Chapter 12 Species Interactions and Interspecific Competition

Question 1

Mutualism

Answer 1

both benefit

Question 2

commensalism

Answer 2

good for one, one neutral

Question 3

Competition

Answer 3

both negative

Question 4

amensalism

Answer 4

one negative, one neutral

Question 5

Species interactions influence the respective populations (species) at two timescales

Answer 5

• population dynamics (demographics birth/death)

- agents of natural selection

Question 6

Coevolution

Answer 6

process in which two species undergo reciprocal evolutionary change through natural selection

Question 7

Fundamental niche

Answer 7

environmental conditions under which a species can survive and reproduce… set up conditions under which a species can persist

Question 8

Realized niche

Answer 8

the portion of the fundamental niche that a species actually exploits as a result of interactions with other species… accounts for interspecific competition that restricts the niche!

Question 9

Niche shift

Answer 9

shift of niche when accounting for interspecific competition… reduced availability of shared resource leads to shift in niche

Question 10

Inter vs intra comp

Answer 10

inter between species

intra in species

Question 11

alpha

Answer 11

represent per capita effect of population of population 2 ON population 1

Question 12

beta

Answer 12

represent per capita effect of population of population 1 ON population 2

Question 13

If a coefficient is 1, then it

Answer 13

isn’t being affected

Question 14

If coefficient is less than 1

Answer 14

helps the population

Question 15

if coefficient is more than 1

Answer 15

hurts that population

Question 16

When they both have lower carrying capacities,

Answer 16

they coexist because there is another resources for both

Question 17

When both have high carrying capacities

Answer 17

competition is fierce and the more abundant species wins!

Question 18

Influence of interspecific competition on carrying capacity. (a) If we assume that the carrying capacity of species 1 (K1 ) is 1000 individuals, and that individuals of species 2 (N2 ) are identical to species 1 (N1 ) in their use of the shared, limited food resource, the presence of each individual of species 2 will effectively reduce the carrying capacity of species 1 by one individual.

Answer 18

true

Question 19

Zero isoclines

Answer 19

the combinations of N1 and N2 that creates 0 population growth for a population… population growth is 0

Question 20

Competitive exclusion principal

Answer 20

two species with the same niche cannot coexist in the same community… one will exclude the other as a result of competition… assumes all same needs for two species, which RARELY ever exist in nature

Question 21

Non-resource factors

Answer 21

temperature, pH, etc

Question 22

Temporal variation in environment

Answer 22

variation in time allows for different species to exist… while there is variation both species will exist… if it were held constant than only one would win!… never fully dies off

Question 23

Mixture vs monoculture

Answer 23

mixture – species share resources/ monoculture, grown separstely

Question 24

Where a species is most abundant does not necessarily reflect its physiological optima (fundamental niche). (t/f)

Answer 24

false!

Question 25

Resource partitioning

Answer 25

differences in resource use by co-existing species is referred to as “resource partitioning” INFLUENCED BY COEVOLUTION

Question 26

Character displacement

Answer 26

when the outcome of competition leads to a change in morphology or behavior or physiology such as darwins birds or aubrey