The research branch of the U.S. Forest Service, a division of the U.S. Department of Agriculture, is the largest forestry research organization in the world, providing scientific information and assistance to federal, state, and local agencies, as well as to private organizations and the international community. In the Alaska region, Forest Service planning personnel often perform analyses of timber tentatively suitable for harvest in the Tongass National Forest. To accomplish this task nowadays, John Day, regional office planner from the Alaska region, and Dr. Keith M. Reynolds, a lead U.S. Forest Service scientist, turn to the Ecosystem Management Decision Support (EMDS) system to develop a sophisticated and accurate picture of timber suitability in the Tongass National Forest.

Prior to EMDS (and the advent of ArcObjects technology within ArcGIS), this task was conducted by writing a series of ARC Macro Language (AML) scripts to create and overlay the necessary attributes in ArcInfo. The primary problem was the challenge of easily evaluating forest attributes among a range of "goodness" values within the AML scripts. For example, a slope of 10 percent was as "good" for harvest as a slope of 70 percent. The complex AML scripts made depicting this range as well as ranges for other attributes unmanageable. The process took a few weeks to complete and resulted in a map with a simple classification of land units as either suitable or unsuitable for timber harvest.

However, in EMDS, Day and Reynolds immediately discovered that the logic modeling ability improved the timber suitability analysis process greatly. Rather than writing hundreds of lines of AML, the evaluation process is entered as a series of connected nodes (a knowledge base). This process took less than a few hours and mimicked exactly what had taken weeks in the past.

One advantage the team in Alaska reaped using a decision support system such as EMDS was that EMDS provided a general application framework in which the user applied existing logic-based models to the specific geographic area of interest. In this case, Day and Reynolds dramatically reduced their development time and generated a more realistic result. The planning staff in the Alaska region saw this as a significant improvement because the logic metric of EMDS expressed degrees of timber harvest suitability on a continuous scale rather than the simple suitable/unsuitable (Boolean) classification developed with ArcInfo alone.

Day and Reynolds also found EMDS' logic-modeling approach especially useful. Forestry personnel could include, in the context of landscape analysis, the ability to reason effectively with incomplete information, evaluate the influence of missing data on completeness of an analysis, develop priorities for missing data, and trace and explain the derivation of model results in an intuitive graphic interface. However, Day and Reynolds noticed EMDS had two notable limitations. EMDS could not provide explicit support for planning decisions that would naturally follow every evaluation, and EMDS lacked the data model needed to represent each project's structure.

Reengineering to New Technology

To make EMDS more user-friendly and improve application functionality, the U.S. Forest Service contracted with Esri Professional Services to reengineer EMDS to the new ArcObjects technology of ArcGIS 8.1 as an extension that supports landscape evaluation. The U.S. Forest Service and Esri had previously released the first versions of EMDS together in 1997, and again in 1998, using ArcView 3.x technology as the basis for operation. For the first time, EMDS provided Forest Service scientists and resource managers with a knowledgebased decision support system for landscape evaluation. Enhancements to these versions of EMDS represent a significant evolutionary advance in system design.

The latest version of EMDS builds on the work done in the first versions and includes full integration of the landscape evaluation component into the ArcGIS interface. The interface is augmented by integrating a new planning component that assists users with prioritizing landscape features for management activities given the results of an evaluation.

John Steffenson, Esri forestry industry manager, comments, "The integration of knowledge engineering, GIS, and planning models is a powerful concept, and EMDS is an excellent example of a robust and very practical achievement of this concept."

The new user interface of EMDS gives resource managers a valuable tool to organize, document, and present results from complex ecosystem evaluation projects. Commenting on the new assessment interface, Reynolds notes, "The organization of information can become rather complex within an EMDS project, because projects support multiple scales of assessment, multiple analyses within an assessment, and multiple scenarios within an analysis." Reynolds is confident that the new tree view of project information will provide a much more intuitive way of graphically navigating through this information.

This latest version of EMDS also emphasizes a user-friendly interface with context menus, wizards, and context-sensitive help files to guide users through the process of setting up and running an assessment. EMDS users will find a highly interactive environment to accomplish a diverse range of tasks including

• Assembling and organizing spatial data
• Selecting scales of assessment and defining assessment regions
• Controlling details of knowledge base processing
• Interpreting results of knowledge base processing
• Exploring alternative scenarios
• Evaluating the logical completeness of an analysis
• Prioritizing missing data
• Prioritizing landscape elements for management activities
• Spatial data exploration

With the release of the current version of EMDS, the U.S. Forest Service expects this rigorous ecosystem evaluation tool to continue supporting Forest Service regional offices, such as Alaska, perform ecosystem management analyses for many years to come.

For more information about EMDS, contact Richard Lawrence, Esri project manager (tel.: 909-793-2853, ext. 1-1700, e-mail: rlawrence@esri.com) or Keith Reynolds (e-mail: kreynolds@fs.fed.us, tel.: 541-750-7434) or visit www.fsl.orst.edu/emds.