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Aquatic Plants and the Environment (SWES, ECOL, WFSc 474/574). Nutrient Cycles in Wetlands Dr. Kevin Fitzsimmons Professor – University of Arizona. Carbon Cycle. digestion and respiration + 3O 2. Photosynthesis. C 6 H 12 O 6. 6 H 2 O + 6 CO 2. C 6 H 12 O 6 + 3O 2.
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Aquatic Plants and the Environment(SWES, ECOL, WFSc 474/574) Nutrient Cycles in Wetlands Dr. Kevin Fitzsimmons Professor – University of Arizona
Carbon Cycle digestion and respiration + 3O2 Photosynthesis C6H12O6 6 H2O + 6 CO2 C6H12O6 + 3O2 sugars andother organics and oxygen sugars andother organics water and carbon dioxide anaerobes, fermentation, andmethanogens CH3CH2OCOOH (lactic acid)other acids (humic and tannic) CH4 + COx
Carbonate Cycle CO2 + H2O H2CO3 H+ + HCO3- H+ + CO32- carbon dioxidedissolved in water carbonic acid bicarbonateion carbonateion
Nitrogen cycle • Nitrogen is often a limiting element in freshwater aquatic system • Adding nitrogen will cause rapid increase in primary productivity • Nitrogen in anaerobic sediments- denitrification (reduction to NH3 or N2 gas)
Phosphorus and orthophosphate. Organic P decomposes and releases PO4, taken up by algae and plants or adsorbs to clay particles and precipitates. Anaerobic conditions can re-release P to water. Phosphorus cycle
Sulphur cycle Organic sulphur, digestedto sulphates, thenreduced to sulphur dioxide,elemental sulphuror hydrogen sulfide
Saturated Soils • Bacteria decompose organics, quickly use available DO • Anaerobic conditions, anaerobes scavenge O release H+ • Reducing conditions • Redox reactions in sediments / soils
Wetland Ecosystem Management Hydric Soils