Basic Ecology

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Basic Ecology
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Four Levels of Investigation

• Organism
• Population
• An interbreeding group belonging to the same
  species
• Community
• All the populations of different species in an
  area
• Ecosystem
• The community and all non living factors of an
  area

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Ecosystem examples
Aquariums
Ponds
Pastures
Coral reefs
Woodlots
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Ecosystems involve exchange of matter and
energy between living and nonliving elements in a
manner that sustains life - includes plants,
animals, air, soil, and water
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Living part of the ecosystem biotic community
plants, animals, insects, etc. Nonliving part
abiotic (physical environment) temperature,
light, substrates, altitude, etc. - biotic and
abiotic exchange energy and material
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Ecosystems consist of several communities ex.
wetland communities

• great blue herons, egrets, ducks, geese, etc.
  bird community
• dragonflies, mosquitoes, damselflies, spiders,
  etc. insect community
• - cottonmouth, garter snake, water snake,
  copperhead, etc. snake community

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The Macrocosm and Microcosm
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• Cosmos Everything that exists anywhere
• Macro Large
• Micro Small
• Macrocosm The universe without
• Microcosm The universe within

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Primary Abiotic Factors

• Solar Energy
• Water
• Temperature
• Wind

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The Atmosphere
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The Origins of the Atmosphere

• Molten metals solidify within the frost line of
  the early solar system
• They become planetary seeds, and continue to grow
  as gravitational attraction brings them together
• As they approach planetary size the force of
  gravity causes a density distribution, with
  denser materials sinking and lighter ones rising
• Volcanic activity begins to spew trapped gasses
  into the air
• H2O, CO2, CO, H2
• Earth is only massive enough to keep heavier
  gasses, H2 and He escape into space
• Oxygen is never released in this manner, and had
  to arrive through biological processing

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Atmospheric Composition
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Parts of the Atmosphere
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Atmospheric Purpose

• It creates pressure which allows water to exist
  in liquid form
• It absorbs and scatter light making daytime skies
  bright
• Absorption allows them to protect from dangerous
  radiation
• They cause wind and weather patterns
• Interactions between atmospheric gasses and the
  solar wind can create a protective magneto sphere
  around planets with a strong magnetic field
• Greenhouse gasses cause planetary temperatures to
  be warmer than they normally would be (H2O, CO2,
  CH4)

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Greenhouse Gasses
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Climate

• Curvature of the earth induces temperature
  variation
• Temperature patterns induce wind
• Evaporation and condensation patterns cause
  rainfall

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Wind Induction
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Water
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The Origins of Terrestrial Oceans

• H2O was emitted by early volcanic activity.
• The major abundance of water on earth is still a
  mystery.
• Scientists speculate large amounts of water were
  brought to earth after it cooled by comets from
  the Kuiper Belt and Oort Cloud.

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Water Ecosystems

• Estuary A freshwater stream or river merging
  with an ocean
• Wetland Inbetween an aquatic and terrestrial
  region where soil is saturated with water
  permanently or periodically
• Intertidal zone A wetland at the edge of an
  estuary or ocean which is sequentially covered by
  the tides
• Pelagic Zone Open ocean

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Pelagic Regions

• Photic Zone Oceanic region where light
  penetrates
• Aphotic Zone Oceanic region where light does not
  penetrate sufficiently for photosynthesis
• Benthic Zone The ocean floor

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Primary Ecosystems
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Biomes worldwide grouping of similar
communities, commonly described by dominant
vegetation
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Temperate Grassland - Big bluestem, Little
bluestem, Grama grass - prairie chicken, western
meadowlark, prairie dog, coyote
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Temperate Deciduous Forest - Oaks, Maples -
ruffed grouse, black-capped chickadee, blue jay,
white-tailed deer, fox squirrel, white-footed
mouse
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Desert - Sagebrush, Creosote bush, Cacti -
sage grouse, burrowing owl, roadrunner, desert
bighorn sheep, desert jackrabbit
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Tundra - Sedges, Lichens, Cranberries - snowy
owl, golden plover, caribou, musk ox, brown
lemming
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Boreal Forest - Spruce, Firs - gray jay,
moose, lynx, snowshoe hare
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Mediterranean Scrub Forest - Coffee-berry,
Scrub oaks (fire-resistant) - California quail,
annas hummingbird, mule deer, bobcat, brush
rabbit
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Density and Dispersion Patterns
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Dispersion Patterns

• Clumped Often results from unequal distributions
  of resources
• Uniform Often results from interactions between
  individuals of a population
• Random Quite rare. Occurs in the tropics.

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Idealized Growth Models

• Exponential Growth G rN
• G Growth Rate
• r Intrinsic rate of increase An organisms
  maximum capacity to reproduce. It can be
  estimated by subtracting the death rate from the
  birth rate.
• N Population size

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Population Limiting Factors

• K Carrying Capacity the maximum population
  size that an environment can support

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What causes non-ideality?

• Declining birth rates
• Rising death rates
• Competition for limited resources

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Boom and Bust Cycles

• The Lynx and the Hare

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Thermodynamics
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History

• The study of energy
• Arose from the need to increase the efficiency of
  steam engines
• Fluidic theory of heat disproved by Boyle
• 1824 Carnot publishes, Reflections on the Motive
  Power of Fire.
• The term, Thermodynamics, coined in 1849 by
  William Thomson (the Lord Kelvin).

Sadi Carnot
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The Laws

• Conservation of Energy The change in the
  internal energy of a closed thermodynamic system
  is equal to the sum of the amount of heat energy
  supplied to the system and the work done on the
  system
• Entropy The total entropy of any isolated
  thermodynamic system tends to increase over time,
  approaching a maximum value.
• Absolute Zero Temperature As a system
  asymptotically approaches absolute zero all
  processes virtually cease and the entropy of the
  system goes to a minimum value.

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The Laws - simplified

• Conservation of Energy The stuff is always
  there you cant get stuff from nothing, and
  stuff cant disappear.
• Entropy The universe is lazy stuff always take
  the path of least resistance. Entropy is a
  measurement of the chaos of the stuff.
• Absolute Zero Heat is actually movement of the
  stuff. If stuff is completely cold, its not
  moving at all.

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Implications

• Disorder is Natural
• Order is unnatural specified complexity is
  extremely rare.
• Many processes are irreversible
• Cant burn something twice
• Eggs shatter, but they dont reassemble
• The universe is running down
• Processes are always losing energy

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Dealing with Entopy

• Entropy is one of the most important scientific
  understandings of the behavior of matter.
• It has serious implications in philosophy as
  well.
• Entropy makes rivers crooked
• People do what is easiest to do
• Ancient people described this as the law of
  disintegration or decay. It was often represented
  by a serpent eating its tail.
• Ezekiels valley of dry bones
• Mummification is a defense against it
• Gold wasso admired for its resistance to decay

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Wisdom Schools and Entropy

• The Gods and the Fates
• Greek Tragedy Man cant win because he doesnt
  know whats coming.

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Their Solution

• No day is like any other you cant know the
  details of tomorrow.
• Despite that, there is a pattern Everything
  moves.
• Does it move in every way? No everything is
  going down.
• Since everything is going down, why didnt
  everything end a long time ago?
• Something is working the other way.
• The sun goes down each year, but it comes back.
• Though we cant know the specifics of tomorrow,
  we can learn its patterns.

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How Modern Science Uses Entropy

• We use equations to model the future.
• If we can describe the trajectory of a cannon
  ball with an equation, we know its future in that
  case.
• The more repeatable the results, the more
  confident we are in our model.
• We understand that we have to put thought
  directed work into matter to order it for our
  purposes.
• Example We dont wait around for a football
  stadium to organize itself, we cause it to happen
  by putting work into the environment.
• Example Even though there is a chance that dust
  will fall on a table in the attic in a perfect
  checkerboard pattern, we know it wont.
• Many times we dont know the specifics of one
  particular thing, but we know it for a group of
  them very well statistics.
• Example the behavior of a fan at a football game
  as opposed to the entire stadium.
• Example radioactive decay - the behavior of one
  atom as opposed to billions of them in an object.
• Implication Stereotypes exist because they are
  mostly correct.

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Energy Flow
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The Origin of Energy

• All energy ultimately comes from mass
• E mc2
• The Big Bang
• As far as we are concerned, from an ecological
  standpoint, almost all energy important to life
  comes from the sun.
• A small portion comes from deep oceanic thermal
  vents.

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The Direction of Energy

• Energy is not recycled in ecosystems.
• It must be imported from the sun.
• Implication of the 2nd Law
• When energy is converted some is always lost as
  heat.
• Recall, this also means, ultimately, that the
  universe is running down.
• Ecosystems have limits placed on them due to loss
  of energy.

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Purpose of Energy in Organisms

• Entropy (ie chaos) is always breaking organisms
  down.
• The only way to counteract this trend is with
  energy applied in very specific ways.
• Organisms use energy in several ways
• builds cells, tissues, and organs (growth)
• thermoregulation
• digestion
• muscle activity

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Trophic Structures

• Sacrifice The Law of Life
• Trophic Of, or relating to nutrition.
• Everywhere along this chain energy is lost.

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Plants are Producers First trophic
level Photosynthesis starts the energy flow
Energy assimilated in photosynthesis Gross
Primary Productivity (GPP) Plants use energy for
maintenance needs
The leftover energy is stored as organic matter
in green plants Net Primary Productivity (NPP)
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Primary consumers Second trophic
level Herbivores (ex. mouse, grasshopper,
caterpillar, deer) - eat plants and obtain NPP
energy - some energy is used for maintenance,
growth, or reproduction - some energy is passed
out of the body as waste - some is lost as heat
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Secondary consumers Third trophic
level Carnivores and omnivores predators (ex.
snake, frog, coyote, etc.) - eat primary
consumers - energy is used for maintenance,
growth, or reproduction

• some energy is passed out of the body as waste
• - some energy is lost as heat

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Tertiary consumers Fourth trophic
level Carnivores top predator (ex. hawk, wolf,
bear, etc.) - eat secondary consumers - energy
is used for maintenance, growth, or reproduction
- some energy is passed out of the body as
waste - energy lost as heat
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Decomposers fungi and bacteria - break down
organic molecules from the ecosystem to obtain
energy
- some is lost as heat
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Limits

• Between each level energy is lost
• This puts limits on the possible levels an
  ecosystem can have
• Consuming meat is simply less efficient than
  consuming plants

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Matter Cycling
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The Origins of Matter

• The first Law informs us that matter and energy
  are related we may think of matter as frozen
  energy.
• The most prevalent elements in the universe
• Hydrogen 98
• Helium 2
• Others (fraction of a percent)
• The Stars are Matter Mill Houses

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The Supernova Stellar Alchemy

• Nearly all the matter present on earth came from
  super nova remnants

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Earth A Closed System

• Matter, essentially, does not enter or leave the
  earth
• A miniscule amount enters from meteors.
• Matter must be recycled by ecosystems.
• Chemicals are cycled between organic matter and
  abiotic reservoirs.

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Water Cycling
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The Carbon Cycle
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The Nitrogen Cycle
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The Phosphorus Cycle
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Finis