Presentation on theme: "Energy Flow In Ecosystems"— Presentation transcript:
1 Energy Flow In Ecosystems Big Idea:What happens to energy stored in Body tissues when one organism eats another?
2 Food Chains & Food Webs How does energy flow through ecosystems? A 1-way stream, from primary producers to consumersFood ChainsA series of steps in which organisms transfer energy by eating and being eaten
3 Food Chains & Food Webs Food Webs A network of feeding relationships; shows all the feeding relationships within an ecosystem
4 Food Chains & Food Webs Food Webs – Very complicated Notebook Time: Describe the ecosystem that is your backyardDraw a food web of that ecosystemBe as specific as possibleDraw a food chain from within your food webWhat role do decomposers & detritivores play in food webs?
5 Food Chains & Food Webs Disturbances In your groups, answer the following questions using the food web below:What effect would an insecticide have on the food web?Would this have an effect on the populations of non-insect eating animals?What populations would increase?What populations would decrease?Would this change any animals eating habits? Which ones & how?
6 Trophic Levels & Ecological Pyramids Each step in a food chainEcological PyramidsShow relative amount of energy or matter contained within each trophic level in a given food chain or food webThere are 3 different types of Ecological PyramidsPyramids of EnergyPyramids of BiomassPyramids of numbers
7 Ecological Pyramids Pyramids of Energy Show relative amounts of energy available at each trophic levelTypically1/10 or 10% of available energy within one trophic level is passed on to the next levelIn other words:1/10 of the solar energy captured and stored in leaves of grasses ends up stored in the tissues of cows
8 Ecological Pyramids Pyramid of Biomass & Numbers Biomass – Total amount of living tissue within a given trophic levelPyramid of BiomassIllustrates the relative amount of living organic matter available at each trophic level of an ecosystem
9 Ecological Pyramids Pyramid of Biomass & Numbers Pyramid of Numbers Shows the relative number of individual organisms at each trophic level in an ecosystem
10 Cycles of Matter How does matter move through the biosphere? Biogeochemical cyclesElements pass from one organism to another and among parts of the biosphere in closed loopsThese loops are powered by the flow of energy.4 Processes involved with biogeochemical cyclesBiological ProcessesAny and all activities performed by living organismsGeological ProcessesVolcanic eruptions, erosion, plate tectonicsChemical & Physical ProcessesFormation of clouds, flow of running water, lightningHuman ActivityDeforestation, burning of fossil fuels, use of fertilizers
11 Water CycleWater moves continuously between, oceans, the atmosphere, land and the organisms in them.TranspirationEvaporation of water from leaves of the plantsEvaporationLoss of water from surface of bodies of waterCondensationWhen water vapor cools & becomes liquidPrecipitationWhen water falls out of the atmosphere
12 Nutrient Cycles3 main Nutrient CyclesCarbonNitrogenPhosphorus
13 Nutrient Cycles Carbon Cycle Found in several large reservoirs in biosphereAtmosphere = CO2Oceans = Dissolved CO2Land = in organisms, soil & rocksUnderground =Coal, Petroleum & Calcium CarbonateIn Life = base of all organic molecules
14 Nutrient Cycles Nitrogen Cycle Required to build proteins, DNA, RNA Atmospheric NitrogenN2 = Non-usable form for most organismsNeeds to be “fixed”Nitrogen FixationProcess of N2 being converted into ammonia, nitrates & nitrites by bacteriaRelatively small amounts of N2 can be fixed by LightningDenitrificationWhen N2 is released by soil bacteria who use nitrates for energyFertilizerHuge human influence in adding excess Nitrates & Nitrites into aquatic ecosystemsCan cause algal blooms
15 Nutrient Cycles Phosphorus Cycle Essential for creation of DNA, RNA Not very abundant in biosphereRemains mostly on land in rock, soil, & sedimentsAs rock & sediments wear down, P is released to environment.
16 Nutrient Cycles Nutrient Limitation Limiting Nutrient In Soil In Ocean The nutrient whose supply limits productivityIn SoilTypically Limiting Nutrients are:Ca, Mg, S, Fe, Mn, P, Fixed N,In OceanFixed N