Book excerpt: "Forest Inventory and Analysis. The Forest Service Forest Inventory and Analysis (FIA) Program is the Nations continuous forest census. Since 1930, we have collected, analyzed, and reported information on the status and trends of Americas forests: how much forest exists, where it exists, who owns it, and how it is changing growing, dying, or being harvested. In response to widening customer interests, the FIA Program is developing a core program that will be implemented in the same manner on all U.S. forest lands. It includes sampling an extended suite of forest health indicators. The purpose of this brochure is to describe these health indicators: what we are measuring, why we believe these measurements are important, how we collect and interpret the data, and examples of what we have found to date. The FIA indicators discussed in this brochure are: crown condition, ozone injury, tree damage, tree mortality, lichen communities, down woody debris, vegetation diversity and structure, soil condition.