Biogeog 3

Question 1

What is a community?

Answer 1

Assemblage of organisms that live in a particular habitat and interacts with one another - spatially defined by habitats

Question 2

What are the marine community zones?

Answer 2

Water depth (litoral, neritic)
Light (photic and aphotic)
Organisms (benthic or pelagic)

Question 3

What is an ecosystem?

Answer 3

A set of biotic and abiotic components in a given environment

Question 4

What is an ecotone?

Answer 4

Edge between two habitat types - often share mix species

Question 5

What is Clement’s view of a community?

Answer 5

(Closed) Communities are distinct spatial entities and developed with one superorganism complex giving way to another
(Ecotones present)

Question 6

What is Gleasonian’s view of community?

Answer 6

(Open) Communities were not tightly linked superorganisms but rather arbitrarily circumscribed by humans and distributed independently to one another

Question 7

What are characteristics of open community?

Answer 7

Individualistic organisation, diffuse boundaries, independent species ranges and uncommon/diffuse coevolution

Question 8

What are characteristics of a closed community?

Answer 8

Holistic organisation, distinct (ecotones) boundaries, coincident species ranges and prominent coevolution

Question 9

What did Robert Whittaker’s research conclude on Smoky Mountains?

Answer 9

Although communities in similar habitats looked superficially similar, individualistic and coincidental responses are present

Question 10

What is an example of what Robert Whittaker found in his investigations in the Smokey Mountains?

Answer 10

Three types of trees: Red oak is most abundant in drier, higher elevations but extends into other forest types. Beech prefer moist conditions. All three occur together in many areas

Question 11

What do mountain plant distributions indicate?

Answer 11

Open community structures and species replace one another gradually

Question 12

What did Margaret Davis find in pollen data of N American trees?

Answer 12

Trees returned northward after glacial retreat and warming over 1000s yrs - individualistic patterns

Question 13

What is species richness?

Answer 13

Count of species in a given area

Question 14

What does species diversity account for?

Answer 14

Evenness or dominance

Question 15

What scale of diversity does alpha measure?

Answer 15

Local diversity

Question 16

What scale of diversity does gamma measure?

Answer 16

Regional - defining diversity hotpots on a geographic scale

Question 17

What does beta measure?

Answer 17

Gradients in the environment and how rapidly species composition changes along gradient

Question 18

What does delta measure?

Answer 18

Measure of dissimilarity between large geographic areas