CH6 notes
Population and Community Ecology
Types of species
● Native Species: species that normally thrive in a particular ecosystem
● Endemic Species: a species from a particular region and nowhere else
● Non-native, exotic, alien species: migrate into an ecosystem or are introduced to an
ecosystem either deliberately or accidentally
● Invasive species: a non-native species that cause problems in the ecosystem
○ They tend to out-compete native species
○ They tend to find their way into new ecosystems because of people!
○ Example: African Bees
■ Africanized sometimes called "Killer Bee“
■ Live south of the Sahara Desert
■ Accidentally introduced into the wild in South and North America during
1956. Brazilian scientists were attempting to create a new hybrid bee in
the hopes of creating an improved honey production. The Africanized bee
escaped and began to dominate honey bee.
● Indicator Species: species that serve as an early warning sign of damage to a
community or ecosystem, generally these organisms are pollution sensitive
○ Example: Salamanders, amphibians
● Keystone Species: species that plays a pivotal role in the structure and function of an
ecosystem
○ Example: Elephants in a grassland ecosystem OR sea otters in a kelp forest
○ Example: Prarie dogs
■ Burrows are homes for other organisms
■ Burrowing loosens & churns soil for plants to grow
■ Food source for black-footed ferret, swift fox, coyotes, hawks, eagles,
badgers
Interaction between species
● Competition
○ Organisms of the same species compete for food, mates, space, shelter,
nutrients, territoriality
○ Different species compete for food, space, nutrients, shelter, sunlight, hiding
spots
○ 2 types:
■ Intraspecific competition: competition between organisms of the same
species
■ Interspecific competition: competition between different species
Population and Community Ecology
Types of species
● Native Species: species that normally thrive in a particular ecosystem
● Endemic Species: a species from a particular region and nowhere else
● Non-native, exotic, alien species: migrate into an ecosystem or are introduced to an
ecosystem either deliberately or accidentally
● Invasive species: a non-native species that cause problems in the ecosystem
○ They tend to out-compete native species
○ They tend to find their way into new ecosystems because of people!
○ Example: African Bees
■ Africanized sometimes called "Killer Bee“
■ Live south of the Sahara Desert
■ Accidentally introduced into the wild in South and North America during
1956. Brazilian scientists were attempting to create a new hybrid bee in
the hopes of creating an improved honey production. The Africanized bee
escaped and began to dominate honey bee.
● Indicator Species: species that serve as an early warning sign of damage to a
community or ecosystem, generally these organisms are pollution sensitive
○ Example: Salamanders, amphibians
● Keystone Species: species that plays a pivotal role in the structure and function of an
ecosystem
○ Example: Elephants in a grassland ecosystem OR sea otters in a kelp forest
○ Example: Prarie dogs
■ Burrows are homes for other organisms
■ Burrowing loosens & churns soil for plants to grow
■ Food source for black-footed ferret, swift fox, coyotes, hawks, eagles,
badgers
Interaction between species
● Competition
○ Organisms of the same species compete for food, mates, space, shelter,
nutrients, territoriality
○ Different species compete for food, space, nutrients, shelter, sunlight, hiding
spots
○ 2 types:
■ Intraspecific competition: competition between organisms of the same
species
■ Interspecific competition: competition between different species
