Biosphere
The biosphere is the global sum of Earth's ecosystems: all organisms and the regions of land, water, and atmosphere where life exists.
Ecosystem: A community of organisms and the physical environment with which they interact. Ecosystems are the constituent units whose global sum forms the biosphere.
Biogeochemical cycle: The circulation of chemical elements between organisms and Earth's atmosphere, water, and rocks. These cycles move essential matter through living and nonliving parts of the biosphere.
Biosphere reserve: A protected area recognized under UNESCO's Man and the Biosphere Programme to support conservation and sustainable development. Reserves apply biosphere thinking to conservation, research, and local livelihoods.
Great Oxidation Event: A major rise in atmospheric oxygen about 2.4 billion years ago, driven largely by oxygen-producing microbes. This early biospheric transformation changed the chemistry of Earth's atmosphere.
Biome: A large ecological region defined by characteristic climate, vegetation, and animal communities. Biomes group ecosystems into broad patterns across the biosphere.
Primary production: The formation of organic matter from inorganic sources, chiefly through photosynthesis or chemosynthesis. It supplies the chemical energy that supports most biospheric food webs.
Biosphere 2: A sealed research facility in Arizona built to study interactions among people and small-scale ecosystems. This experiment tested whether a complex, partly self-contained biosphere could be sustained.
Phanerozoic: The geological eon beginning about 539 million years ago, marked by abundant visible animal life. Its fossil record documents major changes in the biosphere over geological time.
Ecological niche: The conditions and resources that shape how a species lives and interacts in an ecosystem. Niches describe how organisms occupy roles within biospheric ecosystems.
Food web: A network of feeding relationships among organisms in an ecosystem. Food webs transfer energy and nutrients through biospheric communities.