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Cycling of Materials. Chapter 5 Section 2. Carbon Cycle. Carbon cycles between the atmosphere, land, water and organisms Short term part of cycle – producers, consumers and atmosphere Mostly by photosynthesis and respiration Long term part of cycle – carbonates, limestone, and fossil fuels
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Cycling of Materials Chapter 5 Section 2
Carbon Cycle • Carbon cycles between the atmosphere, land, water and organisms • Short term part of cycle – producers, consumers and atmosphere • Mostly by photosynthesis and respiration • Long term part of cycle – carbonates, limestone, and fossil fuels • Formed underground over thousands of years • Human impact– increased carbon (CO2) in the atmosphere • Leads to global warming
Nitrogen Cycle • Nitrogen - used by all organisms to build proteins • 78% of the atmosphere is N2 • Organisms can’t use nitrogen in this form • Nitrogen-fixing bacteria “fix” the nitrogen, converting it to forms that plants can use • Nitrogen fixing bacteria = NFB
NFB live in nodules on the roots of legumes • beans, peas, clover • Plants take in ‘N’ through their roots • Animals eat plants • Both plants and animals die • Decomposers break down wastes and return ‘N’ to soil • Nitrogen in soil can be returned as N2 to atmosphere by another type of bacteria
Phosphorus Cycle • Phosphorus cycles mainly between rocks and organisms in the environment • Very slow cycle • No atmospheric component because phosphorus is rarely a gas • Large amounts of P sink to bottom of ocean and build up in sediment • Becomes part of sedimentary rock
Human Impact • Fertilizer has high amounts of ‘N’ and ‘P’ • Used to increase plant growth • Excess fertilizer usage leads to increased ‘N’ and ‘P’ in runoff • In an aquatic ecosystem, causes algae bloom which leads to lack of oxygen in the water • Kills fish that need oxygen to breathe
Human Impact (cont.) • ‘N’ in form of Nitric Oxide is released from burning wood, coal, & oil • Nitric Oxide is harmful gas, which combines with oxygen and water vapor • Forms Nitric Acid, which dissolves in rain and snow • Result – Acid Precipitation: rain, snow, sleet, fog • Kills organisms, changes pH of ecosystem