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The sequence of communities of primary succession in water isA. phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and tressB. phytoplankton, free floating hydrophysis, rooted hydrophytes, sedges, grasses and treesC. free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and treesD. phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees.

Answer» Correct Answer - D
Primary succession in water is also called as hyrarch, which will lead from hydric to mesic conditions. Phytoplanktons (autotrophic) are generally the first to appear. Later zooplanktons fedding on phytoplanktons also appear. Next stage is characterised by the soft mud on the bottom having organic matter favouring the growth of rooted submerged plants. They are then replaced by free floating hydrophytes (Lemna, Wolffia etc.). Rapid growth of these plants build up bottom so 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.


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