The fascinating world of fungi forensics
The damp conditions of autumn make it the ideal time for fungi foragers.
Fungi come in all kinds of shapes and sizes, from the familiar mushrooms to cups, balls and brackets. But these bizarre structures we’re used to seeing are just the fruiting bodies, which usually only pop up once or twice a year. Like the fruits of a tree, these are temporary, short-lived parts of the larger organism. Their only job is to help the fungus spread.
They do this by releasing microscopic spores, which require dispersal like seeds from a tree and are often spread by the wind. Some fungi fire their spores into the air like a cannon. The puffball, for example, releases a cloud of spores from a hole in its top when a mature mushroom is compressed by rain, a passing animal or an inquisitive human finger.
The main part of a fungus, which lives on long after the toadstools have toppled, is hidden within the substrate from which the fruiting body grows, be it soil, rotting wood, dung or even nuts and seeds. It’s a dense, tangled network of threads (called hyphae) that together are known as a mycelium.
These networks can stretch for metres (or in rare cases miles) through the soil, connecting fungi to the roots of trees, grasses and other plants. In most cases, it’s a win-win relationship: the fungus gives the plant nutrients from the soil and the plant supplies the fungus with carbohydrates formed through photosynthesis.
As well as sharing nutrients, these networks can also be used to send information. Studies have shown that trees under attack, from a harmful fungus or insects like aphids, can send out a warning to nearby trees through the mycelium, giving them chance to prepare and defend themselves.
However, the network can also have a darker side and some plants have found a way to exploit it. The bird’s-nest orchid is a sickly-looking species that grows in caramel-coloured spires in shaded woodland areas and has no chlorophyll, so can’t photosynthesise like most plants to produce food. Instead, it sucks nutrients from the fungal mycelium that connects its own roots to those of the other plants growing around it, giving nothing in return.
So, next time you spot a toadstool sprouting from grass, or a bracket clinging to the bark of a rotting branch, spare a moment to think about the hidden network sprawling beneath your feet, connecting the forest and breathing life into the trees.
To find out more about local wildlife that Hampshire & Isle of Wight Wildlife Trust are working to protect visit https://www.hiwwt.org.uk