Contributed By Michele Miller Houck, NCST
If you’ve got a White Oak in your yard, then you likely already know some of the benefits that these beauties convey to those who live under their branches. Whether you have the seminal species Quercus alba or one of their relatives like I do in Charlotte, you have one of the best species in several areas of environmental performance (1).
The mighty oak boasts over 90 species in the US and more than 400 worldwide. The species dominates most forest landscapes, and it has been said that it delivers more “ecosystem” services than any other species (2). So what do they do that is so special?
Carbon Sequestration
Some of the largest individual oaks are massive, and their sheer size sequesters tons of carbon in their wood and roots and transfers even more to the soil around them. Carbon is locked within these grandparent trees for millennia – many live for more than 900 years (3).
Erosion Control
In coastal regions, oaks slow down water (rainfall) starting in the canopy by breaking the force of a heavy rain preventing compaction of the soil and allowing the water to seep in. Their extensive root systems – some as large as 3X the tree’s canopy – hold the water underground, preventing soil erosion and encouraging rainwater filtration instead of run off. Oak leaves, rich in “lignin” (4), take a long time to break down providing shelter habitat for soil arthropods, nematodes, and other invertebrates (5).
Contribution to Food Webs
Doug Tallamy, in his call-to-action book, Nature’s Best Hope cites the oak’s contribution to food webs as the species greatest contribution to ecosystems. Tallamy’s research team catalogued the caterpillar species living in the oaks of the Mid-Atlantic region of the United States and found a whopping 557 species out of the estimated 934 caterpillar species nationwide, making oaks the best tree to include in your yard or landscape to support native species (6).
Once I learned this, I was thrilled to identify three different species of oak in my yard including the Willow Oak, the Pin Oak, and the Blackjack Oak, that are thriving among the maples, cedars, ash and hickory that grace our small urban forest.
The caterpillars that call the oak home are the basis of most birds’ diets in North America. They are especially important during the nesting season when birds are rearing their young. The soft exoskeleton makes the caterpillar an easily digestible bag of food, high in protein and fats and other important nutrients. The average nestling can eat up to 40 times a day, and with 4-5 nestlings, parents need around 150 caterpillars to meet their growing babies’ nutritional needs (7). Researchers have speculated that “caterpillars are so important to breeding birds that many species may not be able to breed at all in habitats that do not contain enough caterpillars (8).”
So the mighty oak brings great beauty and an active bird population to your yard – I know my yard supports a variety of birds that include Northern Cardinals, Carolina Chickadee, Robins, Grackles, Carolina Wrens, House Finches, Blue Jays, Tufted Titmice, Mourning Doves, among others. And when I add a new tree to the landscape, it will likely be another species of oak to keep all the birds and the rest of the denizens of our little habitat happy. And thanks to Doug Tallamy, we are learning more about how to support a wide variety of wildlife in our acre of paradise.
Acorn Ink Activity
If you are looking for a fun indoor activity during this Winter season, try making acorn ink. You’ll need to gather some acorns from your local mighty oak to do it, but once you find them, you’ll just need a boiling pot and a rusty nail to complete the process. Here is the Curious Minds Worksheet that will make it easy to make this pretty brown ink that renders the natural world in beautiful warm tones.
You can find many other hands-on science and nature activities on our site here.
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References
(1) “Nature’s Best Hope,” Douglas W. Tallamy, Timber Press, 2019, page 142.
(2) Ibid, 142-143.
(3) Ibid, 144.
(4) “The Nature of Lignin,” Alkaline Paper Advocate, Volume 4, Number 4, November 1991, Ellen McCrady, accessed December 14, 2025.
“Lignin is found in all vascular plants, mostly between the cells, but also within the cells, and in the cell walls. It makes vegetables firm and crunchy and gives us what we call “fiber” in our food. It functions to regulate the transport of liquid in the living plant (partly by reinforcing cell walls and keeping them from collapsing, partly by regulating the flow of liquid), and it enables trees to grow taller and compete for sunshine. Researchers see it as a disposal mechanism for metabolic wastes.”
(5) “Nature’s Best Hope,” page 144.
(6) “Ranking lepidopteran use of native versus introduced plants,” D.W. Tallamy and K.J. Shropshire, Conservation Biology, 23 (4); pages 941 – 47, 2009.
(7) “Nature’s Best Hope,” Douglas W. Tallamy, Timber Press, 2019, page 133.
(8) Ibid, page 133, from “Native Plants improve breeding and foraging habitat for an insectivorous bird,” D.L. Naragno, D.W. Tallamy, and P.P, Marra, Biological Conservation 213: pages 44-50.