Solve a,b and c.

(a) .Colonization of rocky terrain is a natural process, known as primary succession. The primary succession occurs in a place which is originally devoid of any soil, vegetation etc. The first organisms that invade the rocky terrain are lichens, algae, fungi followed by grasses, shrubs and then followed by larger trees.  

(b) The following illustrations depicts successional series progress from hydric to mesic conditions.


(c) The climax community of both hydrarch and xerarch succession is the mesic (medium water condition) and is represented by forests in both cases.