Unit 3 Flashcards
Ecological niche
The role a species plays within an ecosystem
What does the k in k-selected mean
Carrying capacity
What does the r mean in r-selected species
Growth rate
Biotic potential
The maximum reproductive rate under ideal conditions
K-selected species characteristics
-few offspring (heavy parental care)
-long lifespan (long time to sexual maturity)
-low biotic potential & slow pop. Growth rate
-more likely to be disrupted by environmental changes
r-selected species characteristics
-many offspring (low parental care)
-shorter lifespan (quick to sexual maturity)
-high biotic potential & high pop. Growth rate
-more likely to be invasive, and can adapt to environmental changes
Survivorship curve
A line that shows survival rate of a cohort in pop. From birth to death
Cohort
Group of same-aged individuals
Type 1 survivorship curve characteristics
-Mostly K-selected species
-high survivorship in early life due to high parental care
-high survivorship in mid-life due to large size & defensive behavior
Type 2 survivorship curve characteristics
-in between r&K selected species
-steadily decreasing survivorship throughout life
Type 3 survivorship curve characteristics
High mortality rate early in life, few make it to mid life;slow steady decline in survivorship in old age
Carrying capacity (K)
Highest pop. Size an ecosystem can support based on limiting resources
Overshoot
When a pop. Briefly exceeds K
Consequences of overshoot
Resource depletion
Damage to environment
Die off
Sharp decrease in pop. Size when resource depletion (overshoot) leads to many individuals dying
Larger size of a pop=
Safer from pop decline
Density
of individuals/area
High density=
Higher competition and possibility for desease
Distribution
How individuals in a pop are spaced out compared to each other
Types of distribution
Random
Uniform
Clumped
Sex ratio
Ratio of males to females
What can a die off cause in sex ratio
Leads to skewed sex ratio, limiting pop growth
What happens if resources are abundant
Pop usually follow the exponential growth trend
Exponenetial growth is what curve?
J-curve