Monitoring nontimber forest products using forest inventory data: an example with slippery elm bark
The USDA Forest Service Forest Inventory and Analysi (FIA) program collects data on a wealth of variables related to trees in forests. Some of these trees produce nontimber forest products (NTFPs) (e.g., fruit, bark and sap) that are harvested for culinary, decorative, building, and medicinal purposes. At least 11 tree species inventoried by FIA are valued for their bark. For example, slippery elm (Ulmus rubra Muhl.) is included in FIA forest inventories, and the bark is used for its medicinal value. Despite widespread use of NTFPs, little quantitative information about abundance, distribution, and harvest is available to support sustainable management. Methods for using the FIA database to monitor and explain the situation regarding selected NTFPs are presented. The focus is on using FIA data to assess for (1) geographic distribution, (2) abundance, (3) applicable metircs (e.g., square feet of bark, and (4) change over time.