Lecture 7- Pop parameters, pop change

Question 1

Population

Answer 1

A group of potentiall interbreeding individuals of the same species at the same place at the same time (N)

Question 2

Natality

Answer 2

Reproduction/fecundity, actual or potential

Question 3

Mortality

Answer 3

Death, realized (actual lifespan) or potential (Max lifespan)

Question 4

Imm/Emigration

Answer 4

dispersal, assumed to be equal

Question 5

Age-structured pop

Answer 5

population made up of different age classes

Question 6

Stage-Structured pop

Answer 6

pops made up of stages (used when age classes are not available, survival/reproduction are more dependant on stage than age)

Question 7

Per capita rates

Answer 7

Average rates per individual in a population

Question 8

Age-specific survival rates

Answer 8

Survival rate for a specific age class

Question 9

Intrinsic rate of increase

Answer 9

The max rate of increase if there was no limit to resources, competition or predation (r^m or rmax)

Question 10

instantaneous rate of increase (r)

Answer 10

The difference between birth and deaths (+=increasing, - = decreasing, and 0=nochange)

Question 11

Finite rate of increase (lamda or R)

Answer 11

Rate of pop change (e^r), (lamda>1 =increasing, Lamda<1=decreasing, lamda=1 stable)

Question 12

Carrying Capacity (K)

Answer 12

The natural limit to population size set by resource availability

Question 13

Basic equation for population growth?

Answer 13

Nt+1 = Nt + B-D

Question 14

What are the equations for per capita birth and death rate?

Answer 14

Per capita (B)= (total births during time t)/Nt
Per capita (D)= (total deaths during time t)/Nt

Question 15

What is the equation for rate of change?

Answer 15

r=B-D

Where r is pop growth rate

Question 16

How does the finite rate of increase (lamda) relate to the instantaneous rate of increase (r) ?

Answer 16

(lamda) = (e^r)

Question 17

express lamda as a result of a ratio of two censuses

Answer 17

lamda = Nt+1/ Nt

Where Nt+1 is the new census and Nt is the previous census

Question 18

how do you find the population in the next time period using lamda?

Answer 18

(lamda)(Nt) = Nt+1

Question 19

What 3 ways can r and lamda express pop change?

Answer 19

Stable- (r=0, Lamda= 1)
Increasing (r>0, Lam>0)
decreasing(r<0)

Question 20

Given r=0.69 and No=50, what will N be after 20 years?

Answer 20

e^rt X No= Nt
(e^0.69x20) X 50 = N20
N20=~49 mil

Question 21

Is rmax (intrinsic rate of increase) typically found in nature?

Answer 21

No, there are often limits to pop growth. Food, comp, pred

Question 22

When can intrinsic rate of increase occur?

Answer 22

Colonizing new areas or recovering from over exploitation

Question 23

How is carrying capacity built into other models (What equation uses L to relate to r or rmax)

Answer 23

r=rmax (1-N/K)
r- intantaneous rate of increa
rm- max rate of increase

Question 24

How does pop ecology deal with variation in traits among individuals?

Answer 24

simplifying assumptions that individuals are identical in a pop. Some pop variations can be predicted as a function of stage/ age. can create models to account for differences.