Norman L. Christensen  

August 18, 2004 North Carolina 2004 Forestry Summit, Keynote Address

   
Sustainable Forest Management in a World of Change
Keynote Address
North Carolina 2004 Forestry Summit
August 19, 2004
Statesville, NC

Presented by
Norman L. Christensen
Nicholas School of the Environment and Earth Sciences
Duke University
19 August 2004

I grew up in the Central Valley of California, a landscape of grassland and agricultural fields. It is, therefore, probably not surprising that the thing that astounded me most 32 years ago when Portia and I moved to North Carolina was forests—everywhere forests. They literally grew wild. Any vacant land left to itself wanted to become a forest as quickly as possible. Newcomers walking in North Carolina’s woods are prone to wax poetic, recalling Joyce Kilmer’s soliloquy on trees or the opening lines of Longfellow’s Evangeline—“This is the forest primeval.”

As an apprentice forest ecologist, my doctoral advisor had advised me to study to the extent possible those areas absent of human influences. In his words, “humans just complicate the world.” But, I quickly discovered that any attempt to follow his advice in North Carolina forests would leave me with virtually nothing to study. In short order, I learned that North Carolina’s woods are as much the product of human history as they are the primeval forces of nature.

Given the will of this landscape to produce forests, the growing chorus of concern regarding their sustainability might seem at the least paradoxical. But, we are justifiably concerned about their future. Here, I would like to share with you some of what I have learned about the history of our forests. More particularly, I want to reflect on the lessons that that history holds for their sustainable management.

There are those who claim that there is nothing new in the phrase “Sustainable Forest Management,” and they are at least partly correct. With the privilege of hindsight, some historical forest practices might be judged to have been, in various senses, unsustainable. But in the context of the times and the state of our knowledge at those times, many of those actions were actually considered best practice. Considering the imperfect state of our knowledge, it is useful to remember that future generations may judge poorly actions that we consider sustainable today.

There is interesting history in the use of the word “sustainability” in the context of forests. In the late 19th century, with leadership from people like Gifford Pinchot, foresters managed for what they called “sustained yield.” Sustained yield management was based on a “demand-side” concern for sustainability. It was management to ensure a steady flow of wood and wood-fiber to the mill and the market. This notion of forest management was completely consonant with a nation literally awash in forests

By the 1930s, it was becoming obvious that the supply of “wild forest” was indeed finite. Our continued ability to sustain the flow of forest resources to the marketplace depended on our ability to grow, harvest and re-grow forests in particular places in much the same way farmers plant, harvest and replant their crops, though on longer rotations. Thus, sustainable forest management began to encompass genuine supply-side concerns. Management began to tackle the challenge of maintaining productivity of individual sites from rotation to rotation and generation to generation.

Sustainable management moved beyond a focus on harvest, and began to incorporate investments such as site preparation, planting and fertilizer applications to replace inevitable losses associated with harvest. Thus was born the science of silviculture.

In the decades that followed, our view of what constitutes sustainable forest management expanded even further as the numbers of us have increased along with the complexity of our expectations for forested landscapes. Sustainable forest management has become synonymous with the concept of multiple use, the recognition that forests provide a multiplicity of values including wood fiber, water protection and control, recreation, wildlife, biological diversity, aesthetic beauty and inspiration. In recent years, we have learned that this list of services provided by forest ecosystems includes purification of the air we breathe and storage of immense amounts of carbon as part of the global carbon cycle.

As Hubert Humphrey said in 1968,

The days have ended when the forest may be viewed only as trees and trees only as timber. The soil and water, the grasses and the shrubs, the fish and the wildlife, and the beauty that is the forest must become integral parts of resource managers’ thinking and action.

In just over one hundred years—since Mr. Pinchot began his pioneering work on North Carolina forests—the number of us has increased six-fold, and our demands for wood products have increased by nearly twice that amount. Our expectations for what might be termed non-market forest values – water protection, wildlife, recreation – have also grown and become more complex. It has only been in recent years that we have come to fully understand that sustainable multiple use is not about trying to everything everywhere. Rather, it’s about doing the right things in the right places.

All of this has happened as the worldwide extent of forests is, in fact, shrinking. In this context—sustainable management of these resources is truly compelling, and it is useful to consider a more fundamental notion of sustainability and how it relates to forest landscapes. In 1987, the United Nations World Commission on Environment and Development defined sustainable management as meeting “the needs of the present without compromising the ability of future generations to meet their own needs. At its core, sustainability is really a matter of intergenerational responsibility.

This seems like an awfully simple notion, but I will submit that it is incredibly complex in ways that are at once exciting and daunting. Despite what the word seems to imply, sustainable management is most certainly not about maintaining the status quo. It is all about another fashionable phrase: “change management”. Three dimensions of change concern us. First, the world is changing—it always has. Climate and weather change continuously on timescales of days to millennia. Natural and human-caused disturbances ensure that our forests are in a state of constant change. Second, we are changing. Human expectations of forests, as well as the technologies we employ to meet those expectations change with each generation. Third, we are changing the world! This has become obvious to us as our numbers on this planet have swollen, but it has been true throughout human history. Any notion of sustainability must include these three aspects of change. Indeed, I shall argue that the capacity to change may be our very best indicator of sustainability. So, let’s consider the history of such changes in North Carolina’s forests, as well as the implications of that change for the management of forests today and in the future.

Imagine we had the benefit of a time machine that could transport us back 10,000 years. This may seem like a long time, but it is only a score or so tree generations. Exiting our machine, the first thing we notice is the different character of the forests that surround us. These forests are a combination of spruce, fir and northern pines, forests not unlike those we would see in southern Canada or the northern Lake States. This is the finale of the last ice age, and the beginning of a period of rapid change in forests and climate. This is the finale of the twentieth such ice age in the span of 2 million years—a period we call the Pleistocene. Each of these cold periods lasted roughly 85 thousand years, and punctuated by 10-20,000 years of relatively warm conditions—conditions such as we enjoy today.

Over the millennia and centuries since that those boreal times, climates have been changing, sometimes gradually and sometimes not so gradually. Against this backdrop of climate change, but at a faster tempo—time spans of tens and hundreds of years—ecosystems were (and are) changing. Natural disturbances such as hurricanes, ice storms, insect epidemics and most especially, fires, set in motion patterns of forest ecosystem change driven by the population dynamics of the plants and animals that make up those ecosystems. These disturbances act continuously across regions and the change that derives from them is inexorable. This ecosystem change often affects the likelihood of future disturbances, as with the accumulation of woody debris that will carry the next fire, or the changes in forest structure that make it more susceptible to wind-throw in the next hurricane. All of this was and is occurring against the backdrop of year-to-year variation in climate and weather.

In North America, this twentieth warm period of the Pleistocene turned out to be unique in one very important respect. It marked the first time people moved onto the continent. We generally think of the influence of these earliest citizens of North America on their world as benign. On the contrary, they were profound. From the beginning, these first Americans took advantage of this changing environment and, in doing so, set in motion new and unique patterns of change.

Within a matter of a few thousand years, the earliest Native Americans had hunted over two hundred species of mammals – from camels to mastodons and wooly mammoths to giant ground sloths – to extinction. Like their forebears in the Old World, they used fire and other tools to make forest landscapes more hospitable and productive. These changes set in motion changes in ecosystems that greatly influenced the resources available to people. Over more than ten-thousand years, these earliest North Carolinians adjusted to, even took advantage of change – first as hunters and gathers, then leading more complex nomadic lifestyles, and finally developing the complex cultures of farmers and fisher people.

Thus, the North Carolina that the first European explorers and colonists encountered 4-500 years ago was not a landscape of forests primeval absent of human influence. By this time, the human population of North Carolina probably exceeded a half million. What those early European explorers saw were forest landscapes shaped by the interactions among the multi-tempo processes of environmental and ecological change and the actions of humans.

A pattern begins to emerge here. Human use of forests is very much determined by the character of the forests available to them. That human use sets in motions patterns of change that will, in time, affect the character of the future forest and, thereby, the nature of future human use.

Through the 17th and 18th centuries European colonization progressed from east to west across North Carolina and brought enormous change in human expectations and technology. In most places, forest clearing and agriculture was initially undertaken on a subsistence basis, forest use and shifting agriculture to meet local needs. With great expenditure of energy, early Tar Heel settlers cleared and farmed small plots. As the productivity of those plots declined—as it inevitably did—they were abandoned and left fallow in favor of newly cleared areas. The fallow land was rapidly re-vegetated by old-field weeds and shrubs. As this happened, the organic matter and nutrient capital lost to cropping was restored. In a matter of a few years, those old fields could be re-tilled. It is easy to see this fallow farming cycle as the earliest form of crop rotation.

In this region, agriculture and forest management to meet the needs of expanding regional, even global markets really began to take hold in the early 19th century. Uplands were cleared for cotton, tobacco, indigo and other market crops, initiating region-wide deforestation. What was not cleared was altered by livestock and selectively cut for everything from railroad ties to fire wood. In the Piedmont and lower elevation mountains, lowland forests were cleared and the energy of most of streams captured by multitudes—thousands—of water driven mills. On our coastal plain, forests were managed for a variety of products generally classified as “naval stores,” that included everything from tall timbers for ship masts to turpentine and rosin.

The expansion and development over the next century might well be judged with the benefit of hindsight as unsustainable. Productivity declined in agricultural systems as nutrients were harvested with crops and soils were eroded and depleted. Fallow cycle farming was abandoned in order to put more land into production. To farm this increasing expanse of land required human resources and an expanding dependency on slave labor. As has often happened through history, environmental, social and economic decline were tightly linked.

By the Civil War, our forest resources had been greatly depleted and much agricultural land was exhausted. Forests had been high-graded of the most valuable timber, with virtually no investment in their future. With the deterioration of these natural resources and no immediate technological replacement for lost slave labor, the economy of this entire region collapsed. Agricultural lands were abandoned. Mill ponds were full of sediment eroded from badly managed uplands and mills were left to decay.

But, change continued. Abandoned fields were quickly invaded, first with weedy herbs and shrubs, then with even-aged stands of pine. During the period from the post-war Reconstruction through the Great Depression, this process of old-field succession set in motion region-wide reforestation. This was reforestation on an unprecedented scale.

These new forests were, however, not at all similar to the forests that had been cleared a century or two before. They were a very much the product of the history of land use and abuse that preceded them. Pines are wonderfully adapted to the relatively poor soil conditions and very high light conditions of eroded old fields, and this landscape became a sea of even aged stands of loblolly, shortleaf and Virginia pine, creating what has become the most productive timber producing region in North America, the “Southern Pinery.”

The story does not stop there; the world has since changed, we have since changed and we have since changed the world. The changes in our forests over the past several decades have involved three important themes.

Theme one is about the increasing prevalence of hardwoods across the North Carolina landscape. Left to their own devices, pine forests will not remain pine forests. Unable to grow in their own shade, pine trees are eventually replaced by the multitude of broadleaved trees that typically grow beneath them. If you wish to regenerate pines, you must make the investment to recreate old-field like conditions. In other words, you must repeat history. Whether or not one sees this trend as good or bad is a matter of personal perspective and values. There is, however, no doubt that it is changing the nature of the resource that our children will inherit.

The second theme relates to a new episode of deforestation and forest loss. The extent of North Carolina’s forest reached a peak in the mid-1970’s and has been declining since then. The rate of that decline has hastened in the past decade. This change is largely due to the rapid growth in the regions near our urban centers as we accommodate the influx of people who wish “to call North Carolina home.”

Theme three is about the influx of a new wave of immigrants, invasive species of microbes, plants and animals, from other continents. This has happened as we humans have broken down virtually all of the barriers that previously kept these species in their native habitats. This list of new comers is long and growing longer. It includes a litany of plants including kudzu, privet, Japanese honeysuckle and bamboo grass. The brown-headed cowbird and the starling are among our most common birds. Pests and parasites such as the chestnut blight, balsam adelgid, hemlock adelgid and dogwood anthracnose threaten the health of some of our most important forest trees.

Reflecting on this history, we might draw several lessons. It could be read as cautionary tale. Hubris and ignorance, or simple disregard for basic environmental processes, can produce unsustainable consequences. As my father is fond of saying, “if you don’t watch where you’re going, you’ll probably end up where you’re headed.” At the very least, this history of change instructs us about the inevitable linkages between land use, culture and human values. Indeed, it is in the linkage of these elements that all notions of sustainable management must be centered. On a more optimistic note, this story speaks to the remarkable ability of ecosystems to adjust to change--even the adverse change

So, it is not too much of a simplification to say that this incredibly productive forested landscape we are enjoying today is a product of the confluence of environmental change, changing human values, and humans changing the world. This landscape is an exemplar of nearly all the lands that humans inhabit.

Those of us who study natural processes of change are prone to see the world as cycles punctuated by disturbances. This begs the question, can we view this linkage of human land use and environmental change as an endless cycle? I most certainly hope so, but it would be tragic folly to take this for granted. The numbers of us are changing and changing the world. Those numbers are twice what they were 30 years ago and 6 times what they were when, over a century ago, Gifford Pinchot proposed his principles of sustained yield forestry. The tempo of change is most certainly increasing, and the nature of the changes we are making in the world are increasingly different from those associated with natural disturbance cycles.

We have come to understand that sustainable forest management is not about some particular form of forest practice, such as selective cutting or forest protection for biodiversity—although these tools may be important. Sustainable forest management is the full repertoire of human forest management. It includes protected areas to ensure the quality of our waters and the well being of our biota. It also includes intensively managed areas to ensure that we can meet the needs for wood fiber for future generations and the development of technologies that will allow us to produce more on less land. More than that, sustainable forestry is centered on an understanding of where best to do what.

Above all, a commitment to sustainable forest management is a commitment to the inevitability—indeed the desirability—of change.