| Moisture levels | Animals and plants are adapted to growing at the moisture levels available |
| Carbon dioxide | Carbon dioxide is required for photosynthesis, so increased concentrations will increase growth and yields |
| Temperature | Animals and plants have evolved to grow healthily at their optimum temperatures |
| Light intensity | Light is required for photosynthesis, and plant species have evolved for optimum growth in the light available in their climate or habitat |
| Soil pH and mineral content | Many plants are sensitive to pH |
| Wind intensity and direction | Wind can increase the supply of carbon dioxide to plants
but wind increases the rate of transpiration and therefore water loss |
| Oxygen for aquatic organism | Oxygen dissolves in water and is required for the animals' respiration |
