The Principles of Ecology

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Chapter 3

• The Principles of Ecology

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I- The Beginning of Ecology

• Natural history lead to ecology
• Science that studies the interaction between
  organisms and their environment
• Combines knowledge between many sciences
  Biology, chemistry, physic and earth science

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I- B. The living Environment Biotic factors

• All living things are found in a layer called the
  Biosphere
• Biosphere is made up of different environments
  Aquatic / Terrestrial
• Environment consist of
• Nonliving factors ( Abiotic factors)
• Living factors ( Biotic factors)

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I- C. Abiotic Factors

• Abiotic factors can have obvious effects on
  living things and often it determines which
  species can survive.
• Example Grasslands only support small plants
  and many grassing animals

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II- Levels of Organization

• All organisms depend on others for food, shelter,
  reproduction or protection.
• Ecologist study interaction among organisms at
  several different levels.
• Levels of organization provide a tool to use in
  planning their research.
• Example Studying bees Vs. foxes

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Levels of organization. Page 59

• Individual
• Populations
• Communities
• Ecosystem
• Biospheres

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II- A. Interaction within Populations

• KINDS OF COMPETITIONS
• among individuals in a population
• between populations in a community
• between communities in an Ecosystem
• HOW TO AVOID COMPETION
• Alternating generation
• Metamorphosis

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ALTERNATING GENERATION
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METAMORPHOSIS
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II- B. Individuals interact in Communities

• No population or organisms lives independently of
  other species.
• Community is a collections of interacting
  populations
• Change in one population causes change in another
• Example more people less vegetation

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II- C. Interaction between Abiotic and Biotic
factors

• Ecosystems are interaction among the populations
  in a community and their physical surroundings.
• Kinds of ecosystems
• Terrestrial
• Aquatic ( 75 of earths surface)

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II- D. Where and how organisms live

• Every organism plays a role in their community
• All help maintain a balance (Homeostasis)
• Role played is the organisms NICHE
• Habitat is place where organism lives
• many species usually share habitats

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III- How organisms Interact

• Feeding relationships How organisms obtain
  energy
• Autotrophs capture and store light energy
• Heterotrophs depend on autotrophs for a food
  source
• Carnivores organism that depends on other
  heterotrophs as a food source

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III- How organisms Interact part 2

• Scavengers depend on dead organisms as food
  source
• Omnivores eat a variety of food both plants and
  animals
• Decomposers break down and absorb nutrients
  from dead organisms

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III- B. Close relationship for survival

• Symbiosis close and permanet association
  between organisms of different species.
• Commensalism one species is benefited and the
  other is neither helped or harmed
• Mutualism both species benefit
• parasitism one benefits at the expense of the
  other

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III- B. Close relationship for survival

• more Symbiotic relationships
• parasitism one benefits at the expense of the
  other

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IV- A. Matter Enery in Ecosystem

• Food Chain
• each link provides less energy then the previous.
  (energy loss by heat and motion)
• 3links in a food chain good / 5 are bad
• each level or link is called a Trophic level
• many food chains cross and interconnect this is
  called a (Food Web)

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Food Web
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Pyramid numbers
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Energy Pyramid
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IV- C. Cycling maintains Homeostasis

• Water cycle
• Carbon dioxide cycle
• Nitrogen cycle
• Phosphorus cycle

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Water cycle
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Carbon Dioxide cycle
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Nitrogen cycle