Ecology is the study of interactions in our environment

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Characteristics of Life
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1. All organisms are made of cells

• Cells are the smallest unit of life

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2. All organisms need energy

• Any living organism needs energy to live
• They take in and use energy.

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3. All organisms respond to the environment

• What happens to an organism depends on the
  environment they are living in.

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4. All organisms reproduce

• Living organisms can make more of themselves
• Two types
• asexual
• sexual.

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5. All organisms grow and develop

• Get bigger as they get older.

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6. All organisms carry DNA

• Carry their own genetic code
• Traits are passed to offspring

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7. Internal Balance (Homeostasis)

• Living things maintain stable internal conditions
• Examples
• Temperature
• Water Balance
• Heart Beat

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Is It Alive?
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ECOLOGY

• Key Knowledge
• Matter cycles, energy flows
• Abiotic factors cause changes in biotic factors
  in a ecosystem

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Ecosystem Structure
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Abiotic Non-living parts of the environment

• Soil
• Sunlight
• Climate
• Temperature
• Rainfall
• Nutrients

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Biotic living parts of the environment

• Plant
• Animals
• Decomposers (Bacteria and
  Fungus)

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General Organization

• Organism any individual living thing
• Population Individual organisms of a single
  species in one area.
• Community more than one population living in the
  same area.

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Different species of fish
Different species of corals (animals)
Starfish (animal)
Example of a Community
Algae (microscopic plants)
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General Organization

• Ecosystem All the populations and abiotic
  factors in an area.
• Habitat the environment that a particular
  species prefers within an ecosystem
• Niche the role that an organism fills job
• Biomes Ecosystems with similar characteristics.

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Characteristics of a Biome

• No distinct boundaries
• Defined by types of plants
• Similar climate conditions, but may be located in
  a totally different part of the world (Africa and
  Asia)
• Classification of biomes
• land biomes
• water biomes (marine or freshwater)

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Can make their own food through energy from the
sun or inorganic substances AKA Primary Producer
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Heterotroph
Other
Feeding
Obtains energy by eating other organisms, AKA
Consumers
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Types of Consumers Primary consumers eat
producers (herbivores) Secondary consumers eats
both producers consumers (omnivores) Tertiary
consumers top predator (carnivore)
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• Trophic levels are a way of identifying what
  kinds of food an organism uses.
• 1st trophic level primary producers
• 2nd trophic level primary consumers
• 3rd trophic level secondary consumers
• 4th trophic level tertiary
• consumer

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Decomposers Scavengers

• Decomposers feed on wastes dead material from
  all trophic levels
• Ex bacteria, fungi
• Scavengers are consumers that eat dead animals
  (like road kill)
• Ex vulture

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Energy in an ecosystem is transferred (cycles)
through the trophic levels of that ecosystem
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Biomass and Energy Transfer
Biomass- total mass of living material in an
area Biomass and energy transfers at the lowest
trophic levels determines the carrying capacity
of each ecosystem 1 hawk 10 snakes 100 mice
feed 1000 plants feed Rule of 10- Only 10
of the energy is transferred to the next
organism.
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Very few animals feed on only one food source,
food webs are a more accurate picture of how
animals feed.
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Biological Magnification

• The build-up of toxins in living organisms with
  movement up the trophic levels .
• The toxins collect in organisms at the top of
  food web because top consumers eat so much.
• Examples

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DDT Dichlorodiphenyltrichloroethane

• Developed during WWII as a pesticide
• Very high levels of DDT were found in top
  consumers.
• DDT is stored in fat.
• Organisms died or had reproductive problems
• Banned in US and Canada during the 70s.
• Still found in almost all living things
• Developing countries are still use DDT

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Methyl Mercury ( Fish)
Current Chemicals of Concern
Dioxin (plastic)
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Community Interactions
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Community Interactions

• In order to sustain an environment, organisms and
  abiotic factors interact
• EXAMPLES
• Symbiosis
• Succession

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Forms of Species Interaction
Symbiosis relationships between two species (3
types)
1. Parasitism one organism benefits at
anothers expense (humans and tape worm)
2. Commensalism one organism benefits while
the other is unaffected (anemone and clown
fish)
3. Mutualism both organisms benefit from the
interaction (rhino and bird)
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Forms of Species Interaction Continued
Competition two species are fighting for the
same resources
Predation one species hunts the other
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Ecological succession change in the types of
species in a community observed over time
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Why does succession happen?

• Communities environments change over time

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1) Primary Succession

• When communities form in new areas
• Ex volcanoes, rocks, etc

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Steps of Primary Succession

• Pioneer species appear ? lichens
• (grow on rock turn it into soil)
• Pioneer Species the first organisms
  to occupy an area
• Grass small plants appear
• Weeds shrubs
• Shallow trees (ex pine trees)
• Climax community ? stable final stage (ex
  deciduous trees)

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2) Secondary Succession

• Occurs in areas that were cleared by disturbance
  (fire, tornado, floods, etc)
• faster than primary (soil already formed)
• Same as primary except pioneer species are
  grasses instead of lichens

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Climax Community
A community that has achieved stability and
species diversity
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Succession leads to..
Population Growth
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FACTORS THAT AFFECT POPULATION GROWTH

1. Birth Rate
2. Death Rate
3. Immigration (movement into an area)
4. Emigration (Movement, exiting an area)

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TYPES OF POPULATION GROWTH
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Exponential Growth

• J-shaped curve on a graph
• Population doubles every generation
• Humans are reproducing this way!

Humans - Trouble ahead?
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Logistic Growth

• Sshaped curve on graph
• How real growth looks
• Populations grow fast early, then slow down, as
  we get closer to CARRYING CAPACITY

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• Biomass
• and
• energy transfer
• at the lowest
• trophic level determines the carrying capacity of
  the ecosystem.

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Carrying Capacity

• Maximum of individuals a population can support
• Populations will increase to carrying capacity,
  and they decrease again once they have reached
  it.

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Limits to Pop. Growth

• 1. Density-dependent limiting factors - reduce
  population growth depends on current population
  size
• Affect crowded populations
• Disease
• Competition (for shelter, food, water)
• Predation (predator eats prey)

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How might the bubonic plague have been different
if the medieval populations didnt live so close
to each other?
Think about it
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• 2. Density-independent limiting factors
  environmental factors affecting a population
  regardless of size
• Affect all populations (crowded or not)
• Weather
• Natural disasters (fire, etc)
• Human activities

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Would the physical effects of hurricane Katrina
be any different in a town of 100, then in a town
of 100,000?
Think about it
New Orleans, LA
Gulf Port , MS
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Matter Cycles!
AKA Nutrient Cycles

• All matter essential for life moves in cycles
  between living things the environment
• Examples of cycles
• carbon cycle
• water cycle
• nitrogen cycle

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Carbon Cycle

• Why is carbon important to us?
• 1) Carbon is used to make hair, muscle, skin
• 2) Carbon stores energy so living things can
  think, move, etc
• 3) Fossil fuels (gas, coal, oil) are made from
  carbon

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Where is carbon found in the environment?

1. atmospheric gas (CO2)
2. rocks (limestone, diamonds)
3. fossil fuels (oil, coal, etc.)

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How does carbon enter living things?

• 1) CO2 gas enters plants
• 2) Photosynthesis allows plants to change CO2
  into a sugar
• 3) Animals then get carbon by eating the sugar
  found in plants

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How does carbon get back into the environment?

• 1. Plants animals release CO2 during
  respiration
• 2. Burning of wood fossil fuels
• 3. Using electricity, (most power plants use
  fossil fuels)
• 4. Cow farts (seriously)
• 5. Decomposition when bacteria and fungus break
  down tissue of dead things

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How are fossil fuels formed?

1. When living things die fall to the bottom of
   water, they are buried compressed 
2. They eventually form coal, petroleum, or natural
   gas

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So whats the cycle?

• the 2 main steps are photosynthesis respiration!

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The Carbon Cycle

• The movement of carbon through the environment
• 2 major driving forces
• Photosynthesis- plants and algae take up CO2
  from the air or water to make sugar
• Cellular Respiration- consumers use sugar for
  energy and release CO2 into the air or water

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Future Predictions

• Due to humans using more fossil fuels, more CO2
  is released each year
• this may result in global warming since CO2 traps
  heat (remember the greenhouse effect)

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What is global warming?
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Facts about Nitrogen

• 78 of air is nitrogen gas (N2)
• Living things cant use nitrogen when its a gas
  (N2)

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Why do living things need Nitrogen?

• To make amino acids proteins
• To make DNA

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The Nitrogen Cycle

• Step 1
• Nitrogen gas (N2) is found in the atmosphere

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Step 2

• Nitrogen Fixation Bacteria living at the
  roots change the N2 gas into a usable form like
  ammonia or nitrates
• Lightning also fixes nitrogen

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• Step 3
• Plants then use the ammonia or nitrates in the
  soil
• Step 4
• Animals get nitrogen from plants by eating them

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Step 5

• When plants animals die, the nitrogen in
  them is released back into the atmosphere as a
  gas (N2)
• This is done by denitrifying bacteria
• Step 6
• Nitrogen gas is released back into the atmosphere

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What are the two process that are responsible
for cycling Carbon in the environment?What
things add carbon?Which things take it away?

• Photosynthesis and Cellular Respiration
• Photosynthesis take it away
• Cellular Respiration, Fossil Fuels and Decaying
  organisms add it.

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Breaking the Water Cycle

• The only way for water to get back to the
  atmosphere is through transpiration (plant
  sweating)
• When we cut down trees they no longer transpire
• So water does not get into the air to become rain
• The area becomes a desert in a very short time
  period
• Really bad in rainforest regions, because the
  soil is so shallow

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HUMAN IMPACT

• A Sad True Story

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Invasive Species

• A species that is brought by HUMANS into a new
  environment and outcompetes the ones already
  there.
• They have no competitors, no diseases so they
  outgrow other populations

Example Africanized honey bees, which will take
over the hive of the honey bees.
Example Zebra mussels attach to boats and cover
piers within months
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Keystone Species

• A species that plays a key role in the ecosystem
• Increases biodiversity by keeping the number of
  each species in balance
• Examples
• Sea otter in the kelp forests
• Beavers in rivers

Beaver
Sea Otter
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An Ecological Mystery

• Long term study of sea otter population along the
  Alaskan and Aleutian Islands
• 1970 Sea Otters healthy and populations growing
• 1990 Sea Otter s declining
• Maybe due to emigration, not deaths
• 1993 800 km area in Aleutian Islands studied
• Sea Otter s reduced by 50

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Vanishing Sea Otters

• 1997 Study of area repeated
• Sea Otter pop. had declined by 90
• 1970 gt 53,000 Otters in the study area
• 2012 lt 2800
• Why?
• Reproductive issues
• Starvation, pollution, disease?

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Cause of the Decline

• 1991 one researcher observed an orca whale
  (killer whale) eating a sea otter.
• Sea lions or seals are the normal prey of orcas.
• Decline in usual prey led to feeding shift.
• Single orca could consume 1,825 otters/year.
• Clam Lagoon (CONTROL GROUP), which was not
  accessible to orcas, had no decline in otter
  population

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No Big Deal.. Right?

• Declines in ocean fish due to over fishing and
  climatic changes led to a reduction in food for
  sea lions seals, so their s decreased
• This forced the orcas to enter into the coastal
  waters where they consumed sea otters.
• Sea otters normally feed on sea urchins. As sea
  otters decreased, the urchins numbers increased.

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• Urchins eat kelp, and the large numbers of
  urchins damaged kelp forests.
• The decline in the kelp forests has had an impact
  on many others species because of the decrease of
  oxygen and an increase in carbon dioxide in the
  water.
• Other Species Affected
• Bald Eagle
• Mussel
• Sea Stars
• Seagulls

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