Communities
I. interactions
A. Competition- resources. 2 types
1. Intraspecific- within the same species (population)
2. Interspecific- between 2 or more species. Leads to the Principle of Competitive Exclusion-when 2 or more species are competing fo the same resources, 1 will "win".  The other/s will either become extripated or they will shift their niche.  Niche- an organism's profession.  Leads to Resource Partitioning- resources are divided up by competing species.  Ex. elk, moose, deer/ broadleaf, conifers.  Exotic Species (non-native)- on the mainland the natives usually win.