Question

A rocky area once bare now has a green forest. The sequence of succession has
A) woody mosses, woody shrubs, mosses, and lichens
B) Lichens, mosses, woody shrubs, annual herbs
C) Mosses, lichens, annual herbs, and woody shrubs
D) Lichens, mosses, herbs, and woody shrubs

Answer 1

When an area is being colonised for the first time, it is said to undergo primary succession. For instance, after a volcanic explosion, once the lava cools down, it is a rocky land which has ever had any life on it.

Complete Answer:
- When an existing area is destroyed by a disaster like a forest fire, and then undergoes colonisation and regrowth, it is going through secondary succession.
- When a rocky area is being colonised, long before it becomes dense green forest, simpler plants will start to grow. In primary succession, lichens appear first.
- As they grow, they break down the soil and provide fertiliser through their decomposing material. This allows mosses to then start colonising the area. Moses also then died, adding to the soil depth and nutrition.
- Around this time, simple ferns will start to grow as well. AS time progresses, woody plants will start to take over, finally larger trees and creepers till a mature forest is formed.

- In option A, woody shrubs are shown to come before mosses and lichens. Option A is incorrect.
- Option B says that annual herbaceous plants come after woody shrubs. This is the wrong order, option B is incorrect.
- According to option C, mosses start colonising the land before lichens. Option C is not the right answer.
- Option D has the succession in the correct order. Lichens prepare the ground for mosses; mosses prepare it for annual herbs, and finally the woody shrubs have a suitable habitat. Option D is the correct answer.

Hence the correct answer is option D.

Note: Many forests that we see today appear to us to be very ancient and primary, but closer examination would show that these in fact are a result of primitive man’s interference. The large grassy moors were once dense forest.