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Chapters 47, 48, and 49 Bell Ringer, 8/14 TURN IN ANY WORK THAT YOU ARE MISSING Pick up your Exit Slips on the back lab table Answer the following question on your bell ringer: Explain guess. the difference between a hypothesis and a Bell Ringer, 8/15 Retrieve your EXIT SLIPS from the back lab table Answer the following questions: In one food chain, a cat eats a mouse, which ate some cheese. In another food chain, a lion eats a meercat that ate some desert grass. Are the cat and the lion on the same trophic level? Defend your answer. What type of CONSUMER OR PRODUCER is each organism in the above food chains? Detritivores vs. Decomposers The two groups are very, very similar DETRITIVORES help break organic wastes into smaller pieces, but they DO NOT actually get rid of it DECOMPOSERS break organic wastes back into its basic nutrients and return it to the environment DETRITIVORES can ingest clumps of matter while DECOMPOSERS cannot Detritivores vs. Decomposers ECOSYSTEMS: AN OVERVIEW (Chapter 47.1-2) What is an ecosystem? An array of organisms and a physical environment, all interacting through a one-way flow of energy and cycling of nutrients Ecosystems run on energy Primary producers: Capture energy from a non-living source (typically sunlight) Consumers: Get energy from feeding on tissues, wastes, or remains of producers and other consumers Primary Producers Main primary producers: Plants and photoplankton Autotroph: Produces its own food from inorganic substances Capture energy from the sun (photosynthesis) or create energy from chemicals (chemoautotrophs) Primary Producers Common misconception: All plants are autotrophs NOT ALL PLANTS ARE AUTOTROPHS Consumers Heterotroph: Consumers other organisms to get energy Can be classified based on their diets Herbivores: Eat plants Carnivores: Eat the flesh of animals Parasites: Live inside or on a living host and feed on its tissues Omnivores: Eat both plant and animal materials Detritivores: Eat small particles of organic matter (detritus) Decomposers: Eat organic wastes and remains What type of consumer is it? Find the Producers/Consumers! Flow in an Ecosystem Energy flow in an ecosystem only goes ONE WAY Light captureliving componentsphysical environment Breaking down food in the ecosystem gives off heat Heat cannot be recycled, making this a one-way process Flow in an Ecosystem Many nutrients cycle in an ecosystem Producers take up nutrients (N, H, O, C) from inorganic sources (air, water) Nutrients move into consumers as they eat the producers After organisms die, decomposition returns nutrients to environment Producers pick them up again http://www.youtube.com/watch?v=bW7PlTaawfQ Trophic Levels Trophic level: One level in the hierarchy of feeding relationship present in all ecosystems When an organism eats another, this energy transfers up to the next trophic level Same trophic level All organisms in a trophic level are the same number of transfers away from the energy input into that system Can one organism be on one trophic level in one food chain and a different trophic level in another? Are they on the same trophic level? A bird eating a worm and a Venus fly trap catching a fly A cow eating grass and a cat eating a mouse A human eating a steak and a lion eating an antelope A mouse eating a piece of cheese and another mouse eating some kudzu A bacteria and fungi breaking down the same weasel Exit Slip 8/14 Draw and label FOUR trophic levels. Include each type of PRODUCER or type of consumer. Food Chains Sequence of steps by which some energy captured by primary producers is transferred to organisms as successively higher trophic levels Simple way to think about who eats who in an ecosystem More than one per ecosystem; often complex Name those trophic levels! AcornSquirrelHawk GrassBunnyFoxBear FlowerSheepWolfLionFungi Star flowersFairiesUnicornsUnicorn ticks THE POINT: The levels are always named the same way, even in a ridiculous example! Food Webs Diagram that illustrates trophic interactions among species in a particular ecosystem Includes multiple connecting food chains Food Chains Food Webs Detrital food chain: Energy stored in producers flows to detritivores Majority of land ecosystems Small amounts of plant matter get eaten, but far more becomes detritus (ex. Leaves falling from trees in fall) Grazing food chain: Energy stored in producer tissues flows to herbivores Predominate aquatic food chains Zooplankton (primary consumer) consumes most of the primary producer so very little ends up as detritus Food Webs Ecologists use food webs to predict how species will relate to one another On average, each species in a food web is only two links away from another “Everything is linked to everything else.” –Neo Martinez Thus, the extinction of any species in a food web may have an impact on MANY other species Energy Transfer Energy captured by producers passes through NO MORE than five trophic levels, even in complex ecosystems Energy is limited Rule of 10: Only 10% of energy is passed up to the next trophic level Ex. Bears vs. bunnies Energy Transfer Food chains are shorter where conditions vary widely over time Food chains are longer where conditions are stable (ex. Ocean depths) You try it! Draw a food chain. Include: Primary producer Primary consumer Secondary consumer Tertiary consumer Quaternary consumer You food chain should be CREATIVE and NEATLY LABELED Have fun! Exit Slip 8/13 Create a food chain for an aquatic environment. Include AT LEAST four trophic levels. Label each trophic level and tell whether the organism is a PRODUCER or a CONSUMER ENERGY FLOW THROUGH ECOSYSTEMS Chapter 47.3 Bell Ringer, 8/20 Get your EXIT SLIP and ECOSYSTEM DRAWING from the second lab table On your bell ringer sheet, fill in the chart on the white board. Energy Capture and Storage Primary Production: Rate at which producers capture and store energy Gross Primary Production: Amount of energy captured by ALL producers in an ecosystem Net Primary Production: Portion of energy that producers invest in growth and reproduction (rather than maintenance) Energy Capture and Storage If three plants each capture and store 30 joules of energy and invest 20 joules in growth and reproduction… What is their gross primary production? What is their net primary production? Energy Capture and Storage If 10 plants capture 100 joules of energy each and invest 50 joules of energy in maintenance each… What is their gross primary production? What is their net primary production? Energy Capture and Storage Factors that affect primary production: Temperature Availability of water Availability of nutrients Net primary production on land is higher, but there are more oceans so they contribute nearly half of earth’s global net primary productivity Ecological Pyramids Show the trophic structure of an ecosystem Biomass pyramid: Shows the dry weight of all the organisms at each trophic level in an ecosystem Usually primary producers are on bottom (more grass than bears) Exception: Aquatic ecosystems where primary producers reproduce quickly (single-celled protists) Typical Biomass Pyramid Ecological Pyramids Energy pyramid: Shows how the amount of USABLE energy in an ecosystem diminishes as it is transferred through an ecosystem Primary producers on base (capture sunlight) Energy diminishes as you move up the pyramid Pyramids are always “right side up” Ecological Efficiency Factors that influence the efficiency of transfer: Consumers Some Not don’t use all their energy to build biomass energy is lost as heat all biomass can be consumed by consumers Herbivores: Can’t break down ligand and cellulose Hair, feathers, bones, external skeletons, and fur are usually indigestible Ecological Efficiency Aquatic ecosystems usually have higher efficiency than land ecosystems Algae lack ligin Higher proportion of ectotherms Ectotherms: “Cold blooded” animals that get their body heat from external sources Don’t lose as much heat as endotherms (“warm blooded” animals that maintain their body temperature internally) Biological Magnification Process by which a chemical that degrades slowly or not at all becomes increasingly concentrated in tissues of organisms as it moves up a food chain Example: DDT in eagles Let’s Practice! Now you try it! For the ecosystem that you drew on Friday… Make an ecosystem chart Make a biomass pyramid Make an energy pyramid Exit Slip, 8/19 Explain why aquatic ecosystems tend to have higher efficiency than land ecosystems. What is the difference between an energy pyramid and a biomass pyramid? Draw an example of each. BIOGEOCHEMICAL CYCLES Chapter 47.5-.10 Bell Ringer, 8/22 Get out your lab handouts. Find your NEW SEAT. Your name will be written in ORANGE MARKER. Tear off (and throw away!) the old taped name tags. You are free from their tyranny!!! On your bell ringer paper, answer the following questions. Explain the concept of biological magnification. What factors influence the efficiency of energy transfer between trophic levels? Bell Ringer, 8/23 Define each of the following: Precipitation, condensation, transpiration, evaporation Yes, I know you haven’t had these notes yet. Do your best! Introductory Video http://www.youtube.com/watch?v=2D7hZpIYlCA&li st=PLOoWeOpoaCHySa2kVvRQ8DkDbbJLoR0nH& index=11 Watch the video; answer the questions What is a biogeochemical cycle? An essential element moves from one or more nonliving environmental reservoirs, through living organisms, then back to the reservoirs N, O, H, C, P, water all cycle Move into organic components through primary producers Nonliving environmental reserves Rocks and Sediment Atmosphere Living Organisms Seawater and Freshwater The Water Cycle Most of the Earth’s water is held in the oceans Sunlight drives evaporation (conversion of water to vapor) Transpiration: Evaporation from the leaves of plants Cool upper layers of the atmosphere cause water to condense Condensation: Conversion of vapor to liquid Water returns to earth through precipitation Precipitation: Fall of water to earth The Water Cycle Watershed: Area from which all precipitation drains into a specific waterway Can be small (valley feeding a stream) Can be VERY large (Mississippi River Valley, which occupies 41% of the continental US) The Water Cycle Most precipitation falling into a watershed seeps into the ground Aquifers: Permeable rock layers that hold water Groundwater: Water held in soil and aquifers When soil become saturated, water becomes runoff Runoff: Water that flows over the ground into streams The Water Cycle Water Cycle Video Write the following on an index card: Run off Evaporation Condensation Precipitation Hold up the appropriate card in the video http://www.youtube.com/watch?v=FAnDlYRycqs&list=P LOoWeOpoaCHySa2kVvRQ8DkDbbJLoR0nH Bell Ringer, 8/26 Move your groups back so you have more room (but still keep the desks in their groups!) Answer the following question on your bell ringer: Do humans affect the water cycle? Defend your answer. Global Water Crisis Most water is too salty to drink or use for irrigation Of our fresh water, 2/3 goes to irrigation Irrigation can be harmful to soil because of its high salt concentration Salinization: Buildup of mineral salts in soil Stunts growth of plants and decreases yields Global Water Crisis Ground water supplies about 50% of the US’s drinking water Pollution of this water=A BIG PROBLEM Expensive and difficult to clean up Overdrafts: Water withdrawn faster from an aquifer than it can be replaced Salt water moves in and replaces the fresh water Global Water Crisis Desalinization: Removal of salt from seawater May help increase freshwater supplies Requires large amounts of fossil fuels Produces HUGE amounts of salt waste that must be disposed of You Try It! Draw, in beautiful full color, the water cycle! On the back, write out the water cycle The Carbon Cycle The process of carbon moving through the lower atmosphere and all food webs to and from its largest reservoirs The earth’s crust (largest reservoir): 66-100 million gigatons The ocean (HCO3- & CO32-): 38,000-40,000 GT Air (CO2): 766 GT Detritus: 1500-1600 GT Living organisms: 540-610 GT The Carbon Cycle Ocean currents move carbon from upper waters to deep reservoirs enters surface waters and is converted to HCO3 Winds and differences in density drive sea water in a loop from the surface of the Pacific and Atlantic oceans to the Atlantic and Antarctic sea floors HCO3- moves into storage reservoirs before water loops back up Helps dampen any short term effects of increases in atmospheric carbon emmissions CO2 The Carbon Cycle Sea floor reservoirs can be emptied through: Uplifting over geological time Combustion of fossil fuels Reenters the atmosphere as CO2 and either: Reenters the ocean Is fixed through photosynthesis in plants The Carbon Cycle Uplifting over time results in terrestrial rocks storing carbon Normal weathering leads to dissolved carbon in soil water Soil water runs off and deposits carbon in the sea Volcanic eruption releases this carbon to the air The Carbon Cycle Carbon passes through the trophic levels Eventually organism dies and is buried over geological time The carbon forms fossil fuels These fuels are released to the atmosphere through the burning of fossil fuels INSERT CARBON CYCLE PIC Humans and the Carbon Cycle Each year, humans withdraw 4-5 GT of fossil fuels Our activities release 6 GT more carbon than can be moved into the ocean Only 2% of this excess is absorbed Excess carbon traps heat, contributing to global climate change Greenhouse Gases & Climate Change Greenhouse gases: CO2 , water, NO, methane, chloroflurocarbons (CFC) Radiation from the sun heats up earth’s surface Earth releases infrared radiation that tries to escape to space These greenhouse gases trap a portion of this energy then emit it back to earth (Greenhouse Effect) Without this, earth would be too cold to support life Greenhouse Gases & Climate Change CO2 follows the alternating cycle of primary production Decline in summer Rise in winter However, the overall trend is increasing over time CO2 at its highest level since 470,000 years ago Global warming: long-term increase in temp near the Earth’s surface http://www.youtube.com/watch?v=9tkDK2mZlOo&list= PL1A6E2D304D264F58 (Inconvenient Truth) Carbon Collage In your groups, use the magazines to make a collage representing the stages of the carbon cycle Be prepared to defend your picture choices verbally and in writing! Carbon Cycle Frayer Model Complete a Frayer Model of the carbon cycle Exit Slip, 8/27 Draw, in full color glory, the carbon cycle. INCLUDE ALL OF ITS STEPS Can be turned in tomorrow if not finished when you leave Bell Ringer, 8/27 On your bell ringer paper, write a poem (AT LEAST FOUR LINES) about the water cycle. Be creative! Bell Ringer, 8/28 On your bell ringer sheet, list: Five ways that energy flows in your front yard Five ways that water cycles in your front yard Five ways that carbon cycles in your front yard The Nitrogen Cycle Atmosphere is 80% nitrogen Most of this cannot be used by plants Combined by a triple bond Plants don’t have the enzyme to break the triple bond Some is converted to a usable form through lightning strikes and volcanic eruptions The Nitrogen Cycle Most usable nitrogen enters food webs through nitrogen fixation Bacteria and nitrogen-fixing plants break all three bonds in N2 and convert into ammonium (NH3) then ammonium nitrate (NH4+) (nitrogen fixation) These are taken up by plant roots The Nitrogen Cycle Nitrogen moves up through trophic levels then ends up in wastes and remains Ammonification: Bacteria & fungi break apart nitrogen-containing and producing ammonium Some is released into soil and picked up by plants Nitrification: Bacteria convert ammonium to nitrate, which can also be taken up by plants The Nitrogen Cycle Ecosystems lose nitrogen through denitrification Denitrifying bacteria convert nitrate or nitrite to gaseous nitrogen or nitrogen oxide Denitrifying bacteria are typically anaerobes that live in waterlogged soils and aquatic sediments The Nitrogen Cycle Ecosystems lose nitrogen through runoff and leaching Nitrogen-rich runoff enters aquatic ecosystems Leaching: Removal of some nutrients as water trickles down through the soil Humans and the Nitrogen Cycle Deforestation and conversion of grassland to farmland increases nitrogen losses Nitrogen from plant tissues is lost Plant removal increases leaching and erosion Farmers can combat nitrogen depletion by rotating their crops Humans and the Nitrogen Cycle Many farmers use synthetic nitrogen-rich fertilizers Improves crop yields, but changes soil chemistry Adds H ions (as well as N) to the soil Increased acidity causes nutrient ions in soil to be replaced by H ions, while the nutrients (Ca and Mg) are washed away as run off Humans and the Nitrogen Cycle Burning of fossil fuel in cars and factories releases nitrogen oxides Wind carry them away from their sources Nitrogen rain occurs, disrupting the natural balance among competing species and causing diversity to decline Especially pronounce in nitrogen-poor areas (high elevation and high latitudes) Humans and the Nitrogen Cycle Nitrogen runoff disrupts aquatic ecosystems Fertilizers run off into rivers and lakes Nitrogen enters rivers through sewage Promotes algal blooms Now draw it! Now model it! Now write it! Write a first person narrative as a nitrogen molecule Follow your molecule throughout all the steps of the nitrogen cycle Should incorporate appropriate vocabulary Should be entertaining Should be creative Should be AT LEAST one page long Exit Slip, 8/28 Turn in your completed Frayer Model of the nitrogen cycle. Bell Ringer, 8/29 On your bell ringer paper, compare and contrast the nitrogen and carbon cycle. How are they similar? How are they different? The Phosphorus Cycle Earth’s crust is the largest reservoir of phosphorus Phosphates are required building blocks for ATP, phospholipids, nucleic acids, and other compounds Phosphates move quickly through food webs, move back from land to ocean sediments, then slowly back to land again The Phosphorus Cycle Phosphorus in rocks is in the form of phosphate (PO43-) Weathering and erosion release phosphate from rocks Phosphate enters streams and rivers which delivers it to the ocean The Phosphorus Cycle Phosphate accumulates as underwater deposits along edges of continents After millions of years, the crust lifts and deposits phosphate rocks on land These rocks are eroded, starting the cycle over again The Phosphorus Cycle Plants take up dissolved phosphates from soil water Herbivores get phosphates by eating plants Carnivores get phosphates by eating herbivores Animals lost phosphate in urine and feces Bacteria and fungi release phosphate from waste and remains and return them to the soil Plants pick up these phosphates again from the soil The Phosphorus Cycle Of all minerals, phosphorus is most often the limiting factor in plant growth Only newly weathered, young soil has abundant phosphorus Tropical and subtropical ecosystems are low in phosphorus and are likely to be affected by human actions Humans and the Phosphorus Cycle Forests get phosphorus through decaying trees and other organisms If these sources are removed, stored phosphorus is lost Crop yields decline Regrowth remains sparse Spreading finely ground phosphorus rock will repair the soil, but developing countries lack this resource Humans and the Phosphorus Cycle In developed countries, phosphorus from fertilizer runs off into aquatic ecosystems Promotes destructive algal blooms Eutrophication: nutrient enrichment of any ecosystem that is otherwise low on nutrients Humans and the Phosphorus Cycle Algal blooms Nitrogen-fixing bacteria keep nitrogen levels high Phosphorus becomes the limiting factor Phosphorus-rich pollutants cause algae populations to soar then crash Aerobic decomposers break down the dead algae, depleting the water of oxygen that fish and other organisms need to survive Now for a rousing game of musical chairs! Draw it! Model it! Exit Slip, 8/30 Make a chart comparing each of the cycles and energy flow that we have studied. Include:
