Out In The Woods: Dead Trees Support Many Kinds of Life

Cavity in dead poplar tree

Photo Credit: University of Massachusetts

Correction: Last week we mistakenly printed the byline for this column incorrectly. The Deering Pond article should have been credited as follows:

Deering Pond – By Kevin McKeon, Director, Mousam Way Land Trust, Adapted from The Natural History of Deering Pond ¹ By Gordon “Bud” Johnston. And the footnote should have been listed as follows: 1. The Natural History of Deering Pond, by Dr. Gordon S. Johnston, Professor of Biology, Nasson College, Aug 1973.

We sincerely apologize for this error.

By Kevin McKeon, Director, Mousam Way Land Trust

During walks along Sanford’s well-known and diverse trails, we are encouraged to value the ability to bathe in Nature so close to town and maybe learn one more thing about the natural world in which we all live. So, let’s explore dead trees.

But are they really dead? Consider the benefits that these witnesses to the passage of time add to a landscape, and the various habitats and ecosystems within, around, and under the still-standing, live-giving tree. Imagine one dead tree that affects one creature, and that creature affecting another creature – the cascading effect can be mind-numbing. Standing dead trees, called snags, provide ecosystems with a bit more diversity than a live tree, or one laying on the forest floor.

Let’s talk about what creatures are supported by snags.

Woodpeckers first come to mind, but what attracts them? Yup – bugs. And what attracts the bugs? Some insects eat the fungi that grow on dead wood. Other insects eat dead wood, making tunnels; and yet other insects use these tunnels for homes and egg-laying. Still other insects eat those eggs; some eat the hatched larvae from those eggs; bigger insects eat smaller insects. There are flies, maggots, aphids, beetles, bees, wasps, spiders, ants…we’re just getting started!

Now that the insects, larvae, and eggs are living in our dead tree, this becomes an attractive dinner plate for other creatures, notably our sharp-beaked friends.

Woodpeckers are a keystone species, meaning that they have a greater effect on their habitat than other creatures – creating cavities in which they, and other birds and creatures nest. There are over 40 species of birds in North America that can’t make their own cavities – sometimes comprising 50% of all birds in certain forests – and must rely on woodpecker holes for nesting. Bigger birds like owls, ducks, and hawks will excavate these cavities further for their nests. Then raccoons, bats, porcupines, squirrels, opossums, martens, fishers, fox, and others den up in the enlarged cavities. (Yes, fox! The grey fox is one of two canids (dogs) on the planet that climb trees…a story for another time.) The creatures of prey and predators all keep an ecosystem healthy and in balance.

Surprisingly, a hummingbird’s diet consists of 50-80% insects – they eat a lot of spiders. One source puts the hummer’s diet at 64% these arachnids! We all love these darting masters of flight, so save those dead trees.

Large and small snags are often cut down, regarded by most folks as an unnecessary eyesore. We must learn to look with a more informed and understanding eye. We are lucky that woodpeckers provide cavities for the woodland community in the absence of natural cavities provided by these dying, but still life-supporting trees. Keeping snags where they stand gives woodpeckers the indispensable resource they need to support our ecological communities. Go here for more info on the importance of conserving “dead” trees.

Editor’s note: Did you see something unusual last time you were out in the woods? Were you puzzled or surprised by something you saw? Ask our “Out in the Woods” columnist Kevin McKeon. He’ll be happy to investigate and try to answer your questions. Email him directly at: kpm@metrocast.net