4.1.1 Biodiversity

4.1.1 BIODIVERSITY

BIODIVERSITY

The amount of biological diversity
per unit area.

It includes: genetic, habitat and
species diversity

GENETIC DIVERSITY

Is the total number of genetic characteristics of a
specific species.

HABITAT DIVERSITY

Variety of forests, deserts, grasslands, lakes, oceans, coral
reefs, wetlands, and other biological communities,

(niches per unit area).

SPECIES DIVERSITY

Is the number of species
or organisms per unit
area

found in different
habitats of the planet.

State of US species.

Projected Status of Biodiversity

1998
–
2018

Critical and endangered

Threatened

Stable or intact

ANTARCTICA

NORTH

AMERICA

EUROPE

AFRICA

ASIA

SOUTH

AMERICA

AUSTRALIA

Pacific

Ocean

Antarctic Circle

Pacific

Ocean

Tropic of Cancer

Tropic of Capricorn

Indian

Ocean

Atlantic

Ocean

150
°

90
°

60
°
E

0
°

30
°
W

90
°

120
°

150
°

0
°

60
°

30
°
N

30
°
S

60
°

Arctic Circle

Arctic Circle

What are the relationships
among ecosystem stability,
diversity, succession and
habitat ?

•

How does diversity change during succession?

•

How does habitat diversity influence species diversity and
genetic diversity?

•

How does ecosystem complexity, with its variety of nutrient
and energy pathways, provide stability?

•

How do human activities (agriculture, mining, logging, etc.)
modify succession?

•

What are the potential positive and negative results of human
activities that simplify ecosystems? (monocrop agriculture)

Why Should We Care About
Biodiversity?

Instrumental value:

usefulness to us.

Intrinsic value:

because they exist,

Regardless of whether

they are useful to us or

not.

Goods


Food, fuel, ecosystems, species, fiber, lumber, paper, …


90% of today’s food crops


40% of all medicines (85% of antibiotics)

Foxglove

Digitalis purpurea
,

Europe

Digitalis for heart failure

Pacific yew

Taxus brevifolia
,

Pacific Northwest

Ovarian cancer

Ecological Services:


Flow of materials, energy, and information in the biosphere


Photosynthesis


Pollination


Soil formation and maintenance


Nutrient recycling


Moderation of weather extremes


Purification of air and water

Information:


Genetic information: adaptation and evolution


Genetic information for genetic engineering


Educational and scientific information

Option:

•
People would be willing to pay in advance to preserve the
option of directly using a resource such as a tree, an elephant,
a forest or a clean lake.

Recreation:


Existence


Aesthetic


Protect natural capital for future generations


Nonutilitarian:

•
Hunting, fishing, swimming, scuba diving, water skiing, . . . .

•
Eco
-
tourism