2EcosystemAn array of organisms and their physical environment, interconnected through a one-way flow of energy and cycling of raw materials
3Modes of Nutrition Photoautotrophs Heterotrophs Capture sunlight or chemical energyPrimary producersHeterotrophsExtract energy from other organisms or organic wastesConsumers, decomposers, detritivores
4Simple Ecosystem Model Energy input from sunProducersAutotrophs (plants and other self-feeding organisms)NutrientCyclingConsumersHeterotrophs (animals, most fungi,many protists, many bacteria)Energy output (mainly metabolic heat)
5Simple Ecosystem Model The role of organisms in an ecosystem
9Which statement about ecosystems is false? energy flows in a cycle between producers and consumersnutrients are recycled by passing from producers to consumers and back again via decomposersin most ecosystems, energy flow begins with the capture of solar energy by photosynthesizersheterotrophs include bacteria and fungi
11Energy Losses Energy transfers are never 100% efficient Some energy is lost at each stepLimits number of trophic levels in an ecosystem
12Two Types of Food Webs Grazing Food Web Detrital Food Web Energy Input:Energy Input:Transfers:Transfers:Producers (photosynthesizers)Producers (photosynthesizers)energy lossesas metabolic heatand as net exportfrom ecosystemenergyin organic wastes, remainsenergy lossesas metabolic heatand as net exportfrom ecosystemenergyin organic wastes, remainsherbivoresdecomposersdecomposerscarnivoresdetritivoresdetritivoresdecomposersEnergy OutputEnergy Output
13Ecological PyramidsPrimary producers are bases for successive tiers of consumersBiomass pyramidDry weight of all organismsEnergy pyramidUsable energy decreases as it is transferred through ecosystem
14Biomass Pyramid Aquatic ecosystem, Silver Springs, Florida Long-term study of a grazing food webthird-level carnivores(gar, large-mouth bass)1.5second-level consumers(fishes, invertebrates)decomposers, detritivores(bacteria, crayfish)1.1first-level consumers(herbivorous fishes,turtles, invertebrates)37primary producers (algae,eelgrass, rooted plants)8095
15Energy PyramidPrimary producers trapped about 1.2% of the solar energy that entered the ecosystem6–16% passed on to next leveltop carnivores21decomposers + detritivores = 5,080carnivores383herbivores3,368producers20,810 kilocalories/square meter/year
16Energy flow at Silver Springs Silver Springs StudyEnergy flow at Silver Springs
17Biogeochemical CycleFlow of an essential substance from the environment to living organisms and back to the environmentMain reservoir is in the environmentGeologic processes, decomposers aid cycles
18Three Categories Hydrologic cycle Atmospheric cycles WaterAtmospheric cyclesNitrogen and carbonSedimentary cyclesPhosphorus and other nutrients
19Hydrologic Cycle atmosphere precipitation onto land 111,000 wind-driven water vapor40,000evaporation from ocean425,000precipitation into ocean 385,000evaporation from land plants (evapotranspiration) 71,000surface and groundwater flow 40,000oceanland
20WatershedA region where precipitation is funneled into a single stream or river
21Hubbard Brook Experiment A watershed was experimentally stripped of vegetationAll surface water draining from watershed was measuredDeforestation caused six-fold increase in calcium content of runoff water
22Global Water Crisis Limited amount of fresh water Desalinization is expensive and requires large amounts of energyAquifers are being depletedGroundwater is contaminatedSewage, agricultural runoff, and industrial chemicals pollute rivers
24water hydrologic hydrodynamic precipitation When the Earth's waters move from ocean to atmosphere to land and back again, it is called the _____ cycle.waterhydrologichydrodynamicprecipitation
25A watershed is _____. a stream or river a river that discharges water directly into the oceana region where precipitation becomes funneled into a single stream or rivera region where precipitation becomes funneled into a reservoir for use in human communities
26Carbon CycleCarbon moves through atmosphere, food webs, ocean, sediments, and rocksSediments and rocks are the main reservoirCombustion of fossil fuels changes natural balance
27bicarbonate and carbonate in ocean water diffusion between atmosphere and oceancombustion of fossil fuelsbicarbonate and carbonate in ocean waterphotosynthesisaerobic respirationmarine food websdeath, sedimentationincorporation into sedimentsupliftingsedimentationmarine sedimentsCarbon Cycle: Marine
28combustion of fossil fuels atmospherevolcanic actioncombustion of fossil fuelsphotosynthesisaerobic respirationcombustion of woodterrestrial rocksdeforestationweatheringland foodwebssoil waterpeat,fossilfuelsdeath, burial, compaction over geologic timeleaching, runoffCarbon Cycle: Land
29My Carbon Cycle 1. I eat carbohydrate molecules. These are molecules of fuel which I will “burn”.Some of the energy released when I burn them will be trapped for me to use. The rest will be lost as heat.The waste products of burned fuel are carbon dioxide and water. I breathe these out.Plants (or other producers) take in carbon dioxide from the atmosphere and use it to make carbohydrate.
30According to the last slide, why do I eat carbohydrates? Because they taste good.Because they contain lots of vitamins.Because they contain lots of energy.Because they are low in calories.
31Energy saved from burning up my fuel is saved in the form of : MuscleATPFatHeat
32The only reason I need to breathe in oxygen is : I need oxygen to “burn” fuel molecules.All living things need oxygen.Oxygen + carbon = carbon dioxide.Oxygen is corrosive.
33Breathing out : Helps me regulate my body temperature. Gets rid of excess fuel molecules.Burns extra calories.Gets rid of the waste products of burned fuel.
34The carbon in the plants I eat comes from : The atmosphere.The food they eat.The soil.Water.
35The carbon in the steak I eat comes from : Supplements in animal feed.Vitamins.The cow’s drinking water.The plants eaten by the cow.
36Greenhouse EffectGreenhouse gases impede escape of heat from Earth’s surface
37Long-term increase in temperature of Earth’s lower atmosphere Global WarmingLong-term increase in temperature of Earth’s lower atmosphere
38Carbon Dioxide Increase Carbon dioxide levels fluctuate seasonallyAverage level is steadily increasingBurning of fossil fuels and deforestation are contributing to the increase
39Other Greenhouse Gases CFCs: synthetic gases used in plastics and in refrigerationMethane: released by natural gas production, livestockNitrous oxide: released by bacteria, fertilizers, and animal wastes