All About Mycorrhizae
Symbiotic relationships exist throughout the natural world. Species tend to develop these mutually beneficial relationships in order to overcome certain obstacles and often they come to depend on the advantage that working together to achieve a common goal supplies. As it turns out one such symbiotic relationship exists that we can take advantage of as gardeners!
I’ll Give You One Hint Because I’m a Fun-Guy (Fungi)
Mycorrhizae is a broad term for a subset of fungal species that are particularly beneficial for most plants we grow! There are two different types of Mycorrhizae and dozens of sub-species that offer different benefits for trees, shrubs, vegetables & flowers throughout the growing season!
Endomycorrhizae “inject” themselves directly into the roots of your plants. They also form spore sacks that emerge from the root and eject spores that can travel for sever feet (hundreds of miles if we were their size) to colonize on other roots. Many scientists believe that the evolution of the symbiosis between plants and these beneficial fungi played a crucial role in the initial appearance on land by plants and in the evolution of the vascular plants – this relationship is known as the arbuscular mycorrhizal symbiosis.
Endomycorrhizae boost the ability of roots to absorb nutrients by providing an extra internal “digestive” system so that the nutrients absorbed from the soil can be more readily converted into energy to sustain root, leaf & fruit/flower growth.
Ectomycorrhizae live in the soil between plant roots and cover the surface of the roots themselves forming a sheath that encases portions of the root system. They were first discovered around the roots of “woody” plants such as birch trees, oaks and pines. Today there are many varieties of ectomycorrhizae that we know of each adapted to handling slightly different levels of nutrients. Our ability to track carbon isotopes has proven that nutrients even travel between different species of trees!
Since Ectomycorrhizae live between root systems they can perform two critical functions: 1) breaking down macro-nutrients that exist in the soil so they can be more easily absorbed by the root systems around them, this process is fairly similar to a mother bird pre-digesting food to feed to her fledglings; 2) passing nutrients from one root network to a neighboring root network!! Transportation is certainly the most critical function of ectomycorrhizae – when one plant has no use of a certain nutrient, ectomycorrhizae will preferentially move those nutrients (when possible) to a neighboring root system that enjoys or requires them. Why? If we could see it from the fungal perspective, we would view these so-called “nutrients” as our waste from digesting what we consume in the soil. How convenient! The fungi found a sustainable way to “take out the trash” and roots have all the nutrients they need to grow healthy and strong!