What is the primary role of fungi in most ecosystems?
Main as a part of natural ecosystem will be decomposition.
Because of their saprophytic nature,Fungi carry out the decomposition of dead remains of plants and animals and other organic matter.Decomposition causes release of many complex elements and compounds trapped in the organic matter which is then absorbed again by the plants,thus fungi helps in keeping the environment healthy and clean.
If we consider humans too in to be part of the ecosystem as a whole then fungi plays a key role in -
Medicine- many life saying drugs like penicillin are made from fungi (name of fungi- penicillium notatum)
Vitamin supplements are made from fungi too. (thiamine,riboflavin)
In Bakery -yeast (which is a fungi) is used in making bread.
They keep the environment balanced.
Fungi are saprophytes. They get their food from dead bodies or their parts. In order to get their food they decompose the dead parts into non-living substances and prevent the environment from degradation. that decomposed products are again used by green plants.
The primary role of fungi is to act as a decomposer
Fungi feed on dead and dying tissues. Fungi do not have chlorophyll so they can not produce food energy. Fungi must get their energy from other organisms.
When a tree dies the fungi attack the tissue of the tree breaking the material of the tree down into its component parts. This releases these compounds back into the environment where they can be used by other plants.
The fungi like mushroom also serve as a source of food energy to other organisms, but this is not their primary role.