Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

21 Cards in this Set

  • Front
  • Back
Clements concept of Community
Assembly of closely linked species
Integrated Hypothesis

Individualistic Hypothesis by Gleason: Community of loosely organized associations of independently distributed species.

Integrated predicts that presence or absence of particular species depends on the presence of absence of the other species.

Individualistic predicts that each species is distributed according to it’s tolerance ranges for abiotic factors.
Interspecific interactions are..4 types?
Potentially links populations

Competition = - -
Predation, Herbivory, Parasitism, Disease = + -
Mutualism= ++
Commensalism= + Neut
Competition occurs

Can Lead to...
when species compete for a particular resource

Can lead to competitive exclusion, the local elimination of one of the two competing species.
Competitive Exclusion Principle
No two species can coexist in the same niche. One of the species will be out competed by the other and driven to extinction. (Such as paramecium)
Difference Btw Fundamental and Realized Niche?
Fundamental - Space occupiable in the absence of biotic interactions
(Where barnacles could live if other barnacles weren't there)

Realized- Is the space that the organism actually occupies (Where barnacles do live)
Resource partitioning is?
Differentiation of niches that enables similar species to coexist at (Ex. lizards and what height they eat at, remember diagrams of different lizards in the different areas of trees)
Character displacement?
The idea that sympatric population will be more divergent than allopatric populations due to the competitive exclusion principle and resource partitioning (Remember the birds w/ different beak sizes each eat different sized fishies)
Predator shapes many attributes of prey such as...
Prey does the same to predator by making them....
Prey develops mimicry, shells, speed, sensory

Predator develops claws, teeth, fangs, stingers, poison.
Aposematic Coloration
Brightly colored animals are colored so to warn predators to stay away from them cause they are poisonous!
Batesian Mimicry

Mullerian Mimicry
Harmless animal mimicy Harmful animal - Density Dependent in regards to the mimic

Harmful mimics harmful - Purpose is to help spread the message that they are harmful?
Herbivory has led to...
Evolution of plant mechanical and chemical defenses a
Mutualism -

Trophic structures found in
Mutualism exploitation - Ants and Agave

Food webs, chain pyramids. The more links in the chain the more productivity exists.
Top down vs. Bottom Up theory?
Top down, top of trophic level determines all else, take away consumers, then you have more primary producers. + - + -

Bottom up - Bottom affects all else, more primary producers, more consumers. + + + +
Dominant Species

Keystone Species

Foundation (Ecosystem engineers)
Has a lot of biomass and great affect on the community

Not leader in the biomass, but holds important impact on community

Influence community w/ physical changes that affect community structure (BEAVERS)
Describe Disturbance and Ecological Succession

Ecological Succession - Occurs after disturbance
Disturbance - event that changes a community by either removing organism or altering the resources available. Sometimes necessary, like wildifre to allow biomass emergence

Occurs when Nothing is there and stuff comes in (Weedy plants)

Secondary Succession - Take over after something is already there (Shrubs)

Climax community - No more succession after this (Big oak trees)
Three modes of succession
Facilitation - Early species make environment more favorable

Inhibition - Early species may inhibit later ones

Tolerance - No impact on later species
Intermediate disturbance hypothesis
Idea that some moderate level of disturbance you have a higher number of diversity than at high disturbance or little to no disturbance (CONTROL BURN)
Community's species diversity depends on...
Latitudinal position and Size

Diversity near tropics is highest
Why do tropics have more species?
Tropics are older
Have higher amount of primary production due to the fact that more sunlight and water are available.
Explain Island Biogeography

How do number of species on an island is a balance btw...
Extincion rates and immigration

Size of island increases species richness,

Immigration on Large close island is great
Small far is low immigration and extinction on smaller island is greater

SMALL ISLAND FAR = Extinction High, Immigration low
Large CLOSE = Extinction Low, Immigration HIGH
Succession is the orderly build-up of a community following a disturbance and may proceed by any or a combo of tolerance facilitation and inhibition. (Diversity highest with intermediate rate of disturbance)