1. Ecology of Individuals and
Populations
Factors that Regulate
Populations
Basilan, Glecy B.
Orenday, Johnrey V.
Ugtuhan, Carren P.
BS Biology III
Basilan | Orenday | Ugtuhan | (c) 2014 1
2. IMPORTANT TERMINOLOGIES
Population
Community
Density
Natality
Mortality
Biotic factors
Carrying capacity
Basilan | Orenday | Ugtuhan | (c) 2014 2
3. Factors Regulating
Population Size
Density-dependent factors -
act on a population such that
the proportion eliminated
depends on the population
density. Basilan | Orenday | Ugtuhan | (c) 2014 3
4. Fig. 1 showing the examples of density-dependent effects
Basilan | Orenday | Ugtuhan | (c) 2014 4
5. Factors Regulating
Population Size
Density-independent - factors
that eliminate a proportion of a
population regardless of
population density.
Basilan | Orenday | Ugtuhan | (c) 2014 5
6. Density-independent
factors
• Forest fire
• Modification of weather
conditions
• Severe storm and flooding
• Earthquakes and volcanic
eruptions
Basilan | Orenday | Ugtuhan | (c) 2014 6
7. Fig. 2 showing the examples of density-independent effect –
Forest fire Basilan | Orenday | Ugtuhan | (c) 2014 7
9. TWO TYPES OF LIFE
STRATEGIES
• K-selected species (Equilibrium)
• Characteristics of r-selected
species (Opportunist)
Basilan | Orenday | Ugtuhan | (c) 2014 9
10. Characteristics of K-selected
species (Equilibrium)
late maturation
longer life spans
more parental care
intense competition for resources
Basilan | Orenday | Ugtuhan | (c) 2014 10
11. Characteristics of r-selected
species (Opportunist)
early maturation
shorter life spans
less parental care
little competition for resources
Basilan | Orenday | Ugtuhan | (c) 2014 11