Unit 3.2 - K-selected and r-selected species

Question 1

K-selected species

Answer 1

• Quality
• Few offspring, heavy parental care to protect them
• Usually reproduce many times
  - Ex: most mammals, birds
• Long lifespan, long time to sexual maturity = low biotic potential = slow pop. growth rate
• More likely to be disrupted by env. change or invasives

Question 2

r-selected species

Answer 2

• Many offspring, little to no care
• May reproduce only once
  - Ex: insects, fish, plants
• Shorter lifespan, quick to sexual maturity = high biotic potential = high pop. growth rate
  - More likely to be invasive
  - Better suited for rapidly changing env. conditions

Question 3

K-selected species involving invasives and disturbances

Answer 3

• Low biotic potential (rep. rate) = hard for pop. to recover after a disturbance (env. change)
• High parental care means death of parent = death of offspring
• Invasives (usually r) outcompete for resources with high biotic potential & rapid pop. growth
• Less likely to adapt & more likely to go extinct

Question 4

r-selected species involving invasives and disturbances

Answer 4

• High biotic potential (rep. rate) = more rapid pop. recovery after disturbance
• Low parental care means death of parent doesn’t impact offspring
• Not as impacted by invasive species since their pop. grow quickly
  - More likely to be the invasive
• Larger pop. & faster generation time = higher chance of adaptation & lower chance of extinction

Question 5

K-selected species traits

Answer 5

• long lifespan
• long time to reproductive maturity
• few number of reproductive events
• few number of offspring
• large size of offspring
• parental care present
• slow population growth rate
• population dynamics are stable near carrying capacity
• population regulation independent are density dependent

Question 6

r-selected species traits

Answer 6

• short lifespann
• short time to reproductivity maturity
• many number of reproductive events
• many number of offspring
• small size of offspring
• parental care absent
• fast population growth
• population dynamics are highly variable
• population regulation dependent on density