energy

advertisement
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
captureliving componentsphysical
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!




AcornSquirrelHawk
GrassBunnyFoxBear
FlowerSheepWolfLionFungi
Star flowersFairiesUnicornsUnicorn 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:
Download