Abiotic factorsSpec 4.7.1.2
Abiotic (non-living) factors can affect a community. If one of them changes, the organisms that depend on it are affected, and so are the species that feed on or depend on those organisms.
| Abiotic factor | How a change could affect organisms |
|---|---|
| Light intensity | Less light means plants photosynthesise more slowly and grow less, so there is less food for the animals that eat them |
| Temperature | Changes the rate of enzyme-controlled reactions, so growth and reproduction speed up or slow down. Too hot or too cold and organisms may die or move away |
| Moisture levels | Plants and animals need water to survive. In drier conditions, fewer organisms can live there |
| Soil pH and mineral content | Plants only grow well in a suitable pH and need mineral ions for healthy growth. Poor soil means fewer plants |
| Wind intensity and direction | Strong wind can damage plants and increases water loss from them. It also affects how easily animals move and feed |
| Carbon dioxide levels for plants | Carbon dioxide is needed for photosynthesis. Lower levels slow the growth of plants |
| Oxygen levels for aquatic animals | Aquatic animals need oxygen for respiration. If levels fall, fewer animals can survive in the water |
To explain the effect of a change, link three steps: what changed, how it affects the organism, and what happens to the community.