Basics

1. Understanding
ecology
components

2. Essential Question
• What are the components of an
ecosystem?
• How do populations grow?

4. Organism

5. POPULaTiOn

6. Community

7. EcosystEm

8. RepRoductive StRategieS

9. Exponential Growth= r-selected
AKA J Curve

10. Occurs when Pops Doubling
OverTime

11. R-selected
Species
1) Many small
offspring
2) Little/no care of
offspring
2) Most offspring die
before reaching
reproductive age
3) High population
growth rate
3) Generalists

12. Logistic Growth: K-
selected
AKA S Curve

13. Carrying Capacity
K = Max. pop. of a species that a
habitat can support over a given
time period.
Can change due to env. conditions

14. K-selected Species
1) Fewer, larger
offspring
2) High parental
care
3) Most offspring
reach
reproductive
age
4) Lower
population
growth rate
2) Specialists

15. Density-DepenDent Factors
•Increasing pop size leads to less
available resources  limiting pop
growth
•DD factors: competition, predation,
disease, poisoning…all increase
when pops grow w/in limited space.

16. Density-inDepenDent Factors
• Limits placed on pop growth (not due
to space issues)
• Ex: Natural disasters or Severe
weather

17. •Proportion of a pop. to survive to breeding
age
•Type I= Late loss: K-strategists.
•Type II = Constant loss: intermediate
reproductive strategists
•Type III = Early loss: R-strategists
Survivorship