Transcript Ecosystems

Ecology
Ecology
• Ecology = the study of interactions of living
organisms with one another and with their
physical environment (soil, water, climate,
etc.)
• Who?  ecologists
• 2 sets of environmental factors
Ecosystem Factors
Biotic Factors
Biotic Factors = factors
in an ecosystem that
are living
Examples:
-Tree
-Rabbit
-Frog
Abiotic Factors
Abiotic Factors =
factors in a ecosystem
that are NONliving
Examples:
-Sun
-Water
-Weather
-Fire
Levels of organization… can you
remember?
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Atom
Molecule
Cell
Tissue
Organ
Organ system
Organism
Population
Community
Ecosystem
Biome
Biosphere
6 Levels of Ecology focus on
organism  biome
1. Organism = one individual
2. Population = 2+ of the same organism
3. Community = All types of living organisms in an
area
4. Ecosystem = All living organisms AND nonliving
factors in an area
5. Biome = group of similar ecosystems
6. Biosphere = all areas on earth where life exists
Habitat
• Habitat = a place where a particular
population lives
What might you find if you turn over a
log?
• Are all of these things competing for the same
food?
• Each population feeds in different ways, on
different materials, and at different times 
this leads to reduced competition
Niche
• Niche = all strategies and adaptations a
species uses in its environment
– How it meets its specific needs for food and
shelter
– How and where it survives
– Where it reproduces
Kind of like an organism’s “job”
Niche
• All strategies and adaptations a species uses in
its environment
• How it meets:
– its food needs
– Its shelter needs
– How and where it survives
– Where it reproduces
– Includes all interactions with biotic and abiotic
factors
Quick Project…
• Find 4 examples of Abiotic Factors
– List pictures of EACH!
• Find 4 examples of Biotic Factors
– List pictures of EACH!
• Define Abiotic Factor
• Define Biotic Factor
• Submit to FUSION when complete, but show Ms.
C before submitting!
Abiotic Factors = nonliving things
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Soil and rocks
Weather
Water/rain
temperature
Biotic Factors = Living things
•
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Plants
Fox
You!
Fungi
Bacteria
Protists
Interactions in Ecosystems
• Competition
• Predator/Prey
• Symbiosis
What is competition?
• Competition = when
organisms compete or
fight over a limited
resource
• Competition can be
reduced by organisms
having different niches
in an ecosystem
Predator/Prey Interactions
• Predator = organism that hunts other
organisms for food
• Prey = organisms that are hunted
• Populations of directly impact each other!
Density Dependent Factors
• Density Dependent Factors = factors in the
ecosystem that can change as a result of the
population density (# of organism in an area)
• Examples:
– Food
– Shelter
– Water
– Disease
Not all interactions among organisms
involve eating each other…
• Symbiosis = organisms living together
• 3 Types of symbiotic relationships
– Mutualism
– Commensalism
– Parasitism
Mutualism
• Mutualism = benefits both organisms in
relationship
Commensalism
• Commensalism = one organism benefits and
the other is unaffected
Parasitism
• Parasitism = one organism benefits and the
other is harmed
– PARASITES (like viruses) don’t immediately kill
host… use it first – sometimes kill it later!
What do all living things need?
All living things must have energy in
order to maintain homeostasis
• Where does ALL energy orginate?
• #1 source of energy = SUN
• Energy flow is a “one way” street
Can you get energy from the sun?
• What organisms can use the sun’s energy for
food?
– Autotrophs!
• Autotroph = organisms that can make their
own food (usually from sun or chemicals in
environment)
– Examples: plants, algae, photosynthetic bacteria,
chemotrophs
• AKA: producers
What are organisms called that can’t
make their own food?
• Heterotrophs = organisms that must “eat”
their food to get energy
• Examples: protists, fungi, animals, you!
• AKA : consumers
How is the flow of energy shown?
• Energy flow is shown with a food chain or
food web.
Types of Heterotrophs
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Herbivore
Carnivore
Omnivore
Scavenger
Decomposer
Herbivore
• Herbivore =
organism that only
eats plants
Carnivore
• Carnivore = organism that eats meat/other
animals
Omnivore
• Omnivore = organism that survives by eating
both plants and animals
Scavengers
• Scavenger = organisms that eat dead material
Decomposer
• Decomposer = organisms that break down
organic matter
How is the flow of energy shown?
• Energy flow is shown with a food chain or
food web.
Food Chain vs. Food Web
• What do you think the difference(s) might be?
Food Chain
Food Web
Chemical Cycles
What are nutrients?
• If nutrients are made
of matter, can we
create or destroy
nutrients?
• Matter (and
nutrients) cannot be
created nor
destroyed!
Of what substance are all living things
made?
• Carbon… and other nutrients!
• Nutrients = substances (elements/compounds)
that are needed for life
How are nutrients cycled through
ecosystems?
• Nutrients cycle between living and nonliving
factors in the environment
• Matter is constantly recycled… never lost!
• What kinds of nutrients/chemicals are cycled
in ecosystems?
The Water Cycle
What is the water cycle?
• Water cycle = the continuous movement of
water from Earth’s surface to the atmosphere
and back
• What powers the water cycle?
• Powered by the SUN which causes
evaporation
Water Cycle Terms
• Evaporation = water  water vapor (gas) in
atmosphere
• Condensation = water vapor in atmosphere 
water droplets (clouds)
• Precipitation = condensed water falling from
atmosphere to ground (rain, snow, sleet, hail)
The Water Cycle
Water Cycle Terms
• Transpiration = water in
plants (from ground) 
water vapor in
atmosphere
• Runoff = water on
surface moving
• Infiltration = water on
surface soaking into
soil/ground becoming
groundwater
The Water Cycle
Human Impacts: Water Cycle
• Water pollution
• Deforestation can
lead to increased
erosion
What processes have we learned
about that involve carbon?
• Carbon Cycle = the movement of carbon from
living things into the atmosphere and back
• Involves: plants, animals, and atmosphere
Carbon Cycle
• All living things are made of carbon
• Where can you find carbon on earth?
• How does it move/cycle around?
Carbon Cycle
Carbon Cycle Terms
• Photosynthesis = carbon (CO2) in air 
carbon in plants (glucose, C6H12O6) + oxygen
• Respiration = cells take in oxygen + glucose 
CO2 + H2O
• Eating = organisms use carbon in food to grow
more cells in their own bodies
=
Carbon Cycle Terms
• Atmospheric CO2 = carbon dioxide in
atmosphere (comes from fuel combustion,
burning, respiration)
• Dissolved CO2 = carbon dioxide in bodies of
water (comes from respiration of bacteria and
fish)
Do fish “breath” water?
Carbon Cycle Terms
• Fuel combustion = burning fossil fuels
• Fossil fuels = hydrocarbons that form from life
forms millions of years ago (petroleum,
natural gas, oil shale, tar sands)
• Does all carbon cycle at the same rate?
• What kind of carbon cycles faster?
• What kind of carbon cycles slower?
Closed Carbon Cycle
•Closed carbon cycle =
carbon burned originated
in atmosphere and can
be replaced within a
human lifetime
•Example: burning wood,
biofuel
•Cellulose  ethanol
•Biodiesel
•Wood chips
•Torrification/gassification
Open Carbon Cycle
• Open carbon
cycle = carbon
burned cannot
be replaced
within a human
lifetime
– Example:
burning fossil
fuels
• Even though the carbon is still being cycled,
why does it make sense that this is called an
“open” cycle?
Nitrogen Cycle
• Where do you use nitrogen?
• 78% of the air in the atmosphere is made up
of nitrogen
• Why do we have to give plants nitrogen in
fertilizer?
• Nitrogen must be converted to a USABLE
form!
Nitrogen Cycle
Nitrogen Cycle Terms
• Nitrogen fixer = plant that converts nitrogen
from the atmosphere into nitrogen in the soil
(usable form) for other plants to use
• Urea = nitrogenous waste released from
animals in urine; puts nitrogen back in soil
Phosphorous: Short Term or Long Term
Phosphorus Cycle: Short Term
– Animals eat phosphorous
 animals die 
phosphorus returns to soil
 plants absorb
phosphorous
Phosphorus Cycle:
Long Term
Phosphates
are washed
into water
 become
sedimentary rock
covered for
millions of
years
 rock is reexposed
 rock erodes
phosphates
are put
back into
ecosystem
Life in a community
• How do plants and animals survive where they
live?
• Various combinations of abiotic and biotic
factors interact around the world.
• What does this mean about the different
communities around the world?
Limiting Factor
• Limiting Factor = any biotic or abiotic factor
that restricts the existence, numbers,
reproduction, or distribution of organisms
• Examples: availability of water/food,
predators, temperature
What is the limiting factor?
Food Production in Saltbush (Altriplex)
16
Food production (mg of glucose)
14
12
10
Temperature
and Food
Production
8
6
4
2
0
0
5
10
15
20
25
30
35
40
Temperature (C)
Can you name the Independent variable?
Dependent Variable?
45
50
Can factors indirectly affect
populations?
• Lack of rain prevents grass from producing
seeds
• Can this indirectly affect another population
(other than just the grass?)
Ranges of tolerance
• What does corn need to survive?
• What if corn is grown in the shade… what will
this do to the crop?
• Tolerance = the ability of an organism to
withstand fluctuations in biotic and abiotic
environmental factors
Food production (mg of glucose)
What is the range of tolerance?
Food Production in Saltbush (Altriplex)
16
14
12
10
Temperatu
re and
Food
Production
8
6
4
2
0
0
5
10
15
20
25
30
Temperature (C)
35
40
45
50
Succession: Changes Over Time
• If you stopped cutting the grass in your front
yard, what would happen?
• In 1 year?
• 5 years?
• 90 years?
Succession
• Ecological Succession = the orderly, natural
changes and species replacements that take
place in the communities of an ecosystem
• Occurs in stages
• Each stage has different plants and animals
• Conditions of each stage are suitable for some
organisms but not others
Succession
• Can you observe succession?
• Can take decades or even centuries to observe
• 2 types of succession:
– Primary succession
– Secondary succession
Primary Succession
• How are islands formed?
• Do islands have dirt?
• Primary succession = the colonization of
barren land by communities of organisms
• Land must have: No living organisms
– Example: island forming/land after lava flow
• Pioneer species = first species to take hold in
an area
– Example: lichen
Lichen on a rock
• What happens to the pioneer species (lichen,
moss) over time?
• Decaying lichen and sediment develop soil
• Soil  small plants
• Small plants die more soil  bigger plants
• Over time the primary succession slows down
and the community becomes stable
Ecological Succession
Climax Community
• Climax community = stable, mature
community that undergoes little or no change
in species
• May last for 100’s of years
• *** If its stable, does it still change?***
• YES!
• … but the changes are balanced!
Secondary Succession
• What if there’s a fire that destroys a
community?
• What if a field isn’t replanted
• What if a building is demolished and nothing
is built on the site?
Secondary Succession
• Secondary succession = the sequence of
changes that takes place after an existing
community is severely disrupted in some way
• What are some possible disruptions?
http://www.youtube.com/watch?v=qIxyUcb2wqI
Secondary Succession
• What does secondary succession have that
primary does not?
• SOIL!
• Will the species be the same?
• Will secondary succession still reach climax
community status?
• Which will get there faster? (primary or
secondary?)
This graph below represents primary and secondary
succession over time. Notice that neither series is
labeled for you…
High
Species
Biodiversity
Series 2
Series 1
Low
Time -->
Which line represents primary succession? Secondary
succession? Explain.
High
Species
Biodiversity
Series 2
Series 1
Low
Time -->
Where is the climax community?
High
Species
Biodiversity
Series 2
Series 1
Low
Time -->
What does the sudden drop in series 1
represent?
High
Species
Biodiversity
Series 2
Series 1
Low
Time -->