What is ecological succession? Distinguish primary succession from secondary succession.

Explanation

The gradual and fairly predictable change in the species composition of a given area is called ecological succession.
Hydrarch succession takes place in wetter ar eas and the successional series progress from hydric to the mesic conditions.
It involves pioneer stage, submerged stage, floating stage, reed swamp stage, marsh meadow stage, woodland stage and forest stage.
Xerarch succession takes place in dry areas and the series progress from xeric to mesic conditions.
The stages include crustose lichen stage, folvose lichen stage, moss stage, herb stage, shrub stage and tree stage.