Umatilla National Forest - Silviculture Fact Sheet

	Silviculture Facts

Introduction Originating, growing, and tending stands of trees is called silviculture. Silvicultural treatments are used to meet the diverse objectives and values of society. On the Umatilla National Forest, silviculture helps sustain the health and productivity of forest ecosystems administered on behalf of the American people. During the pioneer era of Euro-American settlement in the Pacific Northwest, timber harvesting was an important means of economic development. Our forests were considered limitless and there was little consideration or knowledge about forest resources other than timber. Over time, the social values placed on our forests have changed. Non-timber forest resources, such as fish and wildlife, water quality, recreational opportunities, and visual aesthetics, are now recognized and highly valued by the public. At the same time, forest managers are learning more about the complexities of forest ecosystems. The Forest Service no longer manages national forests for sustained timber production. The new philosophy focuses on managing ecosystems and on coming up with strategies to protect endangered fish and wildlife species. In response to these changing values and expectations, timber harvest levels have changed dramatically. For example, timber harvest on the Umatilla National Forest in 1991 was 158 million board feet; by 2001, it had declined to only 24 million board feet.

Surveys Before any silvicultural treatments are implemented, a planning process occurs first. The first step in silvicultural planning is to complete surveys. Plantation surveys, thinning surveys, and stand examinations are examples of silvicultural surveys. During fiscal year 2001, almost 8,000 acres (7,890) of the Umatilla National Forest received a silvicultural survey. Survey information is entered into database systems and is then used for project planning, ecosystem (watershed) analysis, and Forest-wide planning.

Diagnosis Once goals and objectives (called desired future conditions in the Forest Service) have been identified for an area, the second step in silvicultural planning can occur – diagnosis of treatment needs and opportunities. A diagnosis examines options for achieving the desired future conditions of an area. During fiscal year 2001, over 31,000 acres (31,264) of the Umatilla National Forest received a silvicultural diagnosis to identify treatment needs and opportunities.

Prescriptions When a planning process is finished (resulting in an environmental assessment or environmental impact statement), a decision has been made about the silvicultural treatments that can be used in the planning area. The specifications about how a treatment will be implemented are contained in a silvicultural prescription. During fiscal year 2001, over 8,000 acres (8,722) of the Umatilla National Forest were included in a silvicultural prescription. No management activities that modify forest vegetation can occur without a signed silvicultural prescription. Prescriptions became mandatory in 1974 in response to public concerns about Forest Service timber management practices on the Monongahela and Bitterroot National Forests.

Certification Silvicultural prescriptions are prepared by certified (licensed) silviculturists. Prior to certification, silviculturists complete an intensive program of graduate-level training (currently 14 weeks of instruction, primarily at three universities in the Pacific Northwest). Initial certification is for a period of four years. To maintain their certification, a silviculturist must complete at least 120 hours of continuing education coursework during the four-year certification period. The continuing education coursework is distributed among four subject categories. As of fiscal year 2001, the Umatilla National Forest had a total of 8 certified silviculturists, not all of whom regularly prepare prescriptions for silvicultural treatments.

Tree Planting Reforestation is a critical component of forest management on the Umatilla National Forest. All public lands that are harvested (regenerated) must be successfully reforested in five years or less. The National Forest Management Act of 1976 established this requirement. The 5-year regeneration requirement also applies to salvage timber sales where trees killed by wildfire or insect attack are harvested. During fiscal year 2001, more than half a million seedlings were planted on the Forest to replace trees that were harvested, killed by fire, or damaged by insects and diseases. Those seedlings were planted on over 1,300 acres (1,369); about 3,200 acres were harvested in 2001, but not all of them will need to be planted at some point. The Forest Service began planting trees on the Umatilla National Forest in 1910, when red oak, shagbark hickory, pignut hickory, and black walnut were planted experimentally. Tens of millions of trees have been planted since then (note that exotic species like walnut or hickory are no longer planted). During the 1990s, from one to three million seedlings were planted each year. In today’s forests, tree planting helps speed the reforestation process. Continuing advances in research have resulted in higher-quality seedlings, improved planting techniques, and a high survival rate. The first-year seedling survival rate in 2001 was 87%, about the same as it was over 20 years ago (it was 88% in 1980). Third-year survival (survival of seedlings planted three years ago, in the spring of 1999) was 61%, a lower survival rate than 20 years ago (it was 78% in 1980). In fiscal year 2001, six tree species were planted on the Forest, often two or three different species on the same site. These included: Western larch Western white pine Lodgepole pine Ponderosa pine Engelmann spruce Douglas-fir Between 1997 and 2001, most of the Forest’s planting program was designed to help restore sites affected by the Bull, Summit, Tower, and Wheeler Point wildfires, all of which occurred in 1996. All of the trees planted on the Umatilla National Forest originated from seeds collected in wild natural stands. The seeds collected for planting stock come from numerous parent trees growing in the same general area as the planting site. The use of designated seed zones and 500-foot elevation classes ensures that seedlings produced from a particular seed lot will be used in the same area where the seed was collected. It is important that planted seedlings are well suited to their new home. The Umatilla National Forest uses an ecological site classification system to match tree species to environments where they will survive and prosper. Before completing a timber harvest or any other activity that removes trees, a silvicultural prescription is prepared to describe how the area will be reforested, which species will be used in the planting mix (if tree planting is prescribed instead of natural regeneration), and how the new trees will be cared for in the future.

Natural Regeneration On sites where only one or two tree species are planted, natural seeding from other trees in and around the area often serves to enhance diversity. Disturbed areas rapidly regain their plant diversity because trees and other native vegetation reestablish quickly. Dead trees can be replaced by planting a new tree or by natural regeneration, where seeds from cones in surrounding trees fall to the ground, take root, and begin a new forest. Natural regeneration is used for over 75 percent of the areas being reforested, but it often takes about three years longer for a natural seedling to become established. In fiscal year 2001, over 4,400 acres (4,425) were naturally regenerated.

Thinning To grow well, a tree needs a place in the sun and some soil to call its own. Thinnings are one way to provide the growing space that a tree needs. By reducing the number of trees in an area, thinning opens up a stand so that more sunlight, water, and nutrients are available for the remaining trees. During fiscal year 2001, over 2,500 acres (2,514) received a noncommercial thinning. A noncommercial thinning removes trees that are too small to be used for a product, although small trees can sometimes be used as Christmas trees. When thinning occurs in stands with larger trees, the trees being removed can provide lumber or other products. These are commercial thinnings. During fiscal year 2001, the Umatilla National Forest completed 783 acres of commercial thinning. Thinning reduces susceptibility to some insects and diseases, and to a destructive type of wildfire called crown fire, so it is often used to improve forest health. The Blue Mountains experienced chronic forest health problems over the last 30 years and thinning may increase in the future as one response to those problems. To guide thinning and other projects where reducing tree density is an objective, the Umatilla National Forest developed a stocking-level guide. It provides stocking recommendations for up to seven tree species that grow in 44 plant associations on the Forest. Copies of the new stocking-level guide can be requested from the Supervisor’s Office in Pendleton, or can be downloaded from the Forest’s Internet site.