Do you remember the film the series “Planet Earth?” New technology allowed them to zoom in from tremendous distances with crystal clear clarity. Such groundbreaking camera work is not only visually stunning, but scientifically important in studying the behavior of animals while unaware of a human presence. The series included, “Deserts,” “Ice Worlds,” “Great Plains,” “Caves,” and “Mountains,” but missed one of the largest, most fascinating, and crucial parts of our interconnected planet—the soil. So, for the next few paragraphs, let’s take a close look at what we walk on every day.
First, “Soils” takes you to view the largest and heaviest living organism in the world. Not the Pacific Ocean’s Blue Whale or newly discovered Giant Squid, but Eastern Oregon’s honey mushroom. The fungus Armillaria has been growing in the Blue Mountains for over 2,400 years. The mushrooms above ground are only the fruiting bodies of this giant. Below ground, its white filaments, or mycelia, spread over 2,000 acres, penetrating the roots of trees and siphoning off water and carbohydrates.
In this same forest, a rare, slow motion shot captures the dramatic flight of a springtail. The almost transparent arthropod uses its well-developed mandible to graze on fungus at the base of a tree. Suddenly, its arch-enemy approaches—a small ant with a strange, spongy structure between its thorax and abdomen that emits an irresistible odor. Stinger ready, the ant moves closer, but the springtail comes to its senses just in time. It releases a catapulting organ tucked under its abdomen and springs twenty times its own length to safety.
The camera follows the baffled ant as it scurries down into the leaf litter. It is a quiet, moonlit night, and the soil surface comes alive. A night crawler waves a third of its body above the ground in an eery, graceful dance. It finds a leaf and pulls it down into a vertical burrow lined with its own mucous.
Not too far away is a colony of several million ants. These particular ants practice aphid husbandry. They faithfully transport aphid eggs to their nests each autumn, tend them in safety, then take the newly hatched aphids to fresh, spring roots. As a reward, adult aphids leave their sugary droppings, called honeydew, as food for the ants.
Finally, “Soils” films the strange and captivating Tardigrade, or “Water Bear.”* Just as the Polar Bear elicits “oohs” and “aahs” with its antics on the ice, so the tiny Water Bear, only 1/50 of an inch long, is the charmer of soil critters. They come in red, green, orange, yellow, and pink, and their eight legs each end in four tiny claws. Their eggs, spheres decorated with geometrically patterned spines, knobs, and ridges, are fascinating and beautiful. If the humidity level in their microscopic habitat drops, they shrink like a dry sponge into an unrecognizable form. In this state, they can survive temperatures up to the boiling point and down to -200 degrees F. Then, even after 120 years, the dehydrated Tardigrade can be brought back to life. Some scientists are studying this amazing feat of cryptobiosis (hidden life) to see if humans could do the same.
And this is just the beginning. There are thousands of animals and insects that live in symbiosis and competition under the soil—from Ant Lions to Glowworms, from Camel Crickets to Kangaroo Rats. Without them, life above the soil would come to a messy halt. Soil creatures take the minerals and nutrients that drop to the ground from above and incorporate them into the earth’s skin where they resurface as new plant and animal life.
In order to better understand the soil and critters that inhabit the soil, all you have to do is build a compost pile and observe it closely. Ants, springtails, worms, beetles, and maybe even a Tardigrade will appear to transform your detritus. If you would like to see pictures of all of these creatures, check out the book “The World Beneath Our Feet: A Guide to Life in the Soil” by James B. Nardi, and watch the movie, “Microcosms,” a documentary set to classical music depicting the wonder filled life of insects.
*The drawing of the water bear for this post is from the DataBase Center for Life Science (DBCLS) – https://doi.org/10.7875/togopic.2017.5, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=57116616.