• What is ecological succession?
• Primary succession
• Secondary succession
• Examples of ecological succession

We explain what ecological succession is, its relationship with evolution and examples. In addition, primary and secondary succession.

Small plants facilitate the arrival of larger ones, which follow them.

What is ecological succession?

Ecological succession or natural succession is the natural evolutionary process by which some species gradually take the place of others that are less well adapted to the environment. This process occurs without human intervention and occurs within the framework of dynamics from competence between the species of the same ecosystem.

However, the succession and evolution they are not exactly the same. Evolutionary succession, that is, the replacement of one species by a better one adapted to the dynamics of the environment, it occurs over a long period of thousands of years, which is what it takes for a new species to appear.

Instead, the replacement in an ecosystem of one species by another competitor, it can occur in a few hundred years. In any case, the tendency in both cases is to increase the level of complexity of the life, that is, to replace generalist species with specialist species, adapted to increasingly punctual conditions.

Ecological succession is a natural process of organizing life in the same habitat, which tends to drive life towards change and adaptation, which is why it is part of the dynamics of ecosystems. This process can be understood in two stages: the primary and the secondary.

Primary succession

It is called primary succession to what occurs when a new habitat is in formation, being colonized by the first forms of life capable of doing so. For example, newly exposed live rock or newly formed wastelands can be colonized by plant forms such as mosses or small plants, known as pioneer species.

These species benefit from the decomposition of the rock by the erosion and meteorism, serving as the first link for future species that will take advantage of the new habitat, replacing the pioneers as more and more layers of life are added, forming a new ecosystem.

Secondary succession

After a fire, the first plants to gain ground become successors.

Secondary succession differs from primary succession in that it is the result of violent changes in the conditions of an existing ecosystem, that is, of major interruptions such as fires, floods, massive diseases, etc.

In these cases, the succession is restarted, but not from zero as in virgin biotopes, but giving rise to more specialized species, that is, to species adapted to changes in the environment, which take the place of those eradicated by the violent event. happened.

Examples of ecological succession

In the volcanic islands the species succeed one another on the new substrate.

Ecological succession can easily be seen in major geological events, such as a volcanic eruption. For one thing, the ejected magma and boiling materials soon cool, adding new virgin layers of substrate to the Earth, as in the volcanic islands of the Pacific, which gradually expand in size.

Once the new ground has cooled, the primary succession takes place, and through the passage of the weather a new ecosystem will emerge where initially there was nothing.

But at the same time, volcanoes are destroying existing ecosystems, setting fire woods and burrow burrows under the lava. This pushes the species into a struggle to adapt to the devastated territory, allowing certain species to proliferate first and occupy the place that previously belonged to others, as occurs with pyrophilic plant species (which feed on burned land).