Introduction to Ecology

1
Introduction to Ecology

• Ecology- the scientific study of interactions
  between organisms and their environments.
• All organisms interact with other organisms in
  their surroundings and with the nonliving portion
  of their environment.
• This is referred to as interdependence.
• A consequence of interdependence is that any
  change in the environment can affect all the
  species in an ecosystem.

2
Effects of Interdependence

• Figure 18-1 .Page 360
• Connection between acorn production and Lyme
  disease
• more acorns ? more deer and mice ? more ticks ?
  ticks carry bacteria that cause disease ? greater
  chance of bitten by tick

3
What do you mean by environment?

• The environment is made up of two factors
• Biotic factors- all living organisms inhabiting
  the Earth
• Abiotic factors- nonliving parts of the
  environment (i.e. temperature, soil, light,
  moisture, air currents)

4
Abiotic and Biotic Factors

• Create a list of all the abiotic and biotic
  factors that affect the survival of a fish
  species in the aquarium.

5

• Levels of Organization
• Organism- any unicellular or multicellular form
  exhibiting all of the characteristics of life, an
  individual.
• Lowest level of organization. (Most exclusive)

6
Population-a group of organisms of one species
living in the same place at the same time that
interbreed and compete with each other for
resources (ex. food, mates, shelter)
7
Community- several interacting populations that
inhabit a common environment and are
interdependent.
8
Ecosystem- a community and all the abiotic
factors found in a particular place (ex. marine,
terrestrial)
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• Biosphere- life supporting portions of Earth
  composed of air, land, fresh water, and salt
  water.
• Broadest, most inclusive level of organization.
• About 13 miles thick. (5-6 mi above surface to
  deepest part of ocean)

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Biosphere
Ecosystem
Community
Population
Organism
11

• Ecosystem Interactions

• Habitat- the place in which an organism lives out
  its life (address)
• Species do not use or occupy all parts of their
  habitat.
• The specific role, or way of life, of a species
  within its environment is called its niche.
  (job)
• An organisms niche is how it meets its need for
  food, shelter, and reproduction.
• Plants and animals are able to share the same
  habitats because they have different niches.

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• A niche is determined by the tolerance
  limitations of an organism, or a limiting factor.
  
• Limiting factor- any biotic or abiotic factor
  that restricts the existence of organisms in a
  specific environment.
• Examples of limiting factors-
• Amount of water
• Amount of food
• Temperature