To understand why we monitor the health of the forests, it is best to take a historical perspective. When the European settlers first began to colonize the new world, the vast forests of North America were viewed more as obstacles to be conquered than resources to be exploited. In the earliest days of colonization, the pioneers had little opportunity to even capitalize on the potential wealth offered by the virgin wilderness woodlands. Mere survival was paramount to economic development per se, and the quicker and more efficiently the forests could be cleared for life-sustaining agricultural development, the better. By contemporary conservation standards, pioneer land-clearing methods were often abominable. Huge areas were frequently burned, often causing irreparable damage to the fragile underlying soil. Slash and burn agriculture all too often resulted in widespread soil erosion and silting of rivers and streams. So complete was the ecosystem damage in some areas that biologists can sometimes only speculate on the makeup of the fauna and flora just prior to the impact of European colonization.

Unfortunately, land management practices over the next hundred years improved little over those of the earlier first ancestors. Vast southern forests were typically clearcut with reckless abandon, in many cases for conversion to cotton fields. Nevertheless, settlers had a newfound appreciation for the economic value of wood. Now there was practical use for the trees. Timber helped fuel the burgeoning southern economy. Trees meant fuel for steamboats and cotton mills. They meant charcoal for pig-iron works. They meant lumber for building construction and export. Thus, the agricultural South found new uses (albeit not a love) for its forests. So complete was the deforestation in the early to mid-1800's that the percentage of land covered by Southern Piedmont forests is far greater today than in 1860.

In the Reconstruction Era, much of the focus in the highlands shifted from clearing land for agriculture to direct logging. Much of the Southern Appalachian mountains offered little appeal from a farming perspective, but high quality hardwoods (and in the highest elevations, spruce-fir forests) attracted timber barons, eager to feed the growing American industrial engine. Once again, reckless abandon held sway over any semblance of environmentally responsible logging. Clearing the mountain forests was backbreaking, dangerous work, but the steam engine and more sophisticated engineering methods permitted logging of all but the most remote coves and steepest hillsides.

Around the turn of the century, wealthy industrialist and visionary conservationist George Vanderbilt purchased a huge tract of land in western North Carolina. Vanderbilt was appalled by the land abuse that had taken place over much of his holdings. At the urging of the great American landscape architect Frederick Low Olmstead, he hired Gifford Pinchot, and later the German forester Dr. Carl Schenck, to assess and manage his property. Schenck soon realized that he needed skilled assistants to help him in this undertaking, but no professionally trained foresters were to be found in America. Thus, Schenck founded what was to be America's first forestry school near Asheville, North Carolina, in 1898. The first priority for Schenck's young foresters was conservation. Halting and repairing the massive land abuse was a Herculean undertaking. Eventually, a few foresters began to develop a special interest in inventory work. Most of the early surveys were for timber volume estimates, but the fledgling foresters also made notes on the health of the forest stands. Eventually these surveys evolved into more detailed documentation on the incidence of insect and disease conditions. Thus began the earliest contemporary forest health monitoring surveys.

An important milestone in the evolution of forest health monitoring was the increasing role of the Federal government in natural resource management. In the early 20th century, President Theodore Roosevelt, who shared the vision of pioneer conservationists like Schenck and Vanderbilt, worked to provide the government with broad conservation powers. Soon the United States Forest Service was born, and with it the genesis of a rich heritage of professional forestry, including area specialization ranging from wildlife management to forest economics to forest pathology.

Inventory was a high priority in the new Forest Service as surveyors set out to classify the nation's forests. Along the way they increasingly documented various facets of forest health. Forestry in America was rapidly improving, and American foresters were beginning to gain stature comparable to their European counterparts. Surveys no longer represented mere incidence reports, but began to take on statistical reliability. The country was forming the data base for what would be an index of change for all time.

In the 1930's President Franklin D. Roosevelt continued in the tradition of his uncle Theodore. Strengthening the Forest Service, FDR improved the Research branch. Forest Service researchers, in cooperation with colleagues in universities, developed increasingly reliable statistical survey methods designed specifically for American forests.

With the end of World War II, the United States again turned its attention to its forest land, with special attention to southern forests. Piedmont forests still had not recovered from land abuse during the depression era, and President Dwight David Eisenhower signed legislation authorizing massive reforestation of eroded lands. Most of these trees were loblolly and shortleaf pines, which came to be known as "Eisenhower pines." Several of the newly planted lands were to become new National Forests. Meanwhile, forest entomology and pathology became increasingly sophisticated, and some of the most significant forestry research in America's history was published in the 1950's. Much of this work was of an inventory nature, and for the first time addressed specific insect and disease survey methods.

The 1960's saw a quantum leap in insect and disease survey procedures. The new Forest Service Pest Control Section worked closely with the Research Stations and other Forest Service units to develop sophisticated insect and disease survey procedures. Motivated largely by economics of timber production, these surveys were designed to obtain the most accurate data possible in the shortest amount of time. For the first time, aircraft became important survey tools. Pest Control quickly embraced the rapidly developing field of aerial photography, and foresters and pest specialists were publishing the most accurate and useful survey reports to date. Unknown to the surveyors of the era, an important watershed took place-publication of Rachel Carson's Silent Spring, the nonfiction exposé on pesticide pollution. This book would forever change the agency's approach to pest management, while giving birth to a movement known as "environmentalism."

Two milestones marked the 1970's: increasing sophistication in remote sensing and strengthening of State forestry agency programs. Most of the satellite technology to 1970 had been for experimental and military purposes. With the launch of Landsat and similar satellites, remote-sensing imagery for resource management became both useful and cost effective. While primitive by today's standards, the satellite technology of the era offered exciting survey possibilities, and the entomologists and pathologists of the time were quick to embrace it. Also in the 1970's, the State forestry agencies added forest pest specialists to their staffs and, in cooperation with the Forest Service, formed important relationships which endure to this day. The decade also saw the first widespread recognition of the importance of air pollution as a stressor of forests, and the first surveys were carried out to identify point-source pollution.

The geographic information system (GIS) was the hallmark of the 1980's. This elaborate computer system gave insight into stressor relationships undreamed of just a few years earlier. Through the power of high-speed computers, the process allowed "layers" of data to be displayed spatially and in tabular format, while giving investigators insight into the relationship between multiple, overlapping variables such as soil type, weather, forest type, and topography (See Figure 1). The decade also saw widespread recognition of the role of non-point-source air pollution as a stressor of southern forests.

Today, the most significant developments are perhaps not so much technical as political and social. Never before has the American public been so interested in the condition of its forest resources. Fueled by media reports of "acid rain," global warming, and massive clearing of tropical rain forests, pressure is increasing on today's resource managers to report on the status and condition of the woodlands under their charge. Fortunately, this intense interest coincides with the history's most sophisticated and accurate monitoring methodology. In the 1990's, we see the forest not only as an ecosystem in itself, but as a component of a complex, interlinked worldwide ecosystem. We view the forest as a type of bioindicator of planetary health, and resource management agencies around the world are cooperating to establish baseline standards to determine possible deviation from "normal" as time transpires.

This publication summarizes much of the data contained in a huge GIS data base known as the Southern Forest Atlas. Begun in the mid 80's this GIS represents the first central consolidation of a variety of interacting stressor factors, including weather, ozone, and numerous forest pests. Scientists and resource managers now can access this data base for a variety of purposes ranging from predictive modeling to analysis of historical trends.

Donald H. Marx
Frogmore, South Carolina, September 1995

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