Azzam, fungi are a very important link in the ecosystem. Their most significant ecological role is helping with nutrient turnover. When a tree dies, something must act on it to return all the nutrients locked up in it back into the soil and the ecosystem. Well, most fungi help with this. They feed on detritus (dead organic matter) and release its nutrients (like nitrogen) into the soil from where more and new plants can take them up for growth and development. They take from the dead to help the living survive and thrive. In other words, they help to close the loop of nutrient cycles.
Imagine if there were no fungi, all the dead matter would start piling up. Also, eventually, no new plants would grow as all the nutrients are locked up in the dead matter. No plants mean no foundation for any food chain. Thus, the whole ecosystem would eventually die out - and that's how important fungi are!
Imagine if there were no fungi, all the dead matter would start piling up. Also, eventually, no new plants would grow as all the nutrients are locked up in the dead matter. No plants mean no foundation for any food chain. Thus, the whole ecosystem would eventually die out - and that's how important fungi are!