Transcript Ch. 2: Interactions Within Ecosystems

Ch. 2: Interactions Within
Ecosystems
• GROUPS OF LIVING THINGS
INTERACT WITHIN ECOSYSTEMS
• ORGANISMS CAN INTERACT IN
DIFFERENT WAYS
• ECOSYSTEMS ARE ALWAYS
CHANGING
Groups of Living Things Interact
Within Ecosystems
• ORGANISMS OCCUPY SPECIFIC
LIVING AREAS
• THE ENVIRONMENT CAN BE
ORGANIZED INTO FIVE LEVELS
• PATTERNS EXIST IN POPULATIONS
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.
SPECIFIC LIVING AREAS
• HABITAT & NICHE: habitat = physical location
filled with different species, each depending on
habitat’s resources to meet it’s needs. Different
populations interact with each other. Each
organism has a role to play in the habitat, called
it’s 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.
SPECIFIC LIVING AREAS
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.
•
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.
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.