Because pioneer species are the first to return after a disturbance, they are the first stage of succession, and their presence increases the diversity in a region. They are usually a hardy plant, algae or moss that can withstand a hostile environment.
Anaerobic means with out oxygen
Microbes. Bacteria, for example, convert nitrogen and carbon dioxide from the air into usable components that plants and animals can use as essential building blocks. A loss of all microbes would be terrible news for living organisms that can't create or take in these essential nutrients on their own.
