Ecological succession is the gradual process of changes in the structure and composition of a community.
It represents an orderly process of changes in the ecosystem, including changes in the physical environment by the biological community, until reaching the climax stage.
During ecological succession, simpler communities are replaced over time by more complex communities.
The ecological succession goes through three phases: a ecesse, seral and climax.
ecese represents the pioneer community. They are the first organisms to settle in the environment, such as lichens, grasses and insects.
The seral is the middle community. Represented by small, shrub and herbaceous vegetation. During this phase, significant changes take place in the community.
The last phase is the climax, the stabilized community. The community reaches a high number of species, ecological niches are occupied and presents a large amount of biomass.
The community tends to evolve to a climax, when it is formed by populations in balance with the environment.
The stages of ecological succession
Autogenic Succession and Allogeneic Succession
Depending on the forces that drive the process, the succession can be of the following types:
- Autogenic Succession: caused by changes caused by biological processes internal to the ecosystem.
- Allogeneic Succession: when changes occur by forces external to the ecosystem, such as storms, fires and geological processes.
Types of Ecological Succession
The ecological succession can be classified according to the nature of the substrate that gives rise to the process in: primary succession and secondary succession.
Primary Succession
Primary succession begins in an uninhabited area.
It occurs in environments that were not previously occupied by living beings, such as bare rocks, solidified lavas, sand deposits, a recent strip of beach.
The first organisms to settle down are called pioneers.
At pioneer species they manage to establish themselves in inhospitable places, subject to different environmental conditions and pave the way for the establishment of new species.
Examples of pioneer species are lichens and grasses.
The colonization of pioneer species is important for the succession process. From the pioneers, the original conditions of the environment began to change.
As an example, the vegetation cover of pioneer plant species reduces sudden changes in soil temperature and contributes to its stabilization. These conditions favor the arrival of new species to populate the community.
Primary succession is a slow process. A rocky soil can take decades to harbor shrub and herbaceous vegetation.
Secondary Succession
Secondary succession occurs on substrates that were previously occupied by a biological community. Therefore, they present more conditions for the establishment of living beings.
Examples are clearings, deforested areas and abandoned farmland.
Secondary succession develops faster than primary.
One reason is that some organisms and seeds may remain in the soil, making the substrate more favorable for recolonization by other living beings.
Know more about:
- Ecosystems
- terrestrial ecosystem
Exercises
(UFSCar) - The orderly and gradual replacement of one community by another, until a stable community is reached, is called ecological succession. In this process, it can be said that what happens is
a) the constancy of biomass and species
b) biomass reduction and greater species diversification
c) biomass reduction and less species diversification
d) increased biomass and lesser species diversification
e) increased biomass and greater species diversification
e) increased biomass and greater species diversification
(UNESP) - Consider the statements:
1. Ecological succession is the name given to the process of gradual transformations in the constitution of communities of organisms.
2. When a stage of stability is reached in a succession, the corresponding community is the climax community.
3. In an ecological succession, species diversity initially increases, reaching its highest point at the climax and then stabilizing.
4. In an ecological succession there is an increase in biomass. Tick:
a) if all statements are incorrect;
b) if all statements are correct;
c) if only statements 1 and 4 are correct;
d) if only statements 1 and 4 are incorrect;
e) if only statement 4 is correct.
b) if all statements are correct;
(UFJF) Fires, common in the dry season in several Brazilian regions, can cause the destruction of natural vegetation. After the occurrence of fires in a forest, it is CORRECT to state that:
a) over time, primary succession will occur.
b) after the establishment of the lichens, the installation of new species will occur.
c) the climax community will be the first to re-establish itself.
d) only after the animals return will the plants return to the burned area.
e) colonization by pioneer species will facilitate the establishment of other species.
e) colonization by pioneer species will facilitate the establishment of other species.
