Old-Growth Forests in the N orthem

Rocky Mountains

James R. Habeck

DcparUnent of Botany University of -Montana

Missoula, Montana 59812

202 Natund Areas JmJlrnaH

ABSTRACT: Old-growth forests still remain in significant amounts in the northern Rocky Mountains on federal forest lands; old growlh in private ownership has mostly been destroyed. U.S. Forest Service personnel of the NOJ1hem Region (a USDA Forest Service subdivision encompassing northern Idaho, Montana, and the western Dakotas) arc developing their plans to fulfill the management goals specified by the National Forest Management Act of 1976. Old-growth ecosystems arc being preserved on national forests within wildernesses, road less areas, research natural areas, and other special interest areas. In addition, U.S. Forest Service personnel arc designating special management areas 10 provide habitat for wildlife that requires or prefers old-growth forests. The U.S. Forest Service's efforts in old-growth conservation, from natural area prog;ams to specially designated old-growth management units, arc described for the northern Rockies. The perpetuation of viable popUlations of wildlife species lhal arc dependent on old-growth conditions has become the focal point in developing old­groWtJ1 management plans for federal foresLs located in the northem Rocky Mountains. However, olel-growth forests have their own intrinsic ecological value independent of wildlife considerations and deserve conservation in a system of land allocations that represents the range of ecosystems found in the northern Rockies. Such a system would provide for the long-term needs of planL<; and animals with known dependence on old growth, as well as those organisms whose needs we know little about.

INTRODUCTION

Examples of olel-growth forests still remain in the Northern Region's federal lands; they occur in wildernesses, national parks, roadIess areas, botanical areas, research natural areas, and other special management units. State, county, and private lands also support remnants of old-growth forests. Stanels of pristine origin (1700's or earlier), however, have sustained considerable depletion after a century of entry and harvest. Only twenty years ago it was not uncommon to see log trucks fully loaded with five to seven large-diameter (more than 75 em) ponderosa pine, western lmch, or red~ cedar; today, thirty to forty smaller stems generally arc needec! to make a payload. A front-page newspaper article in the June 13, 1987, issue of the Mis.wulian (Mont..'1na) reported a major sawmill's (Champion Intemational Corp.) partial shutdown due to depletion of largc­dimension. old-growth trees on company lands. In the same newspaper on July 3, 1987, a letter to the editor voiced a citizens group's (Friends of the Wild Swan) concerns that old-growth forests in western Montana's S wan Valley arc being "liquidated" at low and mid­elevations, that any old growth remaining is "threatened with extinction" even though it is "incpiaceab1c," and that

habitats of nongame species are being "annihilated." Citizens have become sensitive to the ecological values of old­growth systems and understand the implications of their loss.

These media reports may signal the end of an era for the lumber industry and increased pressure to protect remaining old growth on federal lands. National forest lands in Montana and Ida.~o still support some old growth, and U.S. Forest Service ecologists arc focusing their attention on the ecological role of these forests. Most Northern Region foresters now recognize the importance of preserving whatever old growth remains. They need 10 eletermine, however, whether Current conservation efforts are sufficient to meet future needs.

As a plant ecologist I believe an assortment of old-growth vegetation types, in all elevational zones, should be protected in perpetuity for their own sake, with protection supported on a casc-by-case basis through a variety of si ie-specific documentations. It is now evident that the welfare of those bird and mammal popUlations using old growth has become the major focus for old­growth management planning; this malter has, in fact, become controversial. Emphasis on wildlife conservation is

Volume 8 (3), 1988

useful in generating enthusiasm, but it can detract from the concept that old­growth forests have their own intrinsic value, that is, that the composite of living forms exhibiting mature stages of interaction with each other and their environment should be recognized and accepted as valued pieces of the landscape's total biotic divcrsity. Jones (1984) agrces, stating that "Witll our present knowledge of the old-growth situation, we should probably be maintaining old growth because of ilS importance as a unique ecosystem rather than basing needs on individual species." Old growth on national forcst lands has come under scrutiny because the National Forest Management Act (NFMA) of 1976, Section 6(g), requires forest managers to provide [or biotic diversity. Federal regulations inter~

preting this directive specify that managers are to maintain viable populations of plants and animals, including species that may require or prefer old-growth habitats to complete their life cycles. Old-growth ecosystems were addressed in a symposium at the 1983 Socicty of American Foresters' national convention. At that time Tceguarden (1984) stated that rules and regulations currently in place went beyond the NFMA's statutory language, and he provided an in-depth analysis of the origins of the old-growth/wildlife can troversy.

Below is a gcneral review of the Northern Region's management program for old growth followed by a discussion of several specific efforts that involve the use of special management areas for diversity maintenance.

NORTHERN ROCKY MOUNTAIN FOREST VEGETATION

Vegetation Types a",1 DislrHlution

The northern Rocky Mountains support considerable vegetative diversity, from the moist maritime forest types in north­ern Idaho and northwestern Montana to the montane ai1d subalpine zones typical of the northern Rocieies. The distribution

Volume 8 (3), 1988

of forest vegetation is correlated with complex environmental gradients, with rainfall, slope, aspect, and elevation being most influential (Habeck 1987, Peet 1988). A gcneralized ordering of forest zones follows: Zone '1 ~ cotton­wood (Populus spp.) - dominant in riparian sites; Zone 2 - dry conifer/ woodland types featuring ponderosa pine (Pinus ponderosa) (Figure 1) and limber pine (P. Jlexilis); Zone 3 - montane/ inland maritime zone composed of Douglas-fir (Pseudotsuga menziesii), western larch (Larix occidentalis) (Fig­ure 2), grand fir (Abies grandis), western redcedar (Thuja plicata) (Figure 3), west­ern hemlock (Tsuga heterophylla), west­ern white pine (Pinus monticola) (Figure 4), paper birch (Betula papyriJera), and aspen (Populus tremuloides); and Zone 4 ~ subalpine and timberline zones with subalpine fir (Abies lasiocarpa), spruce (Picea enge/mannii and hybrids of P. engelmannii/P. glauea), whitebark pine (Pinus albicaulis), mountain hemlock (Tsuga mertensiana), lodgepole pine (Pinus contorta), and alpinc lareh (Larix lyallil) (Habeck 1987).

What is Old Growth?

Old-aged stands (more than 200 ycars old) may be formed from any of the conifers listed above. How these "old" trecs might also exist in the old-growth condition is another matter. Northern Region forest planners and others in the Pacific Northwest (Franklin et al. 1981, Franklin and Spies 1984, Whitney 1987) have attempted to detine old growth. At this time no single concept or definition of old growth has been agreed upon; instead, each national forest admin­istration has been creating its own individualized response to the NFMA regulations. Perhaps the reason for this is the difficulty of arriving at a single definition that would apply to the wide range of ecogeographic subdivisions that make up the northern Rockies.

In an effort to provide the Nez Perce and Kootenai national forests with a functional definition and classification of old-growth forests, Pfister (1987) reviewed a number of different usages for the term. Some definitions of old growth

FIGURE 1. Old-growth ponderosa pine (Pinus ponderosa), about 350 years old. Originally maintaincd parklike by low-intensity fires, Douglas-fir (Pseudotsuga menzi­esii) is seen invading the understory. Photograph taken in 1940 near Darby, Montana, Bitterroot National Forest.

Natural Areas Journal 203

..

FIGURE 2. Fire-generated western larch (Larix occidentalis) stand exhibiting dam­aged and dead snags. Stand age is about 300 years. Invading subalpine fir (Abies lasiocarpa) is seen in the understory. Taken in 1965 at Swan Valley, Montana, Flathead National Forest.

interject structural charactcristics that obviously relate to wildlife requirements; some represent parts of schemes or models of sllccessional vegetation, employing such terms as "climax," "overmature," "terminal stage," and "most tolerant." Another approach suggests only a gcneralized definition with the option of making it morc specific for individual old-growth types. Pfister discovered that i[ the most commonly used old-growth criteria were applied collectively, very few individual stands would actually quali[ y as old growth. His analysis revealed that a [ew features such as diameters and densities

204 Natural Areas Journal

ofliving trees and standing snags, as well as the amount of dead and down material (tons per acre), would provide reliable criteria for defining old growth within the variety of mountJin forest zones on these two national foresL<.).

Pfisler's (1987) rer,ort describes and classifies old-growth ecosystems using previously measured stand examination data. Other recent literature accepts the shifting-mosaic steady-state concept [or defining old-growth systems (Bormann and Likens 1979, Wallmo and Schoen 1980, Freedman and Habeck 1984). This refers to a condition wherein the forest

community reaches a dynamic but relatively unchanging state; exhibits a complex, multistoried structure; presents an all-aged composition; and is a mosaic of both carly and late successional slages. Other descriptors of old growth include the presence of heartrot, decadence, and minimum snag densities. Using stand age only to define old growth does not always work since some 200- to 300-year-old forests may not display basic old-growth qualities.

Historically, climatic [actors that influence forest composition and distribution in the northern Rockies were interactive also with wildfire, a major factor in the evolution of forest ecosystems in this part of North America (Habeck and Mutch 1973). Large portions of this region's pre-1900 timber cover were dominated by fire-adapted and/or [ire-dependent conifers; pondcr­osa pine, lodgepole pine, western larch, and western white pine. Many of the original mature seral forests were well over 200 years old in the mid-1800's. Just prior to Euroamerican settlement (1850 and later), [ire-generated or fire­perpetuated forest types dominated vast acreages in the northern Rockies. Both Leiberg (1900) and Ayres (1900) described the prevalence o[ fires and the seral old growth existing in the Northern Region before extensive logging, Lightning-ignited and Indian-ignited fires played major roles in shaping the old-growth structure in this part of the Rockies (Arno 1980, Barrett and Arno 1982).

In western Montana the term old growth often refers to late seraI, mature subelimax forests 200 to 500 years old, maintained originally in an open­canopied savanna state by ti'equent (five­to twenty-year intervals) low-intensity ground fires (Habeck and Mutch 1973, Arno 1980, Antos and Habeck 1981, Freedman and Habeck 1984). The parklike ponderosa pine and western leu"ch stands probably exhibited too few of the dead snag and decadent elements to qualify as old growth in today's context. In ravines and riparian sites subject to infrequent fires, old-growth

Volume 8 (3), 1998

FIGURE 3. Climax western redcedar (Thuja plicata). about 500 years old, in the vicinity of Ross Creek Scenic Area and Ross Creek Research Natural Area, Kootenai National Forest, Montana. Photograph taken in ] 963.

Douglas-fir groves developed; remnanl' of these, with individual dominants morc than 100 cm in diamctcr, are still present.

The montane zones of northern Idaho and norLhwestern Montana, which experience an inland maritime climate (greater moisture), historically supported climatic climax old-growth forests dominatcd by western reclcedar and western hemlock. These sites burned less often (100- to 200-year intervals), but when fire did oceur they were often of high intensity, destroying much or all of the sland (Habeck 1978, 1985) and creating a patchy mosaic of successional stages. The major seral species in the moist part.;; of the Northern Region are western white

Volume 8 (3), 1988

pine and western larch; magnificent old­growth stands of u1cse species were prescnt at the time of settlement.

Forc8ts of centuries-old trees also occurred within the subalpine zone where fires seldom reached. Amo and Habeck (1972) reported the presence of 500- to 700-year-old alpine larch at timberline in the northern Rockies. Stands of ancient whitebark pine arc present in the same zone. Any definition of old growth must accommodate forest types occupying severe habitats at upper timberline, as well as the limber pine/ponderosa pine outliers in the warm, dry grasslands of eastern Montana.

The onset of modern fire suppression has been equal in importance to logging in altering the abundance of old-growth forests throughout the northern Rockies. A large portion of the original old-aged ponderosa pine and western larch stands in western Montana, having survived logging, have become densely stocked with Douglas-fir, grand fir, or subalpine fir regeneration and are now developing without further fire disturbance toward climax stages dominated by shade­tolerant species. The events and circumstances conducive to generating and maintaining some kinds of old-age forest no longer exist; this is being recognized by forest ecologists developing long-term forest plans.

Natural Areas Journal 205

FIGURE 4. Old-growth seral forest, exceeding 200 years, composed of western white pine (Pinus monticola), western hemlock (Tsuga he/erophyl/a), and grand fir (Abies grandis). Montford Creek Research Natural Area, Coeur d'Alene National Forest, Idaho. Photograph taken in 1937.

NATIONAL FOREST OLD­GROWTH MANAGEMENT UNITS

The Research Natural Area System

National forests in the Northern Region use a variety of land classifications to preserve biotic diversity, including old­growth ecosystcms. The largest of these classifications are wildernesses and othcr road less areas that vary in size from a few thousand heck1Tes to nearly half a million contiguous hectares (e.g., the Bob Marshall and Selway-Bitterroot wilder­nesses). Management plans for estab­lished wildernesses provide for the main­tenance of old-growth communities in all forest zones through natural processes. Wildemess management plans also are directed toward perpetuating fire­dependent vegetation types by allowing many natural fires to bum without suppression.

Other types of designated areas are smaller and more localized. These include botanical, scenic, and natural ar­eas. The National Forest Management Act (NFMA 1976) specifically provided

206 Nalural Areas Joumal

for establishment of a rcse.:.'lTch natural area (RNA) system. Early efforts to develop a RNA system in national forests in the northern Rockies date back to the 1930's when four forest sites in Idaho and Montana (featuring old-growth west­ern white pine, western larch, and climax western redcedar/western hemlock) wcre designated as RNA's by scientists from the Northern Rocky Mountain (now Intermountain) Forest and Range Experi­ment Station (Habeck 1979). For half a century these RNA's have served as con­trols in or near U.S. Forest Service ex­perimental forests in ldaho and Montana. Expansion of the RNA system slowed down by the 1950's but was rencwcd in the 1960's under the leadership of C. W. Wellner; morc RNA's wcre added during the 1970's. In the present decadc national forests have emphasized RNA's in their planning, with the aim of setting aside a representative array of ecosystems. A summary and update of how the RNA system in the Northem Region has devel­oped is provided by Juday (1986).

National forest planners have adopted various forest habitat type classifications

(Daubenmire and Daubenmire 1968, Pfister et al. 1977, Cooper et al. 1987) in devcloping a complete RNA system in the northern Rockies. These forest site classifications are based on potential climax vegetation types, each relating to a segment or part of the nordlern Rocky Mountain environmental complex. NFMA regulations 36CFR 219.25 and 36CFR 251.23 require that biotic/ ecologieal diversity be encompassed by the RNA system and provide guid,mee for RNA planning actions. The U.S. Forest Service's Northern Regional Guide (1983) oudines steps necessary to establish RNA's (see U.S. Forest Service Manual Section 4062) and lists specific habitat type assignments to be filled for each national forest.

The U.S. Forest Service's RNA program has targeted the biotic diversity present on federal forest lands; individual RNA's may feature pioneer, seral, climax, or mixtures of successional stages wiulin the various forest habitat types. Old­growth forests mayor may not be present in a given RNA although the presence of old growth is viewed as desirable in selecting RNA sites. Efforts of the Idaho Natural Area Coordinating Committee, the Big Sky (Montana) Field Office of The Nature Conservancy, and other resource management agencies and conservation groups in both states have provided direct support to development of completed natural area systems in the northern Roekies. Bird and Loop (1987) provide an excellent summary of these cooperative efforts in Montana.

Old-Growth Forests in Research Nalural Areas

Research natural areas are typically 120 ha or more and often encompass entire small drainages. RNA's are protected against activities that rn ighl, in any way, modify the natuml ecological processes. Logging is not pennitted, but grazing may be allowed if necessary to maintain eerwin vegetation types. RNA's also may be protected from fires, insects, and disease, with specific protective actions allowed or disallowed based on the

Volume 8 (3), 1988

-

management plan drawn up [or each RNA. Thus, if a RNA supports fire­dependent forest types, that plan will specify the conditions under which fire is allowed.

Fifty-six RNA's have becn eSUlblished or are in the process of being approved in the U.S. Forest Service's Northern Region. With the exception of a few nonforested grassland RNA's, most support some amount of old-growth forest displaying old trees, snags, and decaying logs. At least fifty different forest habitat types, at or near an old­growth condition, occur in these RNA's. Some of these habitat types are represented by fire-dependent old growth (mature seral) dominated by western larch, western white pine, ponderosa pine, or lodgepole pine. Old-growth climax types dominated by western rcdcedar, western hemlock, mountain hemlock, whitebark pine, subalpine spruce-fir, and alpine larch are also well represented in the current listing of RNA's. The RNA program continues to expand as each national forest fulfills the assignments (habiUlt types) given in the regional guide. The completed Northern Region RNA system (164 areas) is intended to be somewhat redundant, so additional amounts of old-aged/old­growth forests will be added to what has been preserved already.

National Forest Old· Growth Management Units

Although protection of biotic diversity is one objective of the RNA program, maintenance of old-growth forests on national forest lands has generated a broadening base of interest and concern within the U.S. Forest Service and among the general public. The current interest in old-growth forests ,md in RNA's is interactive and complemenl.'1fY. How­ever, the realization that special attention is required [or a particular segment of the Northern Region's biotic diversity (old­growth dependent wildlife) has focused concern for old growth in all national forest plans.

Volume 8 (3), 1988

U.S. Forest Service planners are becoming more informed about the ecological relationships between old growth and the wildlife thought to depend on such vegetation. Field research often emphasizes establishing the nature of interactions between wildlife species and old-growth habitat components such as standing snags or downed logs. Such basic knowledge is critical for recognizing and mapping old­growth foresL' in the field. This expanded knowledge also has helped justify to tbe public the necd to designate special old­growth management areas.

Yanishevsky (1987) reviewed national forest management plans for Montana and northern Idaho, assessing how old­growth forests are treated in the planning process. She described what she saw as significant shortcomings or failures in proposals to deal with the maintenance of biotic diversity. One of these results from the common error of equating old age with old growth. She also described faults or problems related to: (1) eslab­lishment of minimum sizes for old­growth management units, (2) geo­graphic distribution of sites dedicated for old growth, (3) employment of sUlndards used to describe old-growth snag sizes and densities, and (4) early detection of managerial failures and other errors that operate against successful maintenance of biotic diversity. The best thinking of ecologists, in and out of the U.S. Forest Service, is needed to sort through conrIicts and/or differences of opinion that have been detected in national forest plans.

The management plan for Lolo National Forest (about 800,000 hal, which was finalized in February 1986, is an example of the old-growth planning progress in the northern Rockies. The Lolo Forest plan has several designated units for management of biotic diversity; these include wilderness and roadlcss areas representing 215,700 ha. In addition there arc special old-growth management units that supplement Lolo Forest's eight established or proposed research natural areas.

The old-growth management units (designated as Management Area 21 in the plan), tOUlling 16,600 ha, represent a wide range of elevations, aspects, and habitats. They arc well distributed throughout the Lolo Forest, being positioned in seventy-one different drainages. Where wilderness was not available, a minimum of 8 percent of each drainage was allocated to old growth. The old growth was also distributed by vegetative type. Figure 5 illustrates one part of the Lolo's Superior District (west of Missoula, Montana) and the specific localities of old-growth units. The Lolo Forest plan states that old­growth timber is intended "for wildlife species dependent upon old growth for habitat"; these species include pileated woodpecker, pine marten, hermit thrush, and goshawk - all old-growth indicator species. The Lolo Forest plan "provides [or Old-growth succession in timber stands with an optimum arrangement of habitat components to maintain viable populations of old-growth-dependent wildlife species." The Lolo's roadless areas (Management Area 11, 68,800 hal are managed for essential grizzly bear habiUlt, as well as old-growth-dependent wildlife species.

Lolo Forest's old-growth units may be used for (I) lives lock grazing when "compatible" with old-growth manage­ment, (2) dispersed recreation, but no campgrounds, and (3) limber harvesting, only "to improve or mainUlin the old­growth habiUlt." This last usage refers to those harvesting procedures that will per­petuate the old-growth seral ponderosa pine and western larch stands in the Lolo National Forest. By definition or descrip­tion the old-growth management units arc to (1) be at least 12 ha in size, (2) exhibit decadent qualities, (3) be multi­storied and fully stocked, (4) contain dead snags, (5) contain down, woody material greater than 37 tons per ha, and (6) have thirty·seven trees per ha greater than 50 em in diameter. No stand age criteria is employed in defining old growth, although the tree diameters (greater than 50 cm) suggest ages of 200 or more YC<.'lfs.

Natural Areas Journal 207

FIGURE S. Distribution of old-growth management areas (stippled) on a portion of the Superior District, near SI. Regis, Lolo National Forest, Montana. Adapted from the Lolo National Forest Plan, February 1986.

Some of the old-growth units shown in Figure 5 are small in size - 65 ha or less - although others are 400 ha or more. Some forest ecologists believe that old­growth communities of fewer than 20 ha provide little benefit to old-growth­dependent wildlife populations (Yani­shevsky 1987), especially if the forests surrounding them are logged. Many of the Lola Forest's small old-growth units are in fact surrounded by management units that have been logged or are ear­marked for standard timber production and harvest. Spatially isolated old­growth units, if islandlilce and lacking connecting corridors to other old-growth or mature seral stands, are likely to have less value for diversity preservation.

208 Natural Areas Journal

Harris (1984a, 1984b) analyzed this par­ticular problem in the context of island biogeography theory; that is, isolated patches of old-growth forest can be ex­pected to lose, over time, some of the biotic diversity that was originally pres­ent. The Lolo Forest plan addresses this concern through a program of monitoring old-growth indicator species to assess biotic diversity in the old-growth units. I believe it is appropriate for the Lolo For­est also to consider construction of (or allow development of) connecting corri­dors and buffer zones composed of closed-canopy forest to assure that old­growth units function as intended.

I examined one of the Lola Forest's old­growth units near Missoula (Tl2N,

R18W, Sections 3 and 4). This is a forest tract of more than 400 ha, portions of which were selectively logged about 1900 for large-dimension western larch and ponderosa pine. Douglas-fir, 200 In 300 years old, with some equally old residual larch and pine (all more than SO cm in diameter) form today's overstory; there are numerous fIre-scarred snags and stumps in the stand. Logging created gaps that later fIlled with western larch and Douglas-fir regeneration, resulting in vertical and horizontal diversity. Down, decaying logs are present, represented by stems less than 38 em in width. Evidence of pileated woodpecker use is abundant throughout. This stand is Obviously not pristine, yet structurally it appears to ful­fill the old-growth concept In the lower forest zones of western Montana, some­what modified stands like the one exam­ined are now uncommon and seldom available for old-growth preservation programs.

Northern Rocky Mountain presettlement old-growth forests occupying lower slopes often were dominated by fire­dependent conifers. Any current forest planning should give serious considera­tion to the redeployment of fire if old­growth fire types are to be perpetuated. The Lola Forest plan states that "wild­fires will be controlled to protect old­growth qualities and resource objectives associated with this type. To achieve management goals and objectives, pre­scribed burning may be planned and exe­cuted to maintain or restore the composi­tion and structure of plant communities or for hazard reduction purposes." The Missoula Ranger District (Lolo National Forest) currently is engaged in such an effort in a nearby recreation area (pattee Canyon) where perpetustion of old­growth ponderosa pine and western larch has been given high management prior­ity; selective logging and prescribed fire are managerial options in this special use area.

Wildlife Use of Old-Growth Forests

A preliminary assessment of wildlife species using old-growth forests based on

Volume 8 (3), 1988

------------------------------------------------~-

literature reviews covering most of the northern Rockies (Hager 1978, Jerry 1984) is provided in Table 1. Four old­growth wildlife habitat components (structural elements) are listed, along with vertebrate llse of each element designated. The degree of restrictive dependency, if any, is not designated; in many cases this is not known. A detailed discussion of old-growth forest managemcnt to meet the needs of wildlife in the Pacific Northwest is provided by Kerrick et al. (1984). They emphasized that forest managers need to understand those habitat characteristics important for sustaining old-growth-dependent wild­life species.

Considerably less well known are plant species that may be dependent on old­growth forest environments for their sur­vival. Forest studies throughout the northern Rockies have produced lists of plant species commonly occurring in old­growth conifer forests of all types. Apparently few vascular plants are dependent upon old-growth environ­ments; some plant species may display reduced abundance or coverage but are usually found in a wide assortment of other stand types (successional stages) as well.

SUMMARY

Although old-growth forests survive in the northern Rockies, their numbers are dwindling in the lower commercial tim­ber zones. Much of what remains is on federal forest lands. The National Forest Managemcnt Act requires the U.S. Forest Service to prescrve biotic diversity, including preserving a representative assortment of old-growth forests. A pri­mary forest management goal is the maintenance of viable wildlife popula­tions. Bird and mammal populations, along with thcir habitats, are to be pro­vided for in all national forest plans. This is interpreted to mean that whenever or whcrevcr it is demonstrated that a par­ticular ecosystem is required by one or more wildlife species, a national forest plan must encompass strategies for the survival and perpetuation of those spe-

Volume 8 (3), 1988

cies. Old-growth forests in the northern Rocky Mountains have become even more important as their role in maintain­ing this region's biotic diversity is acknow ledged.

Forest planners have been partially hampered by the absence of widely accepted standards for defining old growth from the broad spectrum of forest conditions. At this time it may be best to accept the most generalized, inclusive definition of old growth and err on the side of preserving too much rather than not enough. Loss of old growth is continuing at a faster rate than our studies can elucidate the full ecological value of these forests.

As Teeguarden (1984) points out, there is no specific national policy per se that requires conservation of the remaining old-growth forest on public lands, although he has reviewed several federal statutes in which this is hinted at. A case Can be made that "wildlife dependency" is too narrow an ecological justification for preserving old-growth forests, and that it may be, in the long term, detrimental to the remaining old-growth ecosystems and the organisms they support. A complete collection of old­growth ecosystems (each with its own long-term steady state) representing the full range of biotic potential should be planned for, independent of all other considerations. RNA's in tl,e northern Rockies and elsewhere, together with other protected management units, can be a part of this collection. However, the use of lands surrounding RNA's and old­growth units must be considered also. Without foresight and careful planning, areas being set aside may not be able to function as intended.

ACKNOWLEDGMENTS

I wish to thank Wendel Hann, Jack Lyon, Bob Naumann, Bob Pfister, Steve Arno, Jack Losensky, Mike Hillis, and Bill Ruediger for their contributions to the preparation of this paper and for reviews of earlier drafts. Three reviewers also provided excellent and constructive criticism.

LITERATURE CITED

Antos,1. A. and J. R. Habeck. 1981. Successional development in Abies grandis forests in the Swan Valley, western Montana. Northwest Science 55(1): 26-39.

Arno, S. F. 1980. Forest fire in the northern Rockies. Journal of Forestry 78: 460-465.

Arno, S. F. and.!. R. Habeck. 1972. Ecology of alpine larch (Larix /yallii) in the Pacific Northwest. Ecological Monographs 42: 417-450.

Ayers, J. B. 1900. The Flathead forest reserve. pp. 245-316 in Twentieth annual report - part five: forest reserves. U.S. Geological Survey, Department of the Interior, Washing­ton, D.C.

Barrett, S. W. and S. F. Arno. 1982. Indian fires as an ecological influence in the northern Rockies. Journal of Forestry 80(10): 647-651.

Bird, J. R. and D. J. Loop. 1987. The Montana Natural Areas Act: a thirteen year revival. Western Wildlands 13(2): 27-29.

Bormann, F. and G. Likens. 1979. Pattern and process in a forested ecosystem. Springer-Verlag, New York. 253 p.

Cooper, S., K. Neimann, R. Steele, and D. Roberts. 1987. Forest habitat types of northern Idaho: a second approxi­mation. USDA Forest Service General Technical Report INT-236. 135 p.

Daubenmire, R. and J. B. Daubenmire. 1968. Forest vegetation of eastern Washington and northern Idaho. Washington Agricultural Experimen­k~l Swtion, Technical Bulletin 60. l04p.

Franklin, J. F., K. Cromack, Jr., W. Denison, A. McKee, C. Maser, J. Sodell, F. Swanson, and G. Juday. 1981. Ecological characteristics of olel-growth Douglas-fir forests. USDA Forest Service General Technical Report PNW -118. 46 p.

Franklin, 1. F. and T. A. Spies. 1984. Characteristics of old-growth Douglas-fir forests. pp. 10-16 in New

Natural Areas Journal 209

~-------------------------...........

TABLE 1. Utilization 01' old-growth habitat elements by vertebrates in the Northern Region. Arter Harger (1978) and Jerry (1984).

Old-Growth Elements

Large, Living Old-Growth Trees

Large, Standing Dead Trees

Fallen Dead Trees on Terrestrial Sites

Fallen Dead Trees in Stream

210 Natural Areas Journal

Species of Vertebrate Wildlife -----

Goshawk: Accipiter gentilis Bald Eagle: Haliaeetus leucocephalus Wolverine: Gulo gulo Marten: Maries americana Fisher: Martes pennanti Moose: Alees alees Whitetail Deer: Odocoileus virginianu, Caribou: RangiJer caribou N. Flying Squirrel: Glaucomys sabrinu," White-Winged Crossbill: Loxia leuc,ptera Red Crossbill: Loxia curvirostra Ruby-Crowned Kinglet: Regulus satrapa Townsend's Warbler: Dendroica townsendi Hammond's Flycatcher: Empidonax hammandii White-Breasted Nuthatch: Silta carolinensis Red-Breasted Nuthatch: Siua canadensis Clark's Nutcracker: Nucifraga columbiana

Barred Owl: Strix varia Saw-Whet Owl: Aegolius acadicus Fisher: Martes pennanti Marten: M artes americana Wolverine: Gula gula Bald Eagle: Haliaeetus leucacephalus Merlin: Falco columbarius C.-Backed Chickadee: Parus ruJescens N. Flying Squirrel: Glaucamys sabrinas Little Brown Myotis: Myotis lucifugl~' White-Breasted Nuthatch: Slua carolinensis W.-Headed Woodpeeker: Dendrocopas albolarvatus Pileated Woodpecker: Dryocopus pileatus

B. Red·Backed Vole: Clethrianornys gapperi Fisher: Martes pennanti Wolverine: Gula gulo Lynx: Lynx canadensis Saw-Whet Owl: Aegalius acadicus Marten: Martes americana Barred Owl: Strix varia Pileated Woodpecker: Dryocopus pile at us W. Jumping Mouse: Zapus princeps

Cutthroat Trout: Salrna clarkii lewisii

Species Usc of Structural Elements

Nest Nest, Roost Forage Forage Forage Winter cover Winter cover Forage Forage Nest, Forage Nest, Forage Nest Forage Nest, Forage Forage Forage Nest, Forage

Nest Nest Den Den, Forage Den Nest, Roost Nest, Roost Nest Nest Roost Nest Nest Nest, Forage

Forage, Cover Den, Forage Den, Forage Den Forage Den, Forage Forage Forage Cover

Cover

Volume 8 (3), 1988

forests for a changing world -proceedings of 1983 convention of the Society of American Foresters. Society of American Foresters, Portland, Oreg.

Freedman, J. D. and J. R. Habeck. 1984. Fire, logging and whitetailed deer interrelationships in the Swan Valley, nortllwestern Montana. pp. 23-35 in J. E. Lotan and J. K. Brown, eomp., Proceedings of symposium on fire's effects on wildlife habitat. USDA Forest Service General Technical Report INT-186. 96 p.

Habeck, J. R. 1978. A study of climax western redcedar (Thuja plicara) forest communities in the Selway­Bitterroot Wilderness, Idaho. North­west Science 52(1): 67-76.

Habeck, J. R. 1979. Slow progress: a report on research natural areas. Western Wildlands 5(3): 28-31.

Habeck, J. R. 1985. Impact of fire suppression on forest succession and fuel accumulations in long-fire­interval wilderness habitat types. pp. 110-118 in J. E. Lotan, B. M. Kilgore, W. C. Fischer, and R. W. Mutch, tech. coord., Proceedings of symposium and workshop on wilderness fire. USDA Forest Service General Technical Report INT-182.

Habeck, J. R. 1987. Present-day vegetation in the northern Rocky Mountains. Annals of Missouri Botanical Garden 74(4): 804-840.

Habeck, J. R. and R. W. Mutch. 1973. Fire-dependent forests in the northern Rocky Mountains. Journal of Quater­nary Research 3: 408-424.

Harger, R. 1978. Old-growth forests: managing for wildlife. USDA Forest Service, Northern Region, Missoula, Mont. 58 p.

Volume 8 (3), 1988

Harris, L. J 984a. The fragmented forest island biogeographic theory and the preservation of biotic diversity. University of Chicago Press, Chicago, Ill. 211 p.

Harris, L. 1984b. An island archipelago model for maintaining biotic diversity in old-growth forests. Pp. 60-64 in New forests for a changing world­proceedings of 1983 convention of the Society of American Foresters. Society of American Foresters, Portland, Oreg.

Jerry, D. G. 1984. Old-growth manage­mcnt in the Idaho panhandle national forests. pp. 373-380 in W. R. Meehan, T. R. Merrell, Jr., and T. A. Hanley, eds., Fish and wildlife relationships in old-growth forests. Proceedings of symposium sponsored by Alaska District, American Institute of Fishery Research Biologists.

Jones, D. A. 1984. Management of old­growth forests for wildlife habitat P. 423 in W. R. Meehan, T. R. Merrell, Jr., and T. A. Hanley, eds., Fish and wildlife relationships in old-growth forests. Proceedings of symposium sponsored by Alaska District, Ameri­can Institute of Fishery Research Biologists.

Juday, G. P. 1986. The outcome of research natural areas in national forest planning. Natural Areas Journal 6(1): 43-53.

Kerrick, M., K. Johnson, and R. Pedersen. 1984. What information is necessary for planning the manage­ment of old-growth forest for wild­life? pp. 65-68 in New forests for a changing world - proceedings of 1983 convention of the Society of American Foresters. Society of American Foresters, Portland, Oreg.

Leiberg, J. B. 1900. The Bitterroot forest reserve. pp. 317-410 in Twentieth annual report - part five: forest reserves. U.S. Geological Survey, Department of the Interior, Washing­ton, D.C.

Peet, R. K. 1988. Forests of the Rocky Mountains. pp. 63-101 in M. G. Barbour and W. D. Billings, cds., North American terrestrial vegeLation. Cambridge University Press, Cambridge.

Pfister, R. D. 1987. Old-growth defini­tion, classification, and application. Final Contract Report (RFQ 185-131Q), USDA Forest Service, Missoula, Mont. 29 p.

Pfister, R. D., B. Kovalchik, S. Arno, and R. Presby. 1977. Forest habitat types of Montana. USDA Forest Ser­vice Technical Report INT-34. 174 p.

Teeguarden, D. E. 1984. National policy, tradeoffs and issues in managing old-growth forests for multiple benefits. pp. 2-6 in New forests for a changing world -proceedings of 1983 convention of the Society of American Foresters. Society of American Foresters, Portland, Oreg.

Wallmo, O. C. and J. W. Schoen. 1980. Response of deer to secondary forest succession in southeast Alaska. Forest Science 26(3): 448-462.

Whitney, G. G. 1987. Some reflections on the value of old-growth forests, scientific and otherwise. Natural Areas Journal 7: 92-99.

Yanishevsky, R. M. 1987. The rise of plans and the fall of old growth: a comparative analysis of old growth in Region One. Forest Watch 7(11): 23-27.

Natural Areas Journal 211