Communities

6. Which of the following is not an important consideration in the design of wildlife preserves if the objective is to maximize species richness?

a) the preserve should be more or less round rather than long and linear;

b) there should be corridors or stepping stone preserves between major preserves;

c) some of the preserves must be large enough to support minimum viable populations of the top trophic level species;

d) the preserve should minimize the number of habitats within its boundaries.

7. What are the two components of species diversity?

(3) 26. Which of the following is an example of primary succession?

A) The recovery of a forest after a fire;

B) The recovery of an ecosystem after a volcanic explosion buries everything under several feet of ash;

C) The recovery of an ecosystem after 100 years of tobacco farming;

D) The vegetation invading an area after logging.

(3) 27. In our local, Fairfax County ecosystem, which of the following is not part of the successional sequence?

A) A broomsedge dominated stage;

B) A Virginia pine dominated stage;

C) A climax forest consisting of various hardwood deciduous species such as Beech, Oak, Tulip Poplar and Hickory;

D) A Black Spruce forest stage.

(3) 30. Which of the following groups of mammals does not show increased diversity in the tropics?

A) Bats (Chiroptera) B) Primates C) Edentata (Sloths etc.)

D) Rodents E) Insectivora (Shrews etc.)

The major difference between the traditional view of climax communities, as described in traditional succession theory, and the view of MacArthur and Wilson, as described in their equilibrium theory of island biogeography, is:

A) For MacArthur and Wilson, although the number of species may be constant, the climax community is not a stable, unchanging assemblage of species.

B) For MacArthur and Wilson, the climax community is a stable assemblage of species that will not change without an environmental disturbance.

C) For MacArthur and Wilson, extinction is a rare, global phenomenon.

D) For MacArthur and Wilson, the only way new species can be added to climax communities is through evolution.

Consider the following three communities of stream insects, all based on a standard sampling protocol. The numbers represent the number of individuals per species for each community.

Community One Community Two Community Three

Species 1 45 80 10

Species 2 28 10 65

Species 3 30 0 15

Species 4 15 1 22

Species 5 25 15 1250

Species 6 22 0 45

Species 7 33 4 8

Species 8 40 0 40

Species 9 25 0 0

Species 10 10 1 2

Total Number 273 111 1457

Of Individuals

Which of the three communities has the greatest species richness (number of species)?

Which has the least?

Which of the three communities has the greatest evenness?

Which has the lowest evenness?

Which of the three would have the greatest H′ value?

The theory of successional convergence states that:

A) The end point of xeric succession is a desert;

B) The end point of hydric succession is marsh or pond;

C) The end point of both xeric and hydric successions is a mesic community, the climactic climax;

D) The end points of xeric and hydric successions are different communities.