The driving force of an ecosystem is

The correct answer is Solar Energy

Ecosystem: 

• All organisms such as plants, animals, microorganisms and human beings as well as the physical surroundings interact with each other and maintain a balance in nature. All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem.

Food chain: 

A food chain shows the feeding relationship between different organisms in a particular environment and/or habitat.

• A food chain shows how energy is passed from the sun to producers, from producers to consumers, and from consumers to decomposes such as fungi. 
• They also show how animals depend on other organisms for food.

Key Points

The driving force of an ecosystem is Sunlight, it gives power to everything on earth.