(a) How do forests influence the following ? (i) air (ii) soil (iii) water (b) Is the atmosphere on Venus and Mars different from our atmosphere ? How?

(a) (i) Air : Absence of trees will lead to increased CO2 which leads to global warming.
(ii) Soil: Roots bind the soil. Reduction in forest cover will lead to soil erosion by U winds, floods.
(iii) Water: The roots of trees enhance the water holding capacity of the soil.
(b) Yes.
No life exists on them.
So, CO2 is the major component of atmosphere on Venus and Mars.