2025 Urban Inventory of Portland, Oregon, San Diego, California, and the statewide inventory in Washington

This document describes the standards, codes, methods, and definitions for urban Forest Inventory and Analysis (FIA) field data items. It describes FIA field procedures that are consistent and uniform across urban FIA units nationwide, along with some regionally-specific variables. Individual programs may add regional variables that support their core program but may not change or add to the nationally standard urban FIA requirements. Unless otherwise noted, the items in this field guide will be collected by all FIA units as specified. Items or codes specified as optional are not required by individual units; however, if the item is collected or coded, it will be done as specified in this field guide. It is expected that, on average, all items in this guide can be measured by a one or two-person field crew in less than one day, including travel time to and from the plot. Urban FIA plots will be referred to as urban plots throughout the field procedures.