Editor’s note: Evergreen Foundation board member, Mike Newton, is one of the most respected forest scientists in the nation. He holds a PhD in Botany and taught in the Oregon State University College of Forestry for 40 years before retiring in 2000. Still young and very fit at 81, he is still very much engaged in his passion: science-based management of private and public forestlands. In this wide-ranging interview, he discusses his life and career as one of the Douglas-fir region’s premier forest ecologists. In Part I of this three part interview, Dr. Newton answered questions about his teaching career at Oregon State University, and his more than 50 years of field research. We continue.
“As a scientist, I can’t– or shouldn’t – speak to political predilections, but I can tell you that we have choices that stop well short of the horrific ecological damage done by big stand replacing wildfires…If species richness is a measure of species diversity, there is often a lot more of it in an early seral stage forest than there is in a late seral stage forest.”
Mike Newton, PhD Botanist, Professor Emeritus, Oregon State University
Board of Directors, the Evergreen Foundation
Evergreen: Mike, we concluded the first segment of this interview with you telling us that the Northwest Forest Plan makes no accommodation for the wildlife habitats of early seral stage species, like deer and elk, unless the habitat is created by wildfire, and not timber harvesting. So the take home message here is that even species that need old growth habitat also need early seral habitat?
Newton: That’s certainly one of the messages, with the prime example being Douglas-fir that needs sunlight to regenerate, no matter how long it lives. Each of the advancing seral stages allows late-seral species to creep in gradually, allowing long periods of mixed species before the shade-intolerant species die out. But the other equally important message is that wildfires that renew early seral habitat also destroy late-seral habit, causing those species to move on or perish. Wildfires or clearcuts reset nature’s clock, but a management scheme that maintains all arrays of habitat at the same time within a large area also has to involve continuity of disturbance cycles so there is always recently established stands in adequate amounts, as well as late-seral in amounts related to certain features like nesting holes, presence of lichens or other biota that depend on old trees. If the disturbance is significant, meaning a good-sized chunk of real estate is opened to sunlight, nature starts over again at the early seral stage, and we again see large herbivores. And there is really no alternative to periodic deforestation events if all species are to be maintained.
Evergreen: So it’s all good?
Newton: That depends on your definition of the word “good.” Wildfires that occur during the dry summer months leave a lot of debris – fuel for re-burns that usually occur within a decade or two of the first fire. Such was the case after the 1933 Tillamook Fire, which was the first of four burns that razed 365,000 acres in Oregon’s coast range between 1933 and 1951. Each re-burn spread into green timber, retarding forest succession. All well and good in the natural world, but each fire destroyed seed sources and allowed new exotic weeds to gain footholds in fertile soils that should have been recolonized by Douglas-fir seedlings. But this long period of early seral habitat was wonderful for herbivores, including deer and elk, and hunters loved it!
Evergreen: So the big problem stems from the re-burns that start in areas where salvage logging has not occurred and dead wood is easily reignited?
Newton: Well, depending on your point of view as it relates to natural recoveries from wildfire, you can be for or against big fires and re-burns. But re-burns are a fact of life in areas where salvage logging has not occurred, and they often do more damage than the original fire, especially when they burn their way through the forest’s organic layer where seed germination occurs. In such circumstances, the process of regrowth can be delayed by hundreds of years while nature rebuilds organic soils. There is the view that snags provide for beetles, woodpeckers, etc, and that is valid. But there are always some snags in every maturing forest; they are not exclusively the result of wildfire.
Evergreen: So we’re back to the take home message, which is what?
Newton: The take home message is that big wildfires and their re-burns are very costly when measured in human terms. We lose the best structural timber – renewable Douglas-fir – for potentially hundreds of years, and we lose forest environments that are rich in the diverse habitats provided by early, mid and late seral forest cycles when disturbances repeat over large areas. And repeated hot fires are tough on the organic content of soils that take a long time to rebuild naturally.
Evergreen: We don’t seem to have much choice given the current political predilection for allowing nature to take its course in the West’s federal forests.
Newton: As a scientist, I can’t – or shouldn’t – speak to political predilections, but I can tell you that we have choices that stop well short of the horrific ecological damage done by big stand replacing wildfires. Most of my professional life has been devoted to a study of these options and their impacts on land and species. Our field research affirms and reaffirms the fact that most of the good things that fire does – and it does do some good things in terms of species richness– can be replicated or at least mimicked by the careful application of different timber harvesting and regeneration techniques, as long as organized harvesting encompasses long enough periods to allow all stages to exist somewhere, all the time.
Evergreen: Can you give us some examples?
Newton: I can. Clearcutting, which remains controversial because some disapprove of its momentary unsightliness, is easily the most elegant tool we have in the Douglas-fir region for maintaining species that are sunlight dependent. It is thus true that the openings that harvesting creates give life to herbs and herbivores that are the indicators of the health and sustainability of our early seral stage forests. Bear in mind that it is the early seral stage that starts a very long cycle in the development of forests. Eventually, we get old growth, and eventually it dies and we start over again if Douglas-fir is to follow, but without disturbance, the shade-tolerant “climax forest” occupies sites until disturbance does occur. Real climax forests are pretty rare in much of the west because of natural fires. But we can optimize this process by thinning these fast growing shade-intolerant forests periodically, and allow shade-tolerant species to invade. We get products from the timber the trees yield, and we enhance the maturation process so that older habitat niches begin to appear earlier in the life cycle. Eventual clearcutting starts the cycle over again. In such an arrangement, all habitat niches are present somewhere all the time – the added benefit being a handsome timber crop that pays the landowner for having held on to large blocks of aging timber for a long time.
Evergreen: You mentioned species richness. It’s a term we often hear from scientists who seem to be suggesting that species richness is at its zenith in old growth forests. Is this true?
Newton: Unfortunately, species richness – meaning the number of species present – has become its own value judgment, just like old growth. We have a “thing” about diversity. If species richness is a measure of species diversity, there is often a lot more of it in an early seral forest than there is in a late seral stage forest. Richness declines as the forest canopy closes and sunlight disappears from the forest floor. It is the replacement event – a wildfire or a timber harvest – that restarts the cycle that stimulates species richness. But purists don’t see it this way. They believe all species of fungi and wood consuming insects are essential to complete ecosystem function. I’m not sure how essential they are. Nature makes no such value judgments and doesn’t care how frequently wildfires burn.
Evergreen: This seems like a bit of a generalization.
Newton: It is, and one can find widespread exceptions where disturbances do not occur at intervals; for example, wet tropical forests where sometimes there are a hundred species of tree in the overstory. All shade tolerant and capable of exploiting such events as massive herbivory – huge ant colonies for example – but I am not aware of these in fire-dominated forests here in the Pacific Northwest. I grew up on very most forests where fires were virtually absent, and where the big white and red pines and red oaks were most frequently found where settlers had cleared the land, then moved west where there were fewer rocks to plow around!
Evergreen: Do Intermountain dry site mixed conifer forests function the same way that wetter Douglas-fir forest do in the Pacific Northwest?
Newton: There are so many variations in dry site forests that generalizations can’t be applied over large areas in the same way they can here in the wetter Douglas-fir region. Of the prevalent dry site species, only thin-barked lodgepole is highly dependent on fire to reproduce. Its seed cones are serotinous, meaning they can only be opened by the intense heat of fire. On the other hand, big ponderosa pines, larches and Douglas firs have very thick bark and can survive the heat of a pretty intense ground fire, so long as their needles aren’t burned off. Thus, ponderosa tends to reproduce in smaller sunlit openings. Not so western larch and Interior Douglas-fir which, again, tend to require good sized openings to reproduce well, even acknowledging that they also occur under open stands of many descriptions. Interestingly, lodgepole is considered old by the time it is 90, about like us humans, but ponderosa and larch often live for hundreds of years. The diverse mix of species present in the Intermountain region makes it possible for foresters to use a variety of thinning techniques to create the park-like stands of timber the public finds so visually pleasing. Foresters aren’t so lucky in the Douglas-fir region because we are ecologically tethered to eventual clearcutting—or mega-fire.
Evergreen: What you’re saying is that the one-size fits-all regulatory approach the federal government prefers isn’t workable in the real world.
Newton: The natural world makes no accommodation for cookie cutter approaches, or human need.
Evergreen: Let’s go back to clearcutting for a moment. You mentioned its momentary unsightliness. Is there anything foresters or landowners can do about this?
Newton: I want to be diplomatic here because you’ve asked an important question. Let’s begin with the fact that visual quality does not equal forest quality. Ninety percent of our nation’s population doesn’t understand the first thing about forests or forestry. What they want and need is some assurance that the forests they love will always be there, featuring large trees and cool, green, lush understories. What they don’t understand is that nature is indifferent to human perceptions, and small trees are as important as big ones ecologically. So the only way we can assure ourselves of the presence of all forest features is to manage land in ways that perpetuate forest growth. Clearcutting happens to be one of the tools in our tool box. It isn’t appropriate for all forests or forest types, but it is essential if our goal is to perpetuate Douglas-fir and other species that require full sunlight for propagation. The alternative is large scale natural disturbance – big wildfires, insect and disease epidemics, volcanic eruptions or hurricanes. In October 1962, four years after I started teaching at Oregon State, the Columbus Day storm, which packed 160 mile-an-hour winds, toppled 15 billion board feet of timber in western Oregon, western Washington and northern California. One might wonder about the perspective of this being preferable to some clearcuts. Think of the huge fuel load that storm created!
Evergreen: Many environmental groups claim clearcutting creates biological deserts.
Newton: Yes, they do make such claims, and that is a reflection of their not knowing what to look for in forests, especially early seral conditions. Or really understanding the concept of clearing to enhance environments for light-demanding species. The species richness found in early stages of planted or natural Douglas-fir forests usually exceeds that found in an old growth forests. Moreover, the act of logging performs a vital function to the extent that we get sufficient soil disturbance to facilitate the germination of herbs that are essential food sources for many species, including deer and elk, and these are the only places these species can exist in transient populations. Moreover, there are many bird species that depend on these openings altogether. They add to the diversity also provided by those dependent on a closed canopy.
Evergreen: But aren’t these Douglas-fir plantations also monocultures?
Newton: Depends on when we look at them. Early seral habitat is anything but monoculture. The emerging forest consisting of nearly pure Douglas-fir resembles natural stands that are also mostly comparable in overstory diversity or lack thereof, but are the natural state. Ecosystems dominated by a single species are not monocultures, and they are common in nature where many species abound. Our region’s great Douglas-fir forests are a good example. One also sees this in near-pure stands of lodgepole and ponderosa pine forests of the drier eastside forests. The confusion comes from the assumption that Douglas-fir seedlings are genetic mutants grown in test tubes in laboratories. This may occur in labs, but not in the field at all. Foresters very purposefully seek genetic diversity in their seed sources. Moreover, Douglas-fir is naturally very diverse in its genetics. It is this diversity that fosters a resiliency to insects and diseases that might otherwise wipe out an entire plantation. This region’s private forest landowners have spent millions of dollars mastering the art and science of protecting and promoting natural genetic diversity in their forest plantations while culling out certain undesirable traits.
Evergreen: Let’s switch gears for a moment. There is an emerging school of thought which says that riparian zones along streams in western Oregon have cooled water temperatures to a point where fish populations and fish growth are suffering. What can you tell us about this?
Newton: This has been a very long road for all involved. Gradually, science is replacing a few misperceptions about the interrelationships between forests, streams and logging. Let’s begin with the logging component. Back in the 1940s, loggers routinely ran their bulldozers up and down stream beds because it was easier and less expensive than building roads. They also used poorly drained skidding trails and scarified slopes with dozers to facilitate natural seedling regeneration. It worked pretty well, too, but it caused some problems with erosion and siltation in streams, and worse, a widespread public perception of irreparable damage. The visual result was what seemed to be a big mess with lots of trees and stumps occasionally left in stream channels that appeared to be impeding fish passage.
Evergreen: But didn’t the Oregon Forest Practices Act speak to this problem?
Newton: When the Act was rewritten in 1971, no-cut riparian zones were established along fish bearing streams. A major goal was to reduce stream temperatures by shading them from the sun’s rays, but also reduction of debris. George Brown, who later became Dean of our School of Forestry, was a significant player. Dr. Brown, who is a fine hydrologist, had warned that rising stream temperatures with direct sun on water could warm streams to a point that fish could not tolerate. Hence, 50 to 100-foot-wide buffers were established in Forest Practice rules for both sides of fish bearing streams.
Evergreen: Problem solved?
Newton: Yes and no. I’ll explain. After the riparian rules were in place, fish biologists began to lobby for removing logs and other debris that had accumulated in stream channels over the years. The prevailing view was apparently that debris was impeding the passage of spawning fish. So loggers were instructed to clean out the channels, “chunking the streams”, which they did very effectively. But no sooner was the work done than other fish folks began to think it had all been a big mistake.
Evergreen: Why would anyone think removing debris was a mistake?
Newton: Because the hydrological action created by the presence of logs and log jams was actually creating fish habitat, allowing water to do the work of scouring holes beneath and around logs and root wads, creating small sanctuaries where fish could hide during freshets, and building up long gravel beds where fish could lay their eggs. So we reversed course again, hiring loggers to put logs and rocks back into stream channels for their habitat forming value.
Evergreen: So has the combination of riparian zones and restored in-stream habitat done the trick?
Newton: It has if you believe in the “more is better” theory. But scientific reports dating back to the early 1950s suggested that fish were more abundant in segments of streams that had been somewhat exposed to the direct sunlight that clearcuts brought. These reports became more numerous in the 1980s. Now we have fisheries biologists who acknowledge that some sun is needed for maintaining aquatic productivity even if there has been limited warming. I’m not a fisheries biologist, but from my botany experience I can tell you that periphyton feeds a lot of fish. It’s the little green slime that photosynthesis produces in abundance when the sun is shining on the water. Aquatic insects eat periphyton and fish, in turn, eat aquatic insects. Remove the sun and periphyton goes away. The equation here is pretty simple. But will require careful thought to work out rules that balance food with temperature. As it happens, fish tolerate elevated temperature best when well fed.
Evergreen: So what’s the solution?
Newton: We have a regulatory paradox here. The goal was to reduce stream temperatures to protect fish, but the means of providing cooler water leads to poor nutrition. Our research shows that a thin screen of shade trees along the sunny side of a stream, with little or no cover on the north side, offers a useful compromise of limited warming with plenty of stream productivity. As school kids who liked to fish, we all learned that fishing in the sunny stream reaches was more successful as well as pleasant compared to fishing in the shade. I suspect the variation does fish no harm as long as peak temperatures are brief and within reason; there is no doubt that photosynthesis promotes growth in periphyton, hence fish, where moderate sunlight reaches the stream. Of course, in warm valleys, air temperature may remain warm, leading to waters more favorable for warm-water critters like suckers, bass and many other species of fish. There are few biological deserts. With temperature management, one simply determines which fish will show up. In short, good regulations involve common sense, somewhat lacking here.
Evergreen: So how do we account for this in the regulations?
Newton: This is a challenge. The EPA, which administers the Clean Water Act, and is well insulated from the forces of realism, has ordered states to write rules for riparian management that hold temperatures at low levels. Proposed rules force timberland owners in Oregon – and I suppose other timber producing states as well – to limit stream warming in harvest units to one-half degree Fahrenheit. This allows no chance for reducing the width of riparian buffers even to enhance stream productivity, and thus far, there is no apparent acknowledgement that our fish bearing streams are now so shaded that we are undermining food production and, by inference, the size and number of fish. And there is little if any room for compromise to allow favoring the fish. The one-size-fits-all formula applied to a wide range of stream features is simply a very destructive way of regulating.
Evergreen: Once again, the road to hell is paved with the best of intentions?
Newton: You could certainly argue the case, but I think it more important for the public to understand that nature’s power to destroy is far greater than that of man and that native biota have evolved with disturbance. Witness the 1980 eruption of Mount St. Helens in southwest Washington. In a split second, some 1,500 Roosevelt, maybe 5,000 deer and about 200 bears were killed – probably incinerated by the heat of the blast. We have no idea how many salmon, steelhead and songbirds were extinguished in that same moment, but estimates run into the millions. And this didn’t count the 150,000 acres of fine coniferous forests that were flattened or uprooted by the force of the blast. Early fears to the contrary, the deer, elk, bears, songbirds and fish all returned much sooner than anyone expected.
Evergreen: The point being that nature is far more resilient than many people fear?
Newton; Nature is amazingly resilient. But when we humans roll up our sleeves the recovery time following a big fire, or in this case a volcanic eruption, can be dramatically modified to enhance recovery. Take a drive up the Toutle River to see the marvelous work the Weyerhaeuser Company did on the 68,000 acres of timberland that it lost in the blast. Some 850 million board feet of timber were promptly salvaged and more than 18 million seedlings were planted. In 2005, the first commercial thinning operations were completed. It’s a truly remarkable story that speaks powerfully to the economic and environmental benefits that flow from man’s partnership with nature, because wildlife and fisheries exploited the “empty” forests and streams during this incredible hiatus in the natural landscape.