What is the process of ecological succession from a pioneer community to a climax community?

Question

Caleb Allen · Accepted Answer

See below.

Ecological succession, or the process in which the structure of a community evolves over time, typically means a community transitions from pioneer species that create soil to grasses and small shrubs and then to shade-tolerant species such as trees*.

The image below shows one example of ecological succession. Pioneer species are the first to arrive in an otherwise biologically empty environment. These may be grasses, low flowering plants, herbs, mosses, and others. Pioneer species break down rocks and create soil.

Then the populations of these pioneer species, decreases as other species also move to the area. Once there is sufficient soil, pioneer species will be out-competed by weedy like grasses and other plants that thrive in these conditions.

As these plants add biomass to the community, they will be replaced by shrubs and more shade-tolerant species.

A community may eventually reach its climax, the point where the composition remains mostly stable unless some sort of disturbance occurs. Otherwise, communities are constantly changing.

*Note that while some communities may become forests, other communities in the later stages of succession may not include many or any trees. For example, grasslands may or may not include any species of tree.

Succession is also possible in aquatic ecosystems. Learn more here.

Connor Anderson · Answer

undefined Ecological succession is the process by which an ecosystem undergoes predictable and orderly changes over time. It typically begins with a pioneer community, composed of hardy and adaptable species, colonizing a barren or disturbed habitat. As these pioneer species establish themselves, they modify the environment, making it more suitable for other species to colonize. Over time, a series of distinct stages occur, leading to the development of a climax community, which represents a stable and mature ecosystem. The process of succession can be divided into primary succession, which occurs on bare substrates devoid of soil, and secondary succession, which occurs in areas where soil is already present. In primary succession, pioneer species like lichens and mosses colonize the substrate and begin the process of soil formation. Over time, grasses, shrubs, and eventually trees establish themselves, leading to the formation of a diverse and complex community. Secondary succession begins in areas where existing vegetation has been disturbed, such as after a fire or a landslide. In these cases, the process begins with the rapid colonization of pioneer species that can quickly recolonize the area. As the ecosystem matures, more competitive species replace the pioneers, leading to increased biodiversity and complexity. Eventually, the ecosystem reaches a stable state known as a climax community, characterized by a diverse array of species and relatively constant environmental conditions.