POPULATION DYNAMICS

A. What is Diversity and/or Biodiversity
Species diversity - is the extent to which an ecosystem possesses differences in species in terms of genetic variation and distribution.

B. What is population?
Population is a group of interbreeding organism belonging to the same species. It is the interaction between organism that causes a population change (i.e., the national census is taken every ten years in a place at one time).

C. Characteristics of Population
1. Size - pertains to the number of individuals in a population (i.e., the recorded population of people in the Philippines as of August 2008 is 88.9 M)

Factors that contribute to the size of a population
a. Natality - the number of species that are born
b. Mortality - the number of species that die
c. Immigration - the number of species that entered the land
d. Emigration - the number of species that leave the land

TOP 20 LARGEST COUNTRIES BY POPULATION (LIVE)

1  China1,405,671,965

2  India1,289,649,648

3  United States326,255,319

4  Indonesia257,105,474

5  Brazil204,459,292

6  Pakistan189,514,149

7  Nigeria185,800,304

8  Bangladesh161,308,058

9  Russia141,943,539

10  Japan126,793,591

11  Mexico125,936,882

12  Philippines102,594,161

13  Ethiopia100,068,784

14  Vietnam93,809,429

15  Egypt85,335,412

16  Germany82,545,553

17  Iran79,963,363

18  Turkey77,155,144

19  Congo72,100,934

20  Thailand        67,529,331

 


                            Density - it is the number of individuals of a species living in a particular area of that population (i.e., 100 cows/hectare, 200 trees/hectare)

It is dependent upon such factors as availability of space, food, predators, water, light, and heat.

3. Distribution - it tells us how these individuals are located in that area. It is the arrangement of the individuals of a population within a particular space.
Structure: patterns of spatial distribution of individuals and population within the community and the relation of a particular community to its surroundings.

• Individuals within a population can be distributed randomly, clumped together, or in highly regular patterns.
• Larger communities often contain a mosaic of smaller units or subsets of the whole assemblage.
• Subunits develop because each species has a preference for specific, localized conditions.
• Patchiness: patterns of smaller units or subsets of the whole assemblage.
• Distribution in a community can be vertical as well as horizontal.