I believe they cannot start with big trees and bushes because the there is not enough nutrients in the soil, so instead pioneer species pave the way for primary succession.
Answer:
Eukaryotic
Explanation:
Fungi are eukaryotic, non-vascular, non-motile and heterotrophic organisms. They may be unicellular or filamentous. They reproduce by means of spores. Fungi exhibit the phenomenon of alternation of generation.