PAUL HESSBURG: WASHINGTON'S FORESTS - EAST OF THE CASCADES...FIGHTING FIRE WITH FIRE
If we choose wisely, relying on the mechanical thinning, prescribed fire and managed fire, we can still protect most of our remaining forest assets, including the soil and water. But over much of the Intermountain West, the forests in our future are not going to look much like the forests we've been enjoying for the last 60 or 70 years.
26 MINUTE READ
“Over the last 100 years, we have seen a literal epidemic of young trees filling in our forests. When trees are too close together and occur in highly layered conditions, fires can easily spread from tree to tree, and patch to patch. And that’s not all they spread—bark beetle and defoliator outbreaks also favor these dense and layered conditions…
We currently suppress 98 percent of all wildfire ignitions in the US. Repurposing many of these fires, especially those that burn under moderate fire weather conditions, would go a long way towards reducing surface fuel loads and thinning out dense forests. We can also apply thinning and prescribed burn prescriptions where there is a need to be more certain about the spatial arrangement of the outcomes. These and other methods can all be used to break up this contagious and vulnerable forest…
Locals complain about smoke from controlled burns, which they neither like nor want. But fire is inevitable and so is some amount of smoke that comes with it. I think society is going to have to decide how it wants its forests, and how it wants its fire and smoke going forward — whether in mega-fire-size doses, or in smaller fires or moderate severity. We have it in us to decide what kind of future we want to live in. This current wildfire conundrum is a pressing social problem with ecological explanations. We can learn how to better co-exist with wildfires.”
Paul Hessburg, PhD, Research Landscape Ecologist Forest Service Research & Development Pacific Northwest Research Station, Wenatchee, Washington
Paul Hessburg is a Research Landscape Ecologist. He earned his PhD in Botany and Plant Pathology in 1984 at Oregon State University. He has worked in research for 38 years, 27 of them at the Forest Service, Pacific Northwest Research Station in Wenatchee, Washington. He is also an Affiliate Professor at the University of Washington and the University of Idaho where he has research projects with faculty, graduate students, and post-doctoral fellows.
Dr. Hessburg’s research interests include the landscape and disturbance ecology of western forests, climate change effects on forests, wildfire resilience mechanisms of historical forests, and the ecology and sociology of landscape restoration. He has authored and co-authored more than 185 research articles, book chapters, and books, including a recently released Springer title: Making Transparent Environmental Management Decisions: Applications of the Ecosystem Management Decision Support System, available at http://www.springer.com/us/book/9783642319990.
In this interview, Dr. Hessburg explains his understanding of the underlying causes of the current forest health/wildfire challenge that is gripping national forests east of the Washington Cascades, and elsewhere in the West. He urges citizens to get involved in defining the future of forests on public lands, and in choosing how they want their future fires. He recommends the need for a broad toolkit to address these problems, including mechanical thinning and prescribed burning, but goes one step further – introducing “managed fire” as a tool policymakers and foresters can much more widely embrace in the race to protect what remains of the Intermountain region’s fire-prone forests.
This interview includes links to accompanying research material that is both timely and useful: a recent journal article Dr. Hessburg co-authored entitled: Restoring fire-prone Inland Pacific Landscapes: Seven Core Principles; and a multi-agency April 18, 2014 memorandum we found online entitled: The Interior Columbia Basin Strategy [Developed 2003, Revised April 2014]. The memorandum reveals that many of the recommendations included in an unsigned Final Environmental Impact Statement and Proposed Decision for the Interior Columbia Basin Ecosystem Management Project [ICBEMP] were quietly implemented in the ensuing 14 years, even though the project itself was shelved for lack of a signed decision, which occurred concurrent with the transition between the Clinton and Bush administrations.
The latter memorandum is important because it reveals how much of the research work that grew out of the ICBEMP provided a foundation for the Seven Core Principles. We encourage you to read these articles after you finish reading our interview with Dr. Hessburg, because only then will you fully understand why he says what he says in our interview.
We warn you: this is a long and winding road, but very important to our further understanding of what ails Inter-mountain forests, why they are bug-infested and burning, and what society can realistically do to help speed a hoped-for recovery.
Evergreen: Dr. Hessburg, on a scale of one to 10, one being awful and 10 being great, how would you rate the condition of national forests in eastern Washington State?
Hessburg: Conditions in eastern Washington vary from place to place, so it’s difficult to provide a single score. Overall though, I would give them a failing grade, perhaps a three or four on a scale of one to 10. Lots of dead and dying trees, insect outbreaks and disease epidemics and, of course, high wildfire vulnerability. But the great thing is, you can see “good bones” remaining in many forests when you look at them—suitable building blocks for a restored future forest still remain in many areas, and I am hopeful we can make progress.
Evergreen: “Good bones” meaning what?
Hessburg: Some areas of the dry and moist mixed conifer forest have been thinned and prescribed burned, and these look quite good. There has been a fair amount of social license for work, especially in the dry forests, and I’d give the treated portions an eight or nine on your scoring scale. But the need for follow up maintenance burning remains a pressing need, the footprint of treated areas is small, and society, by and large, has unrealistic ideas about preventing future smoke. In the absence of ongoing maintenance burning, I harbor great concern for the future of these forests.
Evergreen: What you’re telling us is that we can’t treat at risk forests just once and walk away.
Hessburg: That’s correct. There is no quick fix, but we do have the needed tools. Dry and moist mixed conifer forests in eastern Washington are really the nut of the current problem. These forests are quite productive and certainly capable of growing medium and large-sized Douglas-fir, ponderosa pine, western larch, and western white pine. But logging methods in favor during most of the 20th century led to the removal of the largest and most fire tolerant trees over fairly large areas. These were the large, old, legacy trees that carried the genes necessary to perpetuate fire- and climate-resilient forests
Evergreen: Logging as it was done following the Second World War has certainly fallen out of favor, hasn’t it?
Hessburg: The kind of selection cutting and clear-cut logging we saw during that period certainly has fallen from grace. And now we face fairly dire consequences from removing so many large fire-tolerant trees, over such large areas. Most folks didn’t understand then what would come of those actions. Congress was appropriating large sums each year for the purpose of harvesting forest to support a rapidly growing nation. Recall that the housing boom was in full swing.
Evergreen: Can you describe those consequences for us?
Hessburg: Basically, we unwittingly created a prime opportunity for smaller, shade tolerant and fire intolerant tree species – mainly grand fir, white fir, and Douglas-fir – to quickly colonize sites that had historically been dominated by large, open grown, shade intolerant and fire tolerant tree species like ponderosa pine, Douglas-fir, and western larch. Fire tolerance was a vital attribute because fires historically burned every five to 20 years at low or moderate intensity. Large size and a thick bark allowed many of these trees to survive frequent fire intervals.
Evergreen: If we’re following you correctly, many of our forests can’t tolerate much fire today, and they don’t look much like the forests of old - before large scale logging began.
Hessburg: That’s right. Today’s mixed conifer forests are dense and layered. The table is set for large and severe wildfires and insect outbreaks, especially during prolonged, droughty periods. There is a strong sense of urgency today among many forestry practitioners. The need for some sort of intentional landscape treatment is large.
Evergreen: We know the harvest story well enough to know that it comes with its own baggage. For example, many conservationists that today support mechanical thinning also support limits on the diameter of trees that can be harvested. This seems self-defeating to us if your goal is to restore forest compositional and structural diversity. Would you agree?
Hessburg: I do agree. But the story here is pretty nuanced. Recall that the focus of 20th century harvesting in historical forests was on large and old trees. They cut the biggest and best, and left the rest in those days. So it stands to reason that folks would be gun shy about harvesting larger trees. The problem is that overly simplified rules thwart some pretty smart restoration work. Repeated 20th century harvests often removed most of the fire tolerant pines. In some of these forests, there is inadequate stocking of pine for a future forest that is fire and drought tolerant, but there are ample Douglas-fir and grand fir of fairly large diameter. Not having strict diameter limits—like the 21-inch rule—allows thoughtful managers the opportunity to regenerate these habitats to pine dominance. This is especially important where shade tolerant forests dominate on dry south-facing slopes and ridge-tops.
Evergreen: Which further minimizes the chances that a subsequent fire would jump into the crowns of trees in areas that have already been thinned or regenerated?
Hessburg: To some extent, yes. Regenerating forests to pine is needed in some places, but recall that until trees get larger, they too can be vulnerable to severe fires for a time. Obviously as the trees get larger, bark gets thicker, and crown bases elevate by self-pruning, this is more of a sure thing under a majority of fire weather scenarios.
Evergreen: Talk to us a bit about managed wildfire. Not much has been written about it until recently. How is it different from prescribed fire?
Hessburg: The sheer size and severity of the problem we face east of the Cascades in Washington tells us that there probably isn’t enough time or money to thin and prescribed burn every acre. We will not likely thin and burn our way out of this problem. That’s an important take away. Thinning and prescribed burning is strategically important and especially effective where there is a need for high certainty about the location and quality control over the finished results. For example, near the wild-land urban interface, and adjacent to important habitats or natural resources.
Managed wildfire is another important tool in the toolbox. It gives wildland firefighters the opportunity to “herd” naturally ignited wildfires through the landscape, when weather and fuel conditions permit. Fuel quantities have to be right, fuel moistures have to be in the sweet spot, and fire weather conditions have to be such that fire managers have high confidence that they can achieve their burn prescription—that is, meet their goals for fire behavior and fire effects on the ground.
Remember we said that 98 percent of wildfire ignitions are currently doused. Well, under moderate fire weather conditions, many of these natural ignitions can be put back to work thinning under-story vegetation, consuming fuel ladders, and reducing surface fuels. Ideally this is done some distance from the wild-land/urban interface because spatial controls are less certain than with prescribed burning, especially where prior thinning has reduced canopy fuels.
Evergreen: Do you think people accustomed to an all-out effort to extinguish wildfires will support the idea of letting some fires burn?
Hessburg: That’s a great question. Perhaps they will, perhaps they won’t. The people I meet and talk with are pretty darn smart. Once they understand the options and the trade-offs, I am betting that they will feel adequately informed to support the choices that make the most sense in their nearby communities. Prescribed burns and managed wildfires can help managers reduce the risk of even larger and more destructive wildfires. It’s a bit of a “duh”. Where wildfires are away from people and infrastructure, I am betting and hoping that folks will be open to putting some of these back to work.
Evergreen: We’ll come back to managed wildfire in a few moments, but can you first address the claim by some that our forest health problems are confined to lower elevations, where most of the harvest activity has been concentrated since the end of World War II.
Hessburg: I’d be glad to. Many feel that high elevation cold forests are doing just fine, but I don’t agree. In my lab, over the last three decades, we have reconstructed and compared early and late 20th century conditions for about 400 landscapes throughout the Inland Northwest. And we have examined a great many forested gradients that extend from the lowland valleys to subalpine and alpine environments. We have found that important changes have occurred in dry, moist, and cold forests, but the changes are quite different among the forest types. And even among individual forest types, they vary from place to place. No one size fits all.
For example, historically, some cold forests – think lodgepole pine, subalpine fir, Engelmann spruce, and mixes of these – saw fire every 150 to 300 years, and the acres burned could be quite large, perhaps 30 to 40 percent of the total area at any one time. That’s a lot of fire! The resulting snapshot of the landscape, at any point in time, would appear as a patchwork of previously burned and recovering areas of varying size and time since fire. This patchwork provided a built-in resilience mechanism that controlled fire flow across the landscape under all but the most extreme fire weather conditions. It essentially limited where many future fires could burn. Fire suppression has eliminated these patchworks in many cold forests.
Evergreen: So this is the counter-intuitive aspect of wildfire. We think we are helping nature along by putting out forest fires before they get big, when all we’re really doing is adding fuel and contagion to subsequent wildfires, to make them burn hotter and over progressively larger areas. And as the fires grow worse, we work harder still to put them out.
Hessburg: That is the case across the Inter-mountain West, and certainly in eastern Washington. The already burned areas, which were numerous and occasionally large – influenced the frequency, severity, and size of subsequent fires in unburned areas. When fires reached already burned areas, their advance was slowed or stopped by the absence of fuel. So our cold forests have their own issues.
Evergreen: We’ve also seen big wildfires drop to the ground when they reach areas where thinning or prescribed burning have done the same thing as the patchworks you describe. Isn’t that true?
Hessburg: It certainly can be true, but the key with thinning is that pile burning and broadcast burning are a necessary follow up. If acres are thinned and not burned afterward, it can actually make things much worse. Thinning reduces canopy fuels but increases surface fuels in the slash that remains afterwards, and these increases can be quite large. These added surface fuels need to be burned shortly after treatment to keep from making the fuel situation worse.
Evergreen: Gross growth, mortality, net growth and removals data shared with us by the Forest Service’s Forest Inventory and Analysis (FIA) group in Ogden, Utah tells us that national forests in Idaho and Montana could slip into the negative growth column in a few years - meaning mortality could exceed gross growth. Is this the case east of the Cascades in Washington State?
Hessburg: To the best of my knowledge, ongoing inventory measurements still show that growth exceeds mortality losses in eastern Washington, but the situation is precarious, for reasons I have already described. Forests continue to manifest a net fire deficit, which is a holdover from 20th century fire exclusion and decades of highly effective fire suppression.
Evergreen: From the early 1900s forward, the hue and cry among foresters in this region was to “run smoke out of the woods.” They got very good at it, didn’t they?
Hessburg: They certainly did. And the historical role fires played in the Intermountain West was soon forgotten by as many as five or six generations of citizens. We simply were able to forget how vital and necessary fires were to our forests.
Evergreen: Is there a hierarchy of blame here: old logging methods versus the publicly popular policy of excluding fire from forests, versus insects and diseases, versus too many trees, versus this whole question of climate change, which many still look upon with skepticism?
Hessburg: Nothing can be gained by blaming. Social values shift. Science contributes new information. Technology provides new methods. What is most important is that we look forward and move forward. We have lots to do.
Evergreen: And you seem to think that the clock runs out in 20 or so years, at least in terms of our ability to protect some of what is still green and growing in eastern Washington national forests?
Hessburg: Twenty years is about it in my estimation. Climate scientists tell us that we can expect a doubling or tripling of area burned by mid-century. That’s game changing.
Evergreen: 2015 was the worst wildfire season in Washington history. And it followed on the heels of 2014, the previous worst season. You obviously believe we face worse fire seasons going forward.
Hessburg: I do. Climatologists forecast that the likelihood of hotter, drier, and longer fire seasons is increasing. In the worst years, the fire season has already increased by four to eight weeks over 50 years ago. Using these weather predictions, fire modelers show that by the middle of this century, the area annually burned could easily double or triple.
Evergreen: We learned recently that the mini-cooling period we experienced during the mid-20th century may have made our problems worse too – as did conventional selective logging methods — by giving shade tolerant plant species the opportunity to dominate over shade intolerant species. What can you tell us about this, and how it may influence what comes next?
Hessburg: In the early 1930s, the Pacific Northwest was still locked in a persistent mild to moderate drought associated with the Dust Bowl period. But by the early 1940s, the climate moderated for a period of about three decades. You can see this clearly in Pacific Decadal Oscillation [PDO] sea surface temperature records. After 1976, the PDO signal flipped back to a warm phase again. Recall that the PDO is thought to be a teleconnection of the El Nino Southern Oscillation in the Northern Pacific Basin.
Evergreen: And so we are back to this whole business of who is at fault for the mess we are in: Mankind or Mother Nature.
Hessburg: It is fairly difficult to statistically attribute causation to any single potential driving variable. However, it is likely that the combination of highly effective fire suppression beginning in the mid-1930s, widespread selective cutting from the mid-1940s until the early 1980s, a period of relative cooling during the mid-20th century, and many good conifer seed production years, all conspired to create dense and layered forests. As it turns out, the shade tolerant trees could not dominate over the intolerant trees unless they lost their superior canopy position via timber harvesting and the absence of thinning fires.
Evergreen: And yet these overstocked, shade intolerant forests are the ones that most Americans revere. How on earth are we going to deliver the news that the forests they love so much look nothing like the ones that historically occupied the Intermountain West, to say nothing of the forests that will apparently dominate our future?
Hessburg: As I go from place to place speaking about these things, I have found that people are pretty smart and they dial in these ideas quicker than you’d think. The first thing they say is not a note of skepticism, but what can we do to help? Personally, I think our two professions have done a poor job of translating complex forest science into plain English that is useful for citizens to know how to weigh in and vote, and for policymakers and stakeholders to be better informed. We need to do better.
Evergreen: We’ve been deciphering science for 31 years and I don’t think we’ve yet made much a dent in the public’s perceptions about forests and forestry, to say nothing of our changing climate. In your view, what role is climate change playing in altering forest species composition; what might national forests east of the Cascades look like in 50 years; and how might we better influence our destiny?
Hessburg: We expect the effect of climate change to be large in some places, and less in others, and it is somewhat difficult to predict which places are which. But a few things are becoming clearer. For example, we expect ecotonal locations - areas where one lifeform or physiognomic type intergrades into another - to be more highly impacted. This often occurs at both the tops and bottoms of mountain slopes. For example where grasslands and sparse woodlands intergrade with dry forests. We expect these lower ecotones to move up the slope. As it turns out, many forest conifers have a wide range of growing conditions they can occupy, once established. But establishment can be a problem. The wild card is the extent and severity of disturbances.
Evergreen: Which is where climate change enters the picture.
Hessburg: Correct. Climate change affects many forests by making local site climate a bit harsher, and by altering disturbance frequency, intensity, and spatial extent. Most of the acres burned these days occur on hot, dry, and windy days. These influences can impact conifers at certain times in their life cycle. For example, one species may be able to grow just fine on a given site once established, but establishment itself may be difficult, because good seed years become less common, or hot dry summers make water unavailable to seedlings with their shallow roots, or soil surface or air temperatures become too hot and extreme. Tree cover moderates local site climate. As trees are removed by fires, site climate often becomes harsher in the summer. Large patches of high severity fire without islands of surviving trees can make it difficult for conifers to re-establish because there is no local seed source and little shade.
Evergreen: You can see evidence of what you describe in still barren areas on the Idaho-Montana state line east of Mullan, near where the Great 1910 Fire crossed from Idaho into Montana 106 years ago. The soil organic layer is still insufficient to support conifer seedling germination.
Hessburg: In areas like the one you are describing, former forests can become shrubfields or grasslands and get stuck in this condition for a long time due to depleted soil nutrients via wildfire volatilization, or a subsequent grass-fire cycle, which can be self-perpetuating. Severe disturbances are often a main factor that changes the species distribution map with climate change. Without significant intentional changes to current surface and canopy fuels, we can expect these scenarios to play out in many places.
Evergreen: What can humankind do? There is great enthusiasm for forest collaboration and forest restoration, which look to us like largely political processes. From a scientific perspective, what can we do, how should we proceed and what are the limits to our ability to restore forests?
Hessburg: The changes to forests of eastern Washington are dramatic and have fairly clear ecological explanations. But restoring forest conditions in light of those changes is a highly social process, requiring value judgements, choices, compromises, and trust developed among new partners. Forest collaboratives are an experiment in co-management and co-planning. Trust building and building a common vision are the prizes, and we struggle with that in some places more than others.
Evergreen: Collaborative group members we’ve interviewed over the last two years tell us that developing trust among stakeholders is the most difficult and most important step in building an effective collaborative group.
Hessburg: I’ve heard the same story. And sadly, some of the Forest Service’s collaborative partners have trust issues with the agency because of past practices and even some current practices. Even within the Forest Service, there is some division. Over the last 35 years, we have developed an entire generation of agency biologists, in both the aquatic and terrestrial realms, who have been engaged in a sort of combat with foresters.
Evergreen: How so?
Hessburg: From the biologists’ vantage point they worked tirelessly and with great care to mitigate the effects of timber harvest and road construction on native fish and wildlife species. It is hard for some biologists to begin to trust and forget the past. When they see some of the same sorts of things still going on in their forests, it serves as an ongoing reminder to remain vigilant. Inside and outside the agency there is need to rebuild trust. But collaboration on the good work of restoration is clearly the route.
Evergreen: We certainly agree that collaboration opens a new and more hopeful chapter in the history of federal forest management, but as we both know, the pace and scale of the work the collaboratives do is still too small to be ecologically significant.
Hessburg: Very true. They are having great difficulty increasing the speed and footprint of restoration because fire suppression activities currently devour up to 50 percent of the Forest Service’s annual budget, up from 10 percent some 25 years ago. And the forecast is for wildfire costs to soon exceed 60 percent, leaving even less money for proactive forest restoration work. Significant new investment is needed in forest restoration. On the Okanogan and Wenatchee national forests, where some of my research is concentrated, wildfire acres burned currently outpace proactive restorative treatments by a wide margin, about six to one.
Evergreen: It must be very discouraging for you, as it certainly is for stakeholder collaboratives that donate thousands of hours of their time to forest restoration planning and projects.
Hessburg: I am sometimes disheartened but I can’t stay there. I have to have optimism for the future. When I walk through these forests I can see a very clear visual of how we can make progress, and that motivates me to stay optimistic. What’s the alternative?
Evergreen: It seems to us that the underlying causes of our collective disappointment are, first, the environmental costs associated with expanded budgeting for fire suppression at the expense of other funding accounts, and, second, a regulatory climate that lacks needed practical, on-the-ground flexibility. Would you agree?
Hessburg: I think you’re right on both counts. Fire suppression funding has steadily risen, while funding for more proactive restorative programs languish. The current regulatory environment impedes management flexibility, and more flexibility is needed. For example, who doesn’t suspect that making late-successional habitats more widely available for owls will broadly increase flammability of east-side forests? But there it is. My sense is that many of the regulations restricting the ability of managers to apply sound restorative treatments at large scales results from the fact that there is still little trust in the Forest Service. It continues to live with the residue of past decisions, and is unable to turn the page on its past. It’s noteworthy that annual timber targets and acres burned are still core agency metrics. You’d think acres restored or stream reaches improved would become the metrics.
Evergreen: There isn’t much trust for local wisdom in the Forest Service, is there?
Hessburg: No as much as there should be. I meet a lot of horsepower on the Districts and Forests where I work.
Evergreen: You have become increasingly candid about this over the years, haven’t you?
Hessburg: I have, because I see what is possible, and just within reach.
Evergreen: And so you and a few others in research have been encouraging an expanded role for restoration.
Hessburg: Yes, that’s right. In Forest Service Research, we have research, development, and application responsibilities. We are funded to create new knowledge, but also to help managers apply that knowledge to improve the quality of their work on the ground.
Evergreen: The social license you often reference begins with the public and regulatory authorities giving managers the flexibility to do work that needs doing on at sufficiently larger scales than is customary.
Hessburg: That’s correct. My sense is that collaboratives are making a difference. Improved consensus about the science and what to do in the forests is beginning to emerge. But agency staffing and resources has been cut so low over the last 25 years by systematic budget reductions for all but fire suppression, that the agency lacks adequate staff and resources to accomplish the needed work.
Evergreen: Do you think public attitudes about wildfire are shifting in the direction of allowing fire to do some of the cleanup work?
Hessburg: I see growing evidence, slow as it is, that the public is more open-minded about the positive role fire can play, and expanding confidence that we can learn to live or co-exist with wildfires in a new way.
Evergreen: What’s your take on the whole collaborative process?
Hessburg: I have great admiration for the diverse stakeholder groups that are working in eastern Washington. They are action oriented folks, problem solvers, unifiers, and educators. They, more than any other group I could name, study the science and want to see it applied on the ground. It takes a long time to develop shared knowledge, and the trust relationships they have developed, but as a result of their shared commitment, they now speak a common language and are prepared to do the needed work.
Evergreen: That’s how we see them, too. Let’s go back to our earlier managed fire discussion for a moment. Fire means smoke, and smoke isn’t popular with the public. How can we overcome the public’s unhappiness with smoke from forest fires?
Hessburg: In reality, the public doesn’t get to decide whether there will be smoke. We can’t put out all of the fires, and success is declining, acres burned are on the rise despite our best efforts. There will be smoke, and lots of it. The public’s only choice is how it wants its smoke. It can have the smaller doses that accompany prescribed burns or managed wildfires, or it can live for weeks many summers with the smoke released by large, destructive wildfires.
The agency needs to clearly and frequently demonstrate that it can safely and effectively use managed wildfire in ways that restore fundamental ecological processes and the patterns of forest conditions that support them. In fact, this year was a great example. The Wenatchee River Ranger District of the Wenatchee National Forest conducted a highly successful and visible managed wildfire within the Glacier Peaks Wilderness. Most of the managed wildfire burned in wilderness, with only a few hundred acres in the Chiwawa late successional reserve. Public awareness was high during the fire and people who were potentially affected by the fire were engaged and informed. My hat is off to them. We need so much more of this kind of work.
Evergreen: Assuming public acceptance of managed fire, tell us a bit about the smoke management challenge you face.
Hessburg: Smoke management is an enormous concern, one of the chief limitations to forward progress, and it is one of the lynchpins to increasing the pace and scale of forest restoration. Fire managers in eastern Washington burn far fewer acres than they could be burning annually. Tight air quality restrictions in the spring, late summer, and fall are the reason.
Evergreen: What’s the downstream impact of these restrictions?
Hessburg: Thinned acres left unburned are typically left in a worsened condition, because they will burn hotter and more completely due to the added slash when they burn in a wildfire. Current smoke restrictions are a bit irrational, really. You can’t keep the forest from burning. It will burn. We have all witnessed that over the last 30 years. The only decision space we really have is—how it will burn. So the management questions are: How do we want our fire, and how do we want our smoke? Wild or prescribed?
One stumbling block is that wildfire smoke gets a free pass each year, while smoke from prescribed burns is regulated as nuisance smoke. But smoke is smoke right? And it’s all harmful to human health. Shouldn’t they be on the same budget? If you want less smoke, prescribed burns and managed wildfires are your options. With prescribed burning, you can significantly reduce the harmful emissions over time because most of the large logs don’t burn.
Evergreen: It sounds pretty simple.
Hessburg: It isn’t simple, but a few clear points emerge and we have discussed them. The science is perhaps more straightforward than the sociology. The social side is complicated by the fact that we’ve been wildly successful at excluding and suppressing fire for about 80 years; some places longer, others shorter. Socially, it has been difficult for us to tolerate the idea of more fires, because we have all seen recent, large, scary and destructive wildfires. And we have been lulled into thinking that our wildly successful 98 percent suppression rate could get even better with more tankers and more engines and more crews. But it can’t. We can’t keep kicking the can down the road.
Evergreen: We confess we have periodically wished aloud that a way could be found to stuff the wildfire genie back in the bottle. But it turns out that the only way to do it is with more fire, again the whole business of thinking intuitively about fire.
Hessburg: Our research and that of many other colleagues tells us that many of the fires we douse could actually do some good if we let them work. Experienced firefighters will tell you the same. In years when burn conditions and fuel moistures are moderate, and where the wildland urban interface is some distance away, we have had the opportunity to allow some fires to burn and do the good work of thinning out dense understories and reducing surface fuels.
Evergreen: Our late friend, Forest Service Chief, Jack Ward Thomas, used to tell us that there was not enough gold in Fort Knox to pay for the cost of restoring all of the West’s national forests. He was referring to the need for sawmilling infrastructure, which could help underwrite some of the tree removal costs, but it seems we can say the same thing about fire as an agent that can help cover some of the restoration costs.
Hessburg: There is neither enough money nor enough time in the next several decades to complete the needed work if thinning and prescribed burning are our only tools. Managed wildfire can fill a big gap in our planning and execution.
Evergreen: Our motto at Evergreen is, “What do you want your forest to look like?” We pose this question because science gives us the opportunity to create or maintain many different forest conditions, depending on objectives. Short of turning the clock back to pre-European times, which is impossible given our social and cultural wants and needs, what target do you think we should be aiming at over the next century?
Hessburg: We should focus on climate- and fire-adapted forests going forward. A clear understanding of the historical ecology gives us important insights about the assembly rules of fire adapted forests. But we need to apply that knowledge in a forward looking manner, asking how these forests can best be adapted to the anticipated future climate. Future forests will share many qualities of historical forests, but they won’t be the forests of 1850 or 1900.
Evergreen: And what of the spoken desire in some quarters to restore national forests to their pre-European condition, what others have called the “historic range of variability”?
Hessburg: The approach is too simplistic. The point of studying historical forests is to understand how patterns of forest conditions drove key processes, and how in turn these processes created patterns and specific kinds of heterogeneity. We have learned much from studying and reconstructing historical forests. In some areas, a return to similar conditions will be restorative, especially where the prognosis for 21st century climate change is little change. But where climatic changes are expected to be large, re-establishing some facsimile of historical conditions will not be enough, and it might even be foolish.
In many areas, we will have to anticipate the effects of climate change and prepare for them. That will mean managing for larger burned areas and areas with drought tolerant trees at lower than historical densities; expecting more areas of reburning; expecting some areas to transition from dry forest to shrubland steppe or grassland; expecting species ranges in some areas to shift in elevation, aspect, and latitude; and expecting that we must provide migratory corridors for such shifting to go on naturally and indefinitely.
Evergreen: We would be remiss in not acknowledging the role Indian burning played in pre-European forests.
Hessburg: We certainly would, if for no other reason than the fact that Native Americans were excellent fire managers.
Evergreen: It will be interesting to see how the political classes and opinion leaders in Seattle react to all of the complex changes you predict.
Hessburg: Seattle folks do a lot of recreating in forests east of the Cascades, so their concerns are valid and understandable. But the notion that the lush, green, moist forests of western Washington can be recreated in eastern Washington – hope-filled thought though it is - is doomed to failure. Nature has other plans.
Evergreen: You don’t paint a very pretty picture, especially in terms of the visual changes we will witness from here forward. But we don’t seem to have many choices in the matter, do we?
Hessburg: We have nothing but choices! As I said earlier, we don’t get to vote on whether or not we will have wildfires. But we can affect how wildfires will come our way. We can apply managed and prescribed fires burning under moderate fire weather conditions to change these future fires. If we choose wisely, relying on the mechanical thinning, prescribed fire and managed fire, we can still protect most of our remaining forest assets, including the soil and water. But over much of the Inter-mountain West, the forests in our future are not going to look much like the forests we’ve been enjoying for the last 60 or 70 years.
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