EEB321H1 Lecture Notes - Lecture 2: Diversity Index, Rarefaction, Species Richness
19 Jan 2017
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Lecture 2 - how to measure species diversity. Want to know why we have more diversity in some places than others. But also need to see how we measure species diversity. Species diversity has 2 parts: richness. Strictly the number of species: evenness. Both communities a and b have same richness but don"t have same evenness: really abundant species might contribute more functionally than a rare species, functionally, community a is more diverse. Each species represented much more in terms of what they do (interactions with other species and with environment: so need to distinguish between richness and evenness, both will show up in measurements we use. Lots of different indices and methods that community ecologists devise to measure species diversities. Simple indices: 1 number that describes whole community, easy to follow, simple numbers that define alpha and beta diversity, reflects species richness and/or evenness. Mid complexity: has information on individual species, but not species identity, species-abundance distributions (sad)
