POPULATION ECOLOGY

POPULATION ECOLOGY

Justin ray m guce2008

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

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

CHARACTERISTICS OF A POPULATION

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

• INCLUDES– Competition– Predation– Parasitism– Disease

DENSITY DEPENDENT FACTORS

Competition

Competition: overcrowding

Predation

Parasitism

Disease

DENSITY INDEPENDENT FACTORS

• affects all population in similar ways

• REGARDLESS of its POPULATION SIZE

• Characteristic crash in population size

• INCLUDES– UNSUAL WEATHER– SEASONAL CYCLES– NATURAL DISASTERS– HUMAN ACTIVITIES

DENSITY INDEPENDENT FACTORS