2.5.4—Seral communities

A sere is a temporary community stage; each stage modifies conditions that allow a later community to establish.

Pioneers weather rock, trap particles and add organic matter. Deeper soil, shade, moisture and nutrients then change competition so grasses, shrubs and larger plants can replace earlier stages. In the classical model, successive seres continue until a relatively stable climax community is reached; Objective 2.5.12 later examines why that endpoint is uncertain.

Lichens on bare rock add organic matter; grasses root in the developing soil, then shrubs alter light and moisture for tree seedlings.

Each sere changes soil, nutrients, shade or water, altering which species can colonize and compete in the next stage.

Succession is not a fixed species shopping list; disturbance and site conditions can change the pathway.