The biodiversity increases when one moves from the pioneer to the climax stage. What could be the explanation?
A rich diversity of flora which can support a larger and diverse consumer set will lead to greater biodiversity of a community.
Lichens, Bryophytes and Pteridophytes are the main plants in the pioneer stage. As these plants do not produce enough food to sustain a diverse fauna, there would be limited biodiversity.
Gymnosperms and Angiosperms become abundant when a community reaches its climax and as they produce enough food to sustain a diverse fauna, biodiversity in such communities will be higher.