Topic 3: Demecology – the ecology of populations
The main idea: Note how mathematical models are used to examine variation in growth of a population.
1. Statistic and dynamic characteristics of population.
2. Growth curves patterns: J-shaped curve and S-shaped curve
3. Population regulation: Density-dependent and density-independent factors. 4. Human population patterns: - Population numbers. - Demographic transition and structure - Population urbanization
1. Statistic and dynamic characteristics of population
Population – is a group of individuals of the same species that live in the same area.
Population is an elementary and evolutionary unit of biosphere.
Statistic characteristics: •…show more content…
• Density-independent factors –are factors that affect populations (reproduction and mortality rates) regardless of population density (natural disasters as forest fire, earthquake, flood etc.).
4. Human population patterns: • Population numbers
| |In 1650 ~ 500 million people. |
|[pic] |In 2000 ~ 6 billion people. |
| |In 2009 ~ 6.5 billion people. |
| |This exponential growth rate can be explained by increase: |
| |in food production |
| |the rise of industry |
| |advances in medicine |
| |Growth rate is about 70 million people per year. It may be |
| |limited by the same density-dependent factors that limit the |