Live tree biomass estimates are essential for carbon accounting, bioenergy feasibility studies, and other analyses. Several models are currently used for estimating tree biomass. Each of these incorporates different calculation methods that may significantly impact the estimates of total aboveground tree biomass, merchantable biomass, and carbon pools. Consequently, carbon markets, bioenergy projects, and similar efforts may be affected. In addition to differences in allometric equations, the various methods are most suitable for particular geographic scales of analysis. We examine three approaches that might be used for midscale analyses (e.g., 25,000 to several million acres) and compare the regional models with equations developed by Jenkins et al. and with the component ratio method (CRM). These three methods produce relatively similar estimates of total aboveground biomass for softwood species in Oregon, but substantially different estimates for the proportion of total biomass that is merchantable . For the major softwood species in Oregon, the total aboveground biomass using the CRM is 3 percent lower than estimates with regional equations, and the Jenkins models produce estimates that are 17 percent higher. However, on average, the proportion of softwood merchantable biomass computed with CRM is about 83 percent of the total aboveground biomass with little variation from species to species, whereas regional models estimate that 72 percent is merchantable, and the Jenkins equations estimate that 78 percent is merchantable.

This study presents techniques for calculating average net annual additions to carbon in forests and in forest products. Forest ecosystem carbon yield tables, representing stand-level merchantable volume and carbon pools as a function of stand age, were developed for 51 forest types within 10 regions of the United States. Separate tables were developed for afforestation and reforestation. Because carbon continues to be sequestered in harvested wood, approaches to calculate carbon sequestered in harvested forest products are included. Although these calculations are simple and inexpensive to use, the uncertainty of results obtained by using representative average values may be high relative to other techniques that use site- or project-specific data. The estimates and methods in this report are consistent with guidelines being updated for the U.S. Voluntary Reporting of Greenhouse Gases Program and with guidelines developed by the Intergovernmental Panel on Climate Change. The CD-ROM included with this publication contains a complete set of tables in spreadsheet format.

Forest Biometrics presents the methods of mathematical statistics and biometrics that are significant to forestry. This book explores other fields related to forestry, which are explained with the help of a large number of practical examples. Organized into 25 chapters, this book starts with an overview of the variety of data that play a significant role in forest management, including the age of trees, the damage caused by storms, the fluctuation of timber prices, bark beetle infestation, and timber volume. This text then examines the factors that are responsible for a random distribution of the values in biological experimentation. Other chapters consider the important advantages of sample surveys compared to complete enumerations, include cheaper samples, wider applicability, quick results, and greater accuracy. The final chapter deals with the factors to be considered in determining the best time for harvesting of timber. This book is a valuable resource for students, research project leaders, and practical workers.

This book is a printed edition of the Special Issue "Forest Operations, Engineering and Management" that was published in Forests