Population Ecology

Population

The smallest unit that can show how evolution works

Dispersion

The pattern of spacing of a population

Mortality

Death rate

Natality

Birth rate

Immigration

The organisms moving into a population

Emigration

The organism moving out of a population

Population density

The number of organisms in a given area

Limiting factor

Things that might slow the growth of a population

Demography

The study of a human population

Carrying Capacity

The maximum number of individuals that an environment can support for the long term

Age Structure

A method of charting population according to gender & specific years of birth.

4 Population Rates

Immigration

Emigration

Mortality

Natality

Environment affect on Population

It gives the resources and the land for the population to survive on

Closed Population

No immigration or emigration, not a typical population. It grows, stabilizes and then die out

Open Population

Natural and typical of most populations where immigration and emigration fluctuates

Exponential Growth

Populations that increase slowly and then rapidly

Represents the ideal conditions available for an organism's growth Rapid increase in population

The larger the population gets the faster it grows

Example: World population

Linear Growth

Growth that is steadily increasing throughout time

Example: USA

Logistic Growth

Growth is steadily increasing and eventually stables off, also called zero population

This occurs when a population stabilizes

The population of the area is not growing but also isn’t declining

Example: Italy

Uniform Dispersion

Organisms are evenly spread out throughout the area

Example: Black bears

Clumped Dispersion

Organisms that live in groups or herds

Example: Buffalo, cattle, gease

Random Dispersion

Organisms spread out without a set pattern, usually wherever the resources are available

Example: Deer

Populations need these factors to survive

What is a limiting factor?  How do these affect a population?

Carrying capacity is reached

When the population starts going down rapidly because there aren’t enough resources for the population.

Population growth problems

Clean water will be limited

Lack of space to live

Lack of wildlife

Lack of food

Lack of opportunities for solitude

More polluted air

More noise

More acid rain

More oil spills

More poverty

The more dense an area is, the more crowded it is. The less dense a area is the less crowded

How does population density relate to crowdedness?