What is the Biosphere?

The biosphere is where all life occurs on Earth. The biosphere is made of three parts, called the lithosphere, atmosphere and hydrosphere. The atmosphere is the air that living organisms use for respiration, and which supports life up to 2,000 meters above the planet’s surface. The hydrosphere is the aquatic portion of the planet, all of which supports life. The lithosphere is the land mass, excluding Earth’s mantle and core, which do not support life.

The Atmosphere

The atmosphere is the gaseous envelope surrounding a planet. On Earth, it is also called air. The lower regions of the atmosphere contain gases such as oxygen and carbon dioxide that are essential for plant and animal respiration. Birds, insects and other life can be found up to approximately 2,000 meters above the earth’s surface. The atmosphere also plays critical roles in shaping the biosphere by deflecting harmful radiation from the sun and determining weather patterns.

The Hydrosphere

The hydrosphere is the aquatic part of the biosphere. This includes oceans, rivers, lakes and other bodies of water. Unlike the lithosphere and the atmosphere, every portion of the hydrosphere supports life. Specially-adapted bacteria grow in hot springs, tube worms form the basis of sulfur-based communities around deep-sea, hydrothermal vents, and in more hospitable regions, life abounds. Water-dwelling individuals of virtually every taxonomic group of plants and animals have been identified as important parts of the biosphere. Water is essential to life, and the hydrosphere also plays an important part in atmosphere formation.

The Lithosphere

The lithosphere is the terrestrial part of the biosphere. It consists of the solid land masses, such as continents and islands. The deeper parts of the lithosphere, known as the lower mantle and the core, do not support life. The rest of the lithosphere supports a variety of life from bacteria to large mammals and trees hundreds of feet tall. The weathering of the lithosphere crust forms soil, which provides minerals and organic waste to support life. In addition, the land provides shelter and protection for animals from weather and predators, and an anchor for plants.

The Biosphere is the worldwide sum of all ecosystems. It is the zone of life on Earth and supports Biodiversity; the variety of life on earth. The biosphere has minimal inputs and outputs and is virtually a closed system. The exception is energy where it is an open system, with photosynthesis capturing solar energy.