Unit 2 Ecology

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Unit 2 Ecology

• Ch. 4 Ecosystems Communities

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The Role of Climate

• Plants animals vary in their adaptations to
  temp., rainfall, etc.
• They also vary in tolerance for conditions
  outside their normal ranges

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What Is Climate?

• Weather - the day-to-day condition of Earths
  atmosphere at a particular time place
• Climate - the average, year-after-year conditions
  of temp., precip. in a particular region

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What Is Climate?

• Climate is caused by trapped heat by the
  atmosphere, latitude, transport of heat by winds
  ocean currents, amount of precip.
• Energy from sunlight drives Earths weather
  helps determine climate

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The Greenhouse Effect

• Carbon dioxide, methane, water vapor, other
  atmospheric gases trap heat energy maintain
  Earths temp. range
• These gases function like the glass windows of
  a greenhouse

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The Greenhouse Effect

• Just as the glass keeps the greenhouse plants
  warm, these gases trap the heat energy of
  sunlight inside Earths atmosphere
• Greenhouse effect - the natural situation where
  heat is retained by the layer of greenhouse gases

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What Shapes an Ecosystem?

• Biotic factors - living things within an
  ecological community
• Ex.) plants, animals, etc.
• Abiotic factors - physical, or nonliving, factors
  that shape an ecosystem
• Ex.) climate, temp., precip., rocks, etc.

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What Shapes an Ecosystem?

• Biotic abiotic factors determine the survival
  growth of an organism
• Habitat - the area where an organism lives

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What Shapes an Ecosystem?

• If an organisms habitat is its address, its
  niche is its occupation or job
• Niche - the full range of physical biological
  conditions where an organism lives the way the
  organism uses those conditions
• Includes how it obtains food, the type of food
  it eats, how it reproduces, etc.

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What Shapes an Ecosystem?

• No 2 species share the same niche in the same
  habitat

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Community Interactions

• Community interactions, such as competition,
  predation, various forms of symbiosis, can
  affect an ecosystem
• Competition
• Occurs when organisms of the same or different
  species attempt to use an ecological resource in
  the same place at the same time

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Community Interactions

• Competition
• Resource - refers to any necessity of life, such
  as water, nutrients, light, food, or space
• Direct competition in nature often results in a
  winner a loser, with the losing organism
  failing to survive

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Community Interactions

• Competition
• Competitive exclusion principle - states that no
  2 species can occupy the same niche in the same
  habitat at the same time

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Community Interactions

• Predation
• Predation - an interaction where 1 organism
  captures feeds on another organism
• The organism that does the killing eating is
  called the predator
• The food organism is the prey

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Community Interactions

• Symbiosis
• Symbiosis - any relationship where 2 species live
  closely together
• Ex. of symbiotic relationships mutualism,
  commensalism, parasitism
• Mutualism - both species benefit from the
  relationship

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Community Interactions

• Symbiosis
• Commensalism - 1 member of the relationship
  benefits the other is neither helped nor harmed
• Parasitism - 1 organism lives on or in another
  organism harms it
• The organism that the parasite is feeding on
  is called the host

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Ecological Succession

• Ecosystems are constantly changing in response to
  natural human disturbances
• As an ecosystem changes, older inhabitants
  gradually die out new organisms move in,
  causing further changes in the community

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Ecological Succession

• Ecological succession - series of predictable
  changes that occurs in a community over time
• It may be caused from slow changes in the
  physical environ., or from a sudden natural
  disturbance from human activities, such as
  clearing a forest

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Ecological Succession

• Primary succession - succession that occurs on
  surfaces where no soil exists
• It occurs on bare rock exposed when glaciers melt
• Pioneer species - the first species to populate
  the area, often lichens

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Ecological Succession

• Secondary succession - community interactions
  that tend to restore the ecosystem to its
  original condition
• Usually takes place after a fire, or when
  land cleared for farming is abandoned

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Biomes

• Biome - terrestrial communities that covers a
  large area is characterized by certain soil
  climate conditions particular plants animals
• Variations in plants animals help
  different species survive under
  different conditions in different biomes

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Aquatic Ecosystems

• Aquatic ecosystems are determined by depth, flow,
  temperature, chemistry of the overlying water

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Aquatic Ecosystems

• Freshwater ecosystems can be divided into 2 main
  types flowing-water ecosystems standing-water
  ecosystems

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Aquatic Ecosystems

• Marine ecosystems can be divided into 3 main
  types intertidal zone, the coastal ocean, the
  open ocean