This essay describes my scientific career briefly. Very many people have helped me—from family to teachers to mentors to practicing foresters and other scientists. I have always hoped to pass on opportunities to others as a show of gratitude. I am intentionally not naming others in this paper, because I am sure to leave out some names that I will later regret. The few names mentioned are for context. My PhD students are listed on my CV; and many of the people that I worked with are coauthors on papers. Others whom I immediately think of are my wife, children, parents, and the whole community where I grew up—Camden, South Carolina; my many teachers, from public school through Sewanee (The University of the South) and graduate school at Yale; Ernie Gould and Walter Lyford of the Harvard Forest; my colleagues at the University of Washington, and some of my mentors and supporters — H.R. (Rock) Oliver, Richard Lloyd, Ken Mitchell, E.C. Burkhardt, Dan Botkin, James White, Hamish Kimmins, John Calhoun, John Stanturf, Ted Leininger, Melih Boydak, Fred Pickering, Michael Bagley, Harriet Buckman, Dr. Cahit Arf, and Congressmen Norm Dicks and Charles Taylor, now both retired.
My father used to take me into the woods when I was in high school and describe the things he wished he knew about forests — things that would make him better at his work. He was a forestry graduate of the University of Georgia and owned his own forestry business in Camden, South Carolina. He managed forests for private landowners and did land surveying on the side.
During summer work in undergraduate school and early graduate school, I both assisted others and conducted my own research projects. But these were commonly narrowly focused, incremental research. I wanted to do things that would be a practical benefit to foresters—so people like my father could manage their forests better.
My first opportunity was when a client of my father sponsored me to determine the cause of longleaf pine growth variation in the Sand Hills of South Carolina. Suspecting that the cause was differences in sand texture, I spent a year taking and analyzing soil cores, cutting trees to develop height growth patterns, and examining the data in many ways. After another six months of agony because I could find no pattern in my data, I had a “crystallization moment” — the instant when the solution becomes clear. The dominant influence, I realized, was the pattern of impermeable layers beneath the sand. The impermeable surface had no relation to the sand surface, but rainwater flowed through the soil and laterally along the impermeable layer, being available to tree roots as it flowed depending on the depth of the overlying sand. These moments are the real excitement of science, and I would wish everyone would have such moments in their life! I have had about five and consider myself very lucky.
I chose to pursue my Ph.D. under Professor David Smith at Yale University, because he was interested in solving integrated, practical questions and because I wanted to think as insightfully as he did. I was still interested in longleaf pine, but a literature review revealed that the next big issue—the “grass stage” — was better solved by people with other specialties. Two concerns had been brewing for several years relative to mixed hardwood species stands dominated by oaks: How do we get oak regeneration after we have harvested the stand—by clearcutting, selection harvesting, or shelterwoods? And, is it inappropriate because the forest is treated in an unnatural way?
In the late 1940’s Professor Smith had heard discussions of stratified, mixed species forests in the tropics; that is, the forest grew in layers, with different species in each layer. Later, while in a fairly young forest in Connecticut, he realized that it, too, was a stratified, mixed species forest. “And,” he said, “I knew it was even-aged, because I remember when it got started.”
Between the issues of oak regeneration and whether these stands were even-aged or not, we realized that we really didn’t know how mixed species forests grew. The dominant theory was that the smaller trees were younger, but that didn’t explain how the oaks—which dominated in the upper canopy—got there. When we clearcut the forest, there were very few oaks in the new forest—less than 20% of the 2,000 regenerating stems per acre.
So, my task was to determine how stratified, mixed species stands presently dominated by oaks had gotten to their current condition, where the oaks came from, and whether the stands were in fact even-aged.
My experience reconstructing height growth of longleaf pines was helpful. And, the Harvard Forest had done reconstruction work and was very supportive. Between the Yale Myers Forest and the Harvard Forest, I selected a series of oak-dominated stands of different ages to study. I used archeology-like removal of debris from the forest floor, mapped and identified all living and dead stems that I found, and cut down trees and cut discs at intervals up the stems. I’d carry these discs to my car—and eventually to New Haven to determine their ages.
Being unmarried at the time, I spent many months alone in the Yale Myers Forest cabin, and commonly camped out on my study areas for a week or more at a time. Much of the research included careful observation, and I first learned how many ideas come over the first cup of coffee in the morning when you’re sitting in the middle of your study.
My second crystallization moment came when I discovered that there never were many oaks in the stand—even when it was regenerating. Being even-aged, as I confirmed, these few oaks consistently outgrew the other species.
As my work progressed, the Harvard Forest offered me a Post-Doctoral position, where I was invited to explore similar reconstruction data that had been meticulously collected 20 years before, but never published. I used this data, along with my own thesis data, to develop many concepts of forest development.
A supportive colleague at the Harvard Forest took my ideas to Professor Robert MacArthur, a prominent ecologist at Cornell University, whose response was: “That idea of even-aged stands may be true of New England, which has been very disturbed by people, but it’s not true of the rest of the world.”
Soon afterward, I accepted a faculty position at the University of Washington, in Seattle. My Master’s students there used the reconstruction techniques that I had worked out to examine the development of various mixed species forests in the western United States.
Slowly, we were documenting that mixed species forests in many other places were also stratified and even-aged, having started from disturbances. Within a few years, we had studied many kinds of mixed forests in the Pacific Northwest — Douglas-fir/western hemlock, Red alder/mixed conifer, and larch/lodgepole pine/fir — and Sitka spruce/hemlock in Southeast Alaska. A hardwood expert in the southeastern United States — who was an expert on alluvial floodplain forests — read some of my early work and encouraged a Ph.D. student from the South who determined that the same principles applied to cherrybark oak and other southeastern hardwood forests. Later, we collaborated on several studies of forest development. Within a few years, we were able to show that this pattern occurred in many places in North America, not just in New England as asserted by Professor McArthur.
Each study provided its unique logistical adventures. At different times we traveled by hiking, float planes, motorboats, helicopters, bicycles, and pickup trucks. And, we stayed in hotels, camped out, stayed in primitive or luxurious cabins, or stayed on houseboats (in Southeast Alaska—to avoid the bears).
We dealt with animals, dry and humid heat, cold, rain, snow, unexpected rockfalls, pea-soup fog, getting our vehicles stuck, and traversing rapids With so much time spent in forests, I have enjoyed nature’s beauty and also had many memorable, chance encounters with wild animals—humorous or dangerous, but all beautiful. These physical adventures have kept my professional life exciting, but the most excitement is learning new things—either by discovery (the “crystallization moment”) or by talking with knowledgeable people.
University faculty are under tremendous pressure to teach courses, obtain research money to fund graduate students, do research, publish papers, consult, and (at the University of Washington College of Forest Resources) teach mid-career courses. This pressure makes us faculty more productive, but certainly not complacent. I would occasionally use other research projects, mid-career courses, or consultant work to glean further insights into forest development.
A key realization from this reconstruction work was that, since the trees all began at a single time—clearcuttings, hot fires, or wind storms — disturbances were very important parts of forest development, not just occasional, minor interferences. By the late 1970’s, others had also begun writing about the importance of disturbances to forests. I had fought forest fires in the South Carolina and in California, and had been fascinated by glaciers from geology courses. Consequently, I took the opportunity to study the Upper Nooksack Valley, a glaciated valley in the North Cascades National Park. We sent in our supplies by helicopter, hiked in, and spent about ten weeks with a base camp and field camps, taking data in the valley.
This perspective and a later study of the isolated Stehekin Valley (which I turned over to my Ph.D. student) set the stage for later studies of forest landscapes. I was also able to observe the immediate effects of the 1980 volcanic eruption of Mt. St. Helens.
Questions by insightful practicing foresters about single species stand development led me back to Dr. Ken Mitchel. He had worked out the development principles of single species stands incredibly elegantly and, soon after I arrived at the University of Washington, sent me a manuscript that was the basis of his computer model (TASS). He had moved to the University of Idaho, and I spent one of my more exciting weekends as a guest in his Idaho home looking at his data and interpreting it with him.
I shared another “crystallization moment” with my some of my graduate students in the mid-1980’s. A population biology issue of the “-3/2 density relationship”—kind of a scientific law—had intrigued me, as had the “correlated curve trends” and the “crossover effect.” These had so many common axes that I felt that, somehow, they could all be reconciled. One morning, after awaking with some ideas, I bought some plastic, wood, and yarn, and invited my students into my office where we worked out a three dimensional model that did indeed reconcile these. It was incredibly exciting — not diminished when my student on leave from the Japanese government translated an article where A. Sato, a Japanese scientist, had developed the model six weeks before. We later published our article and acknowledged Dr. Sato.
A consulting job to Potlatch Corporation forests in Idaho led me and my graduate students to look carefully at uneven-age stands. This led to another “crystallization moment” as my student documented how little younger trees grow when not in full or nearly-full sunlight and that this shade does not need to be directly overhead because that’s not where the sun usually is.
Every seven years, faculty are allowed to take a one-years paid leave in order to conduct distant research, write books, and do similar activities. I spent 1982-83 as a Fulbright Fellow on sabbatical at the Middle East Technical University in Ankara, Turkey. I was invited by the Minister of Agriculture and Forestry to tour all parts of Turkey with their Forest Service and give him reports. It was my first experience abroad, and I used the opportunity to travel to Germany, France, and Switzerland as well. I was struck by how similar the way that the forest and rural people used the land was to the United States. And, I was struck by how ancient people (e.g., Greeks and Hittites) had been so practical in their use of the land and water (based on the archeological ruins). Later, I continued travels in Turkey courtesy of my friend Professor Melih Boydak of the University of Istanbul Faculty of Forestry.
A real satisfaction of scientific research is that once you’ve solved a riddle you’ve captured it forever. My studies increasingly allowed me to walk into a forest and “understand” it—to immediately know what it looked like it the past, the changes that affected it, and how it would look in the future. The more I traveled to different areas, the more I began to realize that forests were behaving similarly in all places that I visited.
A former Superintendent of Mount Everest National Park arrived at the University of Washington on a Fulbright Fellowship to study for a Master’s degree. I became his supervisor, and he received a Ph.D. under my direction—the first Sherpa to receive a Ph.D. One summer, we completed a research trek through his study area in the Mount Everest Park and surrounding area.
His research revealed the dynamic nature of the Sherpa communities, in contrast to the older paradigm of them living in a “steady state” with nature.
I continued writing papers, organizing symposia, teaching on-campus, at the field camp, and to mid-career foresters. In the mid-1980’s E.C. Burkhardt, professional foresters, and other scientists encouraged us to synthesize our understanding of stand development. In 1990, along with a former student, Bruce Larson, I did just that with the publication of the book, Forest Stand Dynamics. The book has a second edition (1996) and we’re working on a third edition that will also include tropical forests (and have former students as coauthors). The book’s title, Forest Stand Dynamics, has a funny history. I was not fond of using that as the title, but believed Bruce and E.C. Burkhardt were so enthusiastic that I went along with it. After publication, both confessed that they had not been fond of it, but acquiesced to me because they thought I wanted it! In the end, we’re all glad we used that title.
During the 1980’s, as my reputation for understanding forests increased, I was invited to join an advisory group on the Olympic Peninsula. The problem was that foresters knew that they could carefully manage each stand, but the resulting landscape often did not provide expected results. This experience — along with teaching mid-career foresters how to write silviculture prescriptions through mid-career Silviculture Certification courses — led me to the (in retrospect, obvious) conclusion that we need to coordinate management across the landscape. Our Stand Dynamics view of forests made me appreciate that we needed a diversity of forest conditions to provide biodiversity, fire protection, and other values. I began studying this “landscape approach” as a way of managing forests. As Norm Dicks, a U.S. Congressman from Washington, learned about my studies through my newspaper editorials and from loggers on the Olympic Peninsula, he engaged me to offer a solution to the spotted owl issue in the Pacific Northwest. In the early 1990’s, I also was invited to join a scientific team to address another western forest issue. Many of us knew by looking at and measuring the forests that catastrophic forest fires were going to get worse unless we took management action. We felt a scientific document was needed to convince Congress.
I had developed a pattern of research that included starting with a practical problem, gaining as many insights about the problem from practicing foresters, and then trying to solve it by looking at the data and eventually the underlying scientific theories—ecological or other. Often, the solution would lead me to suggesting changes to the ecological theory. I also branched into issues such as the pruning, where we worked on both technical pruning machines and the response of trees.
By now my career was often taking me far from the forests. I testified in Congressional hearings in Washington, D.C. on both the fire and spotted owl issues. My position on the spotted owl was that we should not harvest any more “old growth forests.” However, many of the previously harvested forests had now regrown to dense, younger forests that had little value to the spotted owls. Rather than put dense young forests off-limits to any management, we could remove some trees in the dense forests to give them more characteristics of old growth; and, we knew from elsewhere that the spotted owls would use such stands. This approach was the dynamic approach scientifically supported by our book.
On the fire issue, I was in charge of a second scientific report to U.S. Congress at the request of Congressman Charles Taylor, where we again warned of the continued fires and reported that proactive steps could be taken to avoid them. Between the fire and spotted owl issues, I testified before Congress and the Senate more than a dozen times; and was one of thirteen scientists at President Clinton’s nationally televised Forest Summit in 1993. Neither the spotted owl issues nor the western forest fire issues resulted in actions that I had proposed.
During the same time, I also became more involved in international work. My graduate students were beginning to travel abroad for their research. Traveling to Ecuador, I saw my first tropical forests, and was further struck by how similar these forests were to the temperate forests. Later I visited the tropical forests on the Mexico/Guatemala border, Brazil, Thailand, and Chile and was again struck by the similarity of these forests and the land behavior of the ancient Mayan cities there.
I continued my studies of stand development and landscape dynamics as well. At a symposium at Yale University in 1991, I postulated that the stand dynamics patterns that we had described in North America were occurring in forests throughout the world. However, Professor Peter Ashton of Harvard University challenged that these processes were not occurring in tropical forests, reminiscent of Dr. McArthur’s assertions decades earlier. In a true academic spirit, Professor Ashton graciously helped support my Ph.D. student Patrick Baker’s study of a tropical forest in Thailand, where he documented that the same dynamic pattern was occurring that our book described. Professor Ashton served on Patrick’s committee and showed himself to be a true academician in the highest sense of the word.
Through the late 1980’s the practicing foresters had liked my landscape management ideas, but when I described how it would be done, their response was, “That takes too many calculations, we don’t have the time to do it.” And, professional foresters in my mid-career courses had the same concern. My graduate students at the time were very quantitatively oriented and increasingly simplified the analyses by programming the time-consuming parts into a computer platform — the Landscape Management System (LMS). We developed computerized tools that enabled foresters to manage landscapes for multiple values. The University of Washington Pack Forest implemented them. Scientists with the U.S. Forest Service worked in the same building and provided LMS with its visualization capability. The Landscape Management System also served as the basis for the U.S. Forest Service computer platform “Suppose.”
At the beginning of 2002, I accepted an invitation to return to Yale, this time as a professor and Director of the Global Institute of Sustainable Forestry. I have continued research in stand development to document and understand the growing problem of a lack of oaks regenerating in the southern alluvial floodplain forests. With the Stoneville laboratory of the U.S. Forest Service, I have also worked on landscape issues in these floodplain forests, and others in Florida, Connecticut, North Carolina, Armenia, Wyoming, and elsewhere.
On an invited trip to his country, a Ukrainian professor took me to the forests around the failed Chernobyl Nuclear Reactor. About 270,000 hectares had been contaminated, abandoned by humans, and became little tended. I realized what my colleague had already realized: “These irradiated forests are going to burn. This could be quite dangerous.” We spent the next five years documenting the landscape effects, developing proactive solutions, and, more importantly, trying to call the attention of authorities in and out of Ukraine through international conferences and private meetings with world leaders.
The activities are documented at this link, but the whole ordeal reminded me of the spotted owl and fire issues of the previous decade: What if you know something that can avoid a lot of impending hardship, but nobody will listen to you? This time, however, the United Nations has stepped in.
A Ph.D. student from China brought an interesting issue of a large Amur tiger reserve with few tigers in it. Her research, and our visit to the forests there, led us to conclude that the forest, having been clearcut between 30 and 80 years ago, has grown too dense to provide enough grass and other browse for deer. As a result, the Amur tigers have little to feed on. This conclusion is, of course, based on the dynamic perspective of nature.
With about 250 Masters students at the Yale School of Forestry and Environmental Studies — about 25% of whom are non-U.S. citizens — I have a lot of opportunities to work throughout the world. We initiated mid-career Executive Courses in Forestry and had special agreements to help upgrade the Forest Service of India through mid-career training. In conjunction with the United Nations’ Joint South-South Cooperation Unit, I visited Liberia and we sponsored two professionals in their Forest Development Authority to study toward Master’s degrees in Uganda.
While I now have many opportunities for international travel, I now travel only if it can serve a purpose: If I can help with a specific issue where my knowledge will be valuable, if I am giving an important presentation, or if the trip will help advance some project that I am doing.
My wife, Fatma Arf Oliver, and I have just finished writing a book entitled Global Resources and the Environment (I also teach this as a course at Yale). The book is intended to motivate people to think about interactions and tradeoffs among many resources. Changes in a given resource often are more affected by changes in other resources than by actions taken by specialists within the given resource. For advancing this book, I am very grateful to many trips to different parts of China, India, Brazil, Chile, the Russian Far East, Nepal, Bhutan, and Japan. We used these trips to gather background information for the book—and for first-hand confirmation of our interpretations of activities in different regions. This book is being published by Cambridge University Press in mid-2018.
Forests will become increasingly needed for both their commodity and non-commodity values. I want people to learn how to manage them so they can provide both values together. On the one hand, I have also resumed interest in using wood as an environmental resource. Life cycle work on wood is showing it to be very favorable compared to steel and concrete in conserving greenhouse gases and fossil fuels. And my research suggests ways that wood harvesting can protect and even promote biodiversity — again using the dynamic paradigm.
On the other hand, I would like to see the application of landscape management to forests. I feel it is crucial to our maintaining biodiversity and sustaining the many other commodity and non-commodity values — especially with increasing pressures on the forest. We have the prototype technical tools to implement it. It simply will take one place (e.g., government) in the world to step up to apply the system and to support the technical tools to make it a reality. Right now, the General Directorate of Forestry of Turkey and the United Nations Development Programme are taking this leading step–working with Yale (my laboratory) and the University of Washington College of the Environment.
Were I to give insights for the future of science and society, I would say we need two things:
1) We need to find a way to have new scientific ideas accepted more rapidly — although still scrutinized strongly. I’m not sure that our complex society can survive on poor decisions made on outdated science.
2) We need closer scrutiny of how science is interpreted. Years ago, Ralph Nader held for-profit corporations accountable for misleading statements. But now some ENGO’s, for-profit corporations, and news media are mis-stating science—giving society erroneous information.
My insights for people going into science are:
1) Enjoy the adventure. Chase ideas you believe in — not papers, funds, popular topics, trendy techniques, or recognition.
2) Rely on practitioners who apply things in the field in which you are working. They have a lot of experience that you can draw on.
3) Listen to criticism, but decide what parts merit attention. Develop a thick skin to those parts that do not merit attention.
4) Keep your focus on the long term. Remember, the truth will come out eventually.
5) Be willing to go to different places and endure hardships — whether they are physically challenging, remote, hearings and meetings in luxurious surroundings, or difficult courses in technology, statistics, or foreign languages. But, keep in mind that the goal is extending knowledge through research and teaching, not “bagging visa stamps for your passport.”