Factors influencing the rate of plant invasion

At a Conservation Workshop held in September 1996, Dr Rose presented information on the susceptability of short tussock grasslands to vegetation change and weed invasion. Plant invasion is influenced by five interacting factors, shown in the table below. Obviously some factors can be controlled (e.g. intensity of disturbance), while others cannot (e.g. climate).


    Factors influencing rate of plant invasion

Environment, as determined by:




Disturbance:
  • Grazing
  • Browsing
  • Burning
  • Geomorphic e.g. landslides, avalanche paths

Vegetation structure / competition:
  • Canopy cover and height
  • Availability of safe sites
  • Species adaptations and evolutionary history

Life history attributes of invader:
  • Shade tolerance
  • Drought tolerance
  • Nutrient requirements
  • Dispersal mechanisms

Availability of invader propagules:
  • Invasion fronts
  • Location of refugia