Population Size - Coggle Diagram
It is the total number of individuals in a population
Which is one Part of
The statistical characteristics that can be
used to describe a population
are used to estimate
A method of estimating the total number of individuals in an area based on data from direct counts in some portion of the area.
Method of estimating population size of mobile animals by marking individuals, releasing them, then checking the proportion of marks among individuals recaptured at a later time
It is continually change
Individuals are added to a population by
Movement of individuals into a population
If their effect set aside, we will have
Zero Population Growth
Interval during which the number of births equals the number of deaths.
Used to measure
per capita growth rate (r)
Of a population, per capita (per individual) birth rate minus per capita death rate
As long as
remains constant and greater than zero,
A population grows by a fixed percentage in successive time intervals; the size of each increase is determined by the current population size.
Can be calculated for each interval based on the number of individuals (N) and the per capita growth rate (r): N x r = G
Graphing the increases against time results in a
It is a characteristic of exponential population growth
The number of new individuals increases in each generation
Individuals are removed from it by
Movement of individuals out of a population
Maximum possible population growth rate under optimal conditions
Factors that affect biotic potential include
The age at which reproduction typically begins
How long individuals remain reproductive
The number of offspring that are produced each time an individual reproduces.
Limits on Population Growth
Density-dependent limiting factors
Factors that limits population growth and has a greater effect in denser populations
These factors include
Competition for a limited resource
Competition for resources among members of the same species.
When they affect population size over time,
A population grows exponentially at first, then growth slows as population size approaches the environment’s
for that species
Carrying capacity (K)
is the maximum number of individuals of a species that a particular environment can sustain; can change over time
Density-independent limiting factor
Factor that limits population growth and arises regardless of population size.
Human-caused events such as oil spills
A population’s growth rate is affected by its members’
Schedule of how resources are allocated to growth, survival, and reproduction over a lifetime
One way to investigate life history traits is to focus on a
Group of individuals born during the same interval.