Download Ecosystems

Ecosystems: What Are They and
How Do They Work?
Part 1
Intro to Ecology
Cell Theory
1. All living things are
composed of cells.
2. Cells are the basic
units of structure and
function in living
things.
3. All cells are produced
from other cells.
Prokaryotes and Eukaryotes
Pro Karyote
Eu Karyote
Before the
nucleus
After the nucleus
Structure of a Eukaryotic Call and a
Prokaryotic Cell
Your Turn!
 Atoms to Universe
Ecologists Study Connections in Nature
 Ecology - study of how organisms
interact with one another and with their
physical environment of matter and
energy.
Levels of Organization of Life

Organism- a living thing

Population- a group of organisms of
the same species that live in a
particular area

Community- populations of
different species that live in one
particular area
Levels of Organization of Life

Ecosystem- all of the
biotic and abiotic
factors in one
particular area
•
Biotic- living things
•
•
Ex: seaweed, fish, etc.
Abiotic- non-living
things
•
Ex: water temperature,
pH, salinity
Major Biotic and Abiotic Components
of an Ecosystem
How many different organisms are there on
Earth?
Almost 2 million!
•Tremendous diversity
•Scientists estimate between
10 and 14 million species yet
to be discovered
Most are Bugs! Have You Thanked
the Insects Today?
 Pollinators
 Population Control
 Loosen and renew soil
 Reproduce rapidly
 Very resistant to extinction
Habitat vs. Niche
 Habitat – place where an organism lives
• Organisms address
 Niche – role of an organism in an ecosystem
(physical, chemical, and biological conditions that a
species needs to live and reproduce)
• Organisms occupation
 Thousands of organisms can occupy the same
habitat but each organism has its own niche.
Habitat vs. Niche
Niche Video Clip
Core Case Study: Tropical Rain Forests Are
Disappearing
 Cover about 2% of the earth’s land surface
 Contain about 50% of the world’s known plant and
animal species
 Disruption will have three major harmful effects
1. Reduce biodiversity
2. Accelerate global warming
3. Change regional weather patterns
Natural Capital Degradation: Satellite Image
of the Loss of Tropical Rain Forest
Planet Earth Video Clip
 Jungles
• 00:00 – 18:00
 Fill out Atoms  Universe
Worksheet as you watch!
• 5 examples of habitat vs.
niche
Ecosystems: What Are They and
How Do They Work?
Part 2
Life Support Systems
The Earth’s Life-Support System Has Four
Major Components
 Hydrosphere – all the water on or near the Earth’s
surface
• Liquid water
• Ice
• Water vapor
 Geosphere – Earth’s interior; contains
nonrenewable fossil fuels
• Core
• Mantle
• Outer Crust
Natural Capital: General Structure
of the Earth
 Biosphere – parts of
atmosphere, biosphere,
hydrosphere, and
geosphere occupied by
life
• 6 miles above Earth’s
surface to the bottom of
the ocean
If the world were an apple…
 The biosphere would be no thicker than the apple’s
skin!
The Earth’s Life-Support System Has Four
Major Components
 Atmosphere – gasses
surrounding the Earth’s
surface
• Troposphere – inner layer;
11 miles
• Air we breathe:
• 78% Nitrogen
• 21% Oxygen
• 1% water vapor,
carbon dioxide, and
methane
The Earth’s Life-Support System Has Four
Major Components
 Atmosphere – gasses
surrounding the Earth’s
surface
• Stratosphere – outer
layer; 11-31 miles
• Contains ozone layer to
filter sun’s harmful rays
What Happens to Solar Energy Reaching
the Earth?
 Radiation – UV, visible
light, and IR energy
• 95% Absorbed by ozone
• 1% Absorbed by the earth
• Reflected by the earth as
longer IR wavelengths
• Hit greenhouse gases,
vibrate, and release
longer wavelengths
• Radiated by the
atmosphere as heat
Greenhouse Effect
 Greenhouse gasses vibrate
from excess heat and gain
kinetic energy
• Warms atmosphere
• Positive feedback loop
 Without greenhouse gases
the world would be a cold
uninhabitable place
The Greenhouse Effect
Video Clip
 Green House Effect – Lesson 1
Ecosystems: What Are They and
How Do They Work?
Part 3
Energy Transfer
The Main Structural Components
of an Ecosystem
How Organisms get Energy

Autotroph- an
organism that makes
its own food
•
Ex: photosynthetic
plants,
chemosynthetic
bacteria
 Heterotroph- an
organism that cannot
make its own food
• Ex: humans
Predator or Prey?
 Predation – act of one
organism eating
another organism
• Predator – organism
that does the eating
• Prey – organism that
gets eaten
Energy Roles: Producers

Producersorganisms that can
make their own food
•
Examples: plants,
algae, some bacteria,
some protists
Energy Roles: Consumers

Consumers- organisms
that cannot make their
own food; they are
classified based on what
they eat

Herbivore- organisms
that eat producers
(plants)
•
Examples: cows, deer,
grasshoppers
Energy Roles: Consumers

Carnivore- organisms
that eat only meat
• Examples: wolves,
killer whales
Energy Roles: Consumers

Omnivore- organisms
that eat both meat and
vegetation
• Examples: humans,
seal, chimps
Energy Roles: Consumers

Scavenger- organisms
that eat things that are
already dead
• Examples: seagulls,
vultures
Energy Roles: Decomposers

Decomposers - organisms that break down dead
organisms and waste and return those nutrients to
the ecosystem
- Examples: bacteria, fungus

Anaerobic Respiration: byproducts are methane
gases, ethyl alcohol, acetic acid, and hydrogen
sulfide
Detritivores and Decomposers on a Log
A Food Chain
Food Chains and Webs
 Food chains- show the flow of energy throughout
organisms in a community or ecosystem
• First organism is always a producer
• Second organism is an herbivore
• Third organism is a carnivore
Simplified Food Web in the Antarctic
Ecological Efficiency
 When the deer eats the
grass, it does not obtain all
of the energy the grass has
• Much of it is not eaten
 When the wolf eats the
deer, it does not get all of
the energy from the deer
• Much of it is lost as heat
Ecological Efficiency
 No organism EVER receives
all of the energy from the
organism it just ate
 10% Law
• Only 10% of the energy from
one trophic level is
transferred to the next
Energy Pyramids

Energy pyramids- shows the relationship between
consumers and producers at different trophic levels in an
ecosystem
45
Energy Pyramids
• Most energy is available at the bottom of
the pyramid
46
Energy Pyramids
•
As you move up the pyramid, each level has less
energy available than the level below it
47
Tertiary
consumers
(human)
Usable energy available
at each trophic level
(in kilocalories)
Secondary
consumers
(perch)
Primary
consumers
(zooplankton)
10
Heat
100
Heat
1,000
Heat
10,000
Producers
(phytoplankton)
Heat
Decomposers
Heat
Video Clip
• http://magma.nationalgeographic.com/ngexp
lorer/0309/quickflicks/index.html
49
Your Turn!
• Activity: Food Chains and Webs
Some Ecosystems Produce Plant Matter
Faster Than Others Do
 Gross primary productivity (GPP)
• Rate at which an ecosystem’s producers convert
solar energy into chemical energy stored in their
tissues
 Net primary productivity (NPP)
• Rate they create and store energy minus the energy
they use for homeostasis
• Ecosystems and life zones differ in their NPP
Estimated Annual Average NPP in Major Life
Zones and Ecosystems
Humans and NPP
 Humans use, waste or destroy 20-32% of the earth’s
total potential NPP
• They make up less than 1% of the Earth’s biomass!
Planet Earth Video Clip
 Jungles
• 20:00-25:00
 Find an example of:
•
•
•
•
•
Producer
Consumer (various)
Decomposer
Predator/Prey
Food Chain – 3 levels
Ecosystems: What Are They and
How Do They Work?
Part 4
Range of Tolerance
Range of Tolerance for a Population
of Organisms
 Range of tolerance may vary in populations
• Small differences in genetic makeup, health, and age
Several Abiotic Factors Can Limit Population
Growth
 Limiting factor principle
• Too much or too little of any abiotic factor can
limit or prevent growth of a population, even if all
other factors are at or near the optimal range of
tolerance
Strange Days on Planet Earth Video Clip
 One Degree Factor
• 4:00 – 20:00
Ecosystems: What Are They and
How Do They Work?
Part 5
Nutrient Systems
Recycling in the Biosphere
 Energy and matter move through the biosphere very
differently.
• One-way flow of energy
• Matter is recycled within and between ecosystems
Reservoirs
 Temporary storage
sites
• Atmosphere
• Oceans, lakes, rivers,
and ponds
• Underground deposits
Nutrients Cycle in the Biosphere
 Biogeochemical cycles, nutrient cycles
•
•
•
•
•
Hydrologic
Nitrogen
Carbon
Phosphorus
Sulfur
 Connect past, present, and future forms of life
Your Turn!
 Cartoon Guide to the
Environment
• Questions 1-6
Water Cycles through the Biosphere
 Natural renewal of
water quality: three
major processes
•
•
•
•
Evaporation
Precipitation
Transpiration
Runoff
 Fueled by energy from
the sun
Hydrologic Cycle Including Harmful Impacts
of Human Activities
Alteration of the hydrologic cycle by humans
 Withdrawal of large
amounts of freshwater
at rates faster than
nature can replace it
 Clearing vegetation
• Increases temperature
and thus evaporation
 Increased flooding
when wetlands are
drained
Water Pollution
 Pavement prevents soil
from absorbing water
• Increases runoff and
erosion
 Only 0.024% of water is
accessible liquid
freshwater
• Groundwater deposits
• Lakes, river, streams
Science Focus: Water’s Unique Properties
 Properties of water due to hydrogen bonds
between water molecules:
•
•
•
•
•
•
•
Exists as a liquid over a large range of temperature
Changes temperature slowly
High boiling point: 100˚C
Adhesion and cohesion
Expands as it freezes
Solvent
Filters out harmful UV
Water Cycle Video Clip
Your Turn!
 Cartoon Guide to the
Environment
• Pages 7-9
Phosphorous Cycle
 Phosphorus
• Helps form important molecules like DNA, RNA, and
ATP
 Inorganic phosphate PO43- is released into the soil
and water as sediments wear down.
• Eventually enters the ocean, where it is used by
marine organisms
• Does NOT include the atmosphere
Phosphate Cycle
• Organic phosphate
moves through the
food web and to the
rest of the ecosystem.
Organisms
Land
Ocean
Sediments
Phosphorus Cycle with Major Harmful Human
Impacts
Phosphorus Cycle Video Clip
Your Turn!
 Cartoon Guide to the
Environment
• Page 23
• Question 11
Carbon Cycle
 Carbon dioxide in atmosphere is taken in by
plants
 CO2 is also given off by animals, decomposers,
plants and burning fuels
 Composes 0.038% of the volume of the
atmosphere
Carbon Cycle Depends on Photosynthesis and
Respiration
 Link between photosynthesis in producers and
respiration in producers, consumers, and
decomposers
 Additional CO2 added to the atmosphere
• Tree clearing
• Burning of fossil fuels
Carbon Cycle Equations
Cellular Respiration
C6H12O6 + 6O2  6CO2 + 6H2O +ATP
Photosynthesis
6CO2 + 6H2O sunlight C6H12O6 + 6O2
Carbon Cycle
 Marine sediments are
earth’s largest store of
carbon
• Carbon is trapped
between layers of
sediment
• Converted to fossil fuels
when heated and
compressed
Carbon Cycle
 When living things die
and decompose, their
remains may someday
become fossil fuels
• Coal, oil, or natural gas
• Burned to release CO2
Greenhouse Effect
 CO2 in the atmosphere
absorbs and retains
heat
• An overload of CO2 now
exists from burning
fossil fuels
 Component of Earth’s
thermostat
• Too much or too little
causes major problems
Natural Capital: Carbon Cycle with Major Harmful
Impacts of Human Activities
Carbon Cycle Video Clip
Your Turn!
 Cartoon Guide to the
Environment
• Page 22
• Questions 9 + 10
 Carbon Cycle Game
Sulfur Cycles through the Biosphere
 Sulfur found in organisms, ocean sediments, soil,
rocks, and fossil fuels
 Sulfate SO4 2- in the atmosphere
• Sea spray, forest fires, dust storms
 H2S and SO2 released during volcanic eruptions
(toxic)
Sulfur Cycle
 Marine Algae produce dimethyl sulfide (DMS)
• Involved in condensation of water (clouds)
 DMS is converted to SO2 and SO3 and tiny droplets
of sulfuric acid H2 SO4 (acid deposition)
 Absence of Oxygen?
• Bacteria convert sulfate ions into sulfide ions S2• React with metal ions and deposited as rock
Sulfur Cycles through the Biosphere
 Human activities add SO2  sulfuric acid and sulfate
• Burn sulfur-containing coal and oil
• Refine sulfur-containing petroleum to make gasoline
and other heating products
• Convert sulfur-containing metallic mineral ores
• Copper lead and zinc
Natural Capital: Sulfur Cycle with Major
Harmful Impacts of Human Activities
Your Turn!
 Cartoon Guide to the
Environment
• Question 12
Nitrogen
 Essential element
 Needed for amino acids
• Proteins!
 Nitrogen gas makes up
78% of the volume of
the atmosphere
Nitrogen Fixation
 Nitrogen gas cannot be
used by living things
directly
• Converted by lightening
 Bacteria in soil and
ocean convert nitrogen
gas into ammonium
(NH4+) and ammonia
(NH3)
• Fixation
Nitrogen Fixation
 (NH4+) and (NH3)
converted to nitrate
ions
• Nitrification
Assimilation
 Used by plants to
produce amino acids,
proteins, nucleic acids,
and vitamins
• Assimilation
Nitrogen Cycle
 Plants take in ammonia, ammonium, and nitrates
through roots
 Animals get nitrogen by eating plants or other
animals that ate plants
Nitrogen Cycle
 When the animal dies and decomposes the nitrogen
is returned to the soil as ammonia
• Ammonification
 Plants take in the ammonia from the soil
Returning Nitrogen
 Specialized bacteria in soil and bottom of lakes
convert NH3 and NH4+ back into nitrates
• Denitrification
 Nitrates are converted to nitrogen gas and returned
to the atmosphere
Human intervention in the nitrogen cycle
• Additional NO and N2O
• Burning fuels at high
temperatures
• Destruction of forest,
grasslands, and
wetlands
• Add excess nitrates to
bodies of water
• Runoff
• Remove nitrogen from
topsoil
• Harvesting nitrogen rich
crops and irrigation
Annual Increase in Atmospheric N2 Due to
Human Activities
Nitrogen Cycle in a Terrestrial Ecosystem
with Major Harmful Human Impacts
Nitrogen Cycle Video Clip
Your Turn!
 Cartoon Guide to the
Environment
• Page 21
• Questions 7 + 8
Strange Days on Planet Earth Video Clip
 Troubled Waters
 Crown of Thorns and
Nitrogen Fertilizers