Adopt a slogan

Forest ecosystem is distributed in humid areas, and there are many kinds of animals and plants. Forests play an important role in water conservation, soil and water conservation, windbreak and sand fixation, climate regulation, air purification and pollution elimination, and are known as "green reservoirs" and "lungs of the earth". The species of animals and plants are particularly rich.

Wetland ecosystem is an ecosystem formed under the condition of excessive moisture and humidity, which is called kidney of the earth.

So choose: C.