European earthworms are threatening American orchids.
About half of the orchid seeds from Northern American forests won’t live to see the light, according to Smithsonian ecologists.
At fault are the invasive European earthworms, which eat pretty much whatever they find lying on the forest floor.
Sadly, that’s where the dust-sized orchid seeds live. Those that don’t die during the digestion process often end up too deep in the soil to interact with the fungi necessary for germination and growth.
It is very rare that deep soil contains the right fungi.
Glaciers used to cover large areas of Northern America and are believed to have killed all indigenous species of earthworms. When the forests grew, the lack of earthworms contributed to the build-up of the forest floor and allowed flora and fauna to thrive. Today earthworms from Europe and Asia have destroyed parts of those forest floors.
In addition to the earthworms destroying the habitat for flowers, plants, salamanders, and beetles – to name a few – they’re causing forest erosion. As carbon dioxide is absorbed by trees and stored in soil, earthworm movements are re-releasing some of it back into the environment.
Earthworm eradication is complicated, and scientists are currently at work on solutions to the problem.