Question

The sequence of communities of primary succession in water is?

• A. Phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and trees
• B. Phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses and trees
• C. Free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and trees
• D. Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees

Answer 1

The correct option is D Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees

Primary succession in water is also called as hydrarch, which will lead from hydric to mesic conditions. Phytoplanktons(autotrophic) are generally the first to appear. Later zooplanktons feeding on phytoplanktons also appear. Next stage is characterized by the soft mud on the bottom having organic matter favouring the growth of rooted submerged plants. They are replaced by free-floating hydrophytes (Lemna, Wolffia etc). Rapid growth of these plants build up bottom as that water becomes shallow on periphery. In this shallow water, comes the reed-swamp stage(e.g., Typha). They produce abundant organic matter. Next stages are sedge or marsh-meadow stage which transpire rapidly and build up soil, on which the next stage, trees can grow.

So, the correct answer is 'Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees'.