Lecture 23: Communication Ecology II
Diversity, Trophic Levels, Complexity
Patterns in Diversity
Succession, Disturbances, More Diversity!
Competition is major factor that shapes communities and affects the locations of
2 species of mussels
o Smaller species are found on shallow portions of rocks
o Larger species are found deeper portion of rocks
Experiment shows that if your remove larger species, the smaller expand to
deeper portions AND shallow portions.
If you remove shallow water species, nothing happens. Larger species remain in
o Therefore, competition does affect structure of a community, distribution
o It ALSO tells us that the deep-water species are better competitors.
Affects the presence of the smaller species in the deep water.
Species Richness, Evenness, Diversity
Species Diversity of a community reflects 2 aspects:
o Species Richness
Number of different species in a community
Abundance of those different species
What the specie eats and what eats it, is the trophic level
o Level I is Primary Producers (photosynthetic plankton)
o Level II are the Primary Consumers
o Level III Secondary Consumers
o Level IV Tertiary Consumers
o Level V+ …
Majority of energy green plants produce does NOT make it to the food chain top o Rest of this energy dissipates because energy is lost when animal dies.
This energy goes to the decomposing chain.