What you will learn in Populations, energy and where it all goes

1. 1. Levels and populations

   An age pyramid is a prediction. Two populations with identical birth and death rates can be headed in opposite directions.

2. 2. Growth, and its limits

   Exponential growth becoming absurd, logistic growth approaching a ceiling — and what happens when the ceiling moves.

3. 3. Living together

   Six names for relationships between species, derived from a grid rather than learnt as a list.

4. 4. Competition and the niche

   Two experiments — one showing exclusion, one showing that the difference between what a species could occupy and what it does is an observation.

5. 5. Energy through a system

   How long a food chain can be, which pyramids can be turned upside down, and which one refuses.

6. 6. Productivity and cycling

   Gross against net production, rate against total, and what happens to a system when breakdown is slower than input.

7. 7. Change over time

   Succession from bare ground, and what a disturbance does to the idea that it arrives somewhere and stops.