The major source of power for most terrestrial ecosystems is

The major source of power for most terrestrial ecosystems is solar energy. The sun is the ultimate source of energy for almost all life on Earth. Through the process of photosynthesis, plants convert solar energy into chemical energy, which is then passed on to herbivores, and then to carnivores, in a series of interconnected food chains. Solar energy also drives weather patterns and climate, which are important factors in determining the distribution and productivity of different ecosystems. While other sources of energy like geothermal, hydroelectric and nuclear power can be important for human societies, they are not significant sources of energy for natural ecosystems.