Testimony of David A. Perry

Senate Field Hearing on Forest Health

Boise

August 29, 1994.

My name is David A. Perry, I am a professor of ecosystem studies in the Department of Forest Science, Oregon State University (OSU). I have been on the faculty at OSU for the past 17 years, prior to which I was a research forester for Intermountain Research Station in Montana, and a range ecologist for the Montana Dept. of Natural Resources. I hold a BS in forest management an MS in forest economics, an MS in Physics, and a PhD from Montana State University in Ecology. My research interests focus on the dynamics of ecosystems at scales ranging from microscopic to global, with particular emphasis on the role of biological diversity in ecosystem stability. I have authored or co-authored over 75 technical papers and two books. My textbook, Forest Ecosystems, will be published this Fall by Johns Hopkins University Press. I am a member of the Scientific Societies Panel on EastSide Forests, the Marbled Murrelet Recovery Team, and the National Research Council's Committee on Pacific Northwest Forest Issues, I serve on the editorial boards of Conservation Biology and Allelopathy Journal.

I will touch on three issues in this testimony: (1) The nature of health problems in forests of the inland northwest; (2) Potential solutions to these problems; and (3) Infrastructure and institutional support required to adequately address forest health problems. My comments refer primarily to forests of Idaho, eastern Oregon, and eastern Washington

Clearly, there are forest health problems in the interior northwest. These include increased susceptibility of trees to fire, insects, and pathogens, a phenomenon that most scientists agree can be traced to 80 years of fire exclusion and conversion of old-growth pine to younger fir forests. However other health problems exist also, including in particular loss of habitat and possible impacts of management on soil fertility.

I.A. Basic elements of ecological health

Before discussing the above points in more detail, it is important to specify what the term health as applied to a forest ecosystem means to me; I believe my views reflect those of most ecological scientists. A healthy system is one that retains the integrity of its basic structure and processes, including viable populations of indigenous species. Some level of disease and tree death is normal and beneficial in forests; ecosystem health is not so much the absence of disease and death as it is the ability to contain these natural forces within certain bounds and

the robustness to resist or recover quickly from environmental stresses. These system properties of "resistance" and "resilience" are closely associated in turn with species diversity and in particular with the multiplicity of interactions among species that compose the system. Although healthy trees are prerequisite to healthy forest ecosystems, health encompasses much more than trees, and forest health correlates much more closely with structure and processes than with how fast trees are growing.

Because ecological systems seldom have clear boundaries, ecological health spans spatial scales. The structure of landscapes, for example, shapes processes (e.g. hydrology, propagation of disturbances) that influence the integrity of stands and streams. The integrity of streams depends additionally on the integrity of riparian forests, and of upslope forests that control sediment yields. Individual species influence processes in many ways that feedback to help maintain ecological health. One of the more notable examples in eastside forests is the regulatory role played by birds and predatory insects in consuming tree-eating insects (e.g. Torgersen et al. 1990). These natural enemies of insect pests require habitats such as large dead wood, linking the health of the stand back to its own structure (Torgersen et al. 1990). Species, stands, streams, landscapes, and regions compose an interlinked system in which the health of the parts cannot be considered separately from the health of the whole.

I.B. The Nature of Forest Health Problems in the Inland Northwest

Health problems can be grouped into three general categories:. vulnerability to insects, pathogens, fire, and drought; loss of habitat; and soil degradation. These are of course interrelated. Habitats may be lost to fire, drought or insects just as they are lost to chainsaws. Disturbance regimes that are too frequent and severe degrade soils and export sediments to streams faster than they can be cleared through natural processes. Degraded soils grow new forested habitat slowly, and in some cases not at all.

I.B.I. Vulnerability to insects, pathogens, and fire

Herbivorous insects, pathogens, and fire are normal components of inland forests, and as such play valuable ecological roles. The change in behavior that underlies current health problems can be traced to at least three factors. First, and in my opinion most important throughout much of the region, is large-scale conversion from a landscape dominated by old-growth pine to one dominated by younger forests with a high component of true firs and Douglas-fir. This has effectively converted the regional landscape from one that damps and absorbs to one that magnifies the spread of fire, insects, and disease, and is the principal reason that many scientists recommend moving the landscape back toward the historic dominance by large ponderosa pine. The regional change in tree species composition during the

20th century has been dramatic. In eastern Oregon and Washington, the area of commercial forest land dominated by ponderosa pine has shrunk during the 20th century by at least 75% (I'm not aware of comparable data for Idaho). Much of that area is now occupied by Douglas-fir and true firs that once occurred primarily at higher elevations, a change that has influenced the growth and spread of defoliating insects dramatically. Increased vulnerability to crown fires in east side forests can be traced in large part to the same factors that have exacerbated insect problems. The original old-growth ponderosa pine were quite resistant to crown fires, because the frequent ground fires kept fuel levels from building too high. Excluding ground fires, coupled with forestry practices such as clearcutting that convert old-growth to younger stands, has increased the probability of a ground fire moving into crowns and gaining intensity as it spreads.

A second factor contributing to current levels of insects and fire is the nearly decade-long drought experienced in the west, something that, according to climate change models, may well reflect the beginning of a long-term pattern. Drought increases tree susceptibility to some insects (e.g. bark beetles), and its effects are likely exacerbated by high water demand in overstocked forests. This factor is likely to have contributed significantly to the extensive kill of Engelmann spruce by bark beetles.

A third factor contributing to forest health problems is the introduction of exotic insects and pathogens (e.g. larch case bearer, white pine blister rust), organisms that trees of our region have evolved no defenses against. The possibility that yet more exotics may be introduced through log importation is truly sobering.

Considerable evidence from throughout the interior west indicates that spruce budworm outbreaks during this century have been more frequent, more widespread, lasted longer, and have killed more trees than previously. Entomologists agree that the more aggressive behavior on the part of defoliating insects during the 20th century has resulted in large part from the spread of true firs and Douglas-firs, which are hosts for spruce budworm (and also for Douglas-fir tussock moth). Incidence of the root rot Armillaria may also have been increased by the spread of these tree species. A basic ecological principle is at work in the interior west: the greater the abundance of susceptible plants, the faster the growth of pest populations; the faster pest populations grow, the more likely they are to escape from natural ecological controls. Whether that is good or bad for ecosystem health in the long run remains to be seen. Many of the low and mid-elevation forests attacked by defoliators over the past several decades were in an unnatural state to begin with, because historically they did not contain significant numbers of tree species that host these insects. In such cases, infestations tend to move stands back toward their original tree species composition, i.e. a predominance of ponderosa pine (at least

where some pine have survived logging). In other words nature, acting through defoliating insects, has been doing its own healing. The recent crash in spruce budworm populations throughout the northwest may or may not signal the natural healing process is completed; budworm numbers have dropped before only to rise again. Whatever the case, the large numbers of dead and dying trees create a dilemma: on the one hand fire hazard is increased, particularly by the fine fuels, on the other hand dead wood is critical habitat for numerous animal species. Decisions regarding salvage must seek some balance between the beneficial aspects of dead wood and its hazards.

I.B.2 Soil degradation

Impacts on soils are seldom as visually dramatic as an insect infestation or crown fire. Moreover, problems associated with soil degradation may not become apparent for several years. Nevertheless, impacts are well documented. The common practice of using heavy equipment for harvesting and preparing sites on relatively flat ground is well known to compact soils and reduce their fertility. In my opinion the practice should be abandoned immediately.

Soil organic matter, a critical determinant of water-holding capacity, fertility, and ecosystem resilience, is concentrated in the surface layers of most east-side forest soils, where it is vulnerable to loss during harvest and site preparation, or in erosion following harvest. Soil organic matter can probably be protected during harvest if reasonable precautions are taken. However, it is my impression that impacts on soil organic matter (or any other aspect of soil fertility) are frequently ignored in forestry operations. Protecting soils is an essential component of maintaining forest health, and should receive high priority in interior forests.

Another potential problem area is on steep slopes. Some of the more common east-side soils are susceptible to erosion, particularly on slopes greater than 30%. Erosion may be successfully controlled with partial harvesting on some of these soil types, however close monitoring is necessary. ESSSP (1994) recommended no logging or road building in the few remaining watersheds with healthy fish populations.

I.B.3 Status of Habitats

The most obvious impacts on vertebrates in forests in the inland west have been with fish, which are better discussed by others. Except for the bald eagle and the spotted owl (which occurs on the east slopes of the Cascades in Oregon and Washington), no terrestrial forest vertebrates are currently listed as federal T&E species, however the Oregon Dept. of Fish and Wildlife has identified 28 bird and several mammal species associated with OG and mature forests in eastern Oregon. Several of these are considered to be of particular concern, including the flammu-

lated owl, American martens, pileated woodpecker, northern goshawk, and three-toed, blackbacked and whiteheaded woodpeckers These species occur in Idaho, but I am not aware of any assessment of their status (for the most part little is known about their status anywhere in the region). Management aimed at all aspects of ecosystem health will require a much improved assessment of terrestrial vertebrates; sensitivity by managers to the needs of these species is likely to reap benefits by avoiding future problems.

Numerous species are known to require either large trees, large snags, and/or some proportion of older, closed canopy forest within their territories. Flammulated owls and whiteheaded woodpeckers prefer old-growth (OG) ponderosa pine or Douglas-fir forests, and avoid cutover areas. Similarly, goshawks prefer closed canopy mature or OG stands and avoid clearcuts and young open-canopied stands. Lynx, a candidate for listing under the ESA, require mature forest (> 200 years old) for denning. Wolverine, a secretive species that is classified as threatened in Oregon and "protected" in Washington, prefers mature or intermediate-aged stands for foraging. Bald eagles require large trees for nesting.

One of the primary concerns of conservation biologists is maintaining an adequate supply of large trees with heart rot, snags, and logs, all of which are critical habitat in interior forests. Thirty nine bird and 23 mammal species in the Blue Mountains use snags for nesting and shelter, while 179 vertebrate species and an unknown number of invertebrates make at least some use of logs, Pileated woodpeckers excavate large old grand fir trees that are infected with Indian Paint fungus, providing nesting and roosting cavities for themselves and a number of "secondary" cavity nesters. A recent study in the Blue Mountains found that a majority of pileated roosts were within stands of OG grand fir with >60% canopy closure. Other species that depend on cavities include boreal owls,, Vaux's swifts,, white-headed woodpeckers, three-toed woodpeckers, black-backed woodpeckers, redbreasted nuthatches, pygmy nuthatches, and brown creepers. Many of the birds and at least some of the invertebrates that require dead wood (snags or logs) are insectivores that contribute significantly to regulating populations of tree-eating insects.

Winter is a particularly critical time for many species in the interior mountains, because heavy snow restricts movement and foraging. Because they remain relatively snow free, old-growth and closed canopy mature forests provide critical winter range and movement corridors for elk and deer in the Blue Mountains. American martens require large down logs to provide snow-free hunting space during winter.

Other habitat issues in eastside forests include riparian zones and road densities. Of 378 terrestrial vertebrate species in the Blue Mountains, 285 either directly depend on riparian zones are used them more than other habitats (Thomas at al. 1979). A combination of logging and grazing has degraded many of

these areas with clear impacts on fish habitat, but less clear (essentially unstudied) impacts an terrestrial species.

The major challenge facing management is to heal one set of problems without exacerbating others or creating new ones, The basic strategy is to plan carefully at both the stand and landscape scale, paying particular attention not only to improving tree health, but also to protecting critical habitats, soils, and residual trees.

Thinning has been widely discussed and I agree it can be a good tool for reducing fire hazard as well as insect and pathogen spread. However, it must be used judiciously. I recommend the following guidelines:

1. Plan at the landscape scale. Thinning programs should take into account the needs of species that require closed canopy forests. One way to accomplish this is determine where on the landscape these needs exist and thin those areas either very lightly or not at all. In fact, not all forests are likely to need thinning to improve tree health; higher elevations and moist north slopes naturally had lower fire frequencies and greater tree densities than lower elevations and dry south slopes, hence are less likely to be overstocked than the drier forest types. Fires currently burning near McCall, Idaho, are largely restricted to these higher elevation types, and are probably more similar to historic fires than those burning the dry forests. I was able to fly over the Blackwell fire near McCall on Friday, August, 26, at which time the burn pattern was very patchy; the fire had crowned out over only 30% to 40% of the area within the fire perimeter, and no killed patches appeared to be greater than roughly 100 acres in size. This kind of very patchy burn is typical of the moister forest types in the west; in other words, not all fires are ecosystem catastrophes, and the presses' penchant for painting disaster should be viewed with some skepticism, at least until the smoke clears.

The important point is that not all forest types, nor individual stands within forest types, are the same, nor will they require the same treatment to restore health. The day before this hearing, I walked some of the lower elevation dry forests on the bluffs overlooking the Snake River. Some areas within these stands were clearly overstocked to my eye; other areas were not. Thinning strategies need to recognize differences both between and within stands and treat them accordingly. Where heavier thinning is necessary, excessive impacts can probably be avoided by dispersing thinnings in time, so that no one area (e.g. a single watershed) is opened within a short time. Dispersing thinnings allows thinned forests within an area to close canopies before the area is reentered to thin other stands.

Entry into areas that are especially sensitive, such as

roadless areas, should either be avoided or delayed Until possible impacts and techniques for mitigation are better-understood. Given the large area of potential thinnings, delayed entry into sensitive areas is unlikely to delay the thinning program as a whole.

2. Avoid building new roads. Most fisheries biologists agree that sedimentation from roads has significant impacts on salmonids and at least some species of resident trout. This is supported by the fact that the healthiest populations of sensitive species (e.g. bull trout) are consistently found in streams draining roadless areas. Road densities greater than 1mi/mi2 are considered detrimental to elk and wolf populations, although wolves may tolerate higher densities when large unroaded areas are nearby (Jenson et al. 1986, Mech 1989, ESSSP 1994) . Road densities throughout much of the National Forest land in eastern Oregon and Washington exceed 2.5. mi/mi2 (ESSSP 1994).

Recent advances in helicopter logging and the current high market value of small wood combine to make logging without roads much more feasible than in the past.

3. Thin from below, taking small trees and leaving larger. Most ecologists agree that maintaining forest health in the long term necessitates restoring the drier forest types to what occurred there naturally: stands with large trees (especially ponderosa pine and larch) that are relatively resistant to fire, root rots, and defoliating insects. Many of the larger pine and larch were high-graded from interior forests decades ago; those that remain are the building blocks of the future forest and as such should be retained. In the moister forest types, large firs and spruces also represent unique habitats for numerous species. There is no shortage of smaller trees to log, and in terms of forest health one gains much more from cutting these than from cutting the larger trees. Moreover, there are markets for small trees, and there are new engineering options for ecologically sensitive harvest. Last year, for example, personnel of the Ochoco National Forest told me loggers were ready to bid on an understory thinning in a roadless area that required helicopter entry,

It is important to note that logging plans (not forest health related) on at least some National Forests (e.g. the Payette) involve what are essentially clearcuts in drier forest types (a few green trees are being left). If increasing landscape resistance to the spread of catastrophic fire is a regional objective, clearcuts are in my judgment one of the worst things that can be done. The young plantations will probably be relatively fire resistant for some period (because they have low fuels) , however, unless tended by frequent thinning and underburning (which the young trees may or may not survive), they will eventually reach a stage where they are highly susceptible to crown fires. Vulnerability of young stands to fire has been reported by foresters since the early 1900's, and confirmed by

more recent fires in Oregon.

4. Avoid compacting soils and damaging residual trees. Soil compaction is a particularly insidious problem that is difficult or impossible to cure, and that definitely will reduce forest health. Compaction can be minimized or avoided altogether by using the proper equipment and techniques.

5. Reintroduce fire as a management tool. This is an important part of restoring drier forest types to a condition that better resists crown fires. However, it will not be easy given current fuel loading. Controlled underburns will be more feasible once underthinnings have reduced ladder fuels, but some manual labor may be required to lop and scatter logging slash and rake fuels away from the bases of residual trees.

6. Remember that some tree death and disease is ecologically beneficial. Snags and logs, large firs infected with heart rots, and trees with mistletoe or dead tops provide habitat for numerous species, including some that help regulate pest populations. Retaining appropriate amounts of these components and providing for future supplies is an important part of managing for forest health.

7. Make sure the proper resource specialists are fully involved in planning thinning operations.

I will briefly mention four areas where institutional support would significantly aid managers in restoring and protecting forest health.

1. Support research and development of ecologically-sensitive harvesting techniques. These include helicopters and low-impact ground equipment, both of which are being successfully used in various areas of the Pacific Northwest.

2. Support conversion to small-log milling and value-added industries.

3. Direct funds from fire-fighting to fire prevention. The economics of logging aimed strictly at improving forest health is unclear and will probably vary widely depending on circumstances. It seems likely, however, that at least some of these operations will not pay for themselves. In my opinion, one very good option in such cases is to fund deficit sales with money from the rather large accounts set aside for fire fighting. Considering the cost of fighting a major wildfire, such an action is likely to be cost effective for the nation in the long run.

4. Use the National Biological Survey to inventory the status of sensitive species and monitor effects of thinning. Being last on the list does not reflect the priority of this in my mind. Any

sensible management requires an inventory of stocks, which in the case of ecosystem management includes the species composing the system. In talking with wildlife biologists and surveying the literature, I have concluded that very little is known about the status of many forest species in the inland west, and even less is known about these species tolerate different levels of forest management. The USFS is required by law to protect native biodiversity; the managers I know sincerely want to do that and badly need the tools. Providing the necessary information will be expensive, but I see no choice if we are to manage resources wisely and avoid future crises. It seems exactly the kind of thing that NBS was formed to do.