Ch. 2: Interactions Within Ecosystems

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Ch. 2 Interactions Within Ecosystems

• GROUPS OF LIVING THINGS INTERACT WITHIN
  ECOSYSTEMS
• ORGANISMS CAN INTERACT IN DIFFERENT WAYS
• ECOSYSTEMS ARE ALWAYS CHANGING

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Groups of Living Things Interact Within Ecosystems

• ORGANISMS OCCUPY SPECIFIC LIVING AREAS
• THE ENVIRONMENT CAN BE ORGANIZED INTO FIVE LEVELS
• PATTERNS EXIST IN POPULATIONS

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SPECIFIC LIVING AREAS

• Scientists group living things according to
  shared characteristics smallest grouping is
  SPECIES so similar can produce offspring that
  also can produce offspring.
• POPULATIONS group of same species living in
  particular area populations of many different
  species may live in same area.

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SPECIFIC LIVING AREAS

• HABITAT NICHE habitat physical location
  filled with different species, each depending on
  habitats resources to meet its needs.
  Different populations interact with each other.
  Each organism has a role to play in the habitat,
  called its niche. (plants give food nesting
  sites for animals, which leave fertilizing
  droppings and spread plants seeds). Usually no 2
  species will fill the exact same niche. (We all
  have our unique abilities purposes to fill!)
• COMMUNITIES a group of populations that live in
  a particular area interact with one another.
  The Galapagos Island community includes Cacti,
  iguanas, crabs.

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SPECIFIC LIVING AREAS
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Environments can be Organized into 5 Levels

• BIOME very generally describes climate types
  of plants found in similar places around the
  world.
• ECOSYSTEM many ecosystems found in each biome
  includes organisms their local environment
  living non-living factors interact to form
  stable system.
• COMMUNITY the living parts of an ecosystem.
  Different plants, animals, other organisms
  interact with each other within a community.
• POPULATION a group of organisms of the same
  species living in the same area.
• ORGANISM a single individual animal, plant,
  fungus, or other living thing.

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Patterns in Living Space

• Certain plants animals keep specific distances
  apart from each other (Mojave desert bushes,
  bluebirds-100m).
• Distribution of organisms in a habitat is often
  based on how they meet their needs.
• Herring swim in schools wildebeests roam
  African grasslands in herds. Rely on grouping
  for their safety, so better chance of survival.

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Patterns in Time

• Yellow jackets rarely seen in spring, but often
  in fall. (Queen lays eggs in spring and keeps
  doing this all summer as population grows, many
  by fall in winter, all die except for Queen to
  continue next year).
• Many birds migrate south in winter for more food,
  so population changes from season to season.
• Some Cicadas appear only every 17 years. No
  other species can rely on them as food source, so
  they survive long enough to lay eggs when they do
  appear.