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Download Carbon, Nitrogen, & Phosphorus
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How Ecosystems Work Carbon, Nitrogen & Phosphorus Cycles Section 2 How Ecosystems Work Carbon Cycle Carbon - in air, water, and living organisms Exchange of carbon (C) between nonliving environment and organisms Biogeochemical cycle – chemical element or molecule moves between abiotic and biotic components of Earth Section 2 How Ecosystems Work Carbon Cycle C - essential to proteins, fats, and carbohydrates Section 2 How Ecosystems Work Carbon Cycle Producers (plants) convert CO2 into carbohydrates Consumers (animals) obtain C from carbohydrates in producers Section 2 How Ecosystems Work Section 2 Carbon Cycle C stored in organisms - released into soil or air when organisms dies. These molecules can form coal, oil, or natural gas (fossil fuels). How Ecosystems Work Section 2 Carbon Cycle During cellular respiration, some C is released into atmosphere (CO2). How Ecosystems Work Carbon Cycle Section 2 How Ecosystems Work Section 2 Human Affect on Carbon Cycle Humans burn fossil fuels, releasing carbon (CO2) into atmosphere. How Ecosystems Work Section 2 Nitrogen Cycle Process where nitrogen (N) circulates among the atmosphere and living things. N - in proteins N = 78% of atmospheric gasses How Ecosystems Work Section 2 Nitrogen Cycle N must be altered (fixed) before organisms can use it. “Nitrogen-fixing” bacteria fix atmospheric N into compounds that can be used by other organisms. How Ecosystems Work Section 2 Nitrogen-Fixing Bacteria Live within the roots of legumes. Use carbohydrates from legumes to produce N containing compounds. Excess “fixed” nitrogen is released into soil. How Ecosystems Work Section 2 Decomposers and Nitrogen Cycle N within bodies of organisms is returned to N cycle when organisms die. Decomposers break down decaying organisms and wastes. Bacteria turn some N into gas, which returns to atmosphere (completes cycle). How Ecosystems Work Nitrogen Cycle Section 2 How Ecosystems Work Section 2 Phosphorus Cycle Movement of phosphorus (P) in different chemical forms from environment to organisms and back to environment. How Ecosystems Work Section 2 Phosphorus Cycle P - part of nucleotides Plants obtain P from soil and water Animals obtain P from other organisms. How Ecosystems Work Section 2 Phosphorus Cycle P enters soil and water when rocks erode. – Some P dissolve as phosphate. – Plants absorb phosphates. Some P washes off land to ocean. Many phosphate salts are not soluble in water – accumulate as sediment. How Ecosystems Work Phosphorus Cycle Section 2
