In the following four pictures, which belongs to the forest ecosystem is () A.B.C.D

A, it is a forest ecosystem, distributed in humid areas, with a wide variety of animals and plants. Forests play an important role in water conservation, soil and water conservation, wind prevention and sand fixation, climate regulation, air purification and pollution elimination, so they are correct.

B, it is a marine ecosystem, mainly living with various marine life.

C is a grassland ecosystem, distributed in arid areas, with little annual rainfall. There are few tall plants, and although there are fewer species of animals and plants than forest ecosystems, they are still rich. Grassland plays an important role in soil and water conservation, wind prevention and sand fixation.

D, it is farmland ecosystem, mainly crops, belonging to artificial ecosystem.

So choose: a.