Why do trees eat things?

Remember that time you watched Jurassic Park at age 7 and spent the next five years convinced you had to hide under the covers and not breathe or else the T-Rex would get you? If we’ve learned anything from Jurassic Park, it’s that life will find a way, and not just dinosaurs. Plants are plotting their own quiet rebellion and firing up the nightmare-fuel furnace. This is edaphoecotropism, the technical name for when a woody plant engulfs an object in its path.

A tree trunk engulfing a metal railing demonstrating edaphoecotropism — This particular example of edaphoecotropism lives at MK Nature Center along the Green Belt in Boise, Idaho.

Although at a much slower pace than a barreling T-Rex, this powerful process can engulf bicycles, fences, signs, and any other stationary objects that gets in the tree’s way.

The most famous example of edaphoecotropism is Bicycle Tree in Brig O’Turk, Trossachs, Scotland. Seeded in the late 1800s near a blacksmith’s scrap heap, this sycamore tree has engulfed dozens of objects over the years. You can see the handle bars and portions of the frame from the tree’s namesake bicycle emerging from the trunk.

At its core, edaphoecotropism is a stress response. When the tree growth encounters an environment that obstructs its access to sunlight, water, air, or otherwise provides inhospitable conditions, the plant responds by growing in the direction of more favorable environmental conditions. The phenomenon is well documented in plant roots. Sinuous roots exhibit knee-like bends while coursing through the soil avoiding obstacles in search of nutrients (Vanicek, 1973).

In the less mobile, above-ground components of the tree, we are sometimes lucky enough to find examples of the obstruction slowly getting incorporated into the plant structure itself. Both the tree and the obstacle remain physically unharmed in this process, but this is still the most B.D.E. I’ve ever seen a plant exhibit.