Abiotic factors

The biodiversity and distribution of organisms within an ecosystem is due to both abiotic (non-living) and biotic (living) factors.

Abiotic factors are non-living variables that can influence where organisms can live.

Examples of abiotic factors include:

  • light intensity
  • temperature
  • soil pH
  • soil moisture

The values of the abiotic factors in an ecosystem affect the range of species that are found. This is because the individuals in each species are adapted to occupy particular niches.

A bar chart that shows the varying tolerance levels of pH in animals

Abiotic measurement equipment

Abiotic factors can all be measured to show the living conditions in an ecosystem.

Measuring light intensity

Light meters can be used to measure light intensity. The meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

Errors can be made when measuring light intensity by accidentally shading the light meter. The reliability of the results can be checked by taking many samples.

Measuring the pH and moisture of the soil

Soil moisture and soil pH meters are also available. Both are used by simply pushing the probe into the soil and reading the meter.

Errors can be made when measuring pH and soil moisture when probes are not cleaned between readings. The reliability of the results can be checked by taking many samples.

Measuring temperature

The temperature of the air can be measured with a thermometer. The temperature of the soil can be measured with a temperature probe.