Population GrowthAnd Habitat Destruction

Biodiversity is affected by human population size and resource use.

1 person is born every 8 seconds

1 person dies every 12 seconds

That is a net gain of one person every 13 seconds.

Global population growth in one year

6.37

6.38

6.39

6.40

6.41

6.42

6.43

6.44

6.45

J A S O N D J F M A M J J

04 05

5% of our virgin forests are uncut

2% of our native grasslands are left

15% of redwood forests are old growth

Less than 50% of our wetlands remain

Their existence is being deemed less important than others…

Understanding population growth In order for growth to

continue forever, we would need an infinite amount of space, energy, and resources.

So what happens to steady growth in a limited space? EXPONENTIAL

GROWTH

Exponential Growth DEFINITION: The number of

organisms will increase exponentially until nutrients run out.

Typically the first organism splits into two, which then split into four, and then doubles to 8, etc.

Usually doubles or triples, but the human population increases by 1.5x each year.

So what? In that example, the bacteria was only

limited by the space of the bottle. What about human population, that is

limited by the amount of oxygen, food, energy, space, nutrients, disease, etc? Because of these limiting factors,

populations reach their carrying capacity and do not over-run the world.

Greatest threats to biodiversity Habitat destruction Invasive species Population growth (humans) Pollution Over harvesting

HINT: Think of the acronym “HIPPO” to remember these five points