USDA Forest Service

Pacific Northwest Research Station

Pacific Northwest Research Station
333 SW First Ave.
Portland, OR 97204

(503) 808-2100

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» Forest Inventory and Analysis

Census for the Nation’s forests

Andy Gray. Credit-USDA FS.Photo by USDA Forest Service

The Pacific Northwest (PNW) Research Station Forest Inventory and Analysis (FIA) program conducts resource inventories of forests in Alaska, California, Oregon, Washington, Hawaii, and the Pacific Islands. Land area, live and dead tree volume, aboveground biomass, and carbon mass and more are addressed in an analysis and summary report. Inventory data are analyzed to assess current conditions, evaluate how forests have changed over time, and predict future conditions. The PNW-FIA program is one of four such work units in the research branch of the USDA Forest Service.


Contact: Gretchen Nicholas,


Guide highlights Pacific Coast’s ‘most wanted’

Nonnative invasive plants of Pacific coast forests: a field guide for identificationCover design: K. Routman

Nonnative invasive plants affect landscape composition and function and can be costly to eradicate or control. To help managers identify the most problematic and prevalent invasives in coastal forest lands of California, Oregon, and Washington, research ecologist Andy Gray and colleagues published Nonnative Invasive Plants of Pacific Coast Forests: A Field Guide for Identification.

The illustrated guide is the first to combine identification information with plant descriptions and detailed images for this area and highlights 56 species. It was written using a variety of resources, including information from national, regional, and state lists; assessments; and botanical guides. It is used not only by botanists and land managers, but by the FIA program, in its surveys.


Contact: Andy Gray,


Pacific Islands are an FIA focus

General field crew: Caption-FIA crew sometimes uses boats to reach plots in the Pacific Islands. Credit-Mika FalanikoPhoto by Mika Falaniko

FIA’s researchers collect, analyze, and summarize field data gathered on islands throughout the western Pacific, including the Federated States of Micronesia, the Commonwealth of the Northern Mariana Islands, and the Marshall Islands. Data and summaries from these inventories are used by island groups to develop their statewide assessments and resource strategies that enable them to compete for funding. The data also are used to guide resource management and policy decisions. The FIA data are helping to clarify the impacts of things like human land use practices and rising sea levels on the islands’ native plants and ecosystems.


Contact: Joseph Donnegan,


LIDAR estimates Alaska biomass

LIDAR is used to capture data in interior Alaska landscapes. Credit-Hans AndersenPhoto by Hans Andersen

Remote communities in interior Alaska generally rely on fossil fuels for their power and heating needs—with rising diesel costs, these communities often spend more than a third of their household income on utilities. Wood-based energy could be a viable alternative, but, first, estimates of available forest biomass are needed to guide energy production plans.

Researchers tested the ability of LIDAR, a form of airborne laser scanning, to measure biomass availability over large, mostly roadless areas in the interior. They found that LIDAR sampling, conducted using airplanes equipped with scanners, estimated total biomass with an 8-percent level of precision, indicating that the 200 000-hectare study in the upper Tanana valley contained about 8.1 million metric tons of biomass.

As part of the study, researchers also identified measures to take to increase sampling precision. Their findings indicate that airborne LIDAR sampling can be useful in planning bioenergy development in interior Alaska.


Contact: Hans Andersen,


Featured Scientist

Andy Gray.Andy Gray is a research ecologist and leader of the Vegetation Monitoring Science and Applications Team. His research focuses on how disturbance and management affect forest composition and structure and at what scope and scale forest inventory data should be applied. He also is an expert on conditions and trends of Washington’s forest resources.

Gray is applying inventory data in many of his current research projects. Among his studies: he is reconstructing carbon flux through time using inventory and satellite data, improving predictions of tree canopy cover from tree measures, and estimating the regional extent of wildlife habitat from inventory plots.

Gray is based at the Corvallis Forestry Sciences Lab and can be reached at

Tools and Software




PNW-FIADB is a database maintained by the station’s Forest Inventory and Analysis program. It allows users to answer questions about the status and trends of forest resources by summarizing data on live and dead trees, down woody materials (fuels), and understory vegetation. The tool has been used by resource managers and policymakers to inform their decisionmaking processes. It also has been used to quickly respond to requests about biomass size distribution and the availability of wood supplies from national forests. Learn more by contacting Karen Waddell,


US Forest Service - Pacific Northwest Research Station
Last Modified: Tuesday,05August2014 at09:40:53CDT

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