Understanding the Value of Native Oak Trees
Native oak trees are an ecological powerhouse for North America, a refuge and fueling station for countless thousands of species. An oak tree is a community.
For anyone who wants to understand the valuable role of oaks in North American ecosystems, I recommend the work of Dr. Doug Tallamy, whom I have been following and studying since 2016.
Oaks are number one on Dr. Tallamy's list of the most ecologically beneficial plant species. (Actually, oak is a genus, a group of species. But the plural "genera" is awkward and takes time to define, so I avoid it.)
I recommend "The Nature of Oaks" by Doug Tallamy and also "Nature's Best Hope." A good proxy for the ecological value of a plant is the number of caterpillar species it can support. Caterpillars eat leaves. Leaves are toxic. The caterpillars who can eat the leaves of a particular plant species are those who have co-evolved with that plant species and have developed defenses against the toxins that plants put into their own leaves as a defense against consumption. The caterpillars who can eat oak leaves are the ones who can process the "tannins" contained in oak leaves.
Dr. Tallamy teamed up with the US Forest Service and the National Wildlife Federation to create a database of the plants who support the most caterpillars, county by county, nationwide. That database is available to the public at www.nwf.org/nativeplantfinder. Just enter your zip code, to pull up data that is relevant to your county. I used that database to create the following document for my county.
The document is called the Top 100, meaning the Top 100 Plants in my county, in terms of their value to caterpillars.
https://docs.google.com/document/d/1Ei6ewlf2SN-OBjBhIsDv5X733FkeT3M_AWeB8Rj0qik/edit?usp=sharing
The most valuable plant species are the ones who can be consumed by the largest number of caterpillar species. In my county, native oak trees can be consumed by 478 species of caterpillars. Native plums and cherries are edible to 352 species of caterpillars. Native birch are edible to 282 species of caterpillars, etc.
Oak is a genus (quercus). It is a group of species. Plums and cherries are a genus (prunus). Birch is a genus (betula). When we say oaks rank number one in their ecological value, we are only talking about native oaks. This is important when deciding what to plant. When in doubt, you can find the "native range" of any plant species with a quick Google search. For example, you can find the native range of a pin oak on this Wikipedia page. https://en.wikipedia.org/wiki/Quercus_palustris.
"The Nature of Oaks" by Doug Tallamy is a wonderful journey through one year with oaks, one month at a time.
"Nature's Best Hope" is the one book by Dr. Tallamy that I would recommend if you could only read one and wanted to get the most of Dr. Tallamy's philosophy and practical recommendations.I think he is one of the five most important ecologists of the last century in terms of his impact. I don't think there is another individual who has done more to help average Americans understand the vital significance of our home landscapes in supporting our native populations of bees, butterflies and birds.
For one of the best described review of Quercus, I do like A Natural History of Western Trees by Donald Peattie. Mine is a bit ragged now having survived from it's second printing in 1953. In 1967 it was gifted from the Watrous's (my great mentor was Mary Watrous who inspired me to do field study of geology in Connecticut. She also had worked at the American Museum of Natural History that I visited as a child) I found the book years later in Albuquerque at Title Wave Books.
Just take one of the oaks, the Rocky Mountain White Oak. His description includes the setting in Oak Creek Canyon, it's geology, it's ecological setting of Oak Creek with it's composite flowers and other tree species. Then the history of a naturalist named William Gambel who discovered this oak in his 23rd year adding to his list of perhaps 100 discoveries before his passing of typhoid fever at the age of 28. The alternative name given to this species is Gambel Oak. There is more Peattie gives the reader. He describes to the point that one can see the community interactions brought to life.
This new book might be of interest. Henrik Sjöman and 1 more
The Essential Tree Selection Guide: For Climate Resilience, Carbon Storage, Species Diversity and Other Ecosystem Benefits