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 the difference between a
hypothesis and a guess.
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 ProducersCommon 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 againhttp://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
All organisms in a trophic level arethe same number of transfers away from the energy input into that system
Same trophic level
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 ECOSYSTEMSChapter 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 StorageIf 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 StorageIf 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 don’t use all their energy to
build biomass Some energy is lost as heat
Not 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 CYCLESChapter 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&list=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
Atmosphere
Rocks and
Sediment
Seawater and
Freshwater
Living Organis
ms
Nonliving environmental reserves
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=FAnDlYR
ycqs&list=PLOoWeOpoaCHySa2kVvRQ8DkDbbJLoR0nH
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 CO2 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
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:
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