Many fungi perform invaluable, useful activites without which our world would be very different.
Fungi are nature's garbage disposal machines. Many fungi break down the dead bodies of animals and plants to release nutrients back to the soil. If these locked up nutrients were not released back into the ecosystem, it would run out of nutrients and plants and higher organisms would die.
An incredible 85 percent of plants rely on fungi. Many plants have a symbiotic relationship with mycorrhizal fungi which live in or around their root systems. Almost a fifth of the energy a plant makes from photosynthesis goes to the fungi which it needs to survive. It is thought the fungi also form underground netwroks and help pass nutrients from plant to plant.
Lichens are a combination of algae and fungi and here the fungi is the one which provides water and mineral nutrients which the algae needs to survive.
Fungi are also incredibly useful to us. They are used extensively in food and beverage production. Yeasts are used to ferment beer and wine and as a raising agent in breads. Fungi are used throughout the food industry from producing enzymes used in food production such as pectinase in juices, chimosin in cheese making and acidity regulators and antioxidants in food often come from fungal sources.
Many antiobiotics are created by fungi - penicillin, for example, is the mould you see on old cakes and bread. They are even used to create 'stone-washed' jeans and in washing powders.
While a few fungi are harmful in the garden such as honey fungus and dutch elm disease, fungi do far more good than harm. For example, it is the soil fungi which give soil that wonderful 'earthy' smell. This is from a group of fungi called actinomycetes and their prescence is a good indication of aerobic conditions and good soil.
Fungi also play a huge part in controlling climate change and the Earth's chemical cycles. They lock away millions of tonnes of carbon in their tissues. They are also involved in releasing carbon from the decompostion of wood and plant materials.
Fungi also act as mirrors for climate change. As climates change, the fungi fruit earlier or later and the extended period of fruiting is indicative of global warming and can also affect the amount of carbon which is liberated.
Fugni are perhaps underestimated in their importance and usefulness but as indicators and carbon sumps, they are invaluable as well as performing all kinds of other tasks. Without them our world would be a very different place to live in.