population Ecology Flashcards
_______ groups of individuals in one place and time
populations
What are the five characteristics of populations?
1.geographic range
2. habitat
3. density
4. size
5. age structure
______ _______ is the area throughout which a population occurs
geographic range
________: biotic and abiotic feature of its range
habitat
_______ is how individuals are physically spaced out
density
______ is the number of individuals and how that number changes through time
size
T or F: Circumvent inhospitable habitat to colonize suitable, previously unoccupied areas
True
T or F: The last glaciation event extended the ranges of many species
True
_______ ________ are a key factor in expanding range
Dispersal Mechanisms
T or F: Individuals in populations exhibit different spacing patterns
True
________ spacing: individuals do not interact strongly with one another; not common in nature
random
________ spacing: behavioral interactions, resource competition
uniform
_________ spacing: uneven distribution of resources: common in nature
clumped
_________________: occur in areas in which suitable habitat is patchily distributed and is separated by intervening stretches of unsuitable habitat
metapopulations
_______-________ metapopulations some areas are suitable for long-term habitat, other are not
source-sink
_______- populations in better areas
source
______- populations in poorer area
sink
________- the quantitative study of populations
demography
T or F: population growth can be influenced by the population’s sex ratio
True
_______ _______: average interval between birth of an individual and birth of its offspring
generation times
______ ______: determined by the numbers of individuals in a different age group
age structure
Generation time and body size are ______ related
directly
_____: group of individuals of the same age
cohort
______: number of offspring produced in standard time
fecundity
_______: death rate in a standard time
mortality
______ _______ has a critical influence on a population’s growth rate
age structure
__________ percent of an original population that survives to a given age
survivorship
_______ ______ expresses some aspects of age distribution
survivorship curve
What type of survivorship curve is this )
type 1
What type of survivorship curve is this \
type II
What type of survivorship curve is this (
type III
_______ ______ favors traits that maximize the number of surviving offspring left in the next generation by an individual organism
natural selection
_____ ______: the complete life cycle of an organism
life history of
T or F: Larger offspring have a greater chance of survival
True
____-_____ species delay reproduction
long-lived
______-_____ species reproduce early
short-lived
_________ growth model applies to populations with no growth limits
exponential
What is the equation for exponential growth model?
r= (b-d) + (i-e)
r= rate of population increase
_______ ______ e= i, and there are no limits on population growth
biotic potential
What is the equation for biotic potential
dN/ dt= riN
The biotic potential of any population is ________. even when the rate of increase remains constant
exponential
______ ______: symbolized by K, is the maximum number of individuals that the environment can support
carrying capacity
________ growth model: applies to population as they reach K
logistic
What is the logistic growth model equation?
dN/ dt= rN(K-N)/ K
____/____ is equal to the intrinsic rate of natural increase, adjusted for the amount of available resoures
dN/ dt
If you plot N versus t, you obtain a ______ growth curve
sigmoidal
As N approaches K, the rate of population growth begins _____
slow
If N= K the population growth rate is _____
zero
If the population size exceeds K, the population size will decline until it reaches ___
K
_____-_____: factors that affect population and depend on population size
density- dependent
_______-_______: other factors, such as natural disasters, affect populations regardless of size
density- independent
_________ ________ ________ is where the birth rate and death rate are equal, which is equal to K
equilibrium population density
_______ _______ affects life history adaptations
resource availability
When resources are limited, the cost of reproduction is _______
high
________ will favor individuals that can compete and utilize resources efficiently
selection
__-selection populations: adapted to thrive when population is near its carrying capacity
K
__- selected populations: selection favors individuals with the highest reproductive rates
r
What is this adaptation at r and k-selected populations:
age at first reproduction
R: early
K: late
What is this adaptation at r and k-selected populations:
Life Span
R: short
K: long
What is this adaptation at r and k-selected populations:
maturation time
R: short
K: long
What is this adaptation at r and k-selected populations:
mortality rate
R: often high
K: usually low
What is this adaptation at r and k-selected populations:
Number of offspring produced per reproductive episode
R: Many
K:Few
What is this adaptation at r and k-selected populations:
Number of reproductions per lifetime
R: few
K: Many
What is this adaptation at r and k-selected populations:
Parental care
R: none
K: often extensive
What is this adaptation at r and k-selected populations:
size of offspring or eggs
R: small
K: Large
What are the three K-selected life history traits?
- small brood size
- late reproduction
- high degree of parental care
T or F: Birth rate has remained unchanged
True
T or F: Death rate has fallen dramatically
True
Human populations have grown ______-
exponentially
__- selected species are adapted to function well in rapidly changing environements
r
What type of survivorship curve does r-selected species show?
Type III
In r-selected species,
survivorship and fecundity are greatly influenced by ______-_____ factors
density- indepdent
__- selected species thrive in more stable environments
K
What type of survivorship curve do K-selected species have?
Type I and Type II
