Question

Identify the correct sequence of the seral stages in hydroseres.
A. Plankton, submerged, floating, reed swamp, sedge meadow, woodland
B. Plankton, floating, submerged, reed swamp, sedge meadow, woodland
C. Plankton, floating, submerged, sedge meadow, reed swamp, woodland
D. Plankton, submerged, floating, sedge meadow, woodland, reed swamp

Answer 1

Hint: Sere refers to the entire series of communities that occur in a biotic succession. The individual transitional communities are known as the seral stages. Moreover, hydrosere is also known as hydrarch succession. Hydrosere starts in the aquatic habitat.

Complete answer: The succession in the aquatic habitats like the freshly formed ponds is known as the hydrosere. The successional series progresses from the hydric to the mesic conditions. The first stage is the pioneer community. The pioneer community is formed by the phytoplankton. It is made up of the minute microscopic autotrophic organisms like diatoms, unicellular, colonial, or filamentous green algae, or cyanobacteria. The spores of these organisms reach the newly formed ponds and multiply rapidly for the zooplanktons to feed upon. The next stage is the transitional communities. It is first taken upon the submerged plant stage. These plants with their roots are anchored in the mud at the bottom of the water body. It is then taken upon by the submerged free-floating plant stage. This happens due to the accumulation of the dead and decaying remains of plants and animals on the surface. After this comes the reed swamp stage where more shallowing of plants occurs due to continued siltation. After this, it is succeeded by the marsh meadow stage and finally the scrub stage. In the marsh meadow stage, the reed swamp is invaded by the marshy plants. The ponds become shallower. The marsh meadow stage is then replaced by the shrubs. The last community is the climax community where the scrubs are replaced by the trees of greater heights. Therefore, the final order of the succession is Phytoplanktons, Submerged plant stage, Submerged free-floating plant stage, Reed-swamp stage, Marsh-meadow stage, Scrub stage, Forest. Thus, based on the above information we can conclude that the correct sequence of the seral stages in hydrosere is Plankton, submerged, floating, reed swamp, sedge meadow, woodland.
Hence, the correct answer is option (A).

Note: Depending upon the nature of the habitat, the succession is of two types. These two types are – xerosere and hydrosere. Xerosere is also known as xerarch succession. It takes place in dry areas like sand, rocks, and saline conditions. Hydrosere is also known as hydrarch succession, which starts in the aquatic habitat