Author’s Note: This is an excerpt from an article I wrote for Voices! magazine, a publication aimed at Toastmasters- a nonprofit public speaking and leadership organization. It’s set to print at the end of October, but because you’ve been good, you get it a month early.
Imagine a young earth without tall trees. Imagine a place where poplars stretch no higher than your knees, and oaks that come up to your ankle. Imagine fields of fully-grown maples that sway like short stalk wheat, and evergreen firs that blanket valleys like dense, short shrubbery. This is the world we’d occupy, if not for a very special type of fungus.
Recently, thanks to the podcast Radiolab and a series of Scientific American articles by Jennifer Frazer, I was introduced to this alternate, nascent earth. Being a layman in arboreal matters I’ve lived my life believing that tree roots gather all the nutrition the sun and rain can’t provide. I thought trees were utterly self-sufficient, and had formed on this planet as they are now: tall, majestic, and hardy. Not so.
Trees, I learned, are actually quite bad at absorbing minerals and carbon, two key elements needed to grow solid, stable trunks. Carbon and minerals are to trees what iron and rivets are to the Eiffel tower. Water and sunlight? Trees gobble that up. But without minerals and carbon your everyday ponderosa pine wouldn’t have the strength to reach higher than a Great Dane’s snout. It needs outside help to gather these all-important resources. In steps a helpful symbiotic organism—a strain of Amanita fungus.
When a new tree emerges from the soil this specialized fungus, which looks like a tiny bleached-white thread one tenth the width of an eyelash, snuggles up to the new root. The tree recognizes the fungus for what it is, a new partner, and weakens its root in just that spot. And like a new limb this fungal string attaches itself to the root, and a mutually beneficial partnership begins.
You see, this mycorrhizal fungi is a miner. It secretes acids, and it borrows as it grows. It eats through rock, dirt, decaying plant life, and even small creatures and discarded animal matter. If a grizzly eats a salmon near an oak tree, some of that salmon protein will end up in the tree, thanks to this burrowing fungi. Because of this absorption, all trees are technically opportunistic carnivores. And this isn’t even the fungi’s best trick.
Trees have a banking system, through the fungus. The tiny white strands are restless, and will seek out nearby fungal networks and connect to them. Dozens upon dozens of trees can be involved in one of these networks. Scientists call these mycorrhizal networks, or wood-wide-webs. Once connected, trees of any variety will allocate tremendous amounts of their resources to the network, which the fungi can dole out to other trees in need. A redwood might share its nutrients with a sick birch. A hickory might get too dry during a heat wave and make a “withdraw” from the network’s store. The greater the variety of trees in the network, the healthier the forest becomes in general, because different types of trees can cover for different nutritional shortcomings.
Thanks to this network the trees can also “will” their nutrients away when they die, or “warn” other trees of impending danger. If a pine dies of natural causes (rot, beetles, etc.) it will sometimes flush its nutrients into the mycorrhizal network, where the fungus shares its bounty with the nearby trees. These trees, with their largess, will use the excess nutrients to fortify themselves against the coming danger. And the biggest recipient of this dying wealth? Young trees. The fungus will send huge amounts of nutrients to the newest trees in the network—who will be better equipped to deal with the changing environment.
Sitting in my yard, gazing at the oaks and firs near my house, I used to think the most successful trees grew tall because they had the best position; the most light, access to water, good elevation. I thought trees grew for the same reason successful restaurants grows; location, location, location. I believed less competition from other trees and better soil determined the strength of the plant. Boy, was I wrong.
Like all good Toastmasters already know, success is more about the strength of your network than a slight resource advantage. We don’t grow strong by being isolated, standing alone in a field absorbing the benefits that befall us. Like people, the strongest, hardiest, mightiest trees are in the middle of the network, sharing the wealth with all of its neighbors.
Featured image from Wikipedia.