents the seedlings from establishing in the first place (Denham 1959, Tackle and Roy 1953, Roy 1953, Sowder 1959, Rummell 1951, Madany and West 1983, Zimmerman and Neuenschwander 1984). Regardless of fire frequency or suppression tactics, healthy grass cover will prevent excessive pine reproduction and concomitant "forest health" problems. This has led researchers to conclude that overgrazing, not fire suppression is the primary cause of excessive tree densities in the West (Rummell 1951, Madany and West 1983, Zimmerman and Neuenschwander 1984).

The Forest Service usually portrays overgrazing as a problem of the past. While it is true that numbers of cattle on the National Forest have decreased since the turn of the century, it is also true that overgrazing remains a perennial problem. Cattle numbers and allowed forage utilization rates are too high to support healthy forest ecosystems. Zimmerman and Neuenschwander (1984) found that over dense forests began to return to normal fire patterns following the removal of cattle.

The conspicuous absence of limitations on grazing in the current Salvage Rider and the proposed "forest health" bills of Senators Domenici and Kyl are a clear indication that the intent is not to improve the health of the ecosystem, it is to increase the volume of timber produced. This is why the timber and cattle industries contributed so heavily to both senator's election campaigns.


A famous study by the Southwest's first Regional silviculturalist, Theodore Woolsey, Jr., is often cited by the timber industry as proof that destructive crown fires were rare in pre- settlement ponderosa pine forests (Woolsey 1911). Never cited, however, is his additional remark that

"it is after logging that the damage from fires is greatest, on account of the inflammable and unburned slash."

Logging operations generates enormous volumes of unused limbs, tree tops and small trees. These are a major source of fuel loading. Wildfires flair in slash piles and become very hot and difficult to control (Agee 1989, Olson and Fahnestock 1955, Pearson 1950). In 1994, a record fire year, logged over areas burned intensely throughout the west (Huff et al. 1995, DellaSala et al. 1995b). One low intensity fire in Washington state grew to 2,000 acres within 24 hours of moving into an area of heavy slash (USFWS 1994). Logged over areas spawn the most destructive fires in pine forests:

"Where the cut has been heavy and the resulting debris correspondingly large, all the difficulties of fire fighting are proportionally increased. All kinds of waste material left in the woods supply food for the flames, but the leaving of large, unlopped softwood tops on the ground adds enormously to the fury of a brush fire and greatly prolongs the length of time that slash remains a menace to its own and surrounding areas....Fires on cut-over lands usually kill all standing timber left on the area burned, as well as all the young growth" (Chittenden 1905).
"Within the last sixty years, however, fires have done little damage to the virgin timber, although prevalent on the cut-over areas...Fire on these areas is of the hottest character, and once started is extremely difficult and often almost impossible to check" (Cooper and Kelleter 1907).

Some of the Southwest's most devastating wildfires occurred in timber sales.

Horseshoe Fire – 1996

Timber harvest related fires has been a continual problem on the Coconino National Forest (USFS 1974). This year's Horseshoe Fire is only the latest example. The sale operator, Stone Forest Industries, piled and burned slash residues in February, 1996. Smoldering beneath a protective layer of dirt, the slash suddenly burst into flames in mid-May when the forest reached a critically dry and windy state. The fire burned 8,100 acres before being extinguished. The Horseshoe Fire burned through the slash and trees of a freshly thinned forest. It is a warning that thinning is not the fire panacea many would like to believe it is.

Chino Fire - 1996

This 8,000 acre fire on New Mexico's Mescalero Reservation reached tremendous temperatures in logging slash. House sized slash piles defied all fire fighting efforts.

The Dude Fire - 1990

The Southwest's most infamous wildfire, the Dude Fire burned 28,000 acres in 1990, killing six firefighters, and raising a subdivision and the historic Zane Grey Cabin. It quickly became a political lightning rod for timber interests. Gerald Freeman, President of Stone Forest Industries blamed environmentalists and lack of logging for the fire:

"When professional Forester's recommended thinning of National Forest stands to propagate the growth of ponderosa pine...What happened? Preservationists said 'no' we want to keep old growth, natural forests. What happened next? ...a devastating fire rushed through 45 miles of the Tonto National Forest and ruined millions of board feet of timber..The deadly 'Dude' blaze burned trees that were up to 250 years old...consumed grasses and shrubs...and drove off wildlife. But more importantly, cost six lives and wiped out several communities...and left a hundred homeless. Proper forest management could have, would have...prevented that. How? Logging roads would have given access and escape routes for firefighters. Dead and dying timber would have been removed and undergrowth cleared..."(quoted in Montiak 1995).

Jim Mattsen, of Kaibab Forest Products, called the destruction "typical of what our unmanaged forests have become" (quoted in Tolan 1991).

Arizona State Land Commissioner, Jean Hassell, blamed the Endangered Species Act for preventing thinning operations. Lack of thinning, he said, resulted in the loss of 28,000 acre of Mexican spotted owl habitat in the fire (Hassell 1993).

A Forest Service summary, however, revealed that the Dude Fire area was anything but unmanaged (USFS 1991). Most of the old growth was taken out in the late 1880's. The remaining was logged off in the 1940's and early 1980's. Far from being kept out of the woods by environmentalists, the timber industry did not even bid on three timber sales offered in the area in the late 1980's - there was simply no valuable timber left to harvest. Realizing the timber industry would not bid on a commercial timber sale in the area, the Tonto National Forest considered offering it as a non- commercial land service contract.

The Dude Fire was not the first major wildfire on this ravaged country. The 2,500 acre Robert's Mesa fire burned through in 1961 and the 7,200 acre Hatchery Fire burned through in 1968. Both served as fire breaks limiting the spread of the Dude Fire.

Dudley Lake Fire - 1956

Scorching 21,000 acres of ponderosa pine in 1956, the Dudley Lake Fire is the largest wildfire to date on the Coconino National Forest. It was started by a logging operation in a dry, windy season, and was fueled by a heavy accumulation of logging slash (Schaefer 1957).


This primer has focused on Ponderosa pine forests because they are the dominant forest type in the inland West. They are also the most degraded forests because both co-dominant plant communities (pine and grass) have been commercially exploited for hundreds of years. Unfortunately, however, generalizations about ponderosa pine forests are commonly attributed to mixed-conifer forest as well.

Under natural conditions, fires in ponderosa pine forests are frequent and cool burning. They rarely harm the larger, thick-barked trees or cause stand replacement. Mixed-conifer forest, however, naturally burn hot and heavy, but not as often. They are dense, canopied forests, periodically subject to stand replacing fire. Following such fire, aspen often dominates the stand for several decades before the Douglas and true firs return. Aspen regeneration is dependent upon stand replacement fires.

The hysteria generated around "catastrophic" Ponderosa pine fires often spills over into unwarranted concern over mixed-conifer fires. The 20,000 acre HB Fire in the Gila National Forest is a case in point. The 2,000 acres hot burn was deemed catastrophic by the Forest Service and blamed on an unnaturally high tree densities of 100 trees per acre. But 100 trees per acre in mixed-conifer stands is perfectly natural. Lang and Stewart recorded an average of 195 fir trees per acre on the Kaibab National Forest in 1909.

The stand replacing fire was also perfectly natural. The adjacent peak experienced a large hot fire in 1900 and is now covered by a heathy, mature aspen forest. Since mixed-conifer forests may be expanding in the Southwest, while aspen forests are definitely declining, there is little cause for alarm when large wildfires cause conifers to be replaced by aspen.

Sudden concern by the Forest Service and the timber industry over the survival of the Mexican spotted owl and northern goshawk also appear exaggerated. Owls and goshawks have returned unharmed to forests which suffered large wildfires on numerous occasions (see for example, Stacey and Hodgeson 1995).

The confusion of pine and fir ecology, and the resultant exaggerated claims of tree densities and fire damage, appears motivated by the need to justify salvage logging plans. Eagle Peak was scheduled for logging as soon as the HB fire started. The Forest Service claimed that the fire would not have been so destructive had the forest been previously logged down to "natural" densities, that post-fire salvage logging would reduce fuel loading thereby decreasing the damage of the next fire, and that it would speed recovery. That adjacent Buzzard Peak recovered very well on its own after the 1900 fire was not discussed. Buzzard Peak recovered because calls to salvage log the burn in order to prevent future fires (Rixon 1905) went unheeded. The very same reasons are not being used to promote logging of Eagle Peak.

When analyzing the effects and causes of forest fires in the inland West, a distinction must be made between chaparral, ponderosa, mixed- conifer, and spruce-fir forests. They grow, burn, and regenerate differently.


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