Earthworm Ecology

How important are earthworms? Well without them forests in North America would look very different and you might have to pay more for fish. Earthworms provide an essential role in our economy and ecology.

Did you know that earthworms that we know them today were introduced from Europe? In fact, out of every 3 earthworm species in North America, one of them is an invasive species. You might be asking: “They’re still good for the soil right?”. That depends on who you ask… or study. Earthworms were absent from North America since the Ice Age and were reintroduced by Europeans transferring plants to the new world. Once introduced earthworms changed the face of the forest. Since earthworms eat dead material they cycle nutrients in the soil. Old leaves are eaten up and turned into worm poop. The worm poop is rich with nutrients that plants enjoy. Prior to earthworms, it took longer for old leaves and dead plant material to decompose, but with earthworms present, the nutrients are available to the plants much sooner. This quickening in nutrient cycling caused the forest to shift from large trees that do not drop their leaves like evergreen trees to smaller herb plants. Should we be concerned? Should we eliminate earthworms from North America? We could, but it would take a lot of time and resources. Earthworms have been here long enough that the population in the forest has mostly shifted to their presents. Taking them out now would cause another shift, shifting back to the former forest. Earthworms are likely here to stay leaving us to remark on their ability to cause large ecological changes. Our forests aren’t the only area where earthworms leave their mark. Our economy also is relying on earthworms.

The 2014 winter in Canada was particularly bad. Many worm farms in Canada had a shortage. How big of a problem is this? Well, every year Canada exports $20 Million to the United States. The 2014 shortage caused the price of worm that was going to be used for fish bait to double. With an increase in fish bait likely fewer people went fishing in 2014. This would affect the $34 Billion outdoor recreation gear industry.

The smallest of things can have a huge impact. The re-introduction of the earthworm to North America changes the forest forever. A harsh winter changes to price to go fishing. Both driven by a small organism that we see flopping around in the rain. Next time you see an earthworm you’ll know a bit more about them and the role they play in your life.

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Thanks for writing this blog, Elliot.