Invasive earthworms as seed predators of temperate forest species

"The worms crawl in, the worms crawl out, the worms play pinochle on your snout, they eat your eyes, they eat your nose, they eat the jelly between your toes."

This old song from the Crimean War left out the part where non-native earthworms eat LOTS of seeds and reek havoc on our Ontario forests, reducing the diversity of understorey plants and play a major role in forest dynamics. That discovery was made by former M.Sc. student Colin Cassin (Kotanen Lab) and reported in his FIRST PAPER: “Invasive earthworms as seed predators of temperate forest species”, which was just published in Biological Invasions. Colin experimentally investigated whether seed predation by invasive worms might contribute to seed predation of forest plants. First, he found captive worms destroyed 30% of offered seeds over 2 weeks. He then used screening to exclude worms from forest plots, and showed this can improve seed survival in the field, especially for small-seeded species rodents avoid. These results provide evidence that seed predation by earthworms can influence the species composition of forest plant communities.

Congratulations Colin on your first paper!

For more on this, tune into CBC’s Quirks and Quarks.