(2) Grassland ecosystem is distributed in arid areas with little annual rainfall. Compared with the tropical rain forest ecosystem, the grassland ecosystem has fewer species of animals and plants, and its community structure is not as complicated as the former. In different seasons or years, rainfall is very uneven. Marine ecosystem is composed of marine biological community and marine environment. Most plants in the ocean are smiling phytoplankton. There are many kinds of animals, most of which can swim in the water.
Freshwater ecosystem is an ecosystem formed by the interaction between biological communities in freshwater and their environment. Divided into still water and running water. The former refers to freshwater lakes, swamps, ponds and reservoirs. The latter refers to rivers, streams and canals, which are easily damaged and difficult to recover.
Forest ecosystem is distributed in humid or relatively humid areas, and its main characteristics are many kinds of animals, complex community structure, and long-term stable population density and community structure. The plants in the forest are mainly trees, but there are also some shrubs and herbs. There are also many kinds of animals in the forest. Trees, cicadas, mantis and yellowbird are all suitable for living in forest ecosystem.
(3) Producers refer to green plants that can carry out photosynthesis and provide organic matter (food) and oxygen for plants themselves, consumers and decomposers. Consumers refer to animals that cannot carry out photosynthesis and must feed on ready-made organic matter. Decomposers include bacteria and fungi. Therefore, trees are producers in the ecosystem.
So the answer is:
( 1)C
⑵D
(3) Answer