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Population Dynamics - Coggle Diagram
Population Dynamics
Population Growth Rate
Kinds
1) Natality (Birth Rate)
2) Mortality (Death Rate)
3) Emigration ( Moving Away)
4) Immigration (Moving Into)
Exponential Growth Model
Exponential Model (J Shape)
Logistic Model (S Shape)
Understanding
Occurs when growth rate is proportional to population size
Population row slowly (lag phase) at first but accelerate quickly.
All populations grow until they encounter a limiting factor.
PGR:
Explains how fast a population grows
Population Characteristics
Populations:
Groups of the same species in
the same area.
Characteristics of Populations:
Density
Distribution
Growth Rate
Spatial Distribution
Ex:
2) Clumped (flock , herd)
Sheep
3) Random ( Based off of availability of resources)
Deers
1) Uniform
Bears
Dispersion:
The pattern of spacing of population within an area.
Population Density
Def:
Number of organisms per
unit area.
Ex:
Number of guppies in an aquarium
Population Ranges
Def:
A species' range is its distribution across the environment.
A species might not be able to expand its population
range because:
it cannot survive the abiotic conditions found in
the expanded region.(change in temperature )
Biotic factors may present threats in the new
region (predators )
Population-Limiting Factors
Limiting factors are biotic or abiotic forces that
keep populations from increasing indefinitely.
Density-independent limiting
factors
Does not depend on the number of member s in a population per unit area
Usually abiotic, and include:
Weather events
Fire
Human alterations of the landscape
Air, land and water pollution
Crown fire and ground fire
Density-dependent limiting
factors
Any factor in the environment that depends on the number of members in the population per unit area.
Often biotic, and include:
Predation
Disease outbreak (spread easily in high population)
Competition (increase with density
Parasites (negatively affect population)