Process of Succession

Primary autotrophic succession follows a fixed sequence of seven named stages. Nudation is the appearance of a barren area completely devoid of life, which can arise from topographic causes (soil erosion, wind action), climatic causes (hail, storm, fire) or biotic causes (human activity, epidemics). Invasion (or migration) is the arrival of species into that barren area from elsewhere, as seeds, spores or other propagules are carried in by air, water or other agents. Ecesis (establishment) is the successful settling-in of a species after it arrives — the plant adjusts to the local conditions and, once fully established, becomes able to reproduce sexually on site. Aggregation follows as the successfully-established species reproduces and its population grows beyond its initial numbers. Competition sets in once a species has aggregated in an area, as individuals compete with one another (both within and between species) for water, nutrients, radiant energy, CO2, O2 and physical space. Reaction is the process by which the resident species gradually modifies the environmental conditions around it, to the point that the existing community is displaced and replaced by another — the community that gets replaced this way is termed a seral community. **Stabilization (the climax stag …