lecture_notes_9_26_07 - Lecture Notes 9-26-07 COMMUNITY: a...

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Lecture Notes 9-26-07 COMMUNITY: a group of species living together in the same place at the same time. How are Communities Organized? Community Concepts Community Structure--Focus on Diversity “Inputs and Outputs”--Focus on “Island Biogeography Interactions within Communities Competition Exploitation Mutualisms Succession--Change through Time What brings species together to form a community? Similar abiotic environmental requirements: “Individualistic Concept” Dispersal to the site (Chance) Interactions between different species that cause elements of the community to function as a unit: “Interactional Concept” COMMUNITY STRUCTURE: the composition and arrangement of species within a community DIVERSITY : A measure of species abundance within a community. Diversity has two components: Richness: Species Numbers -- Number of species per unit area or volume Equitability(Evenness): The relative abundance of species --The distribution of individuals among species Diversity Index: Shannon-Wiener Index H’ = -∑p i log e p i p i = the proportion of the ith species H’ starts at 0, and goes up Ecologists have long been interested in patterns of species richness and diversity. 3 Different Scales:
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Community Landscape Global Two Possible Explanations for Diversity Differences at the Community Level Include: Differences in the Complexity of Physical Environments (Individualistic Concept) Differences in the Length of Time the Areas have been in Place (Dispersal and Interactive Concept)
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This note was uploaded on 04/29/2008 for the course BIOCORE 301 taught by Professor Howell during the Fall '07 term at Wisconsin.

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lecture_notes_9_26_07 - Lecture Notes 9-26-07 COMMUNITY: a...

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