1. INFLUENCE OF ABIOTIC FACTORS ON ECOSYSTEMS
2.7
A limiting factor places an upper limit on the size of a population. Limiting factors can be biotic (for example, lack of food) or abiotic (for example, access to water).
Every species is able to survive within a range of abiotic factors such as temperature, light, and soil. This range is called the species’ tolerance range.
limiting factor
tolerance range
Species can be successful over a range of abiotic conditions. However, they will become stressed and will die out if conditions exceed their tolerance limits.

2. Key Abiotic Factors
2.7
Vocabulary
limiting factor
tolerance range

3. Influence of Biotic Factors
2.7
Abiotic factors determine where a species can live, while biotic factors often determine how successful the species is in that location.
Many key biotic factors involve interactions between individuals.
Vocabulary
limiting factor
tolerance range

4. Carrying Capacity
2.7
As a population’s size increases, the demand for resources also increases. Eventually, there will not be enough resources.
Also, as individuals become more crowded, they become more susceptible to predators and diseases.
The population of a species will eventually reach an upper size limit based on factors like these.
This size limit is called the carrying capacity of an ecosystem for that particular species.
The carrying capacity can be altered through natural or human activity when resources are removed or added to the ecosystem.
carrying capacity