Community Ecology

  • Community Ecology
    • Community
    • All organisms that live together in a place
      • Interactions
    • The study of interactions among all populations in a common environment
  • Niche
    • Ecological role
  • Niche and Competition
    • Competitive exclusion
    • No two similar species can occupy the same niche at the same time
  • Interspecific interactions
    • Symbiotic interactions
    • Competition
      • -/-
      • Compete for limited resources
      • Competitive exclusion
    • Predation
      • -?/+
    • Mutualism
      • +/+
      • Lichens
      • Algae and fungus
    • Commensalism
      • +/0
      • Barnacles attached to whale
  • Predation Drives Evolution
    • Predators adaptations
    • Locate and subdue prey
    • Prey adaptations
    • Elude and defend
  • Anti-predator Adaptations
    • Hide from predators
    • Avoid detection
    • Camouflage
    • Warn predators
    • Advertise how undesirable they are as prey
    • Aposematic coloration
      • Batesian mimicry
      • Resemble the defensive signaling of a defended species
      • Müllerian mimicry
      • Two or more protected species look like each other
  • Defense Mechanisms
    • Camouflage
    • Cryptic coloration
  • Coevolution in Community
    • Predator-prey relationships
    • Parasite-host relationships
    • Flowers and pollinators
  • Characterizing a Community
    • Community structure
    • Species diversity
      • How many different species
    • Composition
      • Dominant species
      • Most abundant species
      • Highest biomass
      • Keystone species
      • Changes over time
      • Succession
  • Species Diversity
    • Greater diversity means greater stability
    • Greater biodiversity offers:
    • More food resources
    • More habitats
    • More resilience in face of environmental change
  • Keystone Species
    • Influential ecological role
    • Exert important regulating effect on other species in the community
    • Keystone species increases diversity in habitat
  • Ecological Succession
    • Sequence of community changes
    • Transition in species composition over time
    • Usually after a disturbance
    • Primary Succession
    • Begins with a virtually lifeless areas, without soil
      • Bacteria
      • Lichens
      • Mosses
      • Grasses
      • Shrubs
      • Trees
    • Secondary Succession
    • Existing community cleared, but base soil is still intact
    • What causes succession
    • Tolerance
      • Early species are weedy r-selected
      • Tolerant of harsh conditions
    • Facilitation and Inhibition
      • Early species facilitate habitat changes
      • Change soil pH
      • Change soil fertility
      • Change light levels
      • Allows other species to out-compete
  • Climax Forest
    • Plant community dominated by trees
    • Representing final stage of natural succession for specific location
    • Stable plant community
    • Remains essentially unchanged in species composition as long as site remains undisturbed