slide1
Download
Skip this Video
Download Presentation
Review – Consumer-Resource Interactions

Loading in 2 Seconds...

play fullscreen
1 / 40

Review Consumer-Resource Interactions - PowerPoint PPT Presentation


  • 120 Views
  • Uploaded on

Review – Consumer-Resource Interactions. Exploitative interactions (+,-) occur when a consumer species benefits at the expense of a resource species – e.g., herbivory, parasitism, predation Consumers can set limits on the distribution and abundance of resource populations

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 'Review Consumer-Resource Interactions' - roland


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
slide1

Review – Consumer-Resource Interactions

  • Exploitative interactions (+,-) occur when a consumer species benefits at the expense of a resource species – e.g., herbivory, parasitism, predation
  • Consumers can set limits on the distribution and abundance of resource populations
  • Consumer-resource interactions produce cyclical growth and decline in population sizes of the interacting species: predator-prey cycles
slide2

Review – Consumer-Resource Interactions

  • predator-prey cycles generally stable, but environmental changes can act to change intensity, periodicity of cycles
  • Lotka-Volterra model can reproduce predator prey cycles mathematically, but lacks some important aspects of the real process:
    • time lag in predator-prey cycling due to time required to convert energy into actual offspring
    • limits set on growth by carrying capacity
    • limits set on predators by functional response
slide3

Review – Consumer-Resource Interactions

  • consumer-resource systems can have more than one stable state:
    • consumer-imposed equilibrium
    • resource-imposed equilibrium

K

facilitation

Facilitation

commensalism, mutualism & symbiosis

slide6

Facilitation

  • Interaction in which one or both parties benefits, and neither is negatively affected
  • Commensalism (+,0): one individual benefits from interaction, the other is unaffected
  • Mutualism (+,+): both individuals benefit from their interaction
  • Symbiosis: a long-term, close mutualistic association between two organisms
slide10

Mutualism

  • Obligate: one or both partners require mutualistic relationship for survival
  • Facultative: species can live without their mutualistic partner
slide11

Facilitation

  • The beneficial effects of facilitation can be realized in several different ways:
    • reduced environmental stress
    • reduced predation
    • reduced competition
    • increased access to resources
    • transport / dispersal
slide12

Facilitation – refuge from physical stress

  • One species can provide another species with protection from a stressful environment
    • nature of interaction can shift with time or changes in environment
slide14

Facilitation – refuge from predation

  • One species can protect another species from predators
    • physical or chemical shelter (or both)
    • camouflage
slide19

Facilitation – refuge from competition

  • One species can lessen the effects of competition for another species
slide22

Facilitation – improved nutrient / energy availability

  • One species can provide another species with improved access to energy or essential nutrients
ad