Biogeochemical Cycles Ms. Cuthrell

2.1.1 Analyze the flow of energy and cycling of matter (water, carbon, nitrogen and oxygen) through ecosystems relating the significance of each to maintaining the health and sustainability of an ecosystem.

Carbon Cycle Photosynthesis by plants takes in CO2 and converts it to glucose. Glucose travels up the food chain through consumption. Cell respiration is when organisms take in oxygen and release CO2 (breathing). Decomposition of dead organisms by decomposers releases CO2.. Natural processes such as volcanic eruptions and fires release CO2.

Human Influence on the Carbon Cycle Burning of fossil fuels releases an immense amount of CO2 which is leading to global warming.

Nitrogen Cycle Nitrogen-fixing bacteria in roots and soil fix atmospheric nitrogen. Decomposers such as microbes and fungi decompose organisms and urine. Nitrogen is evaporated out of the soil, or assimilated by plants. Animals consume nitrogen when they eat plants, or other animals that consume plants.

Importance of Nitrogen Nitrogen is an essential part of amino acids (which make up proteins) and DNA.

Human Influence on the Nitrogen Cycle Raw sewage and urban runoff can accumulate and cause algae blooms. Algae causes a depletion of oxygen in the water causes organisms to die. If the soil is saturated with nitrogen it becomes very acidic causes plants to die. Burning fossils fuels and wood can cause acid rain which is also deadly.

Ecosystems Introduced Watch the video clip, and write down the food chain discussed. http://videos.howstuffworks.com/discovery/27997-assignment-discovery-the-food-web-video.htm

Energy Pyramid Radiant energy from the sun is converted into chemical energy when producers (autotrophs) photosynthesize. Energy is passed up the food chain through consumption. Producers have the MOST available energy. Energy decreases up the food chain by 90%. Energy is lost as heat and waste.