How Fungi Support Biodiversity in Forest Ecosystems Fungi, including mushrooms, play essential roles in supporting biodiversity in forest ecosystems by forming symbiotic relationships with plants, decomposing organic matter, and providing habitat and food for various wildlife species.  Here's how fungi contribute to biodiversity in forests: Mycorrhizal Relationships : Many trees and other plants form mutualistic relationships with mycorrhizal fungi, where the fungi colonize the plant roots and exchange nutrients with the host plant. In return for carbohydrates from the plant, mycorrhizal fungi extend the plant's root system, enhance nutrient uptake (especially phosphorus and nitrogen), and improve the plant's resistance to pathogens and environmental stress. These symbiotic associations are vital for the health and survival of many plant species in forest ecosystems, ultimately supporting a diverse array of flora and fauna. Decomposition and Nutrient Cycling : Fungi play a