The Forest Inventory and Analysis (FIA) Program of the Forest Service, U.S. Department of Agriculture, conducts a national inventory of forests across the United States. A systematic subset of permanent inventory plots in 38 States is currently sampled every year for numerous forest health indicators. One of these indicators, crown-condition classification, is designed to estimate tree crown dimensions and assess the impact of crown stressors. The indicator features eight tree-level field measurements in addition to variables traditionally measured in conjunction with FIA inventories: vigor class, uncompacted live crown ratio, crown light exposure, crown position, crown density, crown dieback, foliage transparency, and crown diameter. Indicators of crown health derived from the crown data are intended for analyses at the State, regional, and national levels, and contribute to the core tabular output in standard FIA reports. Crown-condition measurements were originally implemented as part of the Forest Health Monitoring (FHM) Program in 1990. Except for crown diameter, these measurements were continued when the FIA Program assumed responsibility for FHM plot-based detection monitoring in 2000. This report describes in detail the data collection and analytical techniques recommended for crown-condition classification.

"This is a forest measurements textbook written for field technicians. Silvicultural applications and illustrations are provided to demonstrate the relevance of the measurements. Special “technique tips” for each skill are intended to help increase data collection accuracy and confidence. These include how to avoid common pitfalls, effective short cuts, and essentials for recording field data correctly. The emphasis is on elementary skills; it is not intended to be a timber cruising guide"--BC Campus website.

Excerpt from Crown Condition Rating Guide: April 8, 1992 The Visual Crown Rating (vcr) Model is presented in the appendix to show how a combination of the crown measurements may be used to describe tree health. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

S2The yield of even-aged hardwoods can be increased by a A program of regular thinnings. The questions are: How much increase can be expected? And what are the effects on quality? The 5-year results from a long-term study of thinning in young northern hardwoods on the Bartlett Experimental Forest in New Hampshire show that heavy thinning increased crop-tree basal-area growth by 53 percent and crop-tree diameter growth by 64 percent. There were no adverse effects on tree quality, and overall stand quality has been improved.S3.