1. ESM 221 Lecture 5 Monday, April 17, 2017
Core concepts from the reading
Discussion
Models to address these
Hypotheses, models
Population dynamics
Variability
Density dependent factors
Extinction/ irreversible loss of biodiversity
Biodiversity loss – strong sustainability would avoid this because it can never be recovered or substituted

2. Key concepts from the text
Should see some of this in Biology courses also

3. Population dynamics Be able to define these terms: Population size
Population distributions
Be able to define these terms:
Population size
Population density
Population distribution
Clumped
Uniform
Random
Sex Ratio
Age Structure
Why do these matter to population growth & stability?

4. Keystone species
Create favorable environmental conditions for other species
Impact beyond just their community production rate (i.e. growth rate)
Examples:
Beavers
Elephants
Alligators

5. Succession
Predictable pattern of plants in a community that varies over time
Earlier species “replaced” with later species
Prepare the environment for them to be successful
Primary – on rock
Secondary – disturbance eliminates plants but leaves soil

6. Human population dynamics
Factors that control growth rate
Demographic transition
Demographic trap
Multiple interacting factors – complex behavior
Malthus prediction
Importance of innovation (Schumpeter)
I = PAT

7. 5-1
Draw the classical “Demographic Transition”

8. Discussion
What can environmental science and science-based policy say about human population and control?
Why is the Malthusian limit concept so important? Does innovation in agriculture really solve the problem of impact from high populations?
What are some of the alternative models or paths for sustainable human society?

9. Population dynamics and management
5-2
Draw logistic growth curves (N vs. time)
Low r, low K
Low r, high K
High r, low K
High r, high K

10. How do we use models and hypotheses
http//web.pdx.edu/~rueterj/courses/objects/models-hypotheses.html