As we passed the autumnal equinox last week, and Michaelmas on Thursday, we are now deep into the rich and fruitful season of Autumn. The leaves are not quite taking on their most glamorous colours yet, but a few are starting to fall. The evenings are drawing in fast and the longer nights are noticeably cooler. Fallen apples and conkers decorate the paths and the air is filled with the rich scent of decay as we enter the dark half of the year. The plant kingdom is laying down its stores of summer carbohydrates in their roots, preparing to hunker down for the winter. Underground life is stirring. This is the time when the ‘flowers’ of the woodland start to bloom. Now is one of the best times of the year to go looking for mushrooms.
I don’t collect any mushrooms for culinary purposes. If you do it’s well worth taking an expert to guide you, and make sure your identification is 100% correct before risking cooking any. I have however grown mushrooms from a kit a few times. This year I collected the spores and have added them to a few rotten logs in the garden. I’m hoping I will be able to harvest oyster mushrooms of my own sometime soon.
My primary interest in foraging for fungi is to learn more about them. I want to be able to identify them better and know how they relate to the habitat in which we discover them. Many have specific requirements, only growing on wood in a particular life stage (from living, to dead, to near mush.) Many will be specific to one particular host plant or only occur in association with certain soil types. They are indicator of the health of the ecosystem and tell us just as much about our environment as the plants, animals or insects we see.
For all that we see going on above the ground, there is just as much at work beneath. Whilst the world of light is easily seen and tangible to us, the dark underworld of the soil and mushrooms can be easily overlooked. We only ever see their tiny fruiting bodies if they choose to make an appearance when the ideal environmental or climatic conditions allow. The giant redwoods of the west coast of the US are often thought of as the biggest organisms on the planet, but they are dwarfed by a leviathan of a mushroom. The giant body of a colony of armillaria mellea (honey fungus) is slowly eating it’s way through the Malheur National Forest in Oregon. It is thought to span 3.4 sq miles, and is possibly the largest single organism on the planet. The world of mushrooms and fungus plays an essential role of recycling nutrients in the environment. Without the approximately 1.5 million species of fungi that exist we would be without bread, beer or soy sauce. Millions would die from a lack of the antibiotics produced by fungi, and yet we still seem to be fearful of them. Perhaps it is their ominous sounding names such as the ‘Death Cap’ or the ‘Destroying Angel’. Maybe it is their association with malevolent imps of the forest, but we seem to push them to the edge of our world.
The hyphae of the soil fungi form a mutually beneficial association with the roots of the plants that live there, called a mycorrhizae (from the Greek mykos – fungus, and riza – root.) This links every plant and fungus living in the ecosystem together. This huge network has been described as a ‘wood wide web’. Recent research has shown that this performs a beneficial function for both plants and fungi. The fungi are able to access the carbohydrates produced by the plants from a summer of photosynthesis. In turn the fungi provide the trees with essential phosphorus and nitrogen from the soil.
By using a special blend of carbon dioxide containing the carbon-13 isotope, researchers demonstrated trees utilised this network for mutually beneficial reallocation of resources. Young saplings, struggling in the shade of more established trees were supported by the matriarchs of the forest. Trees under attack from aphids used the network to warn their neighbours to raise their defences against the impending threat.
This starts to raise the question about if the traditional way we see the boundaries of an organism are really true. Should we start to recognise the forest as one single living, breathing and feeding organism, rather than a host of individuals, all competing for a niche in a laissez-faire, free-market system, as our current interpretation of evolutionary theory suggests we should. If so, how do we start to plug into this network. How can we start to add our own status updates? And how do we start to like the ‘posts’ from our friends and neighbours, the plants and fungi.