What is the ecological role of plants?

Plants play a very important role in the ecosystem of our planet. First of all, they serve as a source of organic matter for herbivores, and those, in turn, are a source of energy for predators. The second role of plants is to release oxygen into the atmosphere. But they emit very little oxygen. Phytoplankton provides 90% of all oxygen production. Plants are in symbiosis with many other kingdoms such as mushrooms or animals. Therefore, their role is very important in nature and ecosystem.