Timber Management

Timber has been critically important for the development of civilizations for thousands of years. The Bronze Age, Iron Age, glass manufacture, shipbuilding railroads, and housing have literally depended on wood. (Interestingly, a single ‘ship of the line’ in the days of the Spanish Armada in 1588 required 2,000 – 6,000 mature oak trees). Centuries of demand for wood resulted in the depletion of European forests. Arguably our current standard of living is directly related to past exploitation of abundant forests to obtain needed wood supplies.

Today, we still need substantial amounts of wood. The 2022 timber harvest in California totaled 1,524,267 board feet with only 7.0% of the volume and 3.7% of the value coming from  National Forests. The market value of this wood in 2022 was $294,098,750. Surprisingly, about 75% of the wood used in California is imported from Oregon, Washington, and British Columbia. This is mainly due to lack of public support for harvesting on national forests and the lack of guaranteed, long-term log supply from public lands that is needed to attract private investment in processing plants. 

There is a major difference between timber harvesting in California prior to the 1950s and today. In the past, most logging was exploitative – controlled by economic and engineering constraints in the context of abundant supply. Today, most private forests are family-owned with owners committed to sustainable forestry. Forest management is also strictly controlled on private land by forest practice rules set by the State Board of Forestry and approved. Timber Harvest Plans must be developed by Registered Professional Foresters. Timber management on federal lands must meet federal statutes and laws and have public input.  In addition, all forest practices on private, industrial timber lands are certified as managed sustainably by one or more third party organizations (see Topic 9).

Timber management is done in the context of consideration of other forestland values. Even where timber production is the primary goal, considerable emphasis is placed on sustaining other values including water yields and wildlife and fisheries habitat. In fact, these considerations are required by law. And because forest land is owned by a mix of owners – federal, industrial, individual private owners, the state, and tribal entities,  this ensures that forest structure is variable across the landscape (See Topic 1).

The methods chosen to harvest forests largely depend on what kind of microclimate is needed to ensure successful regeneration of desired species. Species such as pines require abundant sunlight, so openings are made by variants of clearcutting. 

There is a difficulty, however, in terminology used in timber harvesting. The term “clearcutting” is still used by the public in the context of exploitation.  In professional forestry, however, the term is used to describe the method used to create the desired level of sunlight needed to ensure prompt regeneration of species that need sunlight for early growth such as pines. 

Other harvesting methods are designed to create shade that favors species such as fir. These include methods such as individual tree selection and shelterwood. Other methods are used depending on the mix of species desired. Harvesting / regeneration methods are also defined in terms of whether the structure of forest stands is designed to be even-aged or uneven-aged –  the decision depending on the goals of management and forest structure desired. This, in turn, depends on the mix of uses and values desired – wood, water, wildlife, recreation, carbon storage, and so on. Each of these goals is best achieved in forests of different structure. However, emphasizing one goal usually means less outputs of another use or value. This complexity is what makes forest management such an interesting and challenging field requiring professional education and considerable experience.

[Photo of ‘working forest’]

In addition to harvesting trees at maturity, forest stands are commonly, or should be, thinned to maintain forest health and tree vigor. This control of stand density also reduces fuels – especially ladder fuels that allow flames to reach into the tree canopy. Studies of forest inventories done over 100 years ago show that natural, mature stands had about 60-100 large trees per acre whereas current stands, particularly on public lands, may have 1,000 or more trees per acre of mixed sizes. Specifics of forest management are greatly influenced by the inherent productivity of the site being managed, with high site quality lands with fast tree growth being most responsive.

[Photos of over-dense and thinned stands.]

Timber harvesting by professionals is always done to create the best growing conditions for the next stand. Highest priority is given to ensuring that potential soil erosion is kept to a minimum and that stream-side vegetation is kept intact – in fact these practices are required by law. 

Modern sawmills in California are controlled by computers to ensure that the highest value is obtained from each log. All off-cuts and sawdust are utilized in co-generation plants that produce the electricity needed to run the plant –  excess production is fed into the energy grid. All material, including the bark, is utilized. Nothing is wasted. 

[Photo of modern mill with co-generation plant]

A healthy timber industry is crucial to the welfare of any community. Because wood is a renewable natural resource it should be used in preference to alternative, nonrenewable materials that require more energy in their manufacture. Professional timber harvesting is always done to ensure that, in the long run, removals are less than growth. This ensures that forests will remain for perpetuity (See Topic 9). However, across all forest lands in California, growth far exceeds harvest resulting in stands becoming over-dense and fire prone. 

California is the most highly regulated and costly state to grow timber – despite being one of the most productive states for tree growth. Policies need to ensure that costs of regulating timber harvest do not put industries out of business and cause their lands to be sold to developers resulting in forest loss. This would result in the wood needs of California being increasingly met through imports. The first rule of forestry, especially in the age of climate change, increasing water needs, and recreation is to keep forests as forests.