Clearcutting

By Rex Storm, Certified Forester

The use of clearcutting today in Oregon forests is a science-proven tool for meeting diverse management objectives, including desired conditions for the healthy native tree regeneration to establish a young forest. Many of the mature forests seen today across Oregon are the result of successful past clearcutting and reforestation—which demonstrates its effectiveness at regenerating native trees (such as Douglas-fir and ponderosa pine). In recent years, clearcutting has comprised about 25% of the acres annually harvested on all forest ownerships in Oregon, with the remainder being a thinning harvest or another type of regeneration harvest that appears as a “partial cut.”

Professional foresters and other forest specialists draw from nearly 100-years of local experience and improved science when prescribing clearcutting as a tool to harvest mature trees and establish a new young forest in Oregon. Forest professionals apply clearcutting with prudent consideration of environmental, economic, and social concerns. Oregon’s Forest Practices Act & Rules (OFPA) include many measures that regulate the use of clearcutting on private and non-federal lands—while assuring two key operational results: 1) successful reforestation; and 2) natural resources protection.

Clearcutting and Science. Professional foresters define “clearcutting” as the harvest of nearly all standing mature trees within a specific area for the purpose of then regenerating a new young even-aged forest. Although on the surface this may appear to be a harsh practice (a recent clearcut admittedly is a stark contrast to the prior tall forest), both science and professional experience has proven that clearcutting successfully emulates natural disturbance and regrowth processes that occurred in Oregon forests prior to settlement in the 1800s. Furthermore, scientists have confirmed that the resulting forests, grown after clearcutting, actually can have desired biological characteristics to similar natural forests.

Less well known is the fact that forestry professionals carefully prescribe clearcutting as an effective tool for harvesting and regenerating native Oregon tree species having a “shade-intolerant” (i.e., sun-loving) ecology. Many of Oregon’s forest trees cannot successfully establish and grow well under the shaded canopy of larger trees; these tree species demand open areas having full sunlight created by disturbances—such as clearcutting. Additionally, clearcutting can be the preferred option to harvest and regenerate entire areas where nearly all the overstory trees are very unhealthy, dying, or dead—when such trees are so unhealthy that any other partial-cut harvesting of the area could not be successfully reforested. In these two situations, silvicultural scientists have confirmed in recent decades that clearcutting, and subsequent reforestation, is highly successful at achieving desired biological and productive outcomes similar to natural forests.

The Forest Landscape with Clearcuts. Research by forest scientists has shown that, in large landscapes, a variable, moving pattern of younger to older forests perpetuated by clearcutting provides dynamic and diverse habitat that sustains plant and animal biodiversity. Conversely, in some areas, a lack of disturbance—either clearcutting or natural events—appears to negatively affect some desirable plants and animals. The open-young stage of forest development has an important role and niche in the ecology of Oregon’s forest native flora and fauna.

Oregon’s 30 million acres of forestland prior to settlement in the 1800s, were a “mosaic” of three different forest conditions: 1) young-open forests; 2) middle-aged dense forests, and 3) older complex forests with large trees. These native forests were established after major natural disturbances that killed most trees in an area—wildfire, pest outbreaks, storms, slides and floods. Clearcutting is a way to create a managed forest “mosaic,” by emulating these natural disturbances to regenerate and begin a new forest. Many of Oregon’s current “second-growth” forests illustrate the success of clearcutting and regenerating native, sun-loving trees.

When considering nature and the environment, maintaining a portion of forest area within each of these three ages would be desirable. This makes sense because each of these three forest age-conditions provides their own unique and important ecosystem values that the other two cannot. Each age-condition offers uniquely different tree-size structures, vegetation, aesthetics, biodiversity, aquatic life, birds, wildlife, and forest watersheds.

Managed Forests in a Modern World. Today, the needs and values of both rural and urban communities do not allow us to rely on large-scale, and uncontrolled, catastrophic natural disturbances to regenerate forests. Oregon property owners and rural communities especially cannot accept those large wildfires that threaten life, property, timber, commerce, air quality, and valued forest resources. Instead, foresters carefully prescribe harvest and regeneration methods, including clearcuts, to manage forest areas using methods that mimic natural disturbances, while producing desired timber yields and protecting key resources.

In Oregon, a clearcut area is a temporary condition because the state’s forest law requires prompt reforestation, and a young open forest must be established soon after harvest. Reforestation success on non-federal forests in recent decades has been achieved at a rate of 99% due to improved seedling, planting, and protection technology.

Clearcuts with Reserve Trees. Foresters and forest plans on some forest ownerships have begun to utilize a variation of the clearcutting method, where some standing overstory trees are retained after harvest—called “clearcut with reserves,” or “modified clearcut.” A clearcut with reserves has varying numbers of canopy reserve trees that are not harvested to attain goals other than regeneration. Extra overstory green trees are left indefinitely for strategic purposes, such as structural diversity, habitat, shelter, aesthetics, and/or public policy. The consequence of this extra retention in shade-intolerant trees is slowed regeneration establishment and retaining a second age class of additional overstory, creating a two-aged forest. Depending on habitat needs and other conditions, foresters may plan for trees to be retained within clearcuts individually or in small or large clumps.

Professionals Prescribe & Manage Clearcuts. Forestry is an objectives-driven profession, and the site-tailored prescriptions for clearcutting are best made by forest professionals who seek to accomplish objectives of the forest plan, landowner, and Oregon law. Foresters carefully account for the environmental, social & economic costs and benefits of each harvest & regeneration decision involving clearcutting. Oregon forest professionals and land-management experts for more than a century have continuously improved the science, technology and experience surrounding clearcutting. Forest owners and managers progressively work to improve harvesting methods, while also refining reforestation success following planned harvests. Further monitoring and research continuously improves harvesting methods. Logging operators typically follow detailed directives to effectively implement management prescriptions.

Strong Oregon Laws and Clearcuts. To address concerns about natural resource effects from harvest and reforestation, Oregon has comprehensive forest laws regarding clearcuts. The Oregon Forest Practices Act & Rules (OFPA) safely promotes the economical growing and harvesting of forests. Oregon’s strong program of harvest regulation protects water quality, fish & wildlife habitat, as well as future forest growth. Ongoing monitoring and research assure that specific clearcut practices employ environmental safeguards. The OFPA defines a number of resource protection outcomes applicable to clearcutting, including: limit clearcut size; tree buffers on streams & wetlands; required wildlife leave trees & down logs; prevent ground & vegetation disturbance near water; limit ground disturbance; minimize roads; retain buffer vegetation during burning & release; timely reforestation with native seedlings; and required well-distributed “free-to-grow” young trees within 6-years of harvest.

Effective and Economical Tool. Because forest product markets are competitive and global in scope, clearcutting is attractive as often the most effective and economical method to harvest and regenerate many native Oregon tree species. Related post-harvest activities that promote reforestation success—such as tree planting, vegetation release, or prescribed burning—also are efficiently applied in clearcut areas. Similarly, the control of insect, disease, and wildfire hazards can be easier and more effective when clearcutting is an available management tool. Clearcutting and regeneration is also a viable tool to consider for accomplishing restoration of overcrowded, unhealthy, damaged or dead forests.

Managers making clearcutting decisions choose from a range of management options, consistent with forest laws, valid forest plans, current forest silvicultural principles, time-tested local experience, and locally-tailored science. Professionals engaged in harvest & regeneration decision-making may include the: forester, silviculturist, forest engineer, forest biologist, hydrologist, recreation planner, economist, forest fuel specialist, and others.

Clearcut Controversy. For several decades, extensive public misinformation and litigation surrounding the environmental virtues of clearcutting has clouded the efficacy of using this method to harvest & regenerate an Oregon forest. Most current concerns about clearcutting stem from misinformation and a lack of distinction between past and modern standards for logging & reforestation. Clearcut areas can be relatively unattractive for a few years after harvest and reforestation, which contributes to misperceptions about presumed (wrongly) harm to the environment due to clearcutting. Criticism of clearcutting misuses the term to falsely slander the practice, or even to mislabel activities that are simply not clearcutting—such as land-use change clearing for residential development or permanent forest clearing for agricultural use.

Today’s clearcutting standards have evolved to address those past environmental concerns. Further misunderstandings arise from misinformation and a failure by many to distinguish the validity of different forest plan objectives—such as production forests, or multiple-use forests, managed forests, forested rangelands, roaded natural lands, or private forests—where clearcutting is logically and scientifically a proven tool to manage native forest tree species. Confusion about these very basic matters of current harvest regeneration standards and applicable forest plans has fostered unnecessary controversy about clearcutting.

Biological Diversity. In 2011, I attended a public walking tour to visit a large forested natural area recently purchased by the Portland, Oregon Metro Regional Council of Governments (the 1,200-acre Chehalem Ridge Natural Area). Led by the Area Ecologist, one of the group’s tour stops was within a 35-acre open-grown young forest about 10 years old, which was thriving with a mix of small conifer & hardwood trees, shrubbery, grasses and forbs. The birdlife and wildlife activity was obvious about us that day, as the open forest also afforded panoramic views of the lush landscape surrounding our group. The visitors chattered with interest and satisfaction about the special biological diversity and aesthetic views at this stop.

The Ecologist was proud of this unique patch of young forest; assuring the tour visitors that the natural area’s soon-to-be written forest plan would strive to replicate this young forest opening, by managing to always keep a portion of the forested Natural Area in this young & open forest condition. The Ecologist told us that the forest is always growing, and this particular 35-acre patch would not remain young, open or wonderfully diverse very much longer. As the years passed, this patch would become a dense and darkening grove of trees where the tall tree canopies would overtop the diverse undergrowth, shading and eliminating much of today’s vegetative and wildlife diversity.

The real surprise for many tour visitors came when the Ecologist explained that this biologically-diverse young forest in the Natural Area was created by clearcutting ten years prior! The previous landowner had carefully harvested using the clearcut method, successfully planted conifer tree seedlings, and then tended the area to assure a diverse blend of conifer, hardwood and shrub vegetation establishment. Those quite ordinary—and often criticized—clearcut and reforestation activities completed by the forest landowner 10-years ago are today celebrated by the Natural Area Ecologist and other Area visitors!

As a forester, I also am proud of this wonderfully-diverse patch of the Natural Area, because I know that foresters all over Oregon, every day, manage their forestlands with care to assure that there is biological diversity reestablished in their clearcut harvest areas—just like the bio-diversity found here in this one-time clearcut located in Portland’s Chehalem Ridge Natural Area.

Summary. Clearcutting is a well-proven harvest and regeneration method in many situations or forest types across Oregon, where determined by skilled forestry professionals to be most suitable. Careful planning and implementation of harvest and reforestation prescriptions, in compliance with state regulations, are keys to realizing the benefits of clearcutting while avoiding possible negative impacts. Oregon’s professional foresters and forest operators have the knowledge and experience to understand the benefits and risks of clearcutting. Working with natural resource professionals, foresters provide essential guidance for its proper application in meeting landowner objectives and broad public goals.