So we’ve all seen those slimly wrigglers making their way across the sidewalk on a rainy day, and since earthworms (Oligochaeta) live a mostly hidden life, I sure you’ve all been wondering, what are those little guys up to when they aren’t slimming across the sidewalk and why should I tolerate their gross presence?
Who Are You?
With a little investigation, I found that there are A LOT of people who are big fans of these common invertebrates and apparently for good reasons. They aid in farming, gardening and are a main food source for lots of animals, and have many more jobs in the ecosystem. These seriously undervalued inverts spend most of their time just below the surface of the ground; they depend on the soil for protection against predators, homes, and nutrition, and only come to the surface to quest for food, mates or in the unfortunate case of flooding in their burrows.
Video courtesy of BBC
Video courtesy of Globalzoo
Why So Special?
The reason why earthworms are so valuable is because they have this crazy ability to see forest waste (fallen leaves, decomposing roots and other decomposing matter) as a delicious and tasty meal. They eat the debris on the surface soil then move further back into the depths of the earth through burrows, (okay not that deep, they don’t seem to burrow deeper than 6 ft), slowly digesting all those nutrients. Worms are especially skilled at extracting nutrients from this debris by passing it through several specialized structures, a crop and a gizzard, which if you’re a fan of birds you might recognize those words, and you’d be right to. The crop stores the food and regulates the amount of food entering the gizzard at a time and the gizzard uses muscle contractions to grind food against small bits of sand and stone which act as teeth and break down food to allow for max nutrient absorption. After the food is broken down it passes through its intestines and out into the soil. This doesn’t sound like much, but it is actually crucial to soil ecology, it allows soils to replenish its nutrients and plant life to thrive.
BUT WAIT THERE’S MORE!
A big issue with farming is that plant roots have a restriction on how deep their roots can usually grow, this causes the plants to devour all the nutrients from all the accessible soil in a pretty quick fashion. However soil scientist, Frank Gibbs, has discovered the wonderful relationship between worms and farm crops. With the aid of our favorite creepy crawlers plants roots are able to follow and use worm burrows to grow deeper into the soil and reach more nutrient rich soil. But, earthworm aid goes further than that, by creating this intricate network of burrows it allows for a naturally occurring irrigation to occur. Water no longer runs it off fields but penetrates deep into the soil, keeping nutrients in the soil instead of wandering of with the water flow. To read more about how worms are benefiting farmers and preventing nutrient run-off click here.