Green plants are the producers in an ecosystem. They are the organisms that are capable of producing their own food through the process of photosynthesis. The position of green plants in the food chain or the trophic level can be explained as follows:

First Trophic Level:
Green plants are the primary producers in an ecosystem. They form the first trophic level in the food chain. They are the only organisms that can convert solar energy into chemical energy through photosynthesis. They synthesize their own food from inorganic substances like carbon dioxide, water, and minerals. They are also the source of organic matter for all the other organisms in the ecosystem.

Importance of First Trophic Level:
The first trophic level is the most important level in the food chain. It forms the base of the food chain and provides energy and nutrients to all the other organisms in the ecosystem. The green plants produce organic matter, which is used by herbivores as food. Herbivores, in turn, are eaten by carnivores and omnivores. Thus, without the first trophic level, the entire food chain would collapse.

Conclusion:
In conclusion, green plants occupy the first trophic level in the food chain. They are the primary producers in the ecosystem and form the base of the food chain. They are responsible for converting solar energy into chemical energy through photosynthesis, and they provide organic matter for all the other organisms in the ecosystem. Without green plants, the entire food chain would collapse, and the ecosystem would be unable to sustain life.

Because they are primary source of energy and autotrophs every food chain start with a producer because they produce there own food and pass energy for the other tropical level