“In the absence of worms, North American hardwood forests develop a thick blanket of duff—a mille-feuille of slowly decomposing leaves deposited over the course of years, if not decades. That layer creates a home for insects, amphibians, birds, and native flowers. But when worms show up, they devour the litter within the space of a few years. All the nutrients that have been stored up over time are released in one giant burst, too quickly for most plants to capture. And without cover, the invertebrate population in the soil collapses.

With their food and shelter gone, salamanders suffer and nesting birds find themselves dangerously exposed. Plants like trillium, lady’s slipper, and Canada mayflower vanish, too. This may be because the worms disrupt the networks of symbiotic fungus that many native plants depend on, or because worms directly consume the plants’ seeds. Or that native species, accustomed to spongy duff, are ill-prepared to root into the hard soil left behind when the worms have finished eating. It could be all of the above.

Perhaps most worryingly, early studies suggest that worms can sometimes halt the regeneration of trees.”

Read the full Atlantic story by Julia Rosen, January 23, 2020