California's forests and woodlands are always changing, and it takes time for California's regulatory framework to catch up to what's happening. After years of fire suppression, it is now common to see encroaching conifers (e.g., Douglas-fir) trees moving into the deciduous woodlands of the Northern California and Coast Range.  In these situations, Oregon white oak and California black oak woodlands struggle for light, and within a few decades, they die from the competition of the conifers. Along with this is the loss of the herbaceous plant communities and shifts in wildlife species that can utilize these woodlands.

Oak woodlands support high levels of biodiversity, provide unique habitats for wildlife, and are deeply rooted in the region's human history, as oaks have been sustained by Native Americans, ranchers, and other local groups throughout recent history.  Both black and white oak woodlands are fire-adapted, depending on frequent, low- to moderate-intensity fires to prevent the establishment of invading fire-sensitive vegetation and provide conditions suitable for regeneration.

The decision to manage conifers or oaks is up to the landowner, but for decades, barriers in the California Forest Practice Rules have made managing these woodlands experiencing encroachment difficult. Fortunately, there is good news. New permit options are available for private forest landowners who want to remove these encroaching trees and sell some of the by-products of restoration activities.

Photo by Yana Valachovic, UC ANR

In California, any landowner who sells, barters, or trades timber must have an approved Timber Harvest Plan (THP) or Non-Industrial Timber Management Plan (NTMP) or an Exemption to file one. A THP or NTMP is an environmental review document that is the functional equivalent of an Environmental Impact Report and is required under the California Environmental Quality Act (CEQA).

There are two regulatory pathways for landowners looking to actively manage their white or black oak woodlands.

1. The White and Black Oak Woodland Management Special Prescription provides a silvicultural method allowed under a THP or NTMP.  Under this new prescription, conifers of all sizes may be removed, and post-project stocking requirements can be met by retaining at least 35 feet² per acre of living Oregon white oak or California black oak basal area. There is no requirement to restock with conifer seedlings post-harvest when using this Special Prescription. As with any THP/NTMP, the forester must meet all the normal requirements, including plant and animal special status species surveys, archaeological surveys, geologic reviews, etc. The special prescription will most likely be utilized when other THP/NTMP activities occur on the property and when there are conifers of larger size, as the full THP/NTMP development elements and costs apply.
2. An option for small projects is the oak woodland exemption, which works as an alternative to filing a THP/NTMP to conduct oak woodland restoration. An exemption from filing a THP is not an exemption from following the Forest Practice Rules or other environmental regulations. However, the process is much less costly and can be conducted on a shorter timeline. The idea is that activities exempted from THP/NTMP preparation are of a size and scale that will not significantly impact the environment. With the oak woodland exemption, the stand needs to have 35 feet² per acre of living oak basal area, the harvest area cannot cumulatively exceed 300 acres (in a 5-year period) per ownership per planning watershed, a forester must prepare a notice of exemption, and at present no tree larger than 26 inches at stump height may be removed for commercial purposes. However, in 2024, the legislature approved changes though AB 2276 to the Exemption that will allow for removing conifer trees up to 30 inches in diameter at breast height and possibly larger with CAL FIRE consultation. These changes still need final rule-making approval before the California Board of Forestry but will provide much greater capacity to manage conifer encroachment.

The good news is that both species of oak can thrive when encroaching conifers are removed, reversing the loss of these woodlands. Our research has shown significant growth in canopy and diameter, as well as improved survival rates in the event of wildfires. These new permitting options provide landowners with essential tools to help restore resilience to these important oak ecosystems.

Photo by Yana Valachovic, UC ANR

For more information on managing oak woodlands, read the Forest Stewardship White & Black Oak Management newsletter.