In the last century, on the private lands of the region, loggers first stripped forests of their prime, old growth trees, and then followed up years later by logging most of the medium large trees that remained. While the loss of the often huge, older conifers was a blow to wildlife, the fact that most forest areas were selectively logged at least ensured that the post-logging habitat still contained lots of smaller trees, lots of hardwoods, and many snags and down logs.
Two decades ago, however, Sierra Pacific Industries (SPI) has bought out all its competitors in the region and began systematically applying widespread clearcutting, followed by bulldozing and “site prep” treatments and tree planting that converted the natural forest into 20-acre blocks of tree plantations.
Private forest logging practices
CSERC supports the use of thinning logging methods by private companies on their private lands, but our Center is strongly opposed to widespread clearcutting.
On some sites, SPI has softened the visual impact of clearcuts by leaving a scattering of small trees or leaving a few pockets of tree clumps. Even in those situations, more than 95% of each 20-acre clearcut unit is still logged, bulldozed, sprayed with herbicides, and converted to even-aged tree plantations that lack diversity.
The diverse and healthy forest habitat that originally grew on those sites is mostly destroyed. Many wildlife and plant species struggle to survive in the midst of rows of densely-planted pine trees. CSERC continues to advocate for changes in California’s forest practice rules so that no more than a small percentage of land in any watershed can be clearcut in any decade.
This short video features local scenery, insights into the harms of clearcut logging practices, better solutions, and what you can do to help!
The environmental effects of a clearcut
Clearcutting does more than cause an ugly scenic impact. It harms the forest ecosystem in numerous ways.
Clearcutting first removes all the profitable saw log-sized trees on a clearcut site. Then most clearcuts are bulldozed after logging to strip the site of bushes, young trees, or other plants that might compete with a crop of new conifer seedlings.
Herbicides are usually used to kill the grasses, bushes, and groundcovers that may survive the bulldozing. The resulting denuded hillside exposes bare soils that are prone to erosion to heavy winter rains or spring snowmelt.
Erosion often causes a portion of the exposed topsoil to be washed off the clearcut into downslope streams and rivers. Critical habitat values such as large trees, snags, and down logs are usually removed. The original naturally diverse forest is converted into a more uniform tree plantation- a far less productive environment for the native plants and animals that are part of a forest ecosystem.
Clearcutting on an unprecedented scale
Despite the fact that logging has been occurring in the Northern Yosemite region for 150 years, the scale of forest clearing and SPI’s conversion of the forest to sterile tree plantations is unprecedented. In some watersheds, SPI has cleared as many as 3,000 acres within a decade. Overall, tens of thousands of acres of forest have already been clearcut.
Each year new Timber Harvest Plans by SPI result in additional clearcuts or similar even-age type logging treatments. The sheer magnitude of clearcutting has profound effects on wildlife, water, and scenic resources.
Blue Creek Watershed north of Highway 4
South Fork of the Mokelumne watershed
Clearcuts are followed by herbicides
Conifers are planted to create tree plantations once all the competing vegetation has been removed by herbicides.
A natural forest contains hundreds of plant species besides conifers. Plants such as the Fivespot flower species shown below, can be completely eliminated from an area by herbicides.
Selective thinning instead of clearcuts - a win win solution
Thinning the forest can produce high amounts of lumber, while still leaving trees of various ages behind. Most species of wildlife depend upon a variety of habitat values that simply don't exist in tree plantations.
Large snags and large down logs are the "apartment houses" of a forest, as wildlife use the standing dead trees or the fallen tree trunks for homes or temporary shelter.
Tree farms also lack the fungi, lichens, ground covers, flowers, and structural diversity of natural forest areas. Thinned forests are less likely than tree plantations to have crown fires that escape fire suppression efforts and threaten other resources.
Clearcuts threaten watersheds
When all the trees are cut on a steep hillside, there are fewer roots to hold the soil. When bulldozing follows, the soil is laid bare and easily washes down-slope during heavy rains. Wherever gullies that are formed from skid trails funnel water, the resulting erosion often pours sediment into streams.
If just a single 20-acre clearcut is logged, it may not affect water quality. When many large clearcuts are logged each summer and fall logging season within the local region, these widespread sites with bare soil create a cumulative effect than can pollute many forest streams with sediment.
The next time there are heavy rains, take a drive into the national forest and look at streams flowing off the private timberlands that are interspersed with national forest lands. The streams flowing from recently cutover areas are often brown with sediment whenever heavy downpours flush soil down the steep, denuded slopes. Sediment-choked streams and rivers have a negative impact on water quality for people as well as a diversity of aquatic and plant species that depend on clean and clear water to survive and reproduce.