What role do fungi play in the ecosystem?

All mushrooms are located in the kingdom fungi. There are three factors that characterize a fungus:

• One, the cell walls are made of Chitin.
• Two, the mode of digestion is absorption.
• And three, they are heterotrophic.

Let’s pull these apart one by one to understand the kingdom fungi better.
Chitin is a complex, rigid molecule which also comprises lobster and insect shells. Most human stomachs cannot digest Chitin. Since chitin is primarily indigestible when mushrooms are consumed raw, a majority of the nutritional benefits are locked away behind this chitin and unavailable. This is not to say one can eat poisonous mushrooms raw safely! Some compounds in the mushroom are available to our human system without breaking the chitin down but most require the degradation of the chitin before consumption. Chitin can be broken down simply by heat in the process of cooking or making tea or by alcohol in the case of making tinctures.
The second determining factor of a fungus is their mode of digestion. Fungi are unique from most animals because they do not have stomachs. Fungi secrete enzymes outside of their body, breaking down whatever they are growing in and absorbing the nutrients back into their body. The enzymes that are secreted by fungi are strong compounds that not only break down the food source but also protect the fungus. These enzymes are a cocktail of different antifungals, antibacterials, and probiotics which guide the microbial growth around the mycelial network.
Some mushroom species, such as wine cap, require the presence of certain bacteria in order to fruit. The enzymes that are produced can be signals or food sources for certain bacteria to proliferate. One radically different consequence of this method of nutrition is that fungi need to grow on or in their food source. Fungi cannot survive in the mycelial state separate from their food source.

Lastly, fungi are heterotrophic, meaning they rely on an external food source. Fungi are not capable of photosynthesizing. Unlike plants they cannot transform the sun’s energy into matter. Fungi are the recyclers, the magicians throughout the cycle of life, that transform death into the possibility of life. Decomposition is not the only ecological role fungi play though. Let’s go through three of the most common ecological roles fungi play.