02. Populations: growth and decline

Question 1

Ecology

Answer 1

The study of the relationships of organisms to one another and to the environment

Question 2

Population

Answer 2

includes all individuals of a species that live and reproduce in a particular place

Question 3

Population Ecology

Answer 3

The study of how populations interact and respond to their environment

Question 4

What are the three key features of a population?

Answer 4

1. Size (# of living individuals)
2. Range (the space over which individuals occur)
3. Density (the population size divided by its range)

Question 5

Compare the different patterns of population distribution (clumped, random, uniform)

Answer 5

Clumped: organisms are clustered together in groups
Random: organisms have an unpredictable distribution
Uniform: organisms are evenly spaced over the area they occupy

Question 6

What are the two methods for determining population size?

Answer 6

1. Counting all the individuals

2. Sampling to estimate population size

Question 7

What are the two types of sampling?

Answer 7

1. Sampling - for sedentary organisms, by counting individuals within several areas of the same size and then estimating the population size
2. Mark and recapture - individuals are marked, captured, and some are recaptured. To estimate population size the Lincoln-Peterson index is used

Question 8

Lincoln-Peterson Index & its assumptions

Answer 8

N=(C/R)*M
N - Number of individuals 
C - Number captured
R - Number recaptured 
M - Marked 
Assumptions: population is closed, each individual has an equal probability of being captured.

Question 9

Factors that affect population size (4)

Answer 9

Birth, Mortality, Emigration, Immigration

Question 10

Change in population size formula (ΔN)

Answer 10

ΔN = N1 - N0

= (B - D) + (I - E)

Question 11

Rate of change in population size formula

Answer 11

ΔN/Δt

Question 12

Per capita growth rate formula

Answer 12

r = (ΔN/N0)/Δt
if r > 0 population is increasing
if r < 0 population is decreasing

Question 13

Exponential growth rate formula

Answer 13

Nt = N0*(1 + r)^t

Question 14

Intrinsic growth rate

Answer 14

the maximum per capita growth rate for population

Question 15

Logistic growth

Answer 15

N2 = N1 + rN1[(K-N1)/K] 
K = carrying capacity

Question 16

Density dependent growth

Answer 16

When population size is affected by predation, parasitism, food, mates etc.

Question 17

Density independent growth

Answer 17

When population size is affected by factors that are not associated with density (ex. Forest fires, climate change, etc.)

Question 18

The three survivorship curves

Answer 18

Type I - Survival is high at an early age
Type II - survival remains constant
Type III - Survival is low at an early age

Question 19

r-strategists

Answer 19

-Many offspring, early & frequent reproduction, short life span

Question 20

K-strategists

Answer 20

-Few offspring, delayed & infrequent reproduction, long lifespan, population densities near K

Question 21

Metapopulation

Answer 21

a group of populations linked by immigrants. It is a population made up of smaller populations linked by occasional movements of individuals between them
A population of populations separated by non-hospitable habitat

Question 22

Metapopulation structure

Answer 22

Island biogeography:

diversity depends on the size of the island, and the distance the island is from the mainland

Question 23

Species area relationship:

Answer 23

S = cA^x
S - # of species at equilibrium
c - constant associated with the species in question
A - habitat area
x - experimentally determined exponent between 0.1 and 0.4