Topic 11 + 12

Question 1

What is the difference between interspecific and intraspecific interactions?

Answer 1

Interspecific is between species, intraspecific is within a species

Question 2

What are the two types of competition (which can be inter and intra specific)?

Answer 2

Resource competition (resource is limited supply)
Interference competition (damage to other individuals)

Question 3

Define niche overlap

Answer 3

The set of resources a species consumes is the same as another set of resources another species consumes

Question 4

What is the difference between the fundamental niche vs realized niche?

Answer 4

The fundamental niche is the ideal conditions in which a species can survive and reproduce, while the realized niche is the actual conditions in which a species lives

Question 5

What happens to realized niches with the introduction of a competitor?

Answer 5

It gets smaller

Question 6

What is the difference between the altitude upper and lower limit of barnacle populations according to the Connell study?

Answer 6

The upper limit is composed of barnacles drying out
The lower limit is composed of biotic factors such as competition

Question 7

What theory states that two species with identical niches cannot coexist indefinitely?

Answer 7

The theory of limiting similarity

Question 8

What is competitive exclusion?

Answer 8

If two organisms have too much niche overlap, one will go extinct through this mechanism

Question 9

What is the formula for logistic population growth?

Answer 9

dN/dt = rN(1-N/K)

Question 10

What is the formula for logistic population growth with respect to a competitor n2?

Answer 10

dN1/dt = R1N1 [(K1-N1 - alpha12N2)/k1]

Question 11

What does alpha12 describe?

Answer 11

The effect of an individual of species 2 on species 1

Question 12

What are the 2 effects of competitors on a population?

Answer 12

1. Slow population growth
2. Reduce maximum population size

Question 13

What is the formula to find the number of a population with competition?

Answer 13

N1 = K1 = alpha 12*n2

Question 14

At equilibrium, how can we describe the slopes of competing populations?

Answer 14

The slopes of both are equal to 0

Question 16

What is the logistic population growth graph combined with competition based off other individuals called?

Answer 16

The Lotka-Volterra chart

Question 17

What does Tillman suggest the most successful competitor is able to do?

Answer 17

They are able to reduce the availability of a limiting to a lower lever, (r*)

Question 18

What does Tillman say about the R* of the more effective competitor?

Answer 18

It is lower

Question 19

What happens in a Tillman graph when one resource has a higher r* for one species and the other resource has a higher r* for the other species?

Answer 19

They may coexist, or exclude the other?

Question 20

What can we say about the trajectory of r* values on coexisting species Tillman graphs?

Answer 20

Resource amounts converge to the intersect of the two lines

Question 21

What does the Tillman graph populations depend on?

Answer 21

Where resources start

Question 22

Define niche partitioning

Answer 22

When individuals use an environment in different ways than they can, partitioning between competitors

Question 23

What can niche partitioning lead to?

Answer 23

Character displacement (separation populations into different niche through evolutionary change in the same environment)

Question 24

What is are the 6 types of competition according to Schoener?

Answer 24

1. Consumptive (food)
2. Preemptive (space)
3. Overgrowth (growing over)
4. Chemical - allelopathy
5. Territorial -territory
6. Encounter - I interaction

Question 25

What is diffuse competitions?

Answer 25

Many weak pairwise interactions that are hard to detect individually

Question 26

How was diffuse competition measured?

Answer 26

Control uncleared area with planted seeds compared to a cleared out field with planted seeds

Question 27

What is the Tillman graph called?

Answer 27

The Tilman’s mechanistic model of interspecific competition

Question 28

What is allelopathy?

Answer 28

The release of chemicals by an organism that impacts the growth/survival/reproduction of another.

Question 29

What is competitive release?

Answer 29

It is following the loss of a competing species, increased productivity and distribution of a species

Question 30

What are Diamond’s 1975 rules?

Answer 30

1. Some species never coexist
2. Species occurring together should have a lower niche overlap than two random species

Question 31

What is the formula for diffuse competition?

Answer 31

(SUM[(C-U)/C])/n where C is dry biomass of cleared areas, u is dry biomass of uncleared, and n is the number of species in the cleared area

Question 32

In a zero growth isocline graph, when does the graph converge and when does it diverge?

Answer 32

Converges when K1/K2 is towards origin, diverges when its away from origin.