Fill in the blanks for lecture 6

Question 1

What is competition?

Answer 1

Negative interaction between individuals due to limited resources.

Question 2

A resource is any substance or factor which can lead to ________ _______ _______ ________ as its availability in the environment is increased, and which is consumed by an organism. -Tilman 1982

Answer 2

increased population growth rates

Question 3

Resources are entities which __________ ________ __ _________ ________ and are consumed in the process.

Answer 3

contribute positively to population growth

Question 4

Resources can be classified as either ________ or ________.

Answer 4

Abiotic or biotic

Question 5

Abiotic factors are ___-_______. These include? (4)

Answer 5

non-living. These include minerals, nutrients, light, space.

Question 6

Biotic factors are ______ or _____-_________.

These include? (3)

Answer 6

living or self producing.

prey for predators, plants for herbivores, seeds for granivores

Question 7

_________ competition is between individuals of the same species.

Answer 7

Intraspecific

Question 8

__________ competition is between individuals of a different species.

Answer 8

Interspecific

Question 9

If an individual encounters increasing density of other individuals, it will:
- _________ its growth rate
- be _______ when it matures
- leave _______ offspring
- the offspring will be of _______ quality
- mortality will __________.
This is __________ competition.

Answer 9

1) decrease
2) smaller
3) fewer
4) lower
5) increase
6) Intraspecific

Question 10

______________ competition is likely the major factor influencing community structure.

Answer 10

interspecific

Question 11

Interspecific competition between 2 species occurs where individuals of 1 species suffer a ________ ___ _______ ____ from a second species due to:

1) ________ competition (resource competition)
2) _________ competition (contest competition)

Answer 11

1) reduction in growth rate
2) Exploitative
3) Interference

Question 12

Exploitative competition is also called __________ competition.

Answer 12

resource

Question 13

Interference competition is also called _______ competition.

Answer 13

contest

Question 14

Exploitative competition occurs when two or more species share a limited resource, ________ ______ _________ ________ for the other species.

Answer 14

less resource available

Question 15

Interference competition occurs when one species limits the ______ __ ______ _______ to a ________ __________.
Often involves __________ or occupying a _______ to the exclusion of the other.

Answer 15

1) access of another species
2) limiting resource
3) aggression
4) space

Question 16

________ effects are linked to interference competition.

Answer 16

interference

Question 17

For logistic growth of two species grown _______, there is an exponential growth until one reaches the carrying capacity, K.

Answer 17

alone

Question 18

______-________ competition model.

Answer 18

Lotka-volterra

Question 19

If two species are competing. The per capita effect of species 2 on species 1 is given by _____. The per capita effect of species 1 on species 2 is given by ____.

Answer 19

1) aN(2) (alpha*N of species 2)

2) BN(1) (beta*N of species 1)

Question 20

If the coefficient of competition is zero, then competition is _______.

Answer 20

absent

Question 21

The stronger the competition, the ______ the values of alpha and beta.

Answer 21

larger

Question 22

Suppose that K1 = 100, N2 = 100, alpha = 0.2.

How many individuals is removed from species 1 by species 2?

Answer 22

aN2 = 0.2*100
=20
So, species 2 removes 20 individuals from species 1.

Question 23

aN2 is the total ________ effect of species _ on species _.

Answer 23

competive;2;1

Question 24

For the graphical analogy for interspecific competition, the frame represents the _______ _______ (_) for species 1.

Answer 24

carrying capacity (K)

Question 25

In the graphical analogy for interspecific competition, each individual _______ __ _______ __ ___ ______ _______ ___ __ __________ __ _ ____.

Answer 25

consumes a portion of the limited resource and is represented by a tile.

Question 26

For the graphical analogy of interspecific competition, assume that individuals of species 2 reduce the carrying capacity 4 times as much as species 1. This means that the tiles of species 2 are ___ times the size of species 1. Thus, alpha = __.

Answer 26

4; 0.4

Question 27

Assumptions of the Lotka-Voltera competition model: 1) the effect of one species on the other is ______ 2) Carrying capacities are ________ 3) The environment is ________

Answer 27

1) linear 2) constant 3) stable

Question 28

A species will stop growing when either __ = 0 or __ = 0.

Answer 28

r = 0 or N = 0

Question 29

Zero percent growth is given by a species _______.

Answer 29

isocline

Question 30

To plot the isocline, what values are used?

Answer 30

Recall, N1 = K1 - aN2 Set N1 = 0 aN2 = K1 N2 = K1/a Set N2 = 0 N1 = K1 slope is dN1/dT = 0 N2 on y, N1 on X, when zero, reach fixation.

Question 31

______ the isocline we will see an increase in growth rate until the stable state is reached. _______ the isocline, the opposite occurs.

Answer 31

Below; above

Question 32

The isocline (for species 1) represents all combinations of numbers at which ______ _ _____ _____ _______.

Answer 32

Species 1 will stop growing

Question 33

If there is a mixture of species 1 and 2 above the species 1 isocline, then N1 must ________ = _______ _______ _____

Answer 33

decrease; negative growth rate

Question 34

Similarly, if there is a mix of species 1 and 2 below the species 1 isocline, then N1 must _____ = _____ ______ _____.

Answer 34

increase; positive growth rate

Question 35

Being above or below the species 1 isocline will result in movement that is _______ to the x-axis.

Answer 35

parallel

Question 36

Being above or below the species 2 isocline will result in movement that is ________ to the x-axis.

Answer 36

perpendicular

Question 37

What values and variables are important for the species 2 ZPG isocline?

Answer 37

Recall, N2 = K2 - BN1 Set N1 = 0 N2 = K2 Set N2 = 0 K2 = BN1 N1 = K2/B

Question 38

Now, combine the ZPG isoclines for both species. Identify the regions where _____ ______ ______ and _______.

Answer 38

both species increase and decrease

Question 39

The regions where both species increase or decrease are?

Answer 39

Below both ZPG isoclines or above both.

Question 40

The L-V model makes _ mutually exclusive predictions: | ___ cases of competitive _______ and ___ cases of competitive __________.

Answer 40

4; 2-exclusion; 2-coexistence

Question 41

The four mututally exclusive predictions are?

Answer 41

Exclusion: 1) species 1 wins and species 2 is excluded 2) Species 2 wins and species 1 is excluded Coexistence: 3) Stable, equilibrium coexistence. Both species persist. 4) Unstable non-eqb coexistence. Persistence is short lived.

Question 42

For the competitive exclusion, the distance that the isoclines are apart ______ affect the outcome.

Answer 42

doesn't

Question 43

Draw prediction 1: Species 1 wins. Also note the direction the growth rate is going in each area between, above or below ZPG isoclines.

Answer 43

Refer to notes (27)

Question 44

Draw prediction 2: Species 2 wins. Also note the direction the growth rate is going in each area between, above or below ZPG isoclines

Answer 44

Refer to notes (28)

Question 45

Draw Prediction 3: Stable equilibrium. Also note the direction within each zone delimited by the ZPG isoclines, along with the intercepts. Also note the stable equilibrium point and indicate the densities of both species exist beneath their own K.

Answer 45

Refer to notes (29) (30)

Question 46

Since coexistence occurs, it doesn't matter at what density you begin the population; all ________ on the stable equilibrium point.

Answer 46

converge

Question 47

Draw prediction 4: unstable non-equilibrium exists. Indicate the direction between the ZPG isoclines and the final equilibrium points. Also write the intercepts and which species density belongs to what axis.

Answer 47

Refer to notes (32)

Question 48

There are two types of equilibrium predicted by the L-V model. These are _______ and __________. Equilibrium is only reached when the diagonals ________ each other.

Answer 48

1) stable and unstable | 2) Cross

Question 49

Stable coexistence - both _______ __-_________.

Answer 49

competitors co-exist

Question 50

Unstable coexistence - both competitors can coexist, but __ __ _______.

Answer 50

it is unlikely

Question 51

The coexistence afforded by unstable equilibrium is only __________ and typically ends in the _________ __________ of one of the species.

Answer 51

1) Temporary | 2) Competitive exclusion

Question 52

What are the criticisms of the L-V model? (4)

Answer 52

1) Assumes density independent competition 2) Deals only with competition between 2 species 3) Assumes that we can ignore other ecological processes 4) Assumes constant environmental conditions and logistic growth in the absence of competition

Question 53

Problem: You are studying competition between red and black desert scorpions. For the red scorpion, K = 100 and a = 2 For the black scorpion, K = 150 and B = 3 Suppose the initial population sizes are 25 red scorpions and 50 black scorpions. What is the competitive outcome?

Answer 53

``` 1) Graph the isoclines for each species Note: N1 = K1 - BN2 -make N1 and N2 = zero N2 = K2 - aN1 - make N1 and N2 = zero ``` 2) Plot the initial population sizes 3) Predict the short term dynamics of each population. - unstable coexistence 4) What is the final outcome of the interspecific competition? - black scorpion wins