Question

Various stages of succession are given below. From that rearrange them accordingly. Find out the type of succession and explain in detail.
Reed-swamp stage, phytoplankton stage, shrub stage, submerged plant stage, forest stage, submerged free-floating stage, marsh meadow stage.

Answer 1

Reed-swamp stage, phytoplankton stage, shrub stage, submerged plant stage, forest stage, submerged free-floating stage, and marsh meadow stage.

1. Phytoplankton stage – It is the first stage of succession consisting of the pioneer community like blue-green algae, green algae, diatoms, bacteria, etc., The colonization of these organisms enriches the amount of organic matter and nutrients of the pond due to their life activities and death. This favors the development of the next serai stages.

2. Submerged plant stage – As the result of the death and decomposition of planktons, silt brought from land by rainwater leads to a loose mud formation at the bottom of the pond. Hence, the rooted submerged hydrophytes begin to appear on the new substratum.
   Example: Vallisneria and Hydrilla etc. The death and decay of these plants will build up the substratum of the pond to become shallow.

3. Submerged free-floating stage – During this stage, the depth of the pond will become almost 2-5 feet Hence, the rooted hydrophytic plants and with floating large leaves start colonizing the pond.
   Example: Rooted floating plants like Nelumbo, Nymphaea, and some free-floating species like Azolla, and Pistia are also present in this stage. By the death and decomposition of these plants, further, the pond becomes more shallow.

4. Reed-swamp stage – It is also called an amphibious stage. During this stage, rooted floating plants are replaced by plants that can live successfully in aquatic as well as the aerial environment.
   Example: Typha, Phragmites, Sagittaria, and Scirpus, etc. At the end of this stage, the water level is very much reduced, making it unsuitable for the continuous growth of amphibious plants.

5. Marsh meadow stage – When the pond becomes swallowed due to decreasing water level, species of Cyperaceae and Poaceae colonize the area. They form mat-like vegetation with the help of their much-branched root system. This leads to absorption and loss of a large quantity of water. At the end of this stage, the soil becomes dry and the marshy vegetation disappears gradually and leads to the shrub stage.

6. Shrub stage – Here areas are invaded by terrestrial plants like shrubs (Salix and Comus) and trees (Populus and Alnus). These plants absorb a large quantity of water and make the habitat dry. Further, the accumulation of humus with a rich flora of microorganisms produces minerals in the soil, ultimately favoring the arrival of new tree species in the area.

7. Forest stage – It is the climax community of hydrosere. A variety of trees invade the area and develop any one of the diverse types of vegetation.
   Example.Temperate mixed forest (Ulmus, Acer, and Quercus), Tropical rain forest (Artocarpus and Cinnamomum ), and Tropical deciduous forest (Bamboo and Tectona).