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AP Biology Ecosystems Essential questions What limits the production in ecosystems? How do nutrients move in the ecosystem? How does energy move through the ecosystem? AP Biology Ecosystem All the organisms in a community plus abiotic factors ecosystems are transformers of energy & processors of matter Ecosystems are self-sustaining what is needed? capture energy transfer energy cycle nutrients AP Biology Ecosystem inputs constant energy flows input of through energy nutrients cycle Matter cannot Don’t forget laws of or bethe created Physics! destroyed AP Biology nutrients can only cycle biosphere inputs energy nutrients Generalized Nutrient cycling consumers producers consumers decomposers nutrients nutrients ENTER FOOD CHAIN made available = made available to producers to producers Decomposition connects all trophic levels AP Biology return to abiotic reservoir abiotic reservoir geologic processes Carbon cycle CO2 in atmosphere Diffusion Respiration abiotic reservoir: CO2 in atmosphere enter food chain: Combustion of fuels = photosynthesis carbon fixation in Industry and home Calvin cycle Photosynthesis recycle: return to abiotic: respiration Plants combustion Animals Dissolved CO2 Bicarbonates Photosynthesis Animals Plants and algae AP Biology Carbonates in sediment Deposition of dead material Deposition of dead material Fossil fuels (oil, gas, coal) Nitrogen cycle Carnivores abiotic reservoir: N in atmosphere enter food chain: nitrogen fixation by soil & aquatic bacteria recycle: Herbivores decomposing & nitrifying bacteria return to abiotic: denitrifying bacteria Birds Plankton with nitrogen-fixing bacteria Atmospheric nitrogen Plants Death, excretion, feces Fish excretion Decomposing bacteria amino acids Ammonifying bacteria loss to deep sediments Nitrogen-fixing bacteria (plant roots) Nitrogen-fixing bacteria (soil) Nitrifying bacteria AP Biology soil nitrates Denitrifying bacteria Phosphorus cycle Plants Land animals Soluble soil phosphate Loss in drainage fungi) Rocks and minerals Decomposers Phosphates (bacteria & fungi) in solution Animal tissue and feces abiotic reservoir: rocks, minerals, soil enter food chain: erosion releases soluble phosphate uptake by plants recycle: decomposing bacteria Animal tissue & fungi Urine and feces return to abiotic: loss toDecomposers ocean (bacteria and sediment Aquatic animals Plants and algae Precipitates AP Biology Loss to deep sediment abiotic reservoir: surface & atmospheric water enter food chain: precipitation & plant uptake Solar energy recycle: transpiration return to abiotic: Evaporation evaporation & runoff Water cycle Transpiration Water vapor Precipitation Oceans Runoff Lakes AP Biology Percolation in soil Groundwater Aquifer Transpiration Remember transpiration? AP Biology Breaking the water cycle Deforestation breaks the water cycle groundwater is not transpired to the atmosphere, so precipitation is not created forest desert desertification AP Biology QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Repairing the damage The Greenbelt Movement AP Biology planting trees in Kenya restoring a sustainable ecosystem establishing democracy empowering women Wangari Maathai Nobel Peace prize 2004 Effects of deforestation 40% increase in runoff loss of water 60x loss in nitrogen 10x loss in calcium loss into surface water Concentration of nitrate (mg/l ) 80 nitrate levels in runoff AP Biology 40 loss out of ecosystem! 4 Deforestation 2 Why is 0 nitrogen 1965 so important? 1966 1967 Year 1968 Energy flows through ecosystems sun secondary consumers (carnivores) primary consumers (herbivores) producers (plants) AP Biology loss of energy loss of energy Food chains Trophic levels feeding relationships start with energy from the sun captured by plants 1st sun top carnivore Level 3 Secondary consumer carnivore Level 2 Primary consumer heterotrophs herbivore level of all food chains food chains usually go Level 1 Producer up only 4 or 5 levels inefficiency of energy transfer Level 4 Tertiary consumer all levels connect to decomposers AP Biology autotrophs Decomposers Bacteria Fungi sun Inefficiency of energy transfer Loss of energy between levels of food chain To where is the energy lost? The cost of living! 17% growth only this energy moves on to the next level in the food chain AP Biology energy lost to daily living 33% cellular respiration 50% waste (feces) sun Ecological pyramid Loss of energy between levels of food chain can feed fewer animals in each level 1 100 100,000 1,000,000,000 AP Biology Humans in food chains Dynamics of energy through ecosystems have important implications for human populations how much energy does it take to feed a human? if we are meat eaters? if we are vegetarian? What is your ecological footprint?! AP Biology Food webs Food chains are linked together into food webs Who eats whom? a species may weave into web at more than one level bears humans eating meat? eating plants? AP Biology Any Questions?? We’re working on a lot of them! AP Biology 2006-2007