As drivers of plant growth and agents of decay, we owe a great deal to fungi says Norfolk Wildlife Trust Reserves Officer Robert Morgan.
Any lover of nature associates autumn with different things; migration and hibernation, the wonderful colours of turning leaves, berry-burdened bushes, early morning mists, and of course blustery, troubled weather. For me it is the season of fungi, with rotting vegetation and warm moist air prompting all manner of weird spore-laden ‘fruiting’ bodies to suddenly appear. Even those with only a passing knowledge of natural history, know that they can come in all kinds of peculiar shapes and sizes – while some are edible, others are definitely not. What many people may not realise is that they are ubiquitous and vital to all living things.
Fungi grow on us and in us, they occupy timber, dung, leaf litter and soil, to the extent that most plants form a symbiotic relationship with fungi to enable them to draw up nutrients for growth and seed germination. It has been found that trees can even communicate with each other through the hidden underground ‘root-like’ body of fungi called mycelium; often referred to as the Wood Wide Web. Some species of fungi will conjoin with plant roots and assist with the take up of water, minerals and other nutrients, in return they receive carbohydrates and sugars. In a rather sinister way they drive growth because they are the Earth’s agents of decay, for without life there is no death.
Unlike plants, fungi do not manufacture their own food through photosynthesis, but absorb organic matter externally with their ‘hyphae’ threads. At the risk of becoming too philosophical, one could argue that the vast rainforests, herds of wildebeest and teeming invertebrate life of wood and meadow is propagated as future food for the unknowable number of fungus species that occupy every corner of the Earth.
First appearing over 440 million years ago, during the Silurian period, it was the establishment of fungi that enabled plants to colonise dry land. The Prototaxites, one of the most enigmatic of fossils, has recently been identified as a massive fungus, a structure as tall as a two-storey house. Back then, as is the case now, fungi propagated plants only so they could feed on their rotting bodies. I delve back to such a far distant time because the relevance to us is still pertinent and compelling. Many vascular plants became more complex, and increased in size, evolving wood to hold themselves up. In the great race of life, fungi fell behind. The solid and complicated chemical structure of wood could not be broken down by the biological weapons held by fungi then. During the Carboniferous period, vast forests of undecomposed wood, over millions of years, were laid-down – creating he fossil fuels we now use. Never before, or likely ever again, will so much carbon be locked into the Earth. Carbon dioxide levels fell from 1,500 parts per million to 350 ppm, roughly our current level.
Of course, fungi have caught up, and evolution has them in charge once again. Humanity, for many centuries, has been aware of the hallucinogenic, medicinal and chemical properties of fungus, but we’ve barely scratched the surface in discovering many of their other amazing abilities.
In fact, the largest living organism on the planet has recently been discovered, and yes, it’s a fungus. Less surprising, it’s found in America. Initially the honey fungus provides sapling fir trees with important minerals to encourage quick strong growth, but being a parasitic fungus it becomes impatient and chooses to kill the trees once they reach a certain age. US forest rangers discovered 112 dead trees over a two-kilometre area. This group of trees was found, through DNA testing, to have been killed by an individual honey fungus, its mycelium creeping through the soil over this vast area.
Some species are specialist parasites of insects, even practicing mind control, having the ability to modify the host’s behaviour to suit spore dispersal. Fungi are both a force for growth, and the planet’s recyclers, their existence ensures a constant equilibrium in the natural world. Fungi may be waiting for us to die, but in the meantime, we have managed to harness some of their powers; yeast has helped us with the brewing of beer, fermenting of wine and baking of bread, penicillin has joined us in the fight against infectious bacteria, and a beefsteak isn’t the same without two large Portobello mushrooms.
Header image - fly agaric by Luke Massey/2020VISION