Limiting Factors Unit 11:Biology(9th grade)

DENSITY INDEPENDENT LIMITING FACTORS

a factor that affects the size of a population Regardless of its population density

It’s a Abiotic Factor

Environmental stresses: Forest fires, lightning, tornadoes, etc.

DENSITY DEPENDENT LIMITING FACTORS

a factor that affects the size or growth of a population(Varies with population density)

It’s a biotic facor

Involve factors like availability of food parasitism, predation, disease, etc.

SUCCESSIONS

ECOLOGICAL SUCCESSION

natural changes in the types of species that live in an area when one community replaces another

Changes abiotic and biotic factors

PRIMARY SUCCESSION

begins with NO soil and occurs slowly

Examples: lava flow, landslides on a mountain, receding glaciers

PIONEER SPECIES

species that are first colonize previously disrupted or damaged ecosystems in secondary succession

In primary succession(lichen) are the beginning of ecological succession (lichens break down rock to form soil)

SECONDARY SUCCESSION

begins in a place with soil

Occurs fast and different pioneer species

Examples: Forest fire, floods, tornadoes, anything in a environment that gets destroyed by something)

Climax community

-Stable group of plants and animals, end in succession process.

-Does not always mean big trees

•Grasses in prairies

•Catci in deserts

Range of Tolerance

Ability of any organism to survive when subjected to abiotic or biotic factors is called TOLERANCE

BELL CURVE= NUMBER OF ORGANISMS

DENSITY INDEPENDENT

-Affects the size of a population

-Abiotic

-Basically a natural disasters

DENSITY DEPENDENT

-Affects the size or growth of a pop.

-Biotic

-Basically diseases and harmful stuff

PRIMARY SUCCESSION

-no soil and occurs slowly

Examples: Landslide an lava flow

SECONDARY SUCCESSION

-Soil and occurs fast

Example: anything in a environment that gets destroyed by something

ECOLOGICAL SUCCESSION

Change of species in the environment(one community replaces another.)