How does an ecological community develop? Ecological succession describes this process of development, identifying how the community began as well as how and when it stabilizes.
Ecological Succession Defined
As you develop and grow there are certain predictable changes that will occur, and they usually happen in a specific order. As a baby, you first learn to roll over, then crawl, then walk. You also learn new skills such as how to feed yourself and how to talk, but each skill you learn builds on those learned before it. Your body also changes as you grow taller, your muscles and bones develop, your hair grows longer, etc.Ecological succession is the same idea. It is the observed changes in an ecological community over time. These changes are fairly predictable and orderly.
Within an ecological community, the species composition will change over time as some species become more prominent while others may fade out of existence. As the community develops over time, vegetation grows taller, and the community becomes more established.
Different Types of Ecological Succession
Ecological succession happens for a few different reasons:Primary succession is initiated when a new area that has never previously supported an ecological community is colonized by plants and animals. This could be on newly exposed rock surfaces from landslides or lava flows.
Secondary succession occurs when an area that has previously had an ecological community is so disturbed or changed that the original community was destroyed and a new community moves in. This is more common than primary succession and is often the result of natural disasters, such as fires, floods, and winds, as well as human interference, such as logging and clear-cutting.Seasonal succession is another type of succession, but instead of being the result of a disastrous event, it is caused by cyclical changes in the environment or interactions between the species in a community.
When succession first begins, pioneer species are the first to colonize the new area. Pioneer species are usually fast-growing, opportunistic, and able to disperse easily. These are called r-selected species.
These are things like bacteria, moss, insects, and smaller plants.As succession continues, k-selected species begin to join the community and replace the original pioneer species. These species have more specific environmental requirements and grow more slowly, such as mammals and larger trees like oaks and pines. As more k-selected species enter the community, they begin to compete for resources and space.
This can lead to further changes in the local environment and can cause succession to progress even further.Once a successional community has reached a stable point, it is in ecological equilibrium and is called a climax community. At this point, the environmental conditions and species composition of the community do not tend to change, and new species entering the community must be very competitive to do so.
Ecological succession is the observed changes in an ecological community over time.
The community develops in a new area that may not have been colonized previously or one that was previously colonized but has been severely damaged. Pioneer species create an environment that leads the way to colonization by more stable species. Ecological equilibrium is reached when the community becomes stable and development ends.
|*Primary succession: a new area is colonized by plants and animals *Secondary succession: an area is recolonized with new plants and animals *Seasonal succession: succession caused by cyclical changes in the environment||*Stage1: pioneer species colonize an area *Stage 2: k-selected species move in *Stage 3: ecological equilibrium is reached and the ecological community is called a climax community|
Once you are done, you should be able to:
- Explain what ecological succession is
- Discuss the stages and types of ecological succession
- Explain the difference between r-selected species and k-selected species