Lecture3_Population Dynamics

Question 1

What is Population Dynamics?

Answer 1

The study of how population size and density change over time and space, reflecting organism-environment interactions

Question 2

What are the three main purposes of studying population dynamics?

Answer 2

Conservation strategies, management planning, and risk analysis/projections

Question 3

Define a population

Answer 3

All organisms of a species in a specified area.

Question 4

Define Metapopulation

Answer 4

A population consisting of subpopulations that interact through genetic mixing

Question 5

What is recruitment?

Answer 5

refers to the process by which juvenile organisms, settle, survive, and become part of a specific population or community.

Often describes the transition from larval/juvenile stage to a breeding adult

Question 6

What conditions enable exponential growth?

Answer 6

Exponential growth is idealized and rare in nature. It can occur temporarily under exceptional conditions, such as:
Species introduced to a new environment without predators or plankton blooms in nutrient-rich waters

Question 7

when lookings at a per capita rate of population growth vs population size graph what does density independence look like?

Answer 7

density independence looks like a horizontal line, the rate is the same no matter what the pop. size

Question 8

What characterizes exponential growth?

Answer 8

No individual distinctions (no age/size classes)

no density dependence

constant per capita growth rate

Question 9

What is Sigmoidal Growth? (Logistic Model)?

Answer 9

Density dependent growth

Initially, the population grows rapidly (exponential phase).

Growth slows as resources become limited.

Population stabilizes at the carrying capacity K

Question 10

What is a structured population model?

Answer 10

Typically visualized as population pyramids, which graphically display age and sex distributions.

age structured
sex structured

Question 11

What does R₀ > 1 indicate?

Answer 11

Population is growing

Question 12

whats a life table?

Answer 12

Summarize the likelihood of survival, mortality, and reproduction by age.

Question 13

What do like tables show?

Answer 13

Age Class X
Number in each age class Nx
Proportion of surviving individuals from age 0: Ix
Average fertility of a female of x age class mx

Question 14

What can you calculate from life tables?

Answer 14

reproductive rate: lxmx
stable age distribution: Cx
reproductive value: Vx
intrinsic growth rate: r

Question 15

What is r?

Answer 15

Intrinsic growth rate

Question 16

What information does a Leslie Matrix contain?

Answer 16

Fecundity on top row and survival probabilities on sub-diagonals

Question 17

Why are size-structured models advantageous?

Answer 17

They don’t require age determination and use size compositions for flexible modelling. good for many species such as corals

Question 18

What are the three types of variability in stochastic models?

Answer 18

Environmental, demographic, and measurement error

Question 19

What is the basic population growth equation?

Answer 19

N(t+1) = N(t) + B - D + I - E

Question 20

What parameters are included in stage-based models?

Answer 20

Probability of remaining in stage (Pi), probability of stage transition (Gi), and stage fecundity (Fi)

Question 21

What factors influence recruitment in marine environments?

Answer 21

Stock size and environmental conditions

Question 22

What is the purpose of sensitivity analysis?

Answer 22

To determine which parameters have the greatest effect on population growth

Increase one parameter (e.g., survivorship or fertility) by a set percentage (e.g., +25%).

Measure the effect on λ

Reset the parameter to its original value and repeat with other parameters

Question 23

Whats a stochasticity in Models

Answer 23

Adds variability to model parameters (e.g., fecundity, survival) to reflect real-world uncertainty.

Produces multiple trajectories to reflect variability in outcomes