Oak Woodlands

An Introduction to Oaks


Dr. Jim Griffin worked at Hastings for 25 years as a plant ecologist and was among the first to call  attention to the almost complete reproductive failure of Valley Oaks (Quercus lobata) and Blue Oaks (Quercus douglasii). These massive oaks, among those that lose their leaves each fall, add significant value to the urban and rural landscape and ecology, and thus declines of these giants would be important.

The State of California and Monterey County have been working on a a series of oak woodland conservation efforts revolving around the California Oak Woodland Conservation Act of 2001. Download our “Oak Woodlands in Monterey County, July, 2009”, to learn more about voluntary oak woodland stewardship. The purpose of the county approval of a related voluntary stewardship document is to allow people to apply for state funds to conserve oak woodland.

The loss of oak woodland has become a significant concern to people in California of which the California Oak Foundation has extensive information available to the public.


Curious about the patterns in acorn abundance? Why is it a good year and then a bad year? Read about the phenomena in “The Mystery of Masting in Trees”, by our very own Walt Koenig and Jean Knops.


One of the challenges of oaks is that they can hybridize. Two species sometimes form hybrid trees. This can be confusing. Sometimes your oak tree has intermediate looks and may be hard to identify. You might want to choose a tree that is consistent. Look around the tree and look at several branches and many leaves. Select a few representative leaves.

Hybrids often assume a brushy or shrub form. Before deciding on the name, check the map to see if the matching name you found is attributed to oaks where you found your leaves. For example, you won’t find Valley Oaks in the desert! Then, compare the acorns to see if they match. And to make sure, read about the habitat and see if that matches.