Exam 4

Question 1

The main emergent property of communities

Answer 1

communities exhibit a definite trophic structure

Question 2

The secondary emergent property of communities

Answer 2

species diversity

Question 3

alpha diversity

Answer 3

species diversity that depends on richness and evenness

Question 4

beta diversity

Answer 4

turnover or change in community composition

Question 5

gamma diversity

Answer 5

total number of species counted in a broad geographical area

Question 6

G. G. Simpson

Answer 6

noted five different factors that affected the diversity gradients of North American mammals

Question 7

time hypothesis

Answer 7

tropics weren’t covered by glaciers, so they have a longer geological history

Question 8

spatial heterogeneity hypothesis

Answer 8

tropics are more complex and support more niches

Question 9

competition hypothesis

Answer 9

competition is greater in tropics, so greater niche partitioning and character displacement/release occurs

Question 10

predation hypothesis

Answer 10

predation is greater, thus competitive exclusion does not occur

Question 11

Dan Janzen

Answer 11

proposed pest pressure hypothesis

Question 12

pest pressure hypothesis

Answer 12

specialized pests prevent one species of tree/plant from dominating

Question 13

climate hypothesis

Answer 13

tropical climate is more favorable and stable year-round

Question 14

productivity hypothesis

Answer 14

NPP is higher in the tropics

Question 15

disturbance hypothesis

Answer 15

intermediate levels of disturbance promote high diversity

Question 16

geographic area hypothesis

Answer 16

there is simply more land in the tropics

Question 17

Frederic E. Clements

Answer 17

championed closed community concept

Question 18

Henry A. Gleason

Answer 18

championed idea of open communities

Question 19

John T. Curtis and Robert H. Whittaker

Answer 19

contributed research supporting species continuum concept

Question 20

ecotones

Answer 20

transition zones between different types of habitats

Question 21

primary succession

Answer 21

succession begins from bare rock/substrate

Question 22

secondary succession

Answer 22

succession that follows the opening of niches following a disturbance

Question 23

autogenic succession

Answer 23

succession caused by biotic interactions

Question 24

allogenic succession

Answer 24

succession caused by the physical environment

Question 25

facilitation model of succession

Answer 25

early pioneer species seres prepare environment for climax species seres

Question 26

inhibition model of succession

Answer 26

species settle and alter environment to suppress new colonists until removed via disturbance

Question 27

tolerance model of succession

Answer 27

succession leads to the most efficient species; short-lived species are out-competed by longer-lived ones

Question 28

HSS hypothesis

Answer 28

'the world is green'; herbivores are not food or competition limited, are kept in check by predators

Question 29

ecosystem exploitation hypothesis

Answer 29

'the world is white yellow or green'; competition and top-down control is dependent on productivity of the environment

Question 30

environmental stress hypothesis

Answer 30

lower levels of disturbance and stress result in greater top-down control