Answer: 1. Plants
2. Physical factors (sunlight)
Explanation:
1. The plants are the main source of energy for the ecosystem. They exhibit the major amount of energy as they can produce their own food by the process of photosynthesis. Hence, they are called producers. They are consumed by the consumers like rabbits, inchworms, and robins. The producers are at the lowest trophic level in an energy pyramid. The trophic levels above producers the energy reduces considerably and only 10% energy is utilized in each trophic level.
2. The ecosystem is a biotic community where living beings interact with the non-living components of the environment. Non-living components are water, sunlight, air and others. In this food web the non-living components are absent. The sunlight is the essential non-living component of the ecosystem. It is necessary for photosynthesis, in this the plants use carbon dioxide and water from the environment in the presence of sunlight to produce their food in the form of carbohydrates. So, the supporting role in terms of non-living components is absent in this ecosystem.
