What is the primary source of energy for most ecosystems?

The primary source of energy for most ecosystems is solar energy. Plants, which are the foundation of most food webs, utilize sunlight to carry out photosynthesis, a process that converts solar energy into chemical energy stored in glucose and other organic compounds. This energy then moves through the ecosystem as plants are consumed by herbivores, which in turn may be eaten by carnivores.

Solar energy is fundamental to the growth and development of nearly all living organisms on Earth, playing a critical role in driving various biogeochemical cycles and sustaining diverse life forms. While other energy sources like geothermal, nuclear, and wind energy can influence certain ecological processes or provide energy in specific contexts, they do not serve as the primary energy input for the vast majority of ecosystems. The reliance on solar energy makes it a cornerstone of ecological functioning and energy flow within biological communities.