Deck 13: Interspecific Competition

Question 1

The full range of conditions and resources under which an organism can survive and reproduce is that organism's ________ niche.

Answer 1

fundamental

Question 2

Explain what is meant by the paradox of plankton.

Answer 2

Even though plankton have strongly overlapping niches and live under limiting resource condition, there are many more species than would be predicted based on interspecific competition.

Question 3

________ competition results from the behavioural exclusion of some individuals by others from a specific space that is defended.

Answer 3

Territorial

Question 4

The Russian biologist G. Gause was one of the first to support the Lotka-Volterra equations by studying the competitive interactions of ________.

Question 5

Interspecific ________ is where the competition for space influences access to food and nesting sites.

Question 6

Explain what is meant by a transplant experiment.

Question 7

The ________ equations predict the outcomes of interspecific competition under different conditions.

Question 8

When two organisms use a portion of the same resource simultaneously, it is referred to as ________ overlap.

Question 9

________ competition results when non-territorial behavioural interactions between two species result in negative effects on both species.

Question 10

How can a disturbance influence interspecific competition?

Question 11

In a competitive interaction in which species 1 has a higher carrying capacity (K₁)than species 2 (K₂), it is expected that species ________ will go extinct.

Question 12

________ is a relationship that affects the populations of two or more species adversely.

Question 13

Periods of drought or extreme environmental conditions may depress ________ below carrying capacity (K).

Question 14

The coexistence of competitors due to differences in the range of resources used or environmental tolerances is referred to as niche ________.

Question 15

When a species expands its niche in response to the removal of a competitor, the species has experienced competitive ________.

Question 16

The limnologist G. E. Hutchinson proposed the idea of the niche as a multidimensional response called a(n)________.

Question 17

The ________ principle states that two "complete competitors" cannot coexist.

Question 18

________ competition occurs when the occupation by one sessile individual precludes the establishment by others.

Question 19

Chemical interaction in plants, resulting in interspecific competition, is called ________.

Question 20

The portion of the fundamental niche that an organism actually exploits in the presence of competitors is called its ________ niche.

Question 21

In long-lived individuals, increasing biomass in favourable years to help mitigate interspecific competition during unfavourable years is known as

A)resilience.
B)altruism.
C)storage effect.
D)resource partitioning.

Question 22

In the Heller & Gates study on chipmunks in the Sierra Nevadas, when the least chipmunk was removed from its sagebrush habitat, the yellow-pine chipmunk did not experience competitive release. This is because the yellow-pine chipmunk had a ________ fundamental niche that ________ the sagebrush habitat.

A)general; included
B)specialist; included
C)compressed; excluded
D)restricted; excluded

Question 23

The ________ coefficients represent the per capita effect of an individual of one species on the other.

Question 24

A study which moves potential competitors in or out of sample plots is known as ________ experiments.

A)competitive
B)transplant
C)removal
D)null

Question 25

________ competition results when nonterritorial behavioural interactions between species result in negative effects on one or both species.

A)Consumption
B)Preemption
C)Encounter
D)Overgrowth

Question 26

In theory, when two species compete for the same resources, ________ will result.

A)competitive exclusion
B)coexistence
C)initial competition followed by mutualism
D)parasitism

Question 27

The portion of potential resources and conditions that an organism actually exploits as a result of interactions with other species is its

A)home range.
B)territory.
C)realized niche.
D)fundamental niche.

Question 28

According to the Lotka-Volterra equations, which of the following is NOT an expected outcome of competitive interactions between two species?

A)Species 1 drives species 2 to extinction.
B)Species 2 drives species 1 to extinction.
C)Both species coexist.
D)The population sizes of both species increase to infinity.

Question 29

Which of the following statements is incorrect?

A)Competition between species can occur for multiple resources.
B)Competition can be influenced by non-resource factors such as relative humidity.
C)The competitive relationship between two species may change over time as the environment changes.
D)The conditions assumed by the competitive exclusion principle are often observed in nature.

Question 30

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

A)niche overlap.
B)competitive release.
C)intraspecific competition.
D)territoriality.

Question 31

Competition in which the occupation of space by one individual prevents establishment in that space by another individual is referred to as ________ competition.

A)preemption
B)consumption
C)overgrowth
D)territorial

Question 32

If a species has a broad niche for several key factors it is known as a(n)

A)generalist.
B)specialist.
C)non-competitor.
D)parasite.

Question 33

Interspecific competition through the exploitation of a shared resource is sometimes referred to as ________ competition.

A)preemption
B)consumption
C)overgrowth
D)encounter

Question 34

________ studied the competitive interactions of several Paramecium species and supported the Lotka-Volterra competition models.

A)Charles Darwin
B)Gregor Mendel
C)Thomas Schoener
D)G) F. Gause

Question 35

In the Lotka-Volterra equations, the zero ________ represent the combined values of species 1 and species 2 under which population growth is zero (dN/dt = 0).

Question 36

A shift in a species' morphology, behaviour, or physiology in response to resource competition is referred to as ________.

Question 37

Which of the following is an assumption of the competitive exclusion principle?

A)The competitors have different resource requirements.
B)The competitors have the same carrying capacity (K).
C)The environmental conditions remain constant.
D)The superior competitor will have a lower population growth rate than the inferior competitor.

Question 38

The biologist Tilman used ________ to study competition between species.

A)diatoms
B)prairie plants
C)Paramecium
D)flour beetles

Question 39

In general, demonstrating the occurrence of competition under natural field conditions is problematic for all of the following reasons, EXCEPT that

A)it is difficult to know whether a population is at carrying capacity.
B)competition is impossible to measure in a natural setting.
C)scientists cannot control the environment.
D)scientists lack full knowledge of the life history requirements of natural populations.

Question 40

Which of the following is a nonresource (or nonconsumable resource)that can influence the outcome of competition among plant species?

A)temperature
B)light
C)water
D)nitrogen

Question 41

Two bird species compete in the forest for the same seeds. If α = 0.75 and β = 0.25, then

A)the rate of seed consumption is the same for both species.
B)the environment can supply both species since the sum of competition coefficients equals 1.
C)species 1 "wins" and will outcompete species 2.
D)species 2 "wins" and will outcompete species 1.

Question 42

Because of competition, it is rare that a species is allowed to utilize its entire fundamental niche.

Question 43

Climatic variation can have both density-dependent and density-independent effects on populations.

Question 44

Encounter competition results from the behavioural exclusion of some individuals by others from a specific space that is defended.

Question 45

The outcome of interspecific competition varies with environmental changes over time but does not vary over space.

Question 46

Competition for one resource often influences the ability of an organism to access other resources.

Question 47

The competitive ability of a species remains constant even when environmental conditions change.

Question 48

Competition has been regarded as a major force behind species divergence and specialization.

Question 49

The Lotka-Volterra competition models do not take into account variation between different environments.

Question 50

Preemptive competition occurs primarily among mobile organisms, such as small mammals.

Question 51

The biologist G. F. Gause conducted experiments with Paramecium that supported the predictions of the Lotka-Volterra competition models.

Question 52

The competitive exclusion principle assumes that environmental conditions remain constant.

Question 53

Which of the following is NOT expected following competition?

A)evolution of character displacement
B)evolution of increased niche overlap
C)competitive exclusion
D)increase in resources

Question 54

Changes in the outcome of competition over an environmental gradient are mediated by multiple environmental variables.

Question 55

The diagonal line that represents dN/dt = 0 in the graphical depiction of the Lotka-Volterra competitions equations is called

A)a competition coefficient.
B)the carrying capacity.
C)a zero-growth isocline.
D)a competitive exclusion parameter.

Question 56

The expansion of a species' niche in response to the removal of competition is referred to as competitive release.

Question 57

Interactions among species are always negative.

Question 58

In the experiments carried out by biologist David Tilman, two diatom species were able to coexist as long as silica was continually added to the water.

Question 59

According to the Lotka-Volterra equations, there are two possible outcomes of interspecific competition.

Question 60

The outcome of competitive interactions is determined solely by resource availability.

Question 61

Give several examples to illustrate how temporal and spatial variation in the environment can influence the outcome of competition.

Question 62

Competition rarely influences the evolution of species' niches.

Question 63

Explain the difference between a fundamental niche and a realized niche. Use an example to illustrate the role of competition in the establishment of each niche type.

Question 64

Outline three reasons why competition can lead to long-term coexistence of many species.

Question 65

Describe the competitive exclusion principle and outline its major assumptions. Provide an example of a scientific study that supports the competitive exclusion principle.

Question 66

Because all plants require the same few resources (light, water, essential nutrients), resource partitioning is rarely observed for plants.

Question 67

According to T. Schoener, there are six types of competitive interactions among species. Use examples to describe four types of these competitive interactions.

Question 68

Give an example showing how nonresource factors influence the outcome of competition.

Question 69

Explain how the outcome of competition between two species is a function of both species and environmental characteristics.

Question 70

Use a graph of the Lotka-Volterra equations to show how the outcome of competition between two species depends on the population carrying capacity.

Question 71

Explain the idea of "ghosts of competition past" coined by ecologist J. Connell. What does this concept refer to and why is it important to our understanding of evolution and diversity?

Question 72

Explain how it is possible for a diversity of potential competitors to coexist in the same community, despite the competitive exclusion principle.

Question 73

The findings of a laboratory study are more useful and applicable than the results of a field study.

Question 74

Competition can be difficult to demonstrate in the field because it is difficult to know whether populations are at or below their carrying capacity.

Question 75

Explain the significance between generalists and specialists when describing niche compression and competitive release.

Question 76

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