- Linehan, Peter E.
University of Maine Graduate School
The rapid increase in demands placed in Maine's Forests is forcing managers of commercial timberlands to look critically at their landholdings in order to gain the optimum use of the timber base. Although in terms of economic theory, every tree that is available for harvest could be harvested at some price, market returns, physical factors, machinery limits and legal requirements constrain which forests can or should be harvested.
Selecting attributes for classification is the first step in evaluation operability. This process forces the manager to decide which combination of factors is important in describing the resources.
Of the Decision Support System options available for assisting the forest manager in evaluating operability, an expert system, or rule-based advisor was chosen. Expert systems capture heuristic knowledge in a series of If-Then-Else rules. An inference engine searches the rule base during a consultation.
Harvestable? was written with an expert system development tool, VP-Expert. Through a series of interactive screens it evaluates physical, legal and site productivity aspects of a tract of timberland for operability for harvesting. The user has the option of storing the results of a consultation in a database and making multiple consultations of the rules during a single session. Economic and market considerations were outside the scope of this study.
The present form of the system is most useful as a trainer in understanding operability factors. Future versions of the program can be designed to interface with a GIS to make sure of existing information and make operability ratings that could be added as another layer of data. The system can be adapted to combine market price and demand information with inventory data to indicate areas for harvesting. Ultimately, the expert system can be configured to be an information manager and gatherer in a a larger decision support system for forest management.