1. STAGES OF POPULATION GROWTH

2. Population Growth can be… Exponential ORLimited (J curve)(S curve)

3. STAGES OF POPULATION GROWTH 1) Lag Phase2) Log Phase 3) Stationary Phase 4) Decline/Death Phase

4. POPULATION GROWTH STAGES 1) LAG PHASE – Only a small number of organisms are sexually mature and able to reproduce – The organisms may be adjusting to their environment

5. POPULATION GROWTH STAGES 2) LOG PHASE – Exponential or Logarithmic acceleration – Many organisms have reached sexual maturity – They are able to reproduce – The organisms have adjusted to the conditions around them (able to get food, shelter, water, etc for survival)

6. POPULATION GROWTH STAGES 3) STATIONARY PHASE – Growth ceases (slows down) and population remains relatively fixed in size – The carrying capacity is reached – The number of births and deaths balance each other out – The immigration and emigration rate are roughly the same

8. POPULATION GROWTH STAGES 4) DECLINE/DEATH PHASE – Population dies off – May return to lag phase and the cycle may repeat

9. PREDATOR PREY CURVES

11. PREDATOR/ PREY CURVES Show the rise and fall of predator and prey populations Developed by Italian mathematician Volterra from watching the rise and fall of Adriatic fishing fleets. Shows peaks and valleys when population levels rise and fall in response to the predator-prey feeding relationship

12. PREDATOR/ PREY CURVES theory suggest that… when prey are numerous their predators increase in numbers This reduces the prey population, which in turn causes predator number to decline. The prey population eventually recovers, starting a new cycle.

13. HARE = prey, LYNX = predator

14. YOUR TURN… Using the values on this graph, write 5 sentences to explain what is happening…

15. Credits Mrs K Casha