Ecology

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Ecology

• Ecosystems and Communities

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Weather vs. Climate

• Weather is the condition of the Earths
  atmosphere at a particular time and place.
• Atmosphere is the Earths insulating blanket
• Climate is the average yearly condition of
  temperature and precipitation in a region.

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• Climate is caused by
• Latitude
• Winds and ocean currents which transport heat
  through the biosphere (unequal heating)
• Shape and height
• of landmasses

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Greenhouse Effect

• The temperature on Earth stays suitable for life
  due to the trapping of heat by gases in the
  atmosphere causing a natural phenomenon called
  the Greenhouse Effect.

Phenomenon an occurrence or fact that can be
perceived by the senses.
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Climate Zones

• Three main climate zones
• Polar very low angle
• Temperate
• Tropical near the equator
• Caused by differences in heating of the Earths
  surface.
• Latitude
• Unequal heating of the surface results in currents

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• Wind currents occur because warm air rises and
  cool air sinks.
• Where would you expect to find warm air rising?
  Cold air sinking?
• The same pattern occurs in the oceans.
• Wind over the waters surface also creates
  currents.
• Landmasses also have affect on currents.
• Example Rain shadow

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Latitude determines the angle of the sunlight
striking the earth
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What Shapes Ecosystems
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• Biotic Biological or living factors that
  influence organisms in an ecosystem
• Ex. Plants and animals
• Abiotic Physical or non-living factors that
  influence organisms in an ecosystem
• Ex. Temperature, soil type, sunlight, etc.

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Habitat

• The area where an organism lives
• Contains both biotic and abiotic factors

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Niche

• Full range of physical and biological conditions
  in which an organism lives and the way in which
  the organism uses those conditions
• An organisms habitat is its address its niche
  is its occupation.
• Example Lion lives in the savannah but it
  survives in that habitat by being a top level
  consumer.

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Example of Niche for Anoles Lizard
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Community Interactions

• Competition
• Predation
• Symbiosis
• Mutualism
• Commensalism
• Parasitism

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Competition

• This occurs when organisms try to use the same
  resources (necessities of life).
• Often results in one organism dying out
• Competitive Exclusion Principle No two species
  can occupy the same niche in the same habitat at
  the same time

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Predation
One organism (predator) captures and feeds on the
other (prey)
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Symbiosis

• Occurs when two species live closely together
• Three types
• Mutualism
• Commensalism
• Parasitism

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MutualismBoth species benefit from the
relationship
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CommensalismOne species benefits while the other
is neither helped nor harmed
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ParasitismOne species benefits by living in or
on the other and the other is harmed
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Ecological Succession

• The series of predictable changes over time is
  succession.

Ecosystems constantly change due to natural and
human influences. Ex Further disturbances,
long term climate changes, introduction of
non-native species
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Primary Succession occurs on bare rock surfaces
where no soil exists.Ex Lava flow or glacier
melt
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• Pioneer species are the first species to
  populate an area following a disturbance that
  causes primary succession.
• Ex Lichens

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Secondary Succession occurs when a disturbance
changes a community without removing the soil
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• Climax communities are those that seem to be
  stable and undergoing no more change.
• Changes may occur very slowly due to climate
  changes or introduction of non-native species

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Biomes

• Biomes are groups of communities that cover large
  areas and are characterized by certain soil and
  climate conditions and particular assemblages of
  plants and animals.
• Each biome is identified by its particular set of
  abiotic factors and characteristic ecological
  community and organisms.

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• Tolerance - plants and animals ability to survive
  under conditions that differ from their optimal
  (most desirable or favorable) conditions
• Microclimate climate conditions in a small area
  that differ significantly from the climate of the
  surrounding area

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Aquatic Ecosystems

• Determined by depth, flow, temperature, and
  chemistry of the water (salts, nutrients and
  oxygen).
• Grouped by the abiotic factors that affect them
  (different than land biomes which are determined
  by biotic factors)
• Three main categories of Aquatic Ecosystems
• Freshwater
• Estuaries
• Marine

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Freshwater Ecosystems

• Flowing water Rivers, streams, creeks, and
  brooks
• Standing-water Lakes and ponds
• Plankton- tiny organisms that live in fresh or
  saltwater environments
• Phytoplankton - single-celled algae are producers
  in aquatic food webs
• Zooplankton tiny animals that feed on
  phytoplankton

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• Freshwater wetlands an ecosystem that has water
  covering the soil or is present at or near the
  surface for a portion of the year
• Very productive ecosystems important breeding
  grounds for organisms (birds and insects)
• Bogs, marshes and swamps
• Water can be flowing or standing and fresh, salty
  or brackish(mixture of fresh and salty)

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Estuaries

• Wetlands formed where rivers meet the sea
• Contain a mixture of fresh water and salt water
• Affected by tides
• A lot of detritus (organic material that provide
  food for organisms at base of food web) from
  primary producers
• Examples Salt marsh-Chesapeake Bay and Mangrove
  swamp-Florida Everglades

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Marine Ecosystems

• Photic Zone - well-lit upper layer producers can
  photosynthesize here (0 to 200 meters)
• Aphotic Zone Sunlight can not penetrate due to
  depth (200 meters and deeper)
• Other zones based on depth and distance from
  shore intertidal zone(close to shore), coastal
  zone, open ocean, benthic zone(ocean floor)