Symbiotic harvest: human mushroom foraging and its impact on public land

Abstract

Minnesota has seen an increased interest from 2020-2025 in free, wild food obtained through foraging on public land. Minnesota public land managers are concerned about negative impacts to public land, and as a result have considered restricting harvesting of mushrooms. One concern is that foragers walk off-trail and might negatively impact the forest ecosystem, but there has been little evidence synthesized to inform or validate this concern. Therefore, I examinehuman effects on soil compaction and mushroom productivity by performing a systematic review of peer-reviewed literature. Eight papers were selected in which field research was conducted in areas with seasonal changes including cold weather similar to Minnesota. An additional 16 papers were used to inform the context and discussion surrounding the main findings. I also interviewed five foragers local to the Midwest region of the United States to gain perspective on how foraging practices are carried out on public land. Compaction seems to have a positive but non-linear relationship with foot travel, with foot travel of more than 100 passes not causing a significant increase in compaction. Mycelia is found to grow more readily in soil with greater porosity, but human foot traffic did not seem to have a cumulative negative effect on fruiting body productivity. Human removal of fruiting bodies and the methods of mushroom harvest did not alter fruiting body production in subsequent years. Although there is no evidence in the literature that suggests mushrooms decrease due to human harvest, permitting systems could be implemented to use foragers’ expertise to gather data and teach sustainable and reciprocal practices to new foragers. When considering the carrying capacity of an area for foragers, it is also important to consider traditional ecological knowledge as well as the historic wildlife uses of that area and how that might be replicated by human interaction of foraging on public lands.