community - species found at a certain area
- individualistic concept - community nothing more than collection of organisms that happen to live in same place
- holistic concept - community acts as integrated unit (superorganism)
- ecotones - area where environment suddenly changes
niche - role an organism plays in the ecosystem
- interspecific competition - when not enough resource for 2 organisms
- interference competition - fighting over resources
- exploitative competition - consuming shared resources
- fundamental niche - entire niche that organism can use
- realized niche - actual niche that organism occupies
- competitive exclusion - no 2 organisms can occupy same niche if resources limited
- species that can use resource more efficiently will prevail
- can subdivide niche to avoid direct competition
- grow more similar >> more likely to compete
- sympatric species - avoid competition by living in different parts of habitat or using different resources
- character displacement - natural selection makes competing organisms different
coevolution between predator/prey - populations oscillate since predator depends on prey
- lag and offset oscillations between predator/prey
- keystone species - presence has much influence on the community
- ex. beavers
predation - consuming of 1 organism by another
- kill predator >> increase prey population
- coevolution >> predator/prey continually develop better offense/defense
- plant defenses - mostly uses morphological defenses (thorns, spines, hairs)
- secondary chemical compounds - toxic or disturbs metabolism
- animal defenses - tries to show predators that they taste bad
- chemical defenses - used as weapons against predator
- warning coloration - tells predators that they have toxic chemicals
- cryptic coloration - blends in w/ surroundings
- reduces competition
- indirect effects - 1 organism affecting another indirectly through a 3rd organism
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