Biol 201 4-18-2011

Biol 201 4-18-2011 - of land. How to quantify diversity: o...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Community: all the organisms in a defined area (all individuals of all species). We usually talk about Guilds, which is a group of organisms which inhabit a same habitat. Community Structure: Species richness: number of species Species composition: identity of species Species relative abundances o Animas-usually numbers o Plants-usually biomass. Most species are intermediate abundance: percent cover vs number of species of log scale looks like a bell curve or log normal. How to quantify the relative abundance of species? o Look at the evenness: pick a plot of land and measure the distribution in this plot
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: of land. How to quantify diversity: o There are many quantitative measures o Shannon-Wiener index o Maximized for a given S when species are even. H= -, where s is relative species richness. P i will get close to 1. If one community has a P i = 5/25, 5/25, 5/25, 5/25, 5/25= 0.2, then H=5 (.2) ln(.2)= ln(.2) = 1.609 Visualizing diversity: species richness: The flatter the slope of abundance rank vs proportional pulation, the more rich it is. What causes diversity? Communities that have more realized niches have more diversity. Competition Disturbance Predation, mutualism...
View Full Document

This note was uploaded on 10/13/2011 for the course BIOL 201 taught by Professor Mitchell during the Spring '07 term at UNC.

Ask a homework question - tutors are online