Oak Release

BEST MANAGEMENT PRACTICE

Guidelines

Remove small and large conifers, small oaks and other trees that are competing with and crowding out oaks, especially the larger, older growth oaks.

We recommend starting with conifers that are along the edges since these tend be where the more open form oaks are located and would benefit most from reduced competition. Note - if conifers are intertwined with the oaks, the best practice is to girdle the conifers or remove them completely, starting at the top of the tree and proceeding to the bottom.  Some conifers can be left if they are grouped and not interfering with the oaks.

Remove most small oaks less than 6 inches diameter and any exotic trees. Some small oaks can be left if they have good crown formation and are not competing with other oaks. 

Without active management, oaks can become crowded and overtopped by both conifers (usually Douglas-fir) and other oaks. Many oak-dependent fauna benefit from large, older growth oak trees with lots of lateral branches. A main objective of oak restoration is to promote conditions where there are at least several of these large legacy oaks throughout a stand. We do this through something called an “oak release”. 

Target some Douglas-fir for protection. The Western grey squirrel (listed as a ‘Sensitive Species in Oregon) benefits from having both oak and Douglas-fir as food sources. This requires a strategic approach to planning which Douglas-fir trees to remove and which to keep as part of an oak thinning or oak release project. Douglas-fir trees also provide excellent wildlife habitat (e.g. for cavity nesting birds) if they are de-limbed or girdled.

Douglas-fir trees that are clustered or “wolfy” (trees that retain most of their branches), and that are not competing with oaks are the best candidates for leaving in situ. Note that it may be possible to log and sell some of the more accessible trees to help pay for oak restoration efforts.