Sustained Yield Forestry

Sustained Yield Forestry

What the Law Requires:

O&C timberlands shall be managed for permanent forest production, and the timber thereon shall be sold, cut, and removed in conformity with the principle of sustained yield. The O&C Act, 43 U.S.C. 1181a

Sustained Yield Definition:

Harvesting at a rate that is in balance with, and does not exceed, the growth rate of the forest.

Management According to Principles of Sustained Yield

The O&C Act was the first federal statute that regulated the rate of harvest to ensure a perpetual timber supply and a full range of forest values for future generations. Sustained yield management of the O&C forest can produce an everlasting supply of wood products while simultaneously providing clean water, a broad range of wildlife habitats, carbon storage and ample recreation opportunities. Sustained yield management provides economic benefits for all citizens: funding for vital community services, thousands of family-wage jobs and the ability to maintain necessary industrial infrastructure. Sustained yield management of the O&C forest is vital to the fabric of rural communities in western Oregon.

There is much more to sustained yield management than most people are aware. It uses a wide variety of techniques and intensities to achieve multiple objectives. To learn more about specific aspects of the O&C sustained yield story, scroll down or click on the individual topics below.

Bureau of Land Management

Management Practices

Bureau of Land Management

Sustained yield forestry uses a variety of management practices to sustain and enhance a range of forest conditions across the O&C landscape. These management practices are all tools in the toolbox for maintaining sustainable communities and sustainable environments. Click on individual items below or simply scroll down to learn about these practices.

Regeneration Harvest with Tree Retention

Photo taken 10 years after harvest. This is a multi-aged stand that will develop into complex forest.
Returns to spotted owl habitat conditions more rapidly than without retention.

Regeneration Harvest with No Retention - Clear Cut

Foreground Immediately Following Harvest – Background 30 Years After Harvest

Creates single story/age stands
Economically efficient
Maximizes volume production

Commercial Thinning

Intermediate Harvest – To Improve Tree Growth

Captures volume from the understory trees and provides more growing space and light for the remaining trees.
Improves growth and resiliency of the stand.

Commercial Thinning

Intermediate Harvest – To Speed Structural Complexity

Harvest of a range of individual trees within the stand to advance the development of complex forest conditions in the remaining stand.
Has application in both riparian and older forest emphasis areas.
Openings allow younger trees and vegetation to develop in the understory adding biodiversity of flora and fauna.

Bureau of Land Management

Density Reduction with Fuels Treatment

Intermediate Harvest – For Fire Resiliency

Reduces the density of trees in the stand by harvest of commercial trees and cutting, piling, and burning non-commercial trees and brush.
Can be combined with or lead to subsequent uneven-aged management treatment.
Improves fire resiliency of the stand and surrounding landscape.
Especially applicable in dry forests of southwest Oregon.

Uneven-Aged Management

Photo shows conditions following harvest within a stand that has multi- aged conditions.
Stands with trees of uniform age can receive thinning or other density reduction treatments to create uneven-aged conditions.
Uneven-aged management creates fire resilient forest conditions and also has application in riparian and older forest emphasis areas.

Uneven-Aged Management – With “Gap” Openings

Photo shows young forest developing in a gap opening (in background) created within a stand managed for uneven-aged conditions.
This management practice has application in older forest emphasis areas.

Individual Tree Selection

Selective harvest of individual trees within a stand that does not significantly alter the character of the remaining stand.
Individual tree selection can introduce small openings and promote stand complexity and increase biodiversity.
Individual tree selection has application in riparian and older forest emphasis areas.

Web-Based Forest Management Guides

Cycle of Management

Rotation: The time between planting a new stand and conducting a final (regeneration) harvest.
Cycle of Harvest: The sequence and timing of thinning and regeneration harvest of a stand over the rotation period. In the context of uneven aged management it is a cycle of partial harvest treatments that maintain a level of canopy cover and desired structural composition of the stand. Regeneration in uneven aged management occurs in the openings created within the stand. One complete cycle of harvest has not yet occurred on most of the O&C Forest.

The Cycle of Harvest Can Be Varied to Meet a Range of Objectives

Economics – Managing a forest for purely economic objectives is based on maximizing return on investment and on economic efficiency. These concepts account for the shorter harvest rotations (generally under 50 years) practiced on private industrial forests lands. Purely economic objectives applicable on private industrial forestlands have limited applicability on O&C lands.
Volume – Management that maximizes timber volume output is based on the biological capacity of the forest. Individual site conditions and tree species determine the age at which annual growth will peak. This peak of productivity can be determined. The age of maximum productivity establishes the minimum harvest age to maximize timber volume. For the O&C forest, the age at which annual growth peaks ranges from 80 to 150 years, depending on site and species. The BLM has historically applied these maturity criteria as a minimum harvest age. On O&C lands, volume objectives alone would call for harvests of more than 1.2 billion board feet per year. The O&C Act’s minimum harvest level of 500 million board feet per year (40 percent of the annual volume production) leaves great latitude for reaching other objectives.

Complex Forest Conditions – Achieving complex forest conditions takes time. Characteristics associated with large trees and multi layered conditions generally do not develop until a stand is 80 years old and older. Retaining trees at the time of harvest and planting seedlings among them can reduce the time it takes to achieve complex forest conditions in a stand. Intermediate harvest treatments can also create complexity from uniform stand conditions. In many cases actively managed stands create complex forest conditions in shorter time than required for an unmanaged stand.
Riparian Habitats – Many stands adjacent to streams are younger, denser forests that can benefit from intermediate harvests such as thinning. These benefits include maintaining healthy growth and promoting the development of larger trees that eventually contribute the large woody debris that creates fish habitat within streams. Stands directly adjacent to streams also offer shade that is important to maintaining water temperatures within biologically acceptable ranges. The yield from intermediate harvests within riparian areas declines over time as the younger forest is thinned, but some selective harvest of individual trees for wood recruitment in streams or to help pay for habitat improvement projects can be maintained at lower levels over extended periods.

History and Current Forest Conditions

The history of natural disturbances along with timber harvest has shaped the current conditions of the O&C Forest.

Bureau of Land Management

Current O&C Forest Conditions

Stands under age 80 were created by fire and timber harvest during the “O&C Era” – 1937 to the present day.
Stands over age 80 provide older forest habitats including “Old Growth”.
After 80 years of management, 54% of the O&C Forest continues to provide older forest habitats.

History of Harvest 1937 to 2014

Timber Volume Has Increased

“O&C Era” – 1937 to Today

The rate and type of harvest on the O&C forest since 1937 has affected the forest conditions that exist today. There are generally three distinct management periods.

1937 – 1960: Harvest was well below the forest’s annual productive capacity of 1.2 billion board feet. Retention of “seed trees” for reforestation and selective cutting due to merchantability standards resulted in legacy trees remaining after harvest, creating structurally complex forest conditions.
1960 – 1990: Improved forest inventories and new federal policies raised the annual harvest level to over 1 billion board feet. Higher harvest levels were authorized for salvage after the Columbus Day storm and the Ox Bow fire as well as by congress for the “318” sales.
1990 – Today: The Northwest Forest Plan (NWFP) allocated 27% of the O&C forest for sustained yield management to produce approximately 200 million board feet annually. This was not in compliance with O&C Act requirements to manage all forest lands for sustained yield and harvest a minimum of 500 million board feet per year. BLM never implemented even the NWFP’s deficient timber objectives and resorted instead to “non-controversial” management, primarily thinning of young forest. BLM’s own plan evaluations have consistently found this approach is not sustainable. Very little regeneration harvest of mature forest occurred, which has resulted in a shortage of younger forest age classes and reduces the future sustained yield of the forest.

History & Forest Conditions - Key Points

In 1937 the total standing volume was 50 billion board feet. After 80 years of harvest totaling 50 billion board feet, 73 billion board feet of timber stands today on the O&C Forest.
Over half of the O&C Forest is currently in older forest habitats after 80 years of management.
BLM practices over the last 20 years are not consistent with management under the principles of sustained yield and cannot be sustained. Reliance on “thinning only” has resulted in a shortfall in young age classes that are needed for a balanced harvest over time.
Restoring sustained yield management on the O&C forest and producing 500 million board feet per year can be achieved while continuing to provide older forest habitats, clean water, increasing carbon stores, and a range of recreational opportunities.
More is Possible!

Looking Forward

The O&C Counties have been passionate advocates of sustained yield forestry for 80 years. That advocacy will continue. Departures from sustained yield by the BLM in the recent past have been in conflict with the O&C Act’s primary objective of maintaining sustainable communities side by side with sustainable environments. The BLM’s current management practices are failing to meet this objective.

The Counties were eager participants in a blue-ribbon panel of stakeholder interests convened by Governor Kitzhaber. The panel met repeatedly during 2012-2013 to examine options for solving the O&C conundrum. The panel produced a useful report that has served to inform and educate.

The Counties were also participants in the development of the O&C Trust, Conservation and Jobs Act sponsored by Oregon’s Congressmen DeFazio, Walden and Schrader. The bill would have restored sustained yield management on the O&C lands under management by a board of trustees appointed by the State. The bill passed the House in 2013 as part of HR 1526 but did not move in the Senate. The bill passed the House a second time in 2014 as part of HR 4, and again did not move in the Senate. Senator Wyden introduced his own bill in 2014 and again in 2015, but it would have repealed the O&C Act in its entirety without adequate replacement and for that and other reasons failed to gain support from most of the O&C Counties.

The Counties will continue to seek restoration of proper management on the O&C lands, either under the O&C Act, or under new legislation. Litigation filed by the Counties in 2016 seeks a judicial order requiring the BLM to follow the letter of the law as expressed in the O&C Act. The Act’s mandatory minimum harvest level of 500 million board feet per year can be achieved in many ways, and still maintain clean water, a range of wildlife habitats, and all the other desirable attributes of sustainable environments. The Counties have offered numerous conceptual examples of management strategies that could be followed. Click here to see a slide presentation of one such strategy.

A growing awareness of the virtues of sustained yield forestry bodes well for the future. Community support is at a high level and increasing. With education, it becomes obvious—-More is possible! The O&C Counties will continue with education and advocacy in pursuit of sustained yield forestry on the O&C lands, to produce sustainable communities and sustainable environments.