Commensalism, Amensalism & Parasitism

I. Overview

• Species interactions
• positive, none, & negative effect

II. Commensalism

• (+, 0) interaction
• Epiphytes
  • host trees
  • herbaceous perennials
  • bryophytes
  • lichens
  • found in canopies of trees
  • epiphyte load
  • canopy roots to trap minerals
• Nurse plants
  • seedling survival
  • palo verde and saguaro cactus

III. Amensalism

• (0,-) interaction
• Allelopathy
  • plant adds alleochemical to ground
  • inhibit growth of seedlings
  • maybe due soil microbiology
• Interactions between trophic levels
  • Overstory plants
  • affect soil pH
  • microorganisms
  • organics decompostion
  • phenolics and pH

IV. Parasitic plants

• (+, -) interaction
• Types of parasites
• strangler figs
  • epiphytic
• Miseltoe
  • tap xylem
  • still green
• Dodder (Cuscuta)
  • stems Orange
  • haustoria
  • taps xylem and phloem
• seed dispersal