9.16. (10/23) Competition

Question 1

niche breadth

Answer 1

• variance of organism’s resource use
• can be narrow or broad

Question 2

niche separation

Answer 2

• distance between resource use for two species
• may be close or far

Question 3

niche overlap

Answer 3

• area of niche overlap between resource use of two species
• causes interspecific competition

Question 4

fundamental niche

Answer 4

range of resources usable by an organism when there is no interspecific competition
*true range of resources where this species could survive as long as there were no interactions with other species

Question 5

realized niche

Answer 5

• resource range used by an organism
• subset of fundamental

Question 6

competitive exculsion principle

Answer 6

• how much competition is occurring between two species
• two species cannot coexist indefinitely when they rely on the same resource/ niche

Question 7

what relationship do niche overlap and amount of competition have?

Answer 7

proportional

Question 8

Why can’t we fully trust numerical models for population?

Answer 8

• simpler
• empirical data and assumptions
• abstract
• human-conceived

Question 9

Who are Lotka and Volterra?

Answer 9

• 1926
• 1932
• developed the first mathematical models to simulate the effects of interspecific competition on population growth

Question 10

what is the logistic growth equation?

Answer 10

change in number/time = per capita rate of increase (intrinsic rate of increase) * population size * (K-N/K)
* as n goes to k, rate of change goes to 0
* competition between members of a species increases as N gets closer to K
*models intraspecific competition

Question 11

What is the equation for modeling interspecific competition?

Answer 11

Species 1: dN1/dt=rmax1N1(K1-N1-α12N2/K1)
Species 2: dN2/dt=rmax2N2(K2-N2-α21N1/K2)

Question 12

What terms account for the negative effect of interspecific competition?

Answer 12

competition coefficients α12 and α21

Question 13

What is α12?

Answer 13

effect of species 2 on reducing the abundance of species 1

Question 14

What is α21?

Answer 14

effect of species 1 on reducing the abundance of species 2

Question 15

What happens to the negative effect of the competition coefficient when the competitor population increases?

Answer 15

gets stronger

Question 16

How do we use phase space to model interspecific competition?

Answer 16

number of species on x and y linked through time

Question 17

What are the steps to using interspecific competition modeling?

Answer 17

1. equilibrium point (N1=0, K1-N1-α12N2=0)
   2.

Question 18

species 1 zero growth isocline

Answer 18

N1= K1-α12N2
negative line

Question 19

what does the lotka-volterra model assume?

Question 20

allopatric

Question 21

sympatric

Question 22

character displacement

Answer 22

• islands
• specialize