module 11

Question 1

Competition

Answer 1

Any use or defense of a resource by one individual that reduces the availability of that resource to other individuals
resources may include:
Food
Water
Sunlight
Habitat
Space
Matings

Question 2

Intraspecific
what kind of model?
drives what change?

Answer 2

Competition between members of the same species
Logistic Growth Model
Drives Population Regulation & Evolutionary Change

Question 3

Interspecific
what kind of model
can lead to

Answer 3

Competition between members of >1 species
Depresses Both Populations
Lotka-Voltera Models
Can Lead to Extinction or Extirpation

Question 4

Niches influence

Answer 4

Summarizes environmental factors that influence:
Reproduction of a species.
Growth
Survival

Question 5

Hutchinson defined niche as:

n-dimensional hyper-volume

Answer 5

n-dimensional hyper-volume

n equates the number of environmental factors important to survival and reproduction of a species.

Question 6

limiting resource

Answer 6

Limiting Resource

-One or few resources that establish K

Question 7

fundamental niche

realized niche

Answer 7

Fundamental niche
-hypervolume-all the different ranges of environmental conditions that a species is capable of surviving
Realized niche
-Includes interactions such as competition that may restrict environments where a species may live.

Question 8

Conditions for Competition

Answer 8

Species found in the same area at the same time.

Species utilize a shared Resource
Shared Resource is a Limiting Resource of Species
Shared Resource found in a Limited supply

Question 9

Competitive Exclusion Principle
Gause: Principle of Competitive Exclusion
-2 species with competing for same resource

Answer 9

2 species with competing for the same resource cannot coexist indefinitely.
One will be a better competitor
Thus have higher fitness
Eventually exclude the other.

Question 10

Hardin’s Version

-complete competitors

Answer 10

“Complete Competitors Cannot Coexist”

Two or more species cannot coexist on a single limiting resource

Question 11

If Competitive Exclusion occurs, Only one species persists

Answer 11

Competition difficult to observe

“Ghosts of Competition Past”

Question 12

Human Introductions

Answer 12

Best natural means of observation of Competition

Question 13

Interspecific Competition Among Herbaceous Plants
growth rates increase in ______ density population
competition more intense ate _____ population density
size decreases population density

Answer 13

Plant growth rates and weights have been found to increase in low density populations.
Competition for resources is more intense at higher population densities.
Usually leads to mortality among competing plants.
Self-Thinning

size decreases population density increases

Question 14

Lotka-Volterra

Answer 14

Effect of interspecific competition on population growth of each species:

Question 15

a

Answer 15

α: Effect of individual of species 2 on rate of pop. growth of species 1.

Question 16

b

Answer 16

β: Effect of individual of species 1 on rate of pop. growth of species 2.

Question 17

which model predicts coexistence of two species when, for both species:

Answer 17

LV model
Interspecific competition is weaker than intraspecific competition.
-Allows regulation within species to occur
-Without, stronger competitor will outcompete weaker.

Question 18

Predict population growth for the two species will stop when:

Answer 18

b=d

Zero Growth Isoclines

Question 19

-logistic competition
Outcome Independent of rate of growth (r)

Equilibrium Occurs when

Answer 19

Only affects rate

Isoclines Cross

Question 20

When grown alone

Answer 20

carrying capacity determined by intraspecific competition.

Question 21

When grown together

Answer 21

P. caudatum quickly declined.
Reduced resource supplies increased competition.
-competition

Question 22

Growing the two species together

-suggested interspecific competition restricts the

Answer 22

Suggested interspecific competition restricts the realized niches of both species to fewer environmental conditions.

Question 23

Park-non resource factors

Answer 23

Non-Resource Factors Influence Competition
moist dry
-environmental factors

Question 24

Sympatric Species

Answer 24

Species that that coexist in the same geographic area

Question 25

Allopatric Species

Answer 25

Species whose ranges do not overlap

Question 26

Competition and Niches
-competition can restrict species to their ______
but if completive interactions are strong
it can produce an ______
which will change the ______

Answer 26

Competition can restrict species to their realized niches.
But if competitive interactions are strong and pervasive enough
May produce an evolutionary response in the competitor population.
Changes fundamental niche.

Question 27

The Lotka-Volterra model predicts that stable coexistence of two species is possible only when

Answer 27

intraspecific competition has a greater effect than interspecific competition.

Question 28

Character Displacement

caused by

Answer 28

• Divergence in characteristics of two otherwise similar species where their ranges overlap
• Caused by selective effects of competition between the species in the area of overlap

Question 29

Degree of competition

Answer 29

assumed to depend upon degree of niche overlap

-> Interspecific competition has been predicted to lead to directional selection for reduced niche overlap.