The correct sequence of organisms during hydrarch succession is

Ecological succession is defined as the process of gradual and predictable change in the species composition of an area. Primary succession occurs in those areas where no organism ever existed whereas secondary succession takes place in those areas where organisms once existed but now have lost them due to some reason. In a primary succession of wetland into the forest the first to appear are the phytoplanktons. They are replaced by submerged plants and later submerged and floating plants both appear. Gradually it passes through the reed swamp and marsh meadow stages and lastly scrubs appear before forming it into a forest land.