Species Richness in Ecological Communities

Question 1

species richness

Answer 1

of species present in given ecological community

Question 2

species diversity

Answer 2

variety & relative abundance of species present in ecological community

Question 3

evenness

Answer 3

extent of similarity btwn 2 species based on relative abundance

• types: high or low
• high evenness = more species diversity & richness

Question 4

patter of theory of island biogeography

Answer 4

(1) large patches of habitat contain more species than do smaller ones
(2) ocean islands have smaller # of species than same size on continent

Question 5

process of theory of island biogeography

Answer 5

(1) immigration & emigration

(2) island size & isolation

Question 6

immigration & emigration process of TOIB

Answer 6

(1) immigration decline as island species # increases
(2) competition prevent new species from establishing
(3) extinction rates increase, species richness increase - extinction

Question 7

island size & isolation process of TOIB

Answer 7

(1) immigration rates higher on large islands, close to mainland
(2) extinction rates highest on small islands far from shore
(3) species richness greater on large & near shore islands

Question 8

prominent explanations for latitudinal gradient in species diversity

Answer 8

(1) high-productivity hypothesis
(2) energy hypothesis
(3) area & age hypothesis

Question 9

high-productivity hypothesis

Answer 9

(1) increase speciation rates, decrease extinction rates
(2) increase biomass production -> support more herbivores -> more herbivore predators
(3) higher population -> more intense competition
(4) speciation rates increase as niche differentiation occurs w/in herbivor, parasite, predator & scavenger populations

Question 10

energy hypothesis

Answer 10

extension of high-productivity hypothesis

(1) some highly productive habitats are species poor
(2) high T, more species diversity - increase productivity
(3) high energy inputs = key to high speciation & low extinction rates

Question 11

area & age hypothesis

Answer 11

temperate & arctic latitudes covered w/ ice over last 2 million years but tropical regions were not