Invasive Mushrooms Are Threatening Midwest Forests

Golden oyster mushrooms, a visually striking and culinarily-favored species native to Asia, are now rapidly taking over North American forests and threatening native fungi, according to new research. A study published Wednesday in Current Biology finds these mushrooms are crowding out local fungi, especially around the Great Lakes, and could pose a threat to forest biodiversity. Researchers from the University of Wisconsin–Madison and the US Forest Service analyzed dead elm trees in Wisconsin, comparing fungal diversity in those colonized by golden oyster mushrooms to those without. The findings were stark—the invaded trees hosted only about half as many fungal species as their non-invaded counterparts, reports Smithsonian.

This drop in diversity matters because native fungi are crucial for decomposing plant material, cycling nutrients, and even storing carbon in soil. Some may also produce medically useful compounds, study co-author Aishwarya Veerabahu writes in the Conversation. First introduced to North America in the early 2000s, golden oyster mushrooms may have spread through popular grow-kits or commercial cultivation. They're now popping up in states as far-flung as New York and Texas, with experts warning that climate change may expand their range as control measures remain elusive. As scientists urge more responsible fungal management, they warn that losing native fungi could mean missing out on yet-undiscovered resources for medicine and environmental health.