Next time you’re out for a walk in our lovely neighborhood, try this experiment.  See whether you can imagine the hidden world below your feet.

Start with this metaphor: a tree is like a wine glass on a dinner plate (video is 1 minute, 38 seconds).

So, even at an appreciable distance from a nearby tree, you’re standing on a plate of soil filled with the tree’s small, tiny, and teensy roots, together with the “dinner” of water and nutrients that feed the tree!

Oh, wait, scratch that: you’re probably standing on a section of multiple, overlapping dinner plates. A massively intertwined network of roots reaching out in all directions from multiple trees:

Wait, there’s more! If the soil is good and the trees healthy, you also have immediately below your feet fungi called “mycorrhizae” (my-cor-RYE-zee) attached to those tree roots.

The roots provide essential nutrients to these fungi. In return, the fungi send out tendrils (called “hyphae”) into the soil, and these function as a virtual root system for the trees — the rootlike fungi increase the amount of water and nutrients that the plant can obtain from the surrounding soil.

That’s a symbiotic relationship between plants and fungi that started developing 400 million years ago. Something like 90-95% of all plants depend to some degree on this symbiosis.

But guess what?

In cities, where we compact soils, scrap away soils, bulldoze soils, and otherwise abuse soils, we destroy that symbiosis.

Think about that the next time you see a McMansion going up on a cleared lot that used to feature a smaller house surrounded by trees. Or when a construction crew illegally piles materials underneath a stately oak. Or even when you (and hundreds of others) are taking a shortcut over a tree’s root zone, instead of following the path the long way around!