Question

Some of the stages in the hydrach are labelled as
(A) Marsh meadow stage
(B) Reed swamp stage
(C) Submerged plant stage
(D) Phytoplankton stage and
(E) Submerged free floating plant stage
Identify the choice that represents the correct sequence of these stages.

• A. D, C, E, B and A
• B. C, E, A, B and D
• C. B, D, C, A and E
• D. D, E, C, B and A
• E. E, C, B, A and D

Answer 1

The correct option is A D, C, E, B and A

Various stages in hydrach are :

1. Phytoplankton stage : This constitutes the pioneer community.

2. Rooted submerged stage : As a result of death and decomposition of phytoplankton and their mixing with the slit, brought from the surrounding land by rain waters and by wave action of pond water, there develops a soft mud at the bottom of the pond.

3. Rooted floated stage : They all are rooted hydrophytes with their large leaves floating on the water surface.

4. Reed swamp stage : This stage is also known as the amphibious stage. The plants have well developed rhizomes and form very dense vegetation. The water level is by now very much reduced and finally become unsuitable for these plants.

5. Sedge - meadow stage : The mesic conditions approach the area and marshy vegetation disappears gradually.

6. Woodland stage : By the time of disappearance of marshy vegetation, the soil becomes drier for most time the year. Terrestrial plants now invade this area.

7. Forest stage : Several trees rapidly invade the woodland community