Justin ray m guce
2008

HOW DO WE DEFINE
POPULATION???

TERMS TO REMEBER
• Population
– group of organisms that belong to the same species and live in a given area

CHARACTERISTICS OF A POPULATION
• GEOGRAPHIC DISTRIBUTION
• Describes the area inhabited by a population

CHARACTERISTICS OF A POPULATION
• POPULATION DENSITY
• Number of individuals per unit area

CHARACTERISTICS OF A POPULATION
• POPULATION DISPERSION
– clumped
– uniform
– random

CHARACTERISTICS OF A POPULATION
• GROWTH RATE
– Factors affecting population size
• # of births
• # of deaths
• Immigration and emigration

• ARMM- 3.86%
• Region IV- 3.72
• NCR- 1.06%

WHAT DOES this picture SHOW US???

CHARACTERISTICS OF A POPULATION
• Types of GROWTH
– Exponential
– Logistic

CHARACTERISTICS OF A POPULATION
• Exponential
• J-shaped curve
• reproduction at constant rate
• ideal conditions

CHARACTERISTICS OF A POPULATION
• Logistic
• S- shaped curve
• Growth stops after an exponential growth

CHARACTERISTICS OF A
POPULATION
• AGE STRUCTURE
– growth depend on the age of the population
– age structure diagrams

CHARACTERISTICS OF A
POPULATION
• DEMOGRAPHIC TRANSITION
– Dramatic change in birth and death rates
– Birth rate falls to meet the death rate

LIMITS TO GROWTH
• Limiting factors
– Causes population to decline
– Insufficient supply of nutrients
• 2 types of FACTORS
– DENSITY DENPENDENT
– DENSITY INDEPENDENT

DENSITY DEPENDENT FACTORS
• depends on population size
• becomes limiting when…
– POPULATION REACHES A CERTAIN LEVEL
• large and dense population size

DENSITY DEPENDENT FACTORS
• INCLUDES
– Competition
– Predation
– Parasitism
– Disease

Competition

Competition: overcrowding

Predation

Parasitism

DENSITY INDEPENDENT FACTORS
• affects all population in similar ways
• REGARDLESS of its POPULATION SIZE
• Characteristic crash in population size

DENSITY INDEPENDENT FACTORS
• INCLUDES
– UNSUAL WEATHER
– SEASONAL CYCLES
– NATURAL DISASTERS
– HUMAN ACTIVITIES