Limiting Factors

What is a limiting factor? In an ecosystem, a limiting factor is any biotic or abiotic factor that restricts the number of individuals in a given population. For example, water would be an abiotic limiting factor because it is non-living and it is necessary for organisms to survive, so not having enough water would restrict the number of organisms that could live in this ecosystem. Limiting factors can greatly impact the carrying capacity, which is the number of organisms that an ecosystem can accommodate. In fact, those factors are what determine the carrying capacity. For example, an ecosystem with only a few patches of sunlight will likely only house a few plants, which will make it less habitable for animals who eat those plants. 

In the Great Barrier Reef, there is a new limiting factor problem. Climate change is causing coral reefs to "bleach", or expel the organisms that give them their colour and provide them with food. In this case, the limiting factor is water temperature. Some organisms can't survive in lower or higher temperatures, which qualifies temperature as an abiotic limiting factor. 

This is all happening because of human interaction in ecosystems. These ecosystems aren't used to big changes from an outsider influence and can be severely damaged by them. Humans burn fossil fuels, which causes excess CO2 to build up on the outer layer of the atmosphere. This gas lets heat rays from the sun pass through, but makes it harder for them to come out, which causes an increase in the global temperature. This is exactly what is affecting the coral reefs. Global warming is causing the ocean's water temperature to rise. But not only the coral reefs are affected. The problem with the reefs throws the entire ecosystem off balance. Since the coral serves the fish as a safe habitat from their predators, the fish are now left to be eaten by the predators which could reduce the fish population greatly. The example of the coral reef ecosystem is just one of many ecosystems that are being affected by global climate change.

Click here to watch a video to learn more about the factors that limit population growth.

Click here to download an article on how human activity impacts wildlife.

Photo by Patrick Hendry on Unsplash