This week we are joined by director of The University of Minnesota Center for Forest Ecology, Dr. Lee Frelich to discuss an invasive species problem that threatens plant diversity and ecosystem functioning wherever it occurs. Earthworms are very powerful ecosystem engineers. They alter the entire structure of the soil, affecting everything that grows there. Invasive worms are changing entire ecosystems from the bottom up and it is largely going on out of sight and out of mind. Join us for an enlightening discussion about this issue. This episode was produced in part by Sara, Kenned, Vaibhav, Kendall, Christina, Brett, Jocelyn, Kathleen, Ethan, Kaylee, Runaway Goldfish, Ryan, Donica, Chris, Shamora, Alana, Laura, Alice, Sarah, Rachel, Joanna, Griff, Philip, Paul, Matthew, Clark, Bobby, Kate, Steven, Brittney, McMansion Hell, Joey, Catherine, Brandon, Hall, Vegreville Creek and Wetlands Fund, Kevin, Oliver, John, Johansson, Christina, Jared, Hannah, Katy Pye, Brandon, Gwen, Carly, Stephen, Botanical Tours, Moonwort Studios, Liba, Mohsin Kazmi Takes Pictures, doeg, Clifton, Stephanie, Benjamin, Eli, Rachael, Plant By Design, Philip, Brent, Ron, Tim, Homestead Brooklyn, Brodie, Kevin, Sophia, Mark, Rens, Bendix, Irene, Holly, Caitlin, Manuel, Jennifer, Sara, and Margie.