Article by Sam Waggener, City of Lone Tree Forester
Featured image by @mdjaff on freepik
I Spy Fungi
Soils are littered with bacteria and fungi, depending on what is growing in that soil, and each plant requires either increased bacteria, ample fungi, or equal parts of both. Annuals thrive in soils that have an increased number of bacteria; this is why you add compost to a vegetable garden. Soils for trees found in old-growth forests have an increased total number of fungi. There are three main fungi types, each based on how they react with carbon. The three players are parasitic, saprophytic, and mycorrhizal. Parasitic fungi feed on living plants, saprophytes feed on dead/decaying plants, and mycorrhizal form a mutualistic relationship with the roots, aiding the tree in growth while also feeding the fungus.
Let’s Talk Mycorrhizae
My cro what?! Mycorrhizae (mai-kuh-rai-zee) is a fungus known to be found in 90% of land plants. This is the type of fungus mentioned above that forms a symbiotic relationship with the roots of the plant it adheres to.
Mycorrhizae allows for increased absorption of nutrients and water to the plant, which is then brought to the roots of the tree. The tree is more than willing to provide the precious sugars the fungus needs to survive. These sugars are then infused with carbon, allowing the fungus to have an ample supply of nutrients. The sugars, nutrients, and carbon are needed for both the tree and fungus to survive, and this production of resources is used by both fungus and trees to continue thriving. In fact, conifers are completely dependent on this root fungus for non-photosynthetic nutrients.
Fungi Network: Nature’s WiFi
There are as many as 3.8 million species of fungi (Fantastic Fungi), but all act and perform in similar ways. The fungus can create a network of filaments that bond to each other, while also adhering to trees and other plants’ root systems. This creates a web design allowing for plants to communicate with one another. You might have seen this concept in action on HBO’s sci-fi hit “The Last of Us,” but this communication network isn’t here to harm humans! This communication web can warn other plants in the area that a stressor such as aphids are out on the hunt, so action is needed. This web of filaments called mycelium has two main players, which are Ectotrophic and Endotrophic. Depending on the species of the tree, vegetation will be dependent on the type of fungus that forms this symbiotic relationship. Endo is the term used for fungi that pierce into the roots, ectomycorrhizal fungi stay outside of the root mass, but both still perform the same amazing benefits.
A Budding Relationship
The fungi receive carbon from the plant, and the tree or plant receives the nutrients the mycorrhiza absorbs. This type of fungus is paramount in a plant/trees ability to sequester macro nutrients such as Nitrogen.
Not only do these fungi help with nutrient absorption, but mycorrhizae can aid in water retention in the soil and increase protection against pathogens. This fungus also stabilizes the soil and helps with erosion. Mycorrhizae has a certain property that acts like a glue and can increase the amount of water retention and absorption. One easy way to add this fungus to your trees is to mulch! Mulching with wood chips, sawdust, and leaves is the most organic way to increase fungus production in your yard. But you can always buy inoculates with mycorrhizae to add to your tree wells or when planting, especially conifers!
As always, if you have any tree or plant questions, feel free to contact me at [email protected]. Until next time, happy growing, Lone Tree!