大象传媒

Fungi are beneficial to many plants, particularly in forests. In a spruce forest in western North America, David Attenborough explains how even the tallest, healthiest tree is dependent on fungi which live underground. The tree rootlets have tiny fingal threads wrapped round them. These hugely increase the amount of water and nutrients the tree can absorb. In fact, seedlings that end up in soils without fungi will starve to death. The tree takes the nutrients and water supplied by the fungi, combines it with carbon dioxide and makes food. These fungi are hidden from us except when they emerge to fruit - and this may only happen over only two or three days every 20 years. A timelapse of a fly agaric fungi growing from the ground shows this happening. The fungi also benefit from the symbiosis with trees, because they are given a quarter of the starches and sugars the tree manufactures.