Population Ecology Quiz Flashcards

Terms Definitions
net reproduction
B-D=r
Doubling time equation:
T*d=.69/r
Community
assemblage of populations
Man
effects distribution of species
demography
statistics of population change...life/death rates
k-Selection
Also known as Density-Dependent Selection, it selects for life history traits that are sensitive to population density. Birth rates fall and death rates rise. Negative feedback.
demographic
statistic that describes population size, age structure, density, distribution, and other factors
G=rN
This pattern describes exponential growth
G-time interval
r-per capita rate of increase
N-initial size of population
Population
A group of interbreeding individuals occupying the same area at the same time
Iteroparity
Also known as Repeated Reproduction, the individual produces offspring repeatedly. This occurs often in dependable and stable environments.
climax community
a relatively stable long-lasting community reached in a successional series; usually determined by climax and soil type
demographic transition
repersents transition from high mortality and birth rates to low ones.
associated with better health care, sanitation, and eductation
Density
Number of individuals per unit area
Predator-Prey interaction
When the population of predators depend on the population of the prey. The more prey there is the more food for the predator to eat. The number of predators are controlled by the prey. Ex: Lynx and snow shoe hare
metabolism
use energy to transform matter into energy
ecological footprint
summarizes the aggregate land and water area needed to sustain the pople of a nation, one measure of how close we are to carry capacity, countries vary greatly in this
Equilibrum
a state of balance (in an ecosystem).
limiting factors
elements that prevent a population from attaining its biotic potential
can be categorized into density-dependent and density independent factors
Mimicry
organism looks like something in its environment, non living or living often that gain protection from doing so
R-Strategy
(rate strategy) a group that has adapted to living in an environment which fluctuates in biotic or abiotic factors such as availability of food or change in temperature usually controlled by density-independent
exponential growth
rapid, requires ideal conditions. When plotted #'s vs Time it has a J shaped curve
repeated reproduction
Reproduction in which adults produce offspring over many years; also known as iteroparity.
random dispersion
position of each indvidual is independent of other individuals. It occurs in absence of strong attractions or repulsions among individuals of a population or where key physical or chemical factors are relatively homogeneous across the study area. (plants established windblown seeds like dandilions)
cohort
a group of individuals of the same age
environmental resistance
the combination of all factors that act to limit the growth of a population
reproductive base
the number of actually and potentially reproducing individuals of a population
Countries wtih lowest growth rates
Belarus, Swaziland, Russia, Latvia
what is the primary limiting factor in developed nations?
space
exponential resistance
combination of factors that keeps a population from reaching max growth rate
Type I Curves
Death is high late in life
opportunistic life history
• Take immediate advantage of favorable conditions
• Typically exhibit a Type III survivorship curve
k-selected populations
near carrying capacity due to density dependent factors
Distribution
the area where something is located or where a species lives and reproduces
emigration
the movement of individuals out of a population
Population dynamics
The scientific study of changes in population size over time.
Population Growth
how populations grow and the factors affecting growth
logistic population growth
when populations are well below the size dictated by the carrying capacity of the region they live in, they will grow exponentially, but as they approach the carrying capacity, their growth rate will decrease and the size of the population will eventually become stable
Population Growth Rate
Also known as the "per capita increase," it equals (births - deaths) + (immigration - emigration).
What are 3 different distribution patterns?
random, uniform and clumped
birth rate
the number of live births per 1,000 members of the population in a year.
carrying capacity
max pop size that can be sustained. symbol K
type 2
when death rate for the population is fairly constant at all ages
Boundaries of a habitat
natural features vs. arbitrary lines to define, such as borders of a park, state, or country
exponential population growth
r(max)*N
where B > D
The size of a population that exponentially increases at a constant rate
Equation implies the population accumulates more new individuals per unit of time when it is large than when it is small.
Occurs because population growth depends on N as well as r(max) and larger populations experience more births
What controls population size?
Birth rate and Death rate, Survival and Fecundity, Life History trade-offs
density-dependent limiting factors
factors that become more severe as the size of the population increases.
density independent
a birth or death rate that does not change as a function of population density. usually abiotic, random events such as floods, droughts, hurricanes, volcanic eruptions, wildfire, and human factors.
size of population over area of the habitat
formula for population density
What is on the y-axis of both growth curves and survivorship curves graphs?
number of individuals
Explain a Type I curve
flat at the start (low death rates) during early and middle life and drops steeply as death rates increase among older folks
3 things to think about in terms of population
what species? what time? what area?
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