Plants and animals live in symbiotic relationship; plants produce oxygen which is used by animals, and animals produce carbon dioxide which is used by plants.

Plants and animals: How many are they?

Human beings can use only part of the available fresh water; the rest is reserved for the use of plants and animals.

Human beings are not in competition with plants for water, because plants generate their own water.

Absence of plants means absence of water
(lack of precipitation).