LWB: Lesson - Ecological Tolerance (Topic 2.4) šŸ“–

ā³ Estimated Reading Time: 3 - 5 minutes

Learning Objective

Describe ecological tolerance.

 

Ecological Tolerance


Ecological tolerance refers to the range of abiotic conditions within which a species or population can survive and reproduce, such as temperature, salinity, pH, or oxygen levels.

A graph depicts organism abundance across environmental conditions with five zones: two ā€˜zones of intolerance’ with no organisms, two ā€˜zones of stress’ with fewer organisms, and a central ā€˜optimum range’ with the highest abundance
The optimum range of tolerance for a species will have the most individuals because it is easy for the population to live in this area. Zones of stress will have fewer individuals because only the hardiest individuals will survive. And the zones of intolerance will have no individuals because it is outside the range at which the species can survive.

Different species have different tolerance ranges for the same factor. Some species are highly tolerant and can thrive in a wide range of conditions (known as generalists), while others are more specialized and have narrow tolerances, requiring specific environmental conditions to survive (known as specialists). Ecological tolerance is influenced by the evolutionary history of a species, as well as its capacity to adapt to new environmental conditions. Tolerances can also vary at different life stages or reproductive phases within a species. Ecological tolerance can also apply to populations or communities of organisms that share similar environmental requirements. 

 

Essential Knowledge

Ecological tolerance refers to the range of conditions, such as temperature, salinity, flow rate, and sunlight that an organism can endure before injury or death results.

Ecological tolerance can apply to individuals and to species.

 

The concept of ecological tolerance is particularly relevant when studying how organisms respond to changes in their habitat or face challenges posed by human activities, such as pollution or climate change.

Click through the presentation below to read and see some examples of species that have shown ecological tolerance.

AP Exam Tip

When thinking about the ecological effects of human activities, you should think about the tolerance of individual species.

 

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