MATTER CYCLING IN ECOSYSTEMS Nutrient Cycles: Global Recycling Global Cycles recycle nutrients through the earths air, land, water, and living organisms. Nutrients are the elements and compounds that organisms need to live, grow, and reproduce. Biogeochemical cycles move these substances through air, water, soil, rock and living organisms. Plants & The Carbon Cycle Plants take in carbon dioxide and convert it to sugar which can be stored until used for energy. This process is called photosynthesis. Photosynthesis: CO 2 + H 2 O + sunlight yields O 2 + C 6 H 12 O 6 Plants & The Carbon Cycle Plants release carbon dioxide as a waste product when they convert their stored sugar to chemical energy. This process is called respiration. Respiration: C 6 H 12 O 6 + O 2 yields CO 2 + H 2 O + energy Animals & The Carbon Cycle Animals eat carbon contained in animal and plant tissues and release carbon dioxide as a waste product. This process is respiration. Decay & The Carbon Cycle: Decomposers release the carbon from dead plant and animal tissues back into the atmosphere. Fossil Fuels & The Carbon Cycle: Over millions of years fossil fuels may form from the buried remains of plants and animals. Fossil Fuels & The Carbon Cycle: This carbon reenters the atmosphere during combustion. Man shortened the cycle. The Oceans & The Carbon Cycle: Dissolved carbon dioxide in sea water becomes deposited as calcium carbonate shells and bone. The Oceans & The Carbon Cycle: Over millions of years, these shells and bone form sedimentary rock, like limestone and dolomite and some sandstone. Reservoirs or Sinks of Carbon Ocean deposits are the biggest sink of carbon on the planet. The Rock Cycle ultimately releases carbon stored in sedimentary rock. If man harvests the rock, then the cycle speed is increased. NOT THE ONLY ONE! Man is not the only object on the Earth to put carbon in the atmosphere. Volcanic activity also releases carbon stored in rock. However, the amount is much less than man.