The term for the sum of all ecosystems on Earth is known as biosphere. The biosphere includes all living organisms and their interactions with the atmosphere, hydrosphere, and lithosphere. It encompasses diverse environments, including terrestrial, freshwater, and marine systems. The biosphere is crucial for maintaining ecological balance, as it supports biodiversity and contributes to ecosystem services such as nutrient cycling and climate regulation. Studying the biosphere helps scientists understand ecological dynamics and the impacts of human activities on the planet.