Ecology

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Ecology

• Ecology is the study of interactions among
  organisms and between organisms and their
  environment.

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Ecology Levels of Organization
Individual Population
Community Ecosystem
Biome Biosphere
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Ecological Methods

• Observing simple or complex first step in
  asking ecological questions
• Experimenting test hypotheses in a lab or in the
  field
• Modeling gain insight into complex phenomena
  (global warming)

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Ecological Niche

• Niche defines an animals
• lifestyle
• habitat
• nutrition
• foraging
• territory
• Niche includes everything
• an animal does or uses in
• order to survive.

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Ecology Energy Flow

• Every organism needs energy.
• Sunlight is the main
• energy source for life.
• Less than 1 of sunlight is used by organisms.
• Where does the rest of the sunlight go?

Photograph courtesy philip.greenspun.com
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Ecology Energy Flow

• photosynthesis use of light energy to produce
• carbohydrates
• autotrophs make their own food.
• autotrophs are producers
• Why?

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Ecology Energy Flow

• sunlight is not available to all organisms
• chemosynthesis use of chemical energy to produce
  carbohydrates
• most chemotrophs are bacteria and algae
• are they autotrophs?

Deep sea hydrothermal vent worms
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Ecology Energy Flow

• autotroph produces its own food
• heterotroph acquires energy from other organisms
• What is a producer?
• What is a consumer?
• Are heterotrophs producers or consumers?
• consumers
• primary
• secondary
• tertiary
• quaternary

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Ecology Energy Flow

• heterotrophs are consumers
• herbivores eat plants
• carnivores eat meat
• omnivores eat plants and meat
• insectivores eat _____________
• detritivores feed on remains
• decomposers break down organic matter
• Where are decomposers in a food chain?

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Ecology Feeding Relationships

• Energy flows through an ecosystem in one
  direction (arrows) from the sun or inorganic
  compounds to producers to consumers.
• Food chain diagram that shows simple feeding
  relationships.
• Trophic level each step in a food chain
• All food chains start with a producer.

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Feeding Relationships
Food Chain

• squid (tertiary consumer)
• small fish (secondary consumer)
• zooplankton (primary consumer)
• algae (producer)

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Students be careful!

• Remember the arrow
• shows the direction
• energy flows in an
• ecosystem.
• In this example, the
• Leopard seal eats the
• penguin and as a result,
• gets the energy.

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Ecology Feeding Relationships

• A food web is a network of complex feeding
  relationships that connects multiple food chains.
• If one species is lost from a food web, all other
  species are affected.

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Terrestrial Food Web

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Aquatic Food Web

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My Favorite Food Web
Matt Pendley, Buford High School, Buford, GA
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Ecology Community Interactions

• Competition when organisms try to use a resource
  in short supply at the same time and same place.

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Ecology Community Interaction

• Predation when one organism captures and eats
  another organism.

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Ecology Community Interaction

• Symbiosis any relationship in which two species
  live closely together.

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Ecology Symbiosis

• Mutualism when both
• species benefit from the
• interaction.
• In this example, the sea
• anemone is cleaned by
• the clown fish, who in
• turn is protected by the
• anemones stinging
• tentacles.

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Ecology Symbiosis

• Commensalism when
• one species benefits
• from the interaction
• and the host species is
• unaffected.
• The leafy plant is an
• epiphyte, growing on
• another plant only for
• support.

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Ecology Symbiosis

• Parasitism interaction
• in which one organism
• benefits and the other
• organism (host) is
• harmed.
• Does the host die as a
• result?

Asian tiger mosquito
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Ecological Pyramids Energy Pyramid(energy flow
in a community)

• each trophic level represents a different group
  of organisms in a food chain
• about 10 of the energy available at each trophic
  level is transferred to organisms at the next
  trophic level
• energy is lost as heat and in life processes

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Ecological Pyramids Biomass Pyramid

• biomass is the total amount of living tissue
• expressed as grams of organic matter per unit
  area
• biomass pyramid represents the potential amount
  of food available at each trophic level
• normally the greatest biomass is at the base

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Ecological Pyramids Numbers Pyramid

• based on the numbers of individuals at each
  trophic level
• some number pyramids look like biomass energy
  pyramids, some do not
• in this example, the oak tree has a large amount
  of energy and biomass, but it is only one organism

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Laws of Ecology

• All things are interconnected.
• Everything goes somewhere.
• Theres no such thing as a free lunch.
• Nature bats last.
• Ecology A Pocket Guide by Ernest Callenbach