What Is Ecological Succession

Nothing in this world remains the same. Everything is changing all the time, including the habitats of the living beings of the earth. One thing fades away to make place for the next one. When the ecosystem of the earth changes in the same manner, it is referred to as the ecological succession. Given below is a detailed description about what is ecological succession.

Definition

The gradual process by which the ecosystem changes and develops over a period of time is called ecological succession. This is an important part of environmental science, as in the ecosystem, some species have reduced in number, while some might even have become extinct. Meanwhile, after a certain period, the number of some other species becomes more, or maybe some new species evolves, taking the place of the one that has become extinct.

Causes

There are certain environmental conditions which are suitable for the growth and development of every species in this world. The one that develops the most and the one that reproduces the most, becomes more abundant in number. One of the main causes is when the condition of the environment changes drastically and it becomes impossible for the species to survive. Same thing happened with dinosaurs. Once upon a time they ruled the earth but when the environmental conditions of the earth started changing, they could not adjust to it and they slowly became extinct. In their place, new animals and birds came, who were able to adjust to the new environment. Certain changes might also be due to forest fires or land slides or human activities, which can cause maximum changes in the environment. Even then, one species might become less in number while the other might rule. With change in environment, there is 'survival of the fittest' and only the strong will survive.

Different Stages

Now let us learn about the various stages involved in the ecological system. It has two important kinds of succession; the primary succession stage and the secondary succession stage. This is when succession of some plant or animal species, takes place in an area which never has seen any living life. Some such areas might be an area which was covered by lava, or which had no fertile land where humans could cultivate or where trees could grow. But slowly, as time changes, as the environment changes, the place becomes more suitable for the living beings to survive. This succession is called primary succession.

In secondary succession, life was already there, but due to certain factors, that life passed away and in its place new life emerged. Take the example of the dinosaur again. In there place came the tigers and the lions and other animals. So this was the stage of secondary succession. This succession is more common than primary succession.

Nudation
This stage is the primary stage in which due to proper environmental conditions, such as the correct temperature, the correct amount of water and also with the presence of oxygen in the air, life starts emerging. When the earth cooled down and the above conditions prevailed, life started emerging on this planet for the first time. Small plants like lichens and mosses started growing wherever the conditions were favorable. This was also called the plankton stage.

Invasion
When these small plants died, they decomposed and formed soil. Due to this, more complex plants started growing in their place, such as the Hydrilla, the Vallisneria, etc started growing. This second stage also consisted of the herbs and shrubs and these plants also produced seeds which was one important thing that was needed in order to spread life far across. Although these plants did not survive for long, they left behind their successors. This type of species is what the scientists refer to as 'opportunist species'. Slowly the organisms, the plants as well as animals started increasing in number due to the process of reproduction. Once the population of the organism started growing, the next stage was reached and that was the stage of competition.

Competition
This stage followed the 'survival of the fittest' policy. All those plants and animals who were able to survive the environmental changes and those who were strong enough to fight and survive for place, started growing in number. Once one kind of species started living on this earth, there was a shift to the next stage called the reaction stage.

Reaction Stage
In this stage, the modification of the environment took place. This modification was influenced by the living species who had survived the earlier stage. These species moved on and gave way to new species and the process continued.

Climax Community
This was the final stage. There was a stage of constant species composition. It marked the last stage of ecological succession. Once this stage is reached, it usually remains unchanged for the next hundred years.

Thus, now you know what ecological succession is and you also know what are the various stages of succession. If you read more about it, you will be amazed when you learn about how this whole world was created and how the living beings underwent a change and how some faded away or are fading away, and how some new species are taking birth and slowly spreading across the world.