How could we measure "depressed growth rate"?
neutralism: neither species is adversely affected by the other's presence
amensalism: individuals of only one species are adversely affected by the other's presence
competition: both species are adversely affected by the other's presence
allopatric: occurring in separate, non-overlapping geographic areas
sympatric: occupying the same or overlapping geographic areas
parapatric: within a sympatric geographic distribution areas of occurrence are disjunct
Species too similar in their resource use cannot coexist for long without competitive exclusion (Gause 1932)
Species that coexist do so by sufficient differences in their realized niche
Competition is a powerful evolutionary force selecting for adaptations that allow differential resource use
Distributions of species are often determined by competitive pressures. The result is that similar species will have disjunct ranges (i.e., allopatric or parapatric).
Species may compete by interference or exploitation (i.e., depletion of resources)
Experiments performed on species with substantial overlap in resource use should detect interspecific competition (i.e., depressed population growth or fitness when together and the reverse when one is removed)
C. Approaches to determine importance of competition
Time-series of abundance analysis (approach based on Lotka-Voltera competition model)
Example: Ocelots and bobcats
Example: Stream fish in Oklahoma
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