Assertion : Lichens and mosses are said to form the pioneer community in xerarch succession.
Reason : It is because these species get established later, during the course of succession.

Options

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C. If the assertion is true but the reason is false
D. If both the assertion and reason are false

Answer

C

Explanation

The plants that invade the base land initially, are called pioneer community. Lichens and mosses form the pioneer community in xerarch succession species. The assemblage of pioneer species forms the pioneer. Lichens form a crust over the base rocks and begin to form soil from their organic remains and by stimulating chemical breakdown of the rocks. Lichens are normally followed by mosses, which speed uyp the process of soil accumulation by trapping wind blown particles. Mosses grow in bunch, and together with lichens, and mosses get establishedon barren rock as pioneer species forming the pioneer community. Generally, the pioneer species show high rate of growth but short life span. In time, the pioneer community is replacedby another community with different species combination. This second communtiy is replaced by a third community, and so on. The plant species which get established later, during the course of succession, are known as late successional species. These species are slow growing and long lived. The terminal stage of succession is represented by the climax community which is stable and does not show change in species composition, as long as the environmental conditions remain the same.