What is the primary source of energy for ecosystems on Earth's surface?

Sunlight is the primary source of energy for ecosystems on Earth's surface because it drives the process of photosynthesis. During photosynthesis, plants, algae, and some bacteria capture sunlight and convert it into chemical energy in the form of glucose. This process not only sustains the producers but also forms the foundation of energy flow throughout the entire food web, supplying energy to herbivores and then to carnivores.

While water and soil are essential components of ecosystems, providing nutrients and supporting plant growth, they do not serve as primary energy sources. Wind, while it can influence weather patterns and help with processes like pollination and seed dispersal, does not directly provide energy for ecosystems in the same way that sunlight does. Sunlight is integral to maintaining the balance of life on Earth, making it the cornerstone of energy in various ecosystems.