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Community ecology is the study of interactions between multiple species in a given time and area.
The following are the four main properties community ecologists study, along with what they mean:
IN CONTEXT
Let's say the community spans 1 square mile in the year 2015. A community ecologist observes and records the different species in the forest community, such as squirrels, birds, trees, and shrub species. This is species composition.
The ecologist then measures species abundance and calculates the abundance of each species in relation to each other. The ecologist might discover that there are large populations of squirrels nut-bearing trees but a small population of swallows.
The ecologist also observes the species distribution, and perhaps discovers that there is a sparse but even distribution of oak trees; however, the population of a specific shrub seems to live only in one small portion of the community.
Finally, the ecologist studies the different types of relationships that the species are having, such as the competition between different bird species or the symbiotic relationships between microorganisms and tree roots.
We'll now delve a little deeper into the types of interactions that species can have.
The following are the three types of interactions:
| Interaction | Description | Outcome | Example |
|---|---|---|---|
| Competition | Two species compete for the same food or resources | Negative–Negative: This always has a negative outcome for each species. | Two bird species compete for available materials to build their nests or for food for their young. |
| Predation | One species preys on or consumes another. Predation includes carnivores eating other species, herbivores consuming plants, or species laying eggs on or in another species. | Positive–Negative: This is positive for the predator and negative for the prey. | An eagle catches and eats a snake, which is good for the eagle and bad for the snake. |
| Symbiosis | Two species have a mutually beneficial interaction. Symbiosis is much more common in nature than people realize. Many species, including humans, rely on symbiotic relationships to help digest their food. | Positive–Positive: This is positive on both sides. | Humans have bacteria in their digestive tract, which allows them to digest their food better. Cows also have a symbiotic digestive relationship with bacteria. |
Ecological succession is the process of the creation of a new community either on barren land or on highly disrupted environments.
The following are two different types of ecological succession:
EXAMPLE
Land created from an oceanic volcano is inhabited first by pioneer species like moss and algae and eventually by shrubs, trees, and animals.EXAMPLE
When glaciers receded because of historic planetary warming, the lichen that began to form on the boulders left behind had started primary succession.EXAMPLE
If a forest fire burned a large swath of forest, and over time, new species moved in and began growing (thus modifying the environment), this would be secondary succession. Other disturbances that can cause secondary succession are floods, fires, volcanoes, droughts, overgrazing, and human activity, such as deforestation and overharvesting.Source: THIS TUTORIAL WAS AUTHORED BY JENSEN MORGAN FOR SOPHIA LEARNING. PLEASE SEE OUR TERMS OF USE.
