Autumn’s Fungi: The Silent Stars of the Season

Have you ever wondered why mushrooms are so abundant in the autumn? No need to look mush-further! Bethany Akhtar explains why this season is their best, what roles they play and how to find them.

The infamous Fly Agaric mushroom (Amanita muscaria). Image credit: Bethany Akhtar

Fungi are arguably some of the most iconic symbols of the autumn season, showing up in their best array of colours, shapes and sizes, most commonly as their large fruiting body - mushrooms. Whilst they can be hard to spot, their eye-catching and almost alien look is hard to ignore when found. However, the reasons for their emergence and the vital roles they perform are undeniably more showstopping than their looks!

What Are Fungi?

Perhaps the core reason why fungi are so fascinating is because they belong to their own, unique kingdom; they are neither plant nor animal, and are older than terrestrial plants by around 600 million years. In fact, fungi are more akin to humans than to plants, due to a common ancestor shared between us roughly 1.3 billion years ago. This ancestor was likely to be a single-celled organism that brought about both animal and fungal lineages, but specific details are unknown.

By definition, a fungus is a eukaryotic organism (in essence, a living being with more complex cells!), manifesting itself as either a yeast, mold or a mushroom. Like humans, they obtain their nutrients from organic materials within the surrounding environment. However, fungi are unique in how they do this and what they do with them.

For most fungi, nutrients are obtained from breaking down dead or decaying matter, like leaves, wood or pine needles. Then, nutrients are recycled back into the soil for other life to use. This distinction makes most fungi a specific type of feeder, known as a decomposer.

Other fungi can be parasitic, whereby they forcibly take nutrients from a living host, or they can form mutualistic relationships with plants (mutualisms) where both organisms benefit from each other. However, the majority of fungi are crucial decomposers within the global ecosystem.

Why Autumn is a Mushroom’s Prime Time

All fungi originate as ‘spores’ - microscopic, reproductive cells that are dispersed to help spread fungi to new areas. Amazingly, a single mushroom can release more than 1 billion spores each day! 

Nonetheless, no amount of spores can germinate without the right environmental conditions. For most fungi, autumn brings the best-suited climate, most notably due to its rain and high humidity. The high moisture content in both the air and soil helps to facilitate enzymes which fungi use for decomposition, and allows fungi to take up water needed for growth and the movement of small molecules.

Fungi also prefer moderate temperatures, usually around 20-25 degrees celsius, which are commonly found after summer and during autumn. However, their temperature range for growth can be much wider, allowing for germination throughout the autumn.

When these conditions are available, spores within the environment are able to germinate, leading to their development into thread-like filaments called hyphae. As the hyphae become extensive, they form a denser, interconnected network in the soil named the mycelium, which is able to fruit and grow mushroom-like structures called primordia or pins. As these pins expand and enlarge, they ultimately form a visible mushroom above ground, which are then able to release spores that are carried on the wind. 

Clustered brittlestem mushrooms (Psathyrella multipedata). Image Credit: Bethany Akhtar

The Importance of Fungi in the Environment

Fungi play a host of vital roles for our environment, yet they often go overlooked and unappreciated, even in the scientific world.

As previously mentioned, one of the key roles played by fungi is decomposition. This might seem like a simple process, yet it requires complex digestion using enzymes that break down larger, organic compounds, like wood and leaves, into smaller, inorganic components like phosphorus and nitrogen. As a result, essential nutrients are recycled in the soil for uptake by plants, which rely on this process for their growth and development.

In turn, decomposition is also critical for animals who rely on the growth of plants for food or shelter, such as gastropods like slugs and snails, or large mammals like deer and even humans. 

Without this process, the global ecosystem would effectively fade away.

In addition to recycling plant nutrients, fungi are significant recyclers of carbon due to their reliance on carbon as an energy source. Along with plants, fungi perform an important process called carbon sequestration, which captures carbon from the atmosphere and stores it away in the soil, for up to hundreds of years. Consequently, fungi could be one of our most effective, natural remedies for combating climate change! 

In the same spirit, fungi have also been known to break down plastic pollution through their ability to secrete enzymes that digest plastic polymers. As well as plastic, studies have found different species to be effective at degrading pharmaceuticals and personal care products, reflecting their powerful, yet undeveloped use as a tool for environmental restoration.

So far, fungi have been successfully utilised in other areas of environmental remediation like oil spill cleanups. For example, oyster mushrooms were used to clean up the 2007 COSCO-Busan oil spill in San Francisco Bay, and a variety of species are now being tried and tested in the Amazon Mycorenewal Project to purify hundreds of toxic oil pits in Ecuador.

Other important roles of fungi include their symbiotic relationships with other organisms like algae and plant life, whereby they form a close association with them in exchange for biological benefits. Lichens, for example, are a symbiotic association between a fungus and an alga, which provide ecosystem services like air purification and nitrogen cycling. Additionally, mycorrhizal fungi form symbiotic relationships with plant roots to help improve plant nutrient absorption and other functions, in exchange for sugars and carbon.

Fungi Spotting: Where to Look

Finding fungi doesn’t always require travelling to faraway woodlands or nature reserves, however these are great places to start. In fact, lots of fungi grow, quite literally, closer to our doorsteps than you might think.

For example, the shaggy inkcap mushroom, otherwise known as lawyer’s wig, is commonly observed growing on lawns, parks and roadside verges in the autumn. Damp and shaded grassy areas are the best, particularly where there is plentiful food, such as leaf litter and compost heaps.

Common mycena (Mycena galericulata) on a mossy log. Image Credit: Bethany Akhtar

Fallen logs and tree stumps are another great place to look for mushrooms, since they provide a direct habitat as well as a food source. For the same reasons, mature or decaying trees are also likely to harbour fungi either on their surface or nearby. Looking for woodlands with diverse tree species such as birch, beech, oak and conifers can often bring the best mushroom diversity.

The best way to find fungi, however, is just to explore! On your next walk, have a look high and low, and consider places you wouldn’t normally check, like the damp, shady spots of your garden. There just might be mush-more to uncover than meets the forest floor…

Key Species to Find This Autumn

Since there are over 15,000 species in the UK, it can be helpful to keep some species in mind when mushroom spotting! Here are a few, widespread and easily-identifiable species to discover during the autumn:

1. Dryad’s Saddle

Dryad’s saddle (Cerioporus squamosus) growing on the base of a tree. Image Credit: Bethany Akhtar

Due to its distinct shape and size, Dryad’s Saddle is an easily recognisable mushroom that grows on the sides of tree trunks and decaying stumps, lasting until mid to late autumn. This particular fungus is thought to have received its name due to its saddle-like shape and the Greek mythology surrounding dryads, otherwise known as wood nymphs, thought to be using them to ride around woodlands! 

 

2. Shaggy Inkcap (Lawyer’s Wig) 

Shaggy inkcap or lawyer’s wig mushroom (Coprinus comatus) in its mature life stage. Image Credit: Bethany Akhtar

The shaggy inkcap is an unmistakable autumn toadstool, due to its bell-shaped cap resembling a lawyer’s wig. Interestingly, these mushrooms have an unusual lifecycle, whereby they dissolve themselves within 24-48 hours of emergence in a process called deliquescence. This makes them particularly fascinating to observe over time, as their early, cylindrical shape opens outward and gradually melts upwards, releasing an inky, black liquid filled with spores.

3. Giant Puffball

Giant puffball (Calvatia gigantea) mushroom on a woodland floor. Image Credit: Emily Dalziel

In harmony with its fluffy, marshmallow-like appearance, the giant puffball has been named the safest mushroom in the UK for novice foragers due to its unmistakable look and lack of poisonous twins. This mushroom is particularly distinct because of its size, where it can grow up to the size of a football! Each year, it can be found from July until November, growing in a range of environments like woodlands, grass verges and meadows.

Although the giant puffball is easily recognisable, it should be noted that foraging for most mushrooms can be highly dangerous and potentially lethal, due to a number of mushrooms having poisonous lookalikes! Accordingly, foraging is best carried out with or by an expert, and should not be attempted by amateurs without professional guidance.

For keen identifiers, however, it can be helpful to make use of guidebooks like the “Collins Complete Guide to British Mushrooms and Toadstools”, which details the species you are most likely to see within the UK. For those who are just starting out, apps such as Picture Mushroom and iNaturalist are convenient for quicker and easier identification.

Evidently, mushrooms arise in an incredible assortment during the autumn, and there are plenty to be discovered. As scientists and mycophiles alike continue to explore their fascinating diversity, it becomes increasingly clear that fungi play vital roles for the environment, and realising their full potential could unlock the key to solving many of our contemporary challenges. 

About the author:

Bethany Akhtar is an Environmental Science student at the University of York with a passion for environmental education, conservation and spreading awe for the natural world. Her favourite mushroom is the fly agaric! Details of her experience and interests can be found on LinkedIn.