Plants require sunlight for photosynthesis. Therefore, light is an important factor that affects the distribution of plants, e.g.,
(i) Many species of small plants (herbs and shrubs) growing in forests are adapted to photosynthesise optimally under very low light conditions so they are seen distributed in shady areas under tall, canopied trees.
(ii) Many plants in the shade will grow vertically to gain access to light. These plants will appear to have smaller leafs than others of the same species of the same age found in conditions with better sunlight.
(iii) Large sized trees will be present in areas that get abundant sunlight.
The adaptations of animals to water scarcity are as follows:
(i) Animals like kangaroo rats are capable of meeting the water requirements through internal oxidation of fat.
(ii) They can concentrate their urine so that minimal volume of water is excreted.
(iii) Animals like snails undergo aestivation during hot summers. (IV2)
(iv) Plants dependent on sunlight , to meet their photoperiodic requirements of flowering, will try to be distributed in area where this requirement is being met for their reproductive success.