GEOGRAPHY 316: BIOGEOGRAPHY
B. Holzman, PhD

last edited: 10/03/2002

I.  Factors that Influence Ecosystem
 A. Range of Tolerance
      1. Abiotic Factors
           temperature
           water
           climate
           soil
      2. Biotic Factors
           intra and interspecific competition,
           predation/parasitism
          amensalism, mutualism

Factors that Influence Ecosystem

Limiting Factor:  anything that tends to make it more difficult for a species to live and grow, or reproduce in its environment

Abiotic and Biotic:  physical and      biological factors can work in concert

Limiting Factors
ABIOTIC
temperature
water
climate/weather
soils (mineral component)

BIOTIC
competition:  interspecific and intraspecific
predation/parasitism
amensalism
mutualism

Limiting Factors
Environmental gradients: 
  Range of optimum

Biological factors: Interactions with other organisms

Competitive Exclusion: species prevented from occupying another area b/c of another species presence
   ex. starling (introduced in 1905 in NY Central park, the species had reached the west coast by 1950)_

to be continued.......

Predator/Parasitism:  individual "eats" other individual

Amensalism: interactions that inhibits

Mutualism:  symbiosis, mutual beneficial interactions