Cycles in the Biosphere

I. Recycling in the Biosphere Remember, energy flows in the biosphere in one direction. The sun is the main source of energy Autotrophs (producers) convert this energy to food through photosynthesis Heterotrophs (consumers) eat these producers to attain energy Only 10% of the energy from one trophic level gets transferred to the next Unlike energy, matter is recycled in the biosphere Elements pass from one organism to another and among parts of the biosphere through closed loops called biogeochemical cycles

II. Biogeochemical Cycles As matter moves through these cycles, it is transformed…never created or destroyed 4 main types: Biological processes- eating, breathing, excretion and respiration Geological processes- volcanic eruptions, weathering and erosion of rock Chemical and physical processes- formation of clouds and precipitation Human activity- mining and burning fossil fuels, clearing of land, and use of fertilizers

III. Water Cycle Water continuously moves between the oceans, the atmosphere and the land…sometimes inside living organisms, other times outside of them. Important terms: Precipitation Transpiration Evaporation Condensation Runoff

IV. Carbon Cycle Carbon is a major element making up living organisms. Biomolecules, such as carbohydrates, lipids, proteins and nucleic acids are all made up of carbon Carbon dioxide (CO2) is breathed out by living organisms and used by photosynthetic organisms. CO2 is also dissolved in oceans. Fossil fuels, such as coal, oil and natural gas are “fossilized” carbon. The carbon cycle shows how carbon is constantly being recycled throughout the biosphere

Review How does the way matter flows in an ecosystem differ from the way that energy flows? By what two processes is water cycled from land to the atmosphere? Describe one way in which water from the ocean may make one complete cycle through the atmosphere and back to the ocean. Include the names of each process involved in your cycle. Based on your knowledge of the carbon cycle, what do you think might happen if humans were to continue to clear and burn vast areas of forests for building?