Mushroom Mysteries: Exploring Their Underground Appearance

Mushrooms are a type of fungus that can grow in a variety of environments, including underground. They are known for their unique appearance, with gills, round or flat caps, cylindrical stems, and a range of colours. While the above-ground mushroom is visible, the underground network of roots, or mycelium, is hidden and can sometimes weigh hundreds of pounds. This root system allows the fungi to break down dead organic material and access nutrients and water, forming a mutually beneficial relationship with plants. Mushrooms are often considered a sign of rich and healthy soil, and their growth can be encouraged or discouraged by various methods. The study of mushrooms and their potential applications, such as sustainable packaging, continues to intrigue and fascinate people.

Mushrooms are the 'fruit' of fungi

Mushrooms are the fruit of fungi, and they can be found in various places, from forest floors to tree trunks and even indoors. They are a sign of rich organic matter and fungi in the soil, and their presence indicates a thriving ecosystem. The process by which mushrooms form is fascinating. When spores from above-ground mushrooms fall to the ground, they grow hair-like roots called mycelium. These roots can form a hidden underground network, and when two roots from different spores meet, they can join to create a new mushroom.

Fungi, including mushrooms, play a crucial role in ecosystems. They were among the first life forms to leave the water and pioneer life on land 1.3 billion years ago. Plants followed, and their success was greatly aided by their partnership with fungi. Today, there are over 2,000 species of fungi that work symbiotically with the roots of Douglas firs alone. This symbiotic relationship is known as mycorrhiza, where the fungi attach themselves to the tips of plant roots. By secreting enzymes, fungi break down dead organic material, providing nutrients and water to the roots of plants. In exchange, trees send sugars to the fungi, nourishing them.

The reproductive structure of the fungus, the mushroom, plays a vital role in spreading spores. Mushrooms entice animals or utilise wind and rain to disperse their spores widely. Wildlife, such as flying squirrels, elk, black bears, slugs, and insects, feed on the protein-rich mushrooms. As these creatures consume the mushrooms, they carry the spores and deposit them in nutrient-rich packets called scat. This process ensures the survival and propagation of the fungi.

While mushrooms often grow above ground, some species remain hidden beneath the forest floor in the form of truffles. Truffles are a type of underground fungus that can be unearthed by animals like the Northern flying squirrel, which leaves behind small, rounded holes. Fungi have a preference for damp and shady environments, and they can be found in various habitats, including tree trunks, lawns, and even basements. Their ability to break down organic material and their partnership with plants make them essential for the health and nourishment of ecosystems worldwide.

Mycelium: the mushroom root material

Mushrooms are the fruit of fungi, and what we see above ground is only a small part of the organism. The network of roots from which mushrooms grow is called the mycelium. This is the mushroom's root material, and it can be extensive, sometimes weighing hundreds of pounds.

Mycelium is made up of hair-like roots, which can be thought of as fungal threads. These threads are much finer than root hairs and can increase the surface area of the root by up to 1,000 times. They form a hidden underground structure, penetrating the soil like a network of tiny spider webs. Mycelium can remain dormant for long periods, waiting for the right conditions to produce mushrooms.

Mycorrhizal fungi, or "root fungi", are a type of mycelium that attaches itself to the tips of plant roots. They break down dead organic material, secreting enzymes to facilitate this process, and bring nutrients and water to the roots of plants. In exchange, trees, for example, send sugars down to their roots to feed the fungi.

Mycelium has been found to be incredibly important to the health of ecosystems. They are like invisible workhorses beneath the forest floor, performing dozens of functions that the forest depends on. Mycelium has also been found in stone-like form, with mushrooms sprouting in the ashes after a bushfire.

Mycologists are now looking at mycelium as a possible solution for more sustainable packaging and consumer products.

Mycorrhizal fungi: 'root fungus'

Mycorrhiza, commonly known as mycorrhizal fungi, is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, or root system. Mycorrhizal fungi form an extensive network, known as mycelium, of microscopic thread-like strands or hyphae, which becomes far more extensive than the actual roots of a plant. This network can cover up to 700 times more soil than plant roots alone, greatly increasing the absorptive area of a plant and acting as extensions to the root system.

Mycorrhizal fungi have been around for hundreds of millions of years, with some scholars suggesting they evolved alongside terrestrial plants approximately 450-500 million years ago when plants first began to colonize land. There is a strong consensus among paleomycologists that mycorrhizal fungi served as a primitive root system for early terrestrial plants, as soils were nutrient-sparse and plants had yet to develop root systems. Mycorrhizal fungi form mutualistic relationships with plants, aiding in the absorption of nutrients and water, and helping them grow. In exchange, the plant supplies the fungus with sugars generated by photosynthesis.

Mycorrhizal fungi can attach themselves to the tips of plant roots both intracellularly, as in arbuscular mycorrhizal fungi, and extracellularly, as in ectomycorrhizal fungi. The pattern of root branching differs between each fungus-plant association and is characteristic of it; for example, pines have Y-shaped branches, while beech branches are at right angles. The fungal sheath sends out branches between the surface cells of the roots to exchange nutrients from the soil for sugars from the plants. This network of branches that penetrates the roots is called a Hartig Net.

Mycorrhizal fungi are extremely important to most wild plants, but less significant for garden plants where the use of fertilisers and cultivation disrupts and replaces these associations. Gardeners can boost natural levels of mycorrhizal fungi by composting, mulching the soil with organic matter, and letting leaf litter remain on the soil. Mycorrhizal fungi can also be purchased and added to the planting hole when planting new plants, helping them establish more quickly and boost healthy growth.

Fairy ring fungi

Fairy rings, also known as fairy circles, elf circles, elf rings or pixie rings, are circular areas of abnormal turf growth caused by fungi that feed on decaying organic matter. They are found mainly in forested areas, but also appear in grasslands or rangelands, and on lawns and golf courses.

Fairy rings are detectable by sporocarps (fungal spore pods) in rings or arcs, as well as by a necrotic zone (dead grass) or a ring of dark green grass. The rings may grow to over 10 metres (33 feet) in diameter, and they become stable over time as the fungus grows and seeks food underground. There are two generally recognised types of fairy ring fungus: tethered and free. Tethered fairy rings are found in wooded areas and are formed by mycorrhizal fungi living in symbiosis with trees. Meadow fairy rings, or free fairy rings, are disconnected from other organisms. These mushrooms are saprotrophic.

There are two theories about how fairy rings are created. The first theory states that a fairy ring is begun by a spore from the sporocarpus. The underground presence of the fungus can cause withering or varying colour or growth of the grass above. The second theory, presented by Japanese scientists, shows that fairy rings could be established by connecting neighbouring oval genets of mushrooms. If they make an arc or a ring, they continuously grow about the centre of this object.

Three different types of fairy rings can form depending on soil type, the specific fungus involved, and environmental conditions. Type 1 fairy rings are most common on golf course putting greens and occur when the fungi involved produce compounds that reduce the amount of water that the soil can absorb, leading to drought conditions that cause the grass in the ring to brown and die. Type 2 fairy ring fungi efficiently decay organic matter, releasing nitrogen that promotes lush growth and leads to a dense green ring of grass. Type 3 fairy rings have rings of mushrooms that appear during wet periods, particularly in the fall. These mushrooms may be poisonous.

Mushrooms as a food source

Mushrooms are a curious food source. They don't fit neatly into the plant or animal kingdoms like most other natural edibles. They can be found in damp and shady environments, inhabiting tree trunks, lawns, and even indoors. With their gills, round and flat caps, brown or yellowish hues, and cylindrical stems, mushrooms can appear quite alien. Despite their distinct appearance, mushrooms have become an increasingly popular food item. Chefs and cooks incorporate mushrooms into a variety of dishes, such as risotto, burgers, soups, stews, and stir-fries, to add an umami flavour.

Mushrooms are the fruit of the fungus, and they play a crucial role in ecosystems. They can remain hidden beneath the forest floor in the form of truffles or push above ground as chanterelles or boletus. These mushrooms provide a rich source of protein for wildlife, including flying squirrels, elk, black bears, slugs, and insects. The spores of the mushrooms are then carried and deposited by these creatures, contributing to the spread of fungi.

The process of mushroom growth begins with the spores, which, upon landing on the ground, grow hair-like roots called mycelium. These roots can form a vast underground network, sometimes weighing hundreds of pounds. When two roots from different spores meet, they often join to create a new mushroom. This network of roots is essential for the survival of plants as they break down dead organic material and facilitate the exchange of nutrients and water with the roots of trees and plants.

Mushrooms are not limited to forests and lawns; they can also be cultivated in controlled environments. For instance, Matt Pinstein, the founder of Underground Mushroom Co., grows mushrooms in a few rooms of an industrial marine space. He employs a technique called "spawn to bulk," where he adds specific types of grains to a substrate in a carefully controlled process. This method involves coaxing the mushrooms to grow in bags of sawdust and grains under specific conditions.

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