Cycles of matter are how matter circulates between the Earth, the atmosphere, and living things. Natural cycles of matter are important for life and the environment. They allow the transport and long-term storage of matter. For example: The element carbon is the basis of all life on Earth. Biochemical compounds consist of chains of carbon atoms and just a few other elements. Like water, carbon is constantly recycled through the biotic and abiotic factors of ecosystems. The carbon cycle includes carbon in sedimentary rocks and fossil fuels under the ground as well as carbon in the ocean, the... Show more

Cycles of matter are how matter circulates between the Earth, the atmosphere, and living things. Natural cycles of matter are important for life and the environment. They allow the transport and long-term storage of matter.

For example: The element carbon is the basis of all life on Earth. Biochemical compounds consist of chains of carbon atoms and just a few other elements. Like water, carbon is constantly recycled through the biotic and abiotic factors of ecosystems. The carbon cycle includes carbon in sedimentary rocks and fossil fuels under the ground as well as carbon in the ocean, the atmosphere, and living things.    
Sedimentary rocks, fossil fuels, and the ocean are major reservoirs of carbon. Sediments from dead organisms may form carbon-containing sedimentary rocks. Alternatively, the sediments may form carbon-rich fossil fuels, which include oil, natural gas, and coal. Carbon can be stored in these reservoirs for millions of years. However, if fossil fuels are extracted and burned, the stored carbon enters the atmosphere as carbon dioxide. Natural processes, such as volcanic eruptions, can release underground carbon from rocks into the atmosphere. Carbon in rocks can also be dissolved by flowing water in runoff, rivers, and streams, which may carry the dissolved carbon to the ocean.    
Ocean water dissolves carbon dioxide from the atmosphere. Dissolved carbon may be stored in the deep ocean for thousands of years.    
Major exchange pools of carbon include living things and the atmosphere. Carbon cycles more quickly between these components of the carbon cycle. Photosynthesis by plants and other producers removes carbon dioxide from the atmosphere to make organic compounds for living things. Cellular respiration by living things releases carbon into the atmosphere or ocean as carbon dioxide. Decomposition of dead organisms and organic wastes releases carbon back to the atmosphere, soil, or ocean.    

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