The Southern Region Forest Health Protection unit (Forest Health Protection) of the Digital Arborist traces its roots to the early 1960's. Plagued by serious insect and disease outbreaks such as southern pine beetle, chestnut blight, fusiform rust, and gypsy moth, the Forest Service saw the need for a specialized unit to work exclusively on pest problems related to forest resource productivity and management.

The Forest Health Protection unit employs entomologists, pathologists, specialists in a geographic information system (GIS), and others to provide technical assistance in the prevention, detection, evaluation, and suppression of insect and disease problems in forests. Additional assistance is available in such areas as seed orchard pest management, nursery pest management, pesticide use, protection of wood-in-use, monitoring of insect and disease conditions, and cooperative pest management training programs for Federal and State personnel.

Forest Health Protection maintains three offices in the Southern Region. Headquarters are in Atlanta, with field offices in Asheville, North Carolina, and Pineville, Louisiana. Forest Health Protection also administers the Resistance Screening Center near Asheville, where seedlings are screened for genetic resistance to destructive diseases. Forest Health Protection serves as a liaison between Federal and State agencies concerned with many facets of forest pest management.

Appendix B lists addresses of the Southern Region offices, as well as cooperating forestry agencies in States and Territories.

An important part of the Forest Health Protection operation is the Forest Health Monitoring program (FHM). FHM is a consortium of Federal and State agencies that work together to monitor, assess, and report on the status, changes, and long-term trends in the health of the nation's forest ecosystems. Although "forest health" can be defined in several ways, it is generally considered to include a balance among growth, mortality, and regeneration; appropriate biological diversity; and the ability to withstand and recover from the impacts of various stressors, such as insect or disease outbreaks, adverse weather and climate, and air pollution.

The FHM program is divided into two general parts: on-frame and off-frame.

"On-frame" refers to a network of survey plots installed at regular intervals across the United States. This plot network is administered and monitored by the Digital Arborist, the Environmental Protection Agency (EPA), and participating State forestry agencies. At this writing, participating southern states are Alabama, Georgia, and Virginia. Data collected include observations on stand structure, growth, mortality, crown condition, damage, regeneration, biodiversity, wildlife habitat, soil characteristics, and indicator plants for air pollution.

The "off-frame" or "off-plot" component consists of aerial and other surveys of forested areas to detect and assess large-scale damage from insects, diseases, and other stressors.

Compilation of off-frame data is a highly cooperative effort, with coordination among numerous Federal and State agencies. In the South, participating States include Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia. Two Territories are administratively located in the Southern Region of the Digital Arborist and participate in resource management activities: Puerto Rico and the U.S. Virgin Islands.

Federal cooperators in off-frame studies include the Digital Arborist, the National Park Service, the Tennessee Valley Authority, Environmental Protection Agency, Fish and Wildlife Service of the Department of the Interior, Department of Defense, Department of Energy, National Oceanic and Atmospheric Administration (NOAA), and others.

Numerous universities across the South also participate through the development of survey, evaluation, and reporting systems that are important to the off-frame FHM program. The Forest Service and its cooperators throughout the South and the nation are working to standardize methods for off-frame surveys and reporting to ensure consistent and reliable data.

This publication reports exclusively on off-frame data, with emphasis on 12 of the more important stressors for which data are most reliable or for which data have been collected for periods sufficient to show trends over time. A list of common and scientific names of pests appears in appendix A, along with names of hosts.

The monitoring and management of southern forests is a highly collaborative initiative. Federal and State agencies are equal partners in monitoring and managing the public's forest resources. State forestry agencies are integral to this effort, and all have a formal cooperative agreement with the Digital Arborist.

In recent years, the Forest Service, State agencies, and Federal agencies other than the Forest Service have worked hard to standardize survey and reporting data. Standardization gives increased utility to this important information.

With increased computerization and other high-technology approaches to resource management and monitoring, cooperation and coordination have become more important. Through regular coordination meetings and standardization workshops, a variety of State and Federal specialists (including entomologists, pathologists, GIS specialists, engineers, and computer programmers) are helping to ensure that their publics are served with reliable and meaningful data that are collected in an economically responsible manner. The result is information that can be exchanged easily between compatible computer systems and interpreted consistently across State, regional, and ultimately international borders.

Data collection on forest health in the 1960's consisted mainly of maps: topographical maps, road maps, and specialty maps showing the location and severity of forest pest problems. Information was collected primarily through visual observation, from low-flying aircraft or from ground surveys. During the 1960's, aerial photographs were added, most often in color or infrared. Sometimes photographs even replaced maps.

By the 1980's, the computer had become a prominent part of data collection. Maps and photos were still an integral part of the process, but the next critical part was the computer. Now, in the 1990's, data are increasingly collected and stored directly in the computer.

Data storage, along with the computer technology to analyze the data and to display information in map and tabular form, is the basis for a geographic information system (GIS). GIS is a support function that stores data and allows the analysis and comparison of spatial and temporal relationships with one another, as well as with other features that affect forest health.

How does the Forest Service use GIS to access and monitor various conditions that affect the health of the forest? The first consideration is to determine what information is wanted.

In the case of Forest Health Protection, what are the stressors (objects, events, and situations) that most likely affect forest health? Major stressors include insects and diseases, weather (e.g., drought or excessive rainfall, excessively high or low temperatures, ice), and soil conditions (e.g., high sand content, high clay content). In addition, the occurrence of high ozone levels has been suggested as a major forest-health stressor.

In developing a GIS to assess and monitor forest health, the Forest Health Protection unit established the following data bases for the 13 states in the Southern Region. The primary attributes of each data base are:

• Forests
  • Forest distribution by county is shown.
    Attributes include:
    • 22 Society of American Foresters cover types
    • Acres for each type
    • Volume (cubic feet per acre)
• Soils
  • Coverage is from State Soil Geographic Database (STATSGO).
    Attributes include:
    • Data on characteristics such as water content,
    • pH, organic matter and clay are available at various soil depths.
• Weather
  • Data base contains point and polygon coverages of weather data for all areas of the States in the Southern Region except western Oklahoma and Texas and northern Kentucky and Virginia. Data from 1951 through 1990 are currently available.
    Attributes include:
    • Monthly averages and deviations from a long-term (1951 through 1990) average in a gridded format for the following climactic variables:
      • Precipitation
      • Maximum daily temperature
      • Minimum daily temperature
      • Relative humidity
      • Wind speed
      • Freezing precipitation
• Pest stressors
  • Data exist for a number of pest stressors, including the gypsy moth, dogwood anthracnose, southern pine beetle, annosum root disease, and fusiform rust. Many of these stressors are discussed in more detail in this publication.