What are the main types of ecological succession and their characteristics?

Ecological succession is the process by which an ecosystem changes over time, often as the result of a disturbance. There are two main types of ecological succession: primary succession and secondary succession.

Primary Succession

Primary succession occurs in areas where there is no soil, such as after a volcanic eruption or the retreat of a glacier. Over time, pioneer species, such as lichens and mosses, colonize the area and begin to break down rocks, creating soil. This allows for the growth of other plants and eventually the establishment of a stable community.

Secondary Succession

Secondary succession occurs in areas where soil already exists, such as after a forest fire or the abandonment of farmland. The process is similar to primary succession, but is usually faster because the soil is already present. Pioneer species such as grasses and shrubs colonize the area and are eventually replaced by larger trees and a more complex community.