News: American evolutionary biologist Toby Kiers has been awarded the Tyler Prize for Environmental Achievement for her work related to Mycorrhizal Networks.
About Mycorrhizal Networks
- The word mycorrhiza comes from Greek and means “fungus–root,” describing the close association between fungi and plant roots.
- Mycorrhizal networks are underground systems formed by symbiotic fungi that connect the roots of plants and trees.
- These networks are often referred to as the “Wood Wide Web” because they function like a natural communication system.
- Age and Evolution: Mycorrhizal networks have existed for more than 400 million years. These fungal partnerships appeared before trees, flowering plants, and humans.
- Structure of Mycorrhizal Networks: Mycorrhizal networks are composed of microscopic fungal filaments called hyphae. Hyphae are extremely thin, often only one cell wide. A small amount of forest soil can contain miles of interconnected fungal threads. These threads greatly extend the functional root system of plants.
- Functions performed by Mycorrhizal Networks
- Symbiotic Relationship Between Plants and Fungi: Plants provide mycorrhizal fungi with sugars and carbon produced during photosynthesis. Fungi supply plants with water and essential nutrients such as nitrogen and phosphorus. This exchange benefits both organisms and is classified as a mutualistic relationship.
- Communication and Signaling: Mycorrhizal networks allow plants to communicate through chemical signaling. Warning signals can be transmitted when a plant is attacked by insects or pathogens. Neighboring plants receive these signals and activate defensive responses. This communication increases the overall survival of plant communities.
- Resource Sharing and Forest Cooperation: Mycorrhizal fungi redistribute nutrients and water across the network. Resources are directed toward plants that are stressed or growing in poor conditions. Large, mature trees support younger seedlings through these networks. Some trees remain alive after being cut down because they continue to receive nutrients from nearby trees.
- Types of Mycorrhizal Fungi: There are two main types of mycorrhizal fungi: arbuscular and ectomycorrhizal fungi.
- Arbuscular mycorrhizal fungi enter plant root cells and form structures where nutrients are exchanged. These fungi are associated with most crops, grasses, and flowering plants.
- Ectomycorrhizal fungi form a protective sheath around roots and do not enter root cells. They are commonly found in forest trees such as pines, oaks, and birches. Many well-known forest mushrooms are the fruiting bodies of ectomycorrhizal fungi.
- Ecological Importance: More than 90 percent of plant species rely on mycorrhizal relationships.
- Forests with intact fungal networks are more resilient to drought and disease. These networks improve soil health and ecosystem stability.
- Mycorrhizal fungi play a key role in maintaining biodiversity.
- Mycorrhizal fungi naturally occur in healthy agricultural and garden soils. Adding compost and organic matter supports fungal growth. Mycorrhizal inoculants can help plants establish strong root systems.
