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Download Basic ecosystem principles: Energy flows and nutrients cycle
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• What is ecology? Global human issues Physical limits • Ecosystems • • • • • • Organisms Populations Species Interactions Communities C, H20, P, N... Biogeochemical transformations move nutrients through ecosystems • nutrients reused repeatedly • energy flows once chemical transformations and energy transformations go hand in hand flux size residence time Unavailable Organic PLANTS AND AUTOTROPHIC BACTERIA PEAT, COAL, OIL ROCKS Inorganic ANIMALS ATMOSPHERE Inorganic Organic Available SOIL WATER SEDIMENTS ATMOSPHERE WATER PEAT, COAL, OIL Organic ANIMALS PLANTS AND AUTOTROPHIC BACTERIA Assimilation, Dissimilation, , photosynthesis respiration, fixation excretion, leaching SOIL Inorganic Unavailable Compression Erosion, burning fossil fuels Weathering ROCKS Uplift, Erosion Inorganic Organic Available SEDIMENTS Sedimentay rock formation • Energy transformations – coupled transformations • oxidation (energy-releasing) • reduction (energy requiring) – elements occur in high energy compounds and low energy compunds • • • Major reservoirs Mechanisms of transfer Disruption by industrialized humans Water Carbon Nitrogen Phosphorus Water Carbon Nitrogen Phosphorus LOOK THIS STUDY IT! UP IN YOUR BOOK AND Major reservoir = Ocean (97% of water) Mechanisms of transfer (PHYSICAL!) • Evaporation and precipitation over oceans: Evaporation > precipitation over land: Precipitation > evaporation +transpiration • Wind and runoff Residence time (size/flux) • Atmosphere: 2 weeks • Liquid form on earth surface: 2,800 years Major reservoir = Fossil fuels/ ocean sediments Secondary reservoirs = Atmosphere and Dissolved in ocean Mechanisms of transfer (BIO…, CHEM..) • Photosynthesis and respiration • Chemical equilibria: water-atmosphere / water Carbon dioxide exchange carbonic acid / bicarbonate - carbonate carbonate / calcium carbonate sedimentation • Fermentation Size and transfer of compartments in billions of metric tons (per year for transfers). Atmosphere 640 Dissolved CO2 30,000 Oceans Land Dead stuff 700 Limestone, dolomite 18,000,000 Coal, oil, gas 10,000 Atmosphere 640 Dissolved CO2 30,000 Oceans Algae 5 Limestone, dolomite 18,000,000 Plants 450 Land Dead stuff 700 Coal, oil, gas 10,000 Atmosphere 640 Dissolved CO2 30,000 Oceans Algae 5 Animals Bacteria, organic matter Limestone, dolomite 18,000,000 Animals Plants 450 Land Bacteria Dead stuff 700 Coal, oil, gas 10,000 Atmosphere 640 Exchange 84 Photosynthesis = Respiration 35 Dissolved CO2 30,000 Animals Oceans Photosynthesis = Respiration 50 Bacteria, organic Algae 5 matter Limestone, dolomite 18,000,000 Animals Plants 450 Land Bacteria Dead stuff 700 Coal, oil, gas 10,000 ? • • Major reservoir = Atmosphere is 79% N2 Mechanisms of transfer (BIO) – Fixation by Rhizobium, Aztobacter and blue green algae – Ammonification (hyrdolysis of protein) – Nitrification • Ammonia to Nitrite by Nitrosomas and Nitrosococcus • Nitrite to Nitrate by Nitrobacter and Nitrococcus – Denitrification by Pseudomonas – Once assimilated: moves through trophic exchange Absence in rocks and sediments Limited availability in ocean systems Very important to biology … amino acids are the building blocks of proteins Nitrate is soluble in fresh water and is taken up by plants in this form Specialized bacteria are KEY in the Nitrogen Cycle Gaseous N2 Nitrates NO3 Nitrites NO2 Ammonia NH Water human activities natural pathways Nitrogen: Fig. 23.11 Nitrite Carbon: Fig. 23.6 Nitrogen: Big picture Atmosphere Animals Oceans Algae Animals Bacteria, organic matter Plants Land Water Bacteria Dead stuff Ocean sediments and rocks Phosphorus: Big picture Atmosphere Animals Oceans Algae Animals Bacteria, organic matter Plants Land Water Soil Ocean sediments and rocks Bacteria Dead stuff • Essential – nucleic acids – cell membranes – energy transfer systems – bones – teeth • • Limits productivity Only available at pH 6-7 Major reservoir = Ocean sediments, Geologic Deposits Mechanisms of transfer (GEO..., CHEM..) • Uplifting of continents • Weathering of bedrock • Dissolving of phosphate in water • Assimilation by plants of dissolved phosphates mycorhizzal fungi • Trophic transfer among living things • Precipitates out of water: Sedimentation anaerobic organic sediments denitrifiers nitrogen fixation bacteria and cyanobacteria deep sea vent chemoautotrophic production bacteria use oxygen from seawater to oxidize H2S Pacific hydothermal vent with tube worms who rely on Food produced by chemoautotrophic sulfur bacteria aerobic oxidation of • methane (Methanosomonas, Methylomonas) • hydrogen (Hydrogenomonas, Micrococcus) • ammonia (Nitrosomonas, Nitrosococcus) • nitrite (Nitrobacter, Nitrococcus) • hydrogen sulfide, sulfur, sulfite (Thiobacillus) • ferrous iron salts (Ferrobacillus, Gallionella) Elements cycle because metabolic activities result in chemical transformations. Each type of habitat presents a different chemical environment, • presence/absence of oxygen • possible sources of energy Unlike energy, nutrients cycle nutrient flux related to energy transformations Water, carbon, nitrogen, and phosphorus cycles vary • reservoir and residence times • energetic states • flux and mechanisms of transfer
