a) Air- Forest manages the content of CO2 and O2 in the atmosphere. Plants take up the CO2 to perform photosynthesis and release oxygen which is inhaled by humans and animals. Humans and animals exhale CO2 tat is used by plants in photosynthesis.

b) Soil- Roots of plants bind the soil together and prevent the soil from being eroded away by wind or water.

c) Water- Forest means large number of plants. Forest transpire huge amount of water as water vapour which condenses around the dust particles to form clouds. When the clouds get saturated, rainfall occurs and the water flows into water bodies.