Population Growth

Question 1

Reindeer on St. Paul Island

Answer 1

• Important food source
• population increased exponentially
• eventually population plummeted

Question 2

What do you need to understand to predict a collapse?

Answer 2

• population growth
• density dependence
• resource exploitation
• stochastic events

Question 3

birth rate

Answer 3

number of young born per female

Question 4

fecundity

Answer 4

table of birthrates for females of different ages

Question 5

Annual plants: what are they, which one did we study, and what type of population growth do they have?

Answer 5

• Annual plants live for one year
• we studied phlox drummondii
• They demonstrate geometric growth

Question 6

Geometric rate of increase equation

Answer 6

future population / current population

Question 7

R0 (net production rate)

Answer 7

• growth rate per generation
• in annual plants its the same as the rate of increase
• normally it is Ixmx

Question 8

Exponential population growth

Answer 8

• overlapping generations
• unlimited environment
• constant rate
• usually when a population is coming to a new area for the first time

Question 9

Exponential growth formula for current population

Answer 9

N0e^rt

Question 10

r

Answer 10

intrinsic rate of increase

Question 11

Net population growth (R)

Answer 11

r(change in t)N

Question 12

change in population right now

Answer 12

rN

Question 13

Scott’s pine

Answer 13

• growth seen in pollen accumulation in lakes

- after colonization, experienced exponential growth for 500 years

Question 14

Whooping crane

Answer 14

-after federal protection, they experienced exponential growth

Question 15

Elephants in Kruger park, south africa

Answer 15

• grew at exponential rate after hunting was banned

- not necessarily a good thing. Large mammals tend to reach a peak and then plummet when they grow like this

Question 16

Collared dove

Answer 16

• had new habitat
• grew exponentially at first
• rate of growth started decreasing
• most likely bc of density dependence

Question 17

Density independant growth

Answer 17

growth set by fixed parameters (R, r, or gamma)

Question 18

density independent factors

Answer 18

fires, floods, tornados, etc…

Question 19

Density dependent growth

Answer 19

assumes limiting factor in the environment

Question 20

density dependent factors

Answer 20

food, water, nest sites, disease

Question 21

logistic population growth

Answer 21

for populations that are density dependent

-S curve

Question 22

K (carrying capacity)

Answer 22

the limit to the population that an environment can sustain

-birth and death rates at this number will even each other out

Question 23

equation for current logistic growth

Answer 23

rN(K-N)/K

Question 24

Demography

Answer 24

The study of all these statistics and how they change in a population over time

Question 25

Survivorship curve

Answer 25

Shows log of survival rate at different ages

Question 26

Types of survivorship curves

Answer 26

1. Tend to die when they’re old
2. Constant rate of death throughout life
3. Tend to die when they’re young

Question 27

Age structure diagrams

Answer 27

show history of survival, reproduction, and growth

• blue on bottom, tan in middle, red on top
• steeper pyramid means faster growth

Question 28

White oaks

Answer 28

biased towards young trees

-must be sufficient reproduction for replacement

Question 29

Rio Grande Cottonwood

Answer 29

• old trees weren’t being replaced

- no floods = fewer germination areas

Question 30

life table

Answer 30

age specific summary of survival and reproduction rate within a population
-usually follows a cohort

Question 31

3 types of life tables

Answer 31

1: cohort = identifies individuals born at the same time and keeps records from birth
2: static = records age of death for individuals
3: age distribution = calculates difference in proportion of individuals at different ages