Did You Know? Oaks Rule

Oak tree summer background
Photo credit

Last night, the Owl decided enough with town stuff, let’s check out a webinar on one of her favorite topics. Trees, of course, and this time the talk was given by one of the Big Three–the Owl will drop anything to spend time learning from Sir David Attenborough, E.O. Wilson, or Doug Tallamy. Last night’s Maine Audubon webinar featured Doug Tallamy, who has recently written a book called The Nature of Oaks which follows the life of an oak tree throughout the seasons.

Because none of you come here to learn about actual facts, we’ll be keeping your tree class to a summary acorn. Yes, that was bound to happen. The bottom line, folks, is something I may have said before in the Public Shade Tree Bylaw post, and Arbor Day too: respect your Quercus. The more you learn about them, the more you become obsessed with them–and the more you want to go outside and hug them. Oh wait, maybe that’s just me. The Owl will make you all tree lovers if that is the last thing she does.

“Quer” means “fine” and “cuez” means “tree” in Celtic, and a fine tree it is. There are 91 species of oak in the US, and 435 species globally. Both the red oak and the white oak families are native to the US. If not mown down by evil builders (just kidding people, relax), oaks can be 900-year trees–300 years of growth, 300 years of stasis, and 300 years of decline. Plant an oak–it will be your friend, your kids’ friend, your grandkid’s, and so on until life on earth ends and everyone lives on Mars, where it must be said, they have terrible trees.

Now it’s time to get science-y. Oaks have the highest biodiversity value of any tree. They sequester more carbon dioxide, they are master soil stabilizers, create the best leaf litter (unless you master blaster leaf blow it away which is frankly, idiocy, yes I said it), and promote a healthy watershed. If you didn’t know it, Weston is covered in wetlands and if enough folks cut out their oaks, these will be compromised. Here are the numbers from Weston’s recent inventory of street trees (this does not include our Conservation forest): of our trees, 18% are maple, 25% pine and 28% are oak. We win! You can stop reading there. No, you can’t, keep going.

Red oak. The Class of 2025 tree circa 2018. We should have planted 5!

Here’s a fun fact to whip out at the fire pit: a single oak will produce around 3 million acorns in its lifetime. There are many birds who love acorns, as well as that chubby phalanx of squirrels. Oaks get an extra boost from what Mr. Tallamy calls “an ancient mutualism” between blue jays and oaks–they each get something from their relationship. Blue Jays get food from the acorns, and oaks get to move with the Jay (so much for that theory that trees don’t move). Why are jays the most important, and not the other birds? Because Jays don’t cache acorns–they bury them individually and up to a mile away from the mama tree. In addition, they are like teenage boys and their homework; they’re extremely forgetful. Jays remember where they put only about 1 in 4 acorns, leaving the others to germinate. A busy jay can bury 3,360 oak tree acorns a year. The Owl will leave you with that math problem for how many oaks will then germinate.

From Mr. Tallamy’s slideshow: blue jay planting oaks

There were all kinds of other facts about oaks that make the Owl want to plant a zilion oaks. Oh yes, that was another point. Oaks should be planted in groves, not as specimen trees. They like to hang out together–their roots intertwine and stabilize each other. Oaks are working hard, folks, we should help them–they make an average of 700,000 leaves a year, and from these, support 557 species of caterpillar in the mid-Atlantic region (Mr. Tallamy is from Delaware so I don’t have New England numbers) and 950 species nationwide. Caterpillars hang out in leaf litter and the soil over winter so know that when your landscaper has cleared out every last leaf by gas blower not only has he (or she) made the Owl INSANE with the noise, but the result is a dead landscape and one very unhappy oak tree. They’ve spent a lot of time making their area healthy and you just blew it. Literally. Ditto in the spring which is the worst possible time to clear your leaves. Leave the oak leaves, people. More pointedly: don’t cut down your oak trees–you will affect many creatures and unwittingly (or now wittingly since I have told you so) cut apart the food chain in your backyard.

Oaks as keystone species. From Dennis Tallamy slideshow

Mr. Tallamy also spent time talking about how oaks are built to handle and, in fact, encourage caterpillar and insect munching. A single oak can handle 20,000 cicadas munching away. So don’t worry about the 17-year cicadas. Worry about keeping your oak happy.

And there, the Owl has brought you the knowledge you didn’t know you needed. Now go out, buy 5 oaks, plant them so they grow together, and know that you have done more for the world in one day than anyone on your street. Trees rule.

You can find Mr. Tallamy doing the rounds of the “talk shows” right now (mainly arboretum and land trust webinars). His latest book is The Nature of Oaks, but Nature’s Best Hope is perhaps his own keystone book. Get them both.

Author’s Note: a previous version of this post referred to Mr. Tallamy as “Dennis”. His name is Doug. The Owl knows this as his book is sitting right in front of her. She can only blame a gremlin. She has fired her editor.

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