1. Please take out modules 15, 16, 18, and 20 for check-off!
APES and 11.12
Please take out modules 15, 16, 18, and 20 for check-off!

2. Learning Targets
I can understand the threat posed by invasive species to biodiversity.
I can differentiate between different reproductive strategies of organisms.

3. Multiple Choice Answers
Module 15:
1. B 2. D 3. C 4. D 5. B 6. C 7. A
Module 16:
1. D 2. A 3. B 4. C
Module 18:
1. C 2. A 3. C 4. D 5. A
Module 20:
1. B 2. D 3. B 4. D 5. A

4. Ecocolumns- Water Quality
Find the document on the labs page of my website about freshwater quality indicators
Record on your data table the optimal levels for the abiotic factors we’ve been measuring
Record if your column was healthy or unhealthy this week for each indicator

5. Invasive Species
Remember, Invasive Species are one of the 6 threats to biodiversity:
Habitat Destruction/Fragmentation
Invasive Species
Population Growth
Pollution
Climate Change
Overexploitation

6. Native vs. Alien
Native Species = species that live in their historical range; thrive there due to natural selection
Endemic species = only live in a small area; at greatest risk (i.e. hot springs fish)
Alien Species = species living outside its historical range
Invasive Species= alien species that spreads rapidly across large areas

7. Example: Zebra Mussels
Native to Black Sea and Caspian Sea (Europe, W. Asia)
Cargo ships carrying seawater came over to St. Lawrence River and the Great Lakes in the 1980’s and dumped their unneeded water
Zebra mussels colonized the Great Lakes, killing off native mussels
Can multiply so fast (1 female = 30,000 eggs) that they clog industrial pipes!

8. /

9. Your Turn! Number off by 4’s 1’s: Silver carp, Kudzu
2’s: Scotchbroom, Cane toads
3’s Brown tree snake, Lionfish
4’s: Nile perch, Asian longhorn beetle
For your species:
Where they’re from
Current range
How they spread
Why they are so effective at colonizing new areas
Negative consequences to native ecosystems

10. Principles of Population Growth
Or when your snails will die…

11. Exponential Model of Population Growth
Population increases rapidly with no limit
What will a graph look like?
Rare in nature. Why?
“J” shaped curve
Limit on the amount of resources (food / space)

12. Limiting factors can be:
Limiting Factors on Population Growth
Populations can’t grow exponentially forever because of limiting factors
Limiting factors can be:
BIOTIC– Predators, food, disease, competition from other species
ABIOTIC– Space, water, shelter, salinity, soil, etc.

13. Density and Population Growth
Density-dependent limiting factors: competition, predation, parasitism, disease
Density-independent factors: habitat destruction, weather, natural disasters
Notice that density-dependent factors are biotic, while density-independent factors are abiotic

14. Limited by carrying capacity
Population Growth
Limited by carrying capacity
The number of individuals the
environment can support
over a long period of time

15. Logistic Model of Population Growth
When at carrying capacity,
birth rate is equal to
death rate
Accounts for influence of limiting factors
What will the graph look like?
As population reaches
carrying capacity,
death rate increases
When population is small,
birth rate is higher
than death rate
Stretched out “S”

16. Transitioning to Logistic
Exponential populations don’t just “smooth out”
Usually there is an overshoot, where the population grows beyond carrying capacity
Followed by a die-off
Can happen many times

17. Reproductive Strategies
R-strategists: have tons of offspring, don’t care for them, have short lives
Limited by density-independent factors
Ex: mice, small fish, most insects
K-strategists: have few offspring, care for young, have long lives
Limited by density-dependent factors
Ex: humans, most birds, deer

18. Reproductive Strategies  r vs. K selected species

19. K species’ populations settle near K

20. Reproductive Strategies
R-strategist populations have exponential growth with violent population changes
K-strategist populations remain at a stable carrying capacity
Or do they?...

21. Making Connections # offspring Type of pop. growth Factors limited by
Factors are biotic or abiotic
R-strategists
K-strategists

22. Survivorship Curve
Relationship between death & age for different species
Type I  Death = old age
Type II  same mortality rate in every age group
Type III  Death = young age