Population Ecology Flashcards
(62 cards)
What is a population?
A group of interacting organisms of the same species
What is demographic structure?
Quantified number of individuals of each age/stage
What is population size?
Total number of individuals
What is population density?
How densely packed together individuals are
What is geographic range?
The limits/bounds established by physical limits that species can tolerate
Some examples of geographic range are. . .
Temperature and aridity, encroachment/intrusion of other species
The most basic approach to population growth is. . .
exponential
What does the exponential population growth approach assume?
Assumes that every individual produces two offspring in their lifetime
Growth rate (r) is. . .
the intrinsic rate of natural increase
What is carrying capacity?
The maximum population size that an environment can sustain
What happens to population growth rate as population size increases in an environment with carrying capacity?
The growth rate slows/decreases
What happens when a population reaches carrying capacity?
Growth stops
With the addition of resource limitation, what change do you expect in the number of births as population size increases? In the number of deaths?
Decrease in births, increase in deaths
In real populations, as population size increases and approaches carrying capacity, the amount of intraspecific competition. . .
increases as fewer resources are freely available to each individual
A population of penguins has an annual per capita birth rate of 0.08 and an annual per capita death rate of 0.1. Estimate the net gain or loss of individuals from a population of 1,000 penguins in one year.
20 individuals lost
Populations growing exponentially:
A) have a growth rate (r) that increases with time
B) have a constant r
C) are under density-dependent control
D) add the same number of individuals to a population every generation
E) can continue growing exponentially indefinitely
B) have a constant r
What type of growth does a population under carrying capacity experience?
Logistic growth
What factors can change population size?
Biological and non-biological factors
What factors can regulate population size?
Biological factors
Biological factors are density ________, and nonbiological factors are density ________
dependent; independent
Density affects population regulation by the four factors of. . .
1) territoriality
2) disease
3) predation
4) toxic wastes
How does territoriality regulate population?
Maintaining territory enables individuals to capture enough food to reproduce where space is limited)
How does disease regulate population?
Less dense populations experience slower spread; more dense populations experience faster spread thus increased rate of death > birth
How does predation regulate population?
Predators may concentrate on most abundant prey
