Ecology

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Ecology

• Biology I

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The Hierarchy of Life

• Atoms
• Molecules
• Macromolecules (proteins, lipids, carbs, nucleic
  acids)
• Organelles
• Cells
• Tissues
• Organs
• Organ systems
• Organisms
• Populations
• Communities
• Ecosystems
• Biomes
• bioshere

Population a group of same species all living
together and interacting (ex. A population of
deer) Community all of the different living
things in the same area that interact (plants,
deer, foxes, racoons, etc.) Ecosystem all of
the living and non-living things in an area Biome
like ecosystems found throughout the world
(desert, forest, grasslands, etc.)
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Abiotic vs. Biotic Factors

• Abiotic non-living things
• Biotic living things

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Ecosystem Ecology

• The study of the flow of matter and energy
  through ecosystems
• Food Webs
• Energy Pyramid
• Carbon, Nitrogen, Water Cycles

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Food Webs
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Food Webs show the flow of Energy

• All energy enters the food web by the producers
  (photosynthesis)
• Energy Flows through the food web and is not
  recycled
• Matter is recycled by the decomposers
• Trophic Levels feeding levels

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Food Webs Continued

• Producers - synthesize organic molecules from
  inorganic molecules and the suns energy (produce
  about 170 billion tons or organic material/year)
• Consumers never more than 3-5 trophic levels
  since the producers can only support so many
  consumers
• Primary Consumers eat producers
• Secondary Consumers eat the primary consumers
• Tertiary Consumers eat secondary consumers
• Decomposers break dead things back down to
  inorganic materials

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Food Webs Continued

• Autotrophs make own food (producers)
• Heterotrophs must eat to get food (consumers
  and decomposers)
• Herbivore plant eater
• Carnivore only eat animals
• Omnivore eat either plants or animals

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Energy Pyramid

• Maximum of 3-5 trophic levels
• 5-20 of energy is transferred to the next
  trophic level lose 80-90 of energy in the
  transfer to the next level
• Why is Energy lost before getting to the next
  level?
• Lost in CR (energy is used)
• Energy is lost as heat
• Energy is used to eat and get food
• Lost in feces
• Some of the molecules cannot be broken down and
  used for energy (cellulose, bone, etc.)

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Energy Pyramids
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Cycles

• Matter is recycled - inorganic?organic?inorganic
• Cycles between
• Soil abiotic reservoir for elements
• Air abiotic reservior for elements
• Rocks unusable abiotic reservoir, can be used
  after erosion
• Living Organisms reservoir for organic matter

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Water Cycle
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Water Cycle

• Precipitation going into the soil of bodies of
  water is how water enters the food web
• It leaves the living things by transpiration and
  cellular respiration and evaporation from the
  bodies of water to go back into the air

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Carbon Cycle
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Carbon Cycle

• Carbon enters the food web from the air thru
  photosynthesis
• Passed thru food web by eating
• Returned to the air by cellular respiration,
  decomposition, and combustion

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Nitrogen Cycle
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Nitrogen Cycle

• Nitrogen makes up most of the air but it is
  unusable since it is N2 and almost no living
  things have enzymes that can break that bond
• Special Nitrogen fixing bacteria can turn N2 in
  the air into useable nitrogen that can be sucked
  up by plants and used to convert sugars to aa and
  nucleotides
• Decomposition of dead things and feces and urine
  also puts nitrogen into the soil
• Nitrogen enters the air by denitrifying bacteria

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Nitrogen Cycle
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Human Impact on Cycle

• Acid rain is carried by the wind
• Moving nutrients or removing them all together
• Fertilizer can cause eutrophication of lakes (too
  much nutrients lead to too many photosynthetic
  organisms clog lake)
• Introduce toxins into the enviroment
  (biomagnification)
• Ozone depletion
• Urbanization
• Introduction of exotic species
• Genetically engineering plants to resist
  herbicide and weeds, fish engineered to resist
  cold temps.

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Community Ecology

• The study of interactions and relationships among
  the organisms in an ecosystem (why are certain
  species found together, how do they adapt to one
  another?)

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Community Ecology

• Relationships
• 1. Symbiosis close relationships where the
  organisms are interdependent
• Mutualism good for both (pollination, E-Coli in
  intestine, nitrogen fixing bacteria and plants,
  etc.)
• Commensalism good for one, doesnt help or hurt
  the other (barnacles on whales)
• Parasitism good for one, hurts the other
• Endo tapeworms
• Ecto ticks, leeches

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Mutualism
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Commensalism
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Parasitism
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Relationships Continued

• 2.Predator/Prey causes both behavioral and
  evolutionary adaptations
• Prey
• Behavioral Adaptations learn to hide, warn each
  other
• Evolutionary Adaptations make prey better at
  avoiding being found, captured, or consumed
  selected for over many generations!
• Warning colors
• Mimicry
• Camoflage
• Defensive postures
• speed

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Predator/Prey Relationships Continued

• Predator
• Evolutionary Adaptations makes the predator
  better at finding, capturing, and eating prey
• Teeth
• Camoflage
• Speed
• Heated pits
• Lateral lines
• Spider webs

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Population Cycles

• Amt. of prey controls amount of predator and vice
  versa
• as rabbits go up lag and then predators
  increase because get more to eat - more energy to
  reproduce
• too many predators eat too much prey
  predators start to die off because not enough
  food
• Less predators, more prey survives - s increase
  etc. etc.

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3. Plant/Herbivore Interactions Relationships
Continued

• Evolutionary plants develop defenses
• Prickles
• Thorns
• Tough leaves
• Stick hairs
• Toxic chemicals (nicotine, strychnine, etc.)
• Co-Evolution plant better defends, herbivore
  overcomes defense, plant develops new defense,
  etc. etc.

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4. Competition Still Relationships

• Several species competing for homes, food
• Usually this is not really a relationship because
  it causes behavioral and evolutionary adaptations
  that eliminate the competition
• Behavior Adaptation niche switching animals
  change niches (roles) so no longer competing
  ex. Birds competing for homes in a tree some
  live high in the tree, other species lives lower
• Evolutionary Adaptations (slow gradual change
  over time to organisms best suited competition
  dies off)
• Ex. Plants that release toxins in soil that kill
  surrounding plants like mesquite in the desert
• Ex. Characteristics that allow them to get food
  better finches beak
• Killer bee queen killing other queens at birth so
  there will only be killer bees.

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Succession

• Succession a slow gradual change in a community
  over time not evolutionary adaptations to
  environment due to the and type of organisms
  that live in an area based on things moving in
  and others dying out
• When some plants move in they make it more
  hospitable to other plants enabling them to move
  in and they choke off the plants that were
  originally there

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Succession Continued

• Primary Succession on land that previously
  contained no life ex. New islands, rock, area
  of a retreating glacier
• Secondary Succession replacement of species
  after a major disruption (fire, flood, volcano,
  tsunami, over grazing
• In both the land is colonized by species which
  are gradually replaced

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Succession Continued

• Pioneer Plants (weeds, herbs, tiny shrubs, moss,
  lichens
• Good at colonizing small, fast growing, fast
  reproducing, good seed dispersal
• Grasses trap soil and moisture making it better
  for trees to grow
• Trees usually more competitive and will
  eventually take over shade out smaller plants
• Climax Community stable community succession
  has stopped no more species can fit

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Succession gradual change in species over time
due to new things moving in
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Population Ecology

• The study of what affects the numbers and make-up
  of organisms in a population
• Factors that affect population growth
• Competition within species for same resources
  more organisms, decrease in food and survival
• Predation (more deaths as population increases)
• Build up of toxins
• Stress (high density induces stress and makes
  hormonal changes to animals, reproduce less and
  die quicker
• Climate
• Natural Disasters
• Disease

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Population Ecology Continued

• Population cycles populations vary with
  regularity caused by
• Stress due to overcrowding population gets too
  big and then declines
• Inability to find food, homes, shelter, etc. when
  population gets large
• Build up of toxins in a large population
• Build up of prey, followed by a build up of
  predators which eat more prey making them
  decrease, which causes death of predators since
  they dont have enough food

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Organismal Biology

• Study of how organisms are adapted to their
  environment
• Abiotic Factors determine what things can live in
  an area
• Types of Adaptations
• Behavioral (animals only) migration, hiding
  under a rock, burrowing into the ground
• Physiological (reversible) takes minutes to
  weeks ex. Ability to constrict blood vessels to
  respond to the cold, making more RBCs when go to
  high elevations that are lower in oxygen

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Organismal Ecology Continued

• Morphological Adaptations change form or
  anatomy (grow fur, change coat color, change leaf
  shape)
• Evolutionary Adaptations cactus having spiny
  leaves and super thick cuticles

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Biomes areas with similar environments and also
similar living things

• Aquatic oceans, freshwater, wetlands, estuaries
• Terrestrial tropical rainforest, temperate rain
  forest, deciduous forest, coniferous forest
  (taiga), temperate grassland, tropical grasslands
  (Savanna), chaparral, tundra, desert