There are two principal Kingdoms that seemingly dominate this lush planet on which we reside; the plants (Plantae) and the animals (Animalia). However, there’s another Kingdom of secretive organisms that are also easily overlooked given their hidden activities, unseen growth and generally mysterious nature – a group that is globally significant in nutrient cycling and soil health. I’m referring to Fungi of course! In this article I won’t be delving into the fungi that we typically think of though – those lovely edible field mushrooms that taste so good, or the fairy-tale-like growths that sprout up on rotting wood in the garden – but instead I’ll be exploring the array of industrious soil dwelling fungi, the ones that in reality, every other creature on this earth relies upon.
These organisms are one of the most important groups on the planet, due to their resourceful nature, and humans have utilised their benefits for thousands of years (using yeast for the fermentation of beer is one well-loved practice)! However when it comes to soil fungi, these diligent soil organisms don’t tend to get the praise they deserve. Whether this is because of their modest appearance, their silent operations beneath the ground or their connotations with more sinister consequences (blights, mould and other related diseases). It seems as though the fungi that live beneath us, although crucial for our survival, have been a bit neglected. In this blog I want to highlight what attributes define fungi as a Kingdom, what survival tactics they employ, how these are fundamental in maintaining life and lastly why we, at 59 Degrees, are passionate about encouraging them back into the soil.
The Nitty Gritty
When you see the fruiting body of a fungus (referred to as a mushroom), you are viewing the very tip of a potentially massive, intelligent and vital underground organism. But delve beneath the fruiting body into the soil and there are many thread-like structures called hyphae. These form a vast underground network which make up the bulk of the fungi – in fact, it’s suggested that some individuals can stretch for hundreds of meters and the largest individual organism on the planet is actually a huge fungus (not a blue whale as we were led to believe)!
These enigmatic organisms may appear to be very similar to plants in their structure and life cycle, yet they are classified in a completely different Kingdom. Originally scientists believed that fungi were indeed plants, because they shared many of the same features, however later on it was found that fungi also possess characteristics similar to those in other Kingdoms, particularly animals. With that in mind, what are the distinctive characteristics that separate fungi from animals and plants?
Well, the most distinctive trait of a fungus is its cell wall, which is made up of a substance called Chitin (a long chain derivative of glucose – the same stuff insects use to form exoskeletons) and they combine these with glucans (another complex compound made up of glucose monomers). Fungi are unique as they are the only organism that joins these two structural molecules together in their cell wall. These substances enable fungi to maintain strength in their cell walls and enable rapid modifications to be made if a stressor occurs. Excitingly it has recently emerged that chitin has a significant role to play in the activation of immune responses in fungi, since it’s also a key component in the cell walls of pathogenic fungi, amoebae, nematodes and the exoskeletons of invertebrate vectors of human disease such as mosquitoes and ticks.
Like animals, fungi do not photosynthesis and require organic compounds as a source of energy, however their method for harvesting energy is quite peculiar. Rather than digesting their ‘food’ internally like most animals, they secrete digestive enzymes into the environment, which dissolves organic matter into smaller molecules. The fungi can then absorb the nutritious pulp and use the carbon for growth – yummy! This characteristic is one of the reasons this Kingdom is so valuable to all life on Earth, as through this process they break down organic matter releasing the otherwise locked up nutrients into the soil – therefore completing the cycle of nutrients. Or to be terse, without beneficial fungi breaking down nutrients, we animals are screwed!
As you most likely already know, humans have made use of fungi in many ways over the centuries; we’ve eaten them, utilised their medicinal benefits to control the spread of disease and even used them to create alcohol. The list of fungi that are beneficial to us, both globally and as a species is extensive, but the fungi I really want to investigate are those that reside in the soil, of which there are three main groups (a fascinating detail here is that each group is defined by its approach to, or rather its ‘method’ of harnessing energy).
First up are the pathogens or parasites – the ones that have given fungi a bad name amongst growers. Some types of these fungi can colonise plants, which leads to plant death or reduced production, and these are the fungi that farmers and gardeners want to kill – who can blame them when their whole crop has been destroyed by a microscopic organism. However many parasitic fungi in this group can actually help to control disease or be used as a bio-control, which is particularly useful for regulating some species of insect or even types of disease-spreading nematodes. These methods of pest and disease control are growing in popularity due to their environmental credentials and importantly, their sustainability (and cost effectiveness) compared to that of any other synthesised chemical – again, another fascinating subject that will be touched upon in the future.
Next are the mutualists – or the mycorrhizal fungi. The last blog briefly touched on these incredible organisms and they will also be the subject of the next article (the wood wide web). These fungi colonise plant roots and form a symbiotic relationship which revolves around the reciprocated transfer of nutrients and energy. As I mentioned in the last post, the mycorrhizae make soil nutrients, such as phosphorus, nitrogen and other micronutrients, more soluble for the plant in exchange for carbon from the plant. Not only do these tiny filaments enhance the root system by increasing surface area, they also form an information highway through the soil, allowing communication from plant to plant.
There are a couple of major mycorrhizal groups (which will be of significance in further posts); the ectomycorrhizae, they grow on the surface of tree roots (mostly) and the endomycorrhizae, they grow within the root cells and are commonly associated with other plants such as grasses and vegetables (crops) and shrubs. This group has immense potential in the world of agriculture and could revolutionise the way we farm the land!
The last, and by no means least important, group of soil fungi are the decomposers, the saprophytes. These fungi feast on dead organic material (including the complex substrates in wood, cellulose and lignin) what remains are rich nutrients, which make up an important component of soil, as well as other by-products such as carbon dioxide and organic acids. Decomposers are essential for breaking down the carbon ring structures in some pollutants, and like bacteria, these fungi also facilitate the highly important role of nutrient retention in soil. Without this specific group of fungi, life would not be sustainable. Dead organic matter (including all those fallen leaves in autumn!) would pile up, which would not only suffocate the living plants, but would also break the cycle of nutrients – needless to say, with no complete nutrient cycle life as we know it would cease to exist. Hence, the importance of these impressive fungi!
So there we have it, the three major groups of soil fungi, each with their own niche in the environment and each employing their own tactics in order to survive. Whether they know it or not they are also inadvertently allowing the rest of the world to survive. They take the food chain, and make it into a food cycle, an attribute that cannot be overlooked, for without it, we simply would not be here!
Why we love them
Put simply, fungi are brilliant. By better understanding how they behave, what their needs are and thus, how important they are to our needs, we are deliberately able to derive better, more nutrient dense crops and yields from smaller plots whilst reducing a whole host of inputs (soluble nutrients and water to name but a few). In order for these benefits to manifest however, a diverse array of fungi need to be present, this is nature’s secret; Diversity. A healthy soil needs the full range – the decomposers, the mutualists and all those other symbiotic organisms – in order for everything to work just as it should, the way nature intended.
When we delve into the world of soil, what we see above ground is merely a result of the world beneath our feet. This vast and complex system that supports all life on land is nourished by the strange but wonderful Kingdom that is fungi. We are super passionate about bringing back the balance to soil by observing nature and applying the tried and tested 4.6 billion year old formula to our own products in order to promote growth. We humans don’t need to reinvent the wheel. We just need to get the fungi back.
At 59 Degrees we love fungi, because we know that without them, there is no soil at all!