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Influences of Population Size - Coggle Diagram
Influences of Population Size
Fundamental Factors
Birth Rate
Death Rate
Immigration
Arrival of new from another population
Emigration
departure to another residence
Limitations
Density-dependent Limiting Factors
Slow birth rates
High death rates
Population growth rate decreases
Factors Include
Predation
Parasitism and diseases
Competition for limited resources (Intraspecific Competition)
Logistic growth
S-shaped curve
small population with little effect, but population grows exponentially
Then there is limitation on growth, which causes the plateau at carrying capacity
K-selection
Density-Independent Limiting Factors
Causes
Natural disasters
Weather related events
Human-caused events
limitations that occur irregardless of population size
Exponential Growth
Zero Population Growth
birth rate = death rate
per capita growth rate = birth rate - death rate
r-selection
Biotic Potential
Growth under ideal conditions
Life History Patterns
Cohort
Survivorship Curve
Type I
Convex
Death occurs later in life
K-selection
Type II
Diagonal
Death rate does not affect age
Type III
concave
death occurs early in life
r-selection
Human Population Growth
Total Fertility Rate
Replacement Fertility Rate
Age Structure
Reproductive Base
Wide base = Higher Growth Expectancy
Narrow base = Lower growth rate