Test 2

Question 1

In their classic test of the equilibrium theory of island biogeography, Simberloff and Wilson removed arthropods from a set of small mangrove islands in the Florida Keys, then tracked the recovery of the arthropod fauna on these islands through time. Which of the following can be inferred from the figure?

Answer 1

Near islands recovered their original species richness before far islands did.

Question 2

The figure shows the relationship between size of habitat and the number of mammalian species. Based on the relationship between size and habitat, the area would have to increase approximately ____________ times in order to support an additional five species

Answer 2

10

Question 3

In the figure above, the top line has a slope of 1 where regional and local species richness are always equal. Suppose that the middle line has a slope of 0.7. Which of the following relationships shown illustrates a scenario in which local processes most strongly influence species richness in a community?

Answer 3

bottom

(low local richness and high regional richness means local processes influence overall species richness the most)

Question 4

The figure above shows a species accumulation curve (aka collector’s curve), indicating the number of species found in a community as a result of increasing sampling effort, I.e., the number of individuals identified and counted. The leveling off of the curve at higher levels of sampling indicates that

Answer 4

additional sampling will result in few new species being found

Question 5

Based on the Shannon index, rank the species diversity from highest to lowest.

Answer 5

Community 1> community 2> community 3

Question 6

Character displacement is likely to _________ the competition coefficients in two competing species and to ________ resource partitioning.

Answer 6

lower, increase

Question 7

Suppose that two species of Darwin’s finches live on the same island and eat seeds, but one species tends to eat larger seeds than the other one does. Based on this observation, we can conclude that these species are engaged in

Answer 7

resource partitioning

Question 8

An unknown diatom is collected from a sample of sea water. The researcher Is asked to grow the diatom, in the laboratory and identify it based on the culture’s density and silica level. At day 10, 20 , and 30, the diatom density is almost 10^4 and silica levels are almost zero. Which species has the researcher cultured?

Answer 8

Synedra

Question 9

Two species of birds feed on berries. The birds are active at different times of the day and do not come into contact with one another. Nonetheless, the presence of one species limits the survival and reproduction of the other. What type of competition is this?

Answer 9

Exploitation

Question 10

When a predator enhances the coccus’s of inferior competitors by suppressing a superior competitor, the interaction is called:

Answer 10

keystone predation

Question 11

How many dimensions are there in Hutchenson’s n-dimensional hyper-volume?

Answer 11

n dimensions, where n = number of limiting nutrients and physical drivers

Question 12

What doesn’t control alpha diversity?

Answer 12

beta diversity

Question 13

MacArthur’s Warblers occupying different parts of coniferous trees are an example of which of the following:

Answer 13

niche partitioning

Question 14

Which of the following are not drivers of alpha diversity?

Answer 14

Number of bird species

Question 15

Alpha diversity is to gamma diversity as community is to

Answer 15

meta-community

Question 16

Beta diversity refers to diversity observed

Answer 16

between two sites

Question 17

Nitrogen fixation by Alder trees early in the growth of an Alaskan forest is an example of

Answer 17

facilitation

Question 18

Succession that occurs on a site not previously occupied by a community, for example a lave field or a glacier moraine, is called ____________ succession.

Answer 18

primary

Question 19

During the early stages of succession, diversity typically

Answer 19

increases

Question 20

Groups of sites within an area with similar climate and soils that are at different stages of succession are known as

Answer 20

chronosequences

Question 21

_______________ changes in environmental conditions, which are common in plant succession, are brought about by the actions of organisms.

Answer 21

autogenic

Question 22

The progressive series of changes in community composition that follows abandonment of an agricultural field is called:

Answer 22

secondary succession

Question 23

Which of the following is/are critical to maintaining diversity in successional communities.

Answer 23

Disturbance

Question 24

Changes in community composition over time are called

Answer 24

succession

Question 25

In contrast to the deterministic view of plant communities that prevailed in the early 20th Century, ecologists now believe that community composition at any given location is determined by:

Answer 25

responses of multiple species to environmental conditions and landscape history

Question 26

The view of communities, advocated by Frederick Clements, that communities are deterministic and integrated units of species, is referred to as the ______________ concept of communities.

Answer 26

organismic

Question 27

In general, the degree of environmental heterogeneity of a community has a _________ effect on the species diversity of that community.

Answer 27

positive

Question 28

The theory of island biogeography was experimentally tested by Wilson and Simberloff in the mangrove islands of the Florida Keys in the 1960s. Species richness of insect communities on several small mangroves islands were surveyed. The islands were then fumigated with methyl bromide to clear their arthropod communities. Following fumigation the immigration of species onto the islands was monitored. What did they find?

Answer 28

Islands closer to the mainland recovered faster than those further away

Question 29

In the figure above, which vegetation type supports the insect community with the lowest species evenness?

Answer 29

Site 73, wiregrass dominated cover (steepest slope on a rank abundance curve)

Question 30

Which vegetation type supports the insect community with the greatest species richness

Answer 30

Site 336, low herbaceous cover (most amount of dots on a rank abundance curve)

Question 31

Plant community structure along an environmental gradient can often be explained by __________________

Answer 31

a tradeoff among species with respect to competitive ability and stress tolerance

Question 32

One of the goals of restoration ecology is to increase the complexity of structure within a degraded habitat. Based upon Huffaker's work with mites and mite predators on artificial substrates, how would an increase in habitat complexity affect predator-prey dynamics in the restored habitat?

Answer 32

Both predator and prey populations will ultimately persist due "hide-and-seek" predator-prey cycles.

Question 33

Which statement about biodiversity is true

Answer 33

Diversity scales as a function of area

Question 34

A dominant species in a community may

Answer 34

all of these answers - make the largest contribution to energy flow or nutrient cycling - occupy the most space - possess the highest biomass - be the most numerous

Question 35

Which of the following terms best describes the relationship between a flowering plant and an animal that harvests its pollen?

Answer 35

mutualism

Question 36

Which description is true for most communities?

Answer 36

A few species are common and the remainder are rare.

Question 37

Measures of diversity (e.g., Simpson's, Shannon-Weiner) are calculated from:

Answer 37

the number and relative abundances in a community

Question 38

Species richness is

Answer 38

the number of species in a community.

Question 39

The group of species that occupy a given area, interacting either directly or indirectly, is a(n):

Answer 39

community

Question 40

Which of the following symbiotic mutualism involves a fungus?

Answer 40

lichens and mycorrhizae

Question 41

Which of the following is the least likely outcome of a host-parasite interaction?

Answer 41

The host population evolves to become more susceptible to the parasite

Question 42

The figure below illustrates which of the following types of species interactions?

Answer 42

mutualism (both ZGIs are increasing)

Question 43

Which of the following describe species interaction where two or more organisms of different species live together in close physical and/or biochemical association?

Answer 43

symbiosis

Question 44

A host species which harbors only a developmental phase of a parasite is called a(n)

Answer 44

intermediate host

Question 45

The ___________________ describes reciprocal co-evolutionary changes observed in species of : predators and prey, host and pathogen, and competitor species living in close associations over evolutionary time.

Answer 45

Red Queen Hypothesis

Question 46

Which of the following describes a system of species interactions in which an individual of one species lives in or on its host, feeding on it but usually not killing it.

Answer 46

parasitism

Question 47

In Lotka-Volterra predator-prey models, predators regulate prey populations by functioning as a

Answer 47

source of density dependent mortality

Question 48

The Lotka-Volterra predator-prey model of population growth:

Answer 48

assumes that when predators are absent the prey population grows exponentially.

Question 49

The figure above shows the interaction between predator (P) abundance and prey abundance (N). Given populations of lynx and hares are located at the star. Based on the Lotka-Volterra predator-prey model, we would expect the number of prey to __________ and the number of predators to _________.

Answer 49

Increase; increase

Question 50

The net outcome of predator-prey interactions in the basic Lotka-Volterra models is that

Answer 50

predator and prey populations oscillate.

Question 51

What is the outcome of competition between species 1 and species 2 indicated by the figure below?

Answer 51

Species 2 wins (parallel ZGIs, species with the larger carrying capacity wins)

Question 52

In the graphical depiction of the Lotka-Volterra competition equations, the diagonal lines representing combinations of densities of two species for which dN/dot = 0 are called the

Answer 52

zero-growth isoclines

Question 53

Which of the following would NOT be expected to result from competition?

Answer 53

evolution of increased niche overlap

Question 54

The portion of potential resources and habitat that an organism actually uses in the presence of competitors is called the _____________________of that organism.

Answer 54

realized niche

Question 55

Which of the following is most likely to prevent or stop an arms race between host and parasite?

Answer 55

A trade-off between a host's survival when parasitized and its reproductive success in the absence of parasitism

Question 56

The full range of space, resources and environmental conditions to which an organism is adapted to live in and/or use is referred to as the __________ of that organism.

Answer 56

fundamental niche

Question 57

The biologist G.F. Gauze used Paramecium species grown in test tubes to illustrate which prediction of Lotka-Volterra competition models?

Answer 57

competitive exclusion

Question 58

When two or more organisms use a portion of the same resource simultaneously, it is referred to as

Answer 58

niche overlap

Question 59

Competition between species arises due to:

Answer 59

scarcity of resources in the environment