Ecology
Lecture 1 Population Ecology 16/02/21
Introduction
- The study of factors that affect population size, such as birth rate, death rate, immigration
rate, and emigration rate.
- The study of ecology allows us to understand the distribution and abundance of organisms
and how they conserve them.
Population growth
- Robins: from 2, to 6, to 18 in 2 generations.
- 9 pairs x 6 = 54 robins (27 pairs).
- 27 x 6 = 162 robins (81 pairs).
- 81 x 6 = 486 robins (243 pairs) and so on…
- After 12 generations, you have over 1 million robins.
Exponential growth
- This is a J-shaped population trajectory.
- Aka geometric growth.
- Basically, the population increases at an
ever-increasing rate.
How do we model this?
- To understand how populations grow, we need to model population growth.
- If we know: the current population size (N 0), the amount of time over which the population
grows (t), the intrinsic growth rate of the population (t) (this is the highest possible rate of
growth that is achievable by the population),
- We can estimate how a population will grow over time under ideal conditions.
Exponential growth model
Lecture 1 Population Ecology 16/02/21
Introduction
- The study of factors that affect population size, such as birth rate, death rate, immigration
rate, and emigration rate.
- The study of ecology allows us to understand the distribution and abundance of organisms
and how they conserve them.
Population growth
- Robins: from 2, to 6, to 18 in 2 generations.
- 9 pairs x 6 = 54 robins (27 pairs).
- 27 x 6 = 162 robins (81 pairs).
- 81 x 6 = 486 robins (243 pairs) and so on…
- After 12 generations, you have over 1 million robins.
Exponential growth
- This is a J-shaped population trajectory.
- Aka geometric growth.
- Basically, the population increases at an
ever-increasing rate.
How do we model this?
- To understand how populations grow, we need to model population growth.
- If we know: the current population size (N 0), the amount of time over which the population
grows (t), the intrinsic growth rate of the population (t) (this is the highest possible rate of
growth that is achievable by the population),
- We can estimate how a population will grow over time under ideal conditions.
Exponential growth model
