slide1
Download
Skip this Video
Download Presentation
Outline

Loading in 2 Seconds...

play fullscreen
1 / 43

Community Ecology - PowerPoint PPT Presentation


  • 102 Views
  • Uploaded on

Outline. The Concept of the Community Diversity and Composition Models The Structure of Communities Island Biogeography Habitat and Ecological Niche Competition Between Populations Predator-Prey Interactions Symbiotic Relationships Community Development Community Biodiversity.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Community Ecology' - terrian


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
outline
Outline
  • The Concept of the Community
    • Diversity and Composition Models
  • The Structure of Communities
    • Island Biogeography
    • Habitat and Ecological Niche
    • Competition Between Populations
    • Predator-Prey Interactions
    • Symbiotic Relationships
  • Community Development
  • Community Biodiversity
community concept
Community Concept
  • An assemblage of populations interacting with one another within the same environment
    • Composition is a listing of various species in the community
    • Diversity includes both species richness and species diversity
diversity and composition models
Diversity and Composition Models
  • Gleason - Individualistic Model
    • Each population is there because its abiotic requirements are met
  • Clements - Interactive Model
    • Community is the highest level of organization
    • Dependent on biotic interactions
island biogeography
Island Biogeography
  • MacArthur and Wilson
    • Developed a general model of island biogeography
    • Explains and predicts how the community diversity of an island is affected by
      • Distance from the mainland, and
      • Size of the island
community structure1
Community Structure
  • Competition
    • When two species compete, the abundance of both species is negatively impacted
    • Predation (or parasitism)
      • Expected to increase the abundance of the predator (or parasite)
      • And reduce the abundance of the prey (or host)
habitat and ecological niche
Habitat and Ecological Niche
  • Habitat
    • The area an organism lives and reproduces in
  • Ecological niche
    • The role a species plays in its community
      • Includes its habitat, and
      • Its interactions with other organisms
    • Fundamental niche - All conditions under which the organism can survive
    • Realized niche - Set of conditions under which it exists in nature
competition between populations
Competition Between Populations
  • Interspecific competition
    • Members of different species require the same resource
    • The supply of the resource is limited
  • Competitive Exclusion Principle
    • No two species can occupy the same niche at the same time
    • Resource Partitioning decreases competition
    • Can lead to character displacement
predator prey interactions
Predator-Prey Interactions
  • Predation
    • One living organism, the predator, feeds on another, the prey
      • Predator is larger
      • Predator has lower reproductive rate
      • Prey usually entirely consumed
    • Presence of predators can decrease prey densities, and vice-versa
prey defenses
Prey Defenses
  • Prey defenses
    • Mechanisms that thwart the possibility of being eaten by a predator
      • Spines
      • Tough Epidermis
      • Poisonous Chemicals
      • Camouflage
      • Bright Coloration
      • Flocking Behavior
mimicry
Mimicry
  • Mimicry
    • One species resembles another species
    • Mimicked species possesses an overt antipredator defense
  • Batesian Mimicry - Mimic lacks defense of the organism it resembles
  • Müllerian Mimicry - Mimic shares same protective defense
symbiotic relationships
Symbiotic Relationships
  • Symbiosis
    • Interactions in which there is a close relationship between members of two species
    • Parasitism
      • Parasite derives nourishment from a host, and may use host as habitat and mode of transmission
        • Endoparasites
        • Ectoparasites
commensalism
Commensalism
  • Symbiosis, cont.
    • Commensalism
      • A symbiotic relationship in which one species benefits and the other is indifferent
        • Remoras and Sharks
      • Many supposed examples may turn out to be mutualism or parasitism
      • Inferred amount of harm or benefit two species do to one another is subject to investigator bias
mutualism
Mutualism
  • Symbiosis, cont.
    • Mutualism
      • A symbiotic relationship in which both members of the association benefit
      • Need not be equally beneficial to both species
        • Cleaning Symbiosis
      • Often help each other obtain food or avoid predation
        • Bacteria in human intestinal tract
community development
Community Development
  • Ecological Succession
    • A predictable pattern of change in species replacements following a disturbance
      • Primary Succession occurs in areas where there is no soil formation
      • Secondary Succession begins in areas where soil is present
        • Pioneer Species
succession models
Succession Models
  • Facilitation Model
    • Each stage facilitates invasion and replacement by organisms of the next stage
    • Succession in a particular area will always lead to the same type of community
    • Climax Community
succession models1
Succession Models
  • Inhibition Model
    • Colonists remain and inhibit growth of other plants until the colonists are damaged or die
  • Tolerance Model
    • Different types of plants can colonize an area at the same time
    • Chance determine which seeds arrive first
community diversity
Community Diversity
  • Community stability can be recognized in three ways
    • Persistence through time
    • Resistance to change
    • Recovery once a disturbance has occurred
intermediate disturbance hypothesis
Intermediate Disturbance Hypothesis
  • If widespread disturbances occur frequently, diversity will be limited
  • If diversity is high, only moderate disturbances have been occurring with moderate frequency
predation competition and biodiversity
Predation, Competition, and Biodiversity
  • Predation by a particular species may reduce competition and increases diversity
    • Such predators are referred to as keystone predators
  • Exotic species
    • May lead to unbridled competition
    • Resultant reduction in biodiversity
review
Review
  • The Concept of the Community
    • Diversity and Composition Models
  • The Structure of Communities
    • Island Biogeography
    • Habitat and Ecological Niche
    • Competition Between Populations
    • Predator-Prey Interactions
    • Symbiotic Relationships
  • Community Development
  • Community Biodiversity
ad