Producer: In the biological classification, there are mainly various green plants, including chemosynthetic bacteria and photosynthetic bacteria, all of which are autotrophs. Plants and photosynthetic bacteria use solar energy to synthesize organic matter, while chemosynthetic bacteria use the energy released by redox reaction of some substances to synthesize organic matter. For example, nitrifying bacteria use chemical energy to synthesize organic matter by oxidizing ammonia into nitrate. Producers play an important role in biological communities. They absorb energy in inorganic environment. Assimilation amount inputs the total energy of the ecosystem and maintains the stability of the whole ecosystem. Among them, all kinds of green plants can also provide habitats and breeding grounds for all kinds of creatures.
Decomposer: also known as "reducer", it is a kind of heterotrophs, which is mainly composed of various bacteria and fungi, and also includes saprophytes such as dung beetles and earthworms. Decomposers can decompose all kinds of inanimate complex organic matter (corpses, feces, etc.). ) in the ecosystem into water, carbon dioxide, ammonium salt and other substances that producers can reuse, and complete the cycle of substances, so that decomposers, producers and inorganic environment can form a simple ecosystem.
Consumer: refers to heterotrophs, who lives by ingesting other organisms. The range of consumers is very wide, including almost all animals and some microorganisms (mainly eubacteria), which transmit energy in the ecosystem through predation and parasitism. Among them, consumers who feed on producers are called first-class consumers, and those who feed on first-class consumers are called second-class consumers, followed by third-class consumers and third-class consumers. The same consumer may play multiple roles in a complex ecosystem, especially omnivores. They may feed on plants (as primary consumers) and various herbivores (as secondary consumers), and the consumption level of some organisms will change with the seasons.
The decomposer is heterotrophs, who decomposes animal and plant residues, feces and various complex organic compounds, absorbs some decomposition products, and finally decomposes organic matter into simple inorganic matter, which can be reused by autotrophs after participating in the material cycle. The decomposers are mainly bacteria and fungi, including some protozoa and large saprophytes, such as earthworms, termites and vultures.