Ch. 5Ch. 5

Biodiversityand

Conservation

Biodiversityand

Conservation

I. Biodiversity I. Biodiversity - the variety of life in an area- As extinction reduces biodiversity,

ecosystem stability decreases.

A.Types of Biodiversity A.Types of Biodiversity 1.Genetic Diversity

- the variety of genes in a population (gene pool)

- could include useful genes such as disease or drought resistance

A.Types of Biodiversity A.Types of Biodiversity 1.Genetic

Diversity

2.Species Diversity 2.Species Diversity - the number and relative

abundance of species in an area

Teosinte

Maize

3.Ecosystem Diversity 3.Ecosystem Diversity - the variety of ecosystems in a

region or the biosphere

3.Ecosystem Diversity 3.Ecosystem Diversity

B. Importance of

Biodiversity B. Importance of

Biodiversity - biodiversity provides direct and

indirect value to humans

1.Direct Economic Value 1.Direct Economic Value - plants and animals provide

food, clothing, energy, medicine, shelter

1.Direct Economic Value 1.Direct Economic Value - also provide sources for new

medicines, crops, useful genes

1.Direct Economic Value 1.Direct Economic Value - also provide sources for new

medicines, crops, useful genes

2.Ecosystem Services 2.Ecosystem Services - functions provided by

nature that benefit all humans and other organisms

- oxygen, drinking water, pollination, flood control, nutrient cycling

3. Aesthetic and Scientific

Value 3. Aesthetic and Scientific

Value - Their true value is realized

when they are lost.

II. Threats to

Biodiversity II. Threats to

Biodiversity A. Extinction Rates

1. Background Extinction

- the ‘natural’ rate of

extinction~ 1 species per 1,000

species per year

2.Mass Extinction 2.Mass Extinction - catrastrophic, global events that

causes extinction of a large percentage of species

- 5 mass extinctions have occurred.

Diversity of Life and Periods of Mass

Extinction

Diversity of Life and Periods of Mass

Extinction

Cam

bri

an

Pro

tero

zoic

eon

Ord

ovic

ian

Silu

rian

Devonia

n

Carb

onifero

us

Perm

ian

Tri

ass

ic

Jura

ssic

Cre

tace

ous

Pale

ogene

Neogene

Num

ber o

f fam

ilies ( )

Number oftaxonomic

familiesExtinction rate

Cretaceous mass extinction

Permian mass extinction

Millions of years agoExti

nct

ion

rate

(

)

Paleozoic Mesozoic

0

20

60

40

80

100600 500 400 300 200 100 0

2,500

1,500

1,000

500

0

2,000

Ceno-zoic

2.Mass Extinction 2.Mass Extinction - catastrophic, global events that

causes extinction of a large percentage of species

- 5 mass extinctions have occurred.- We are probably witnessing the

6th mass extinction.

Passenger Pigeons, now extinct, was numbered more than 3.5 billion.

Passenger Pigeons, now extinct, was numbered more than 3.5 billion.In 1866 one flock of passenger pigeons was estimated to be 1.5 miles wide and 300 miles long, taking 14 hours to pass.

In 1866 one flock of passenger pigeons was estimated to be 1.5 miles wide and 300 miles long, taking 14 hours to pass.

B.Factors That Threaten Biodiversity

B.Factors That Threaten Biodiversity - Today’s high extinction

rate is human caused.~ 1,000 times the

background extinction rate.

1.Overexploitation 1.Overexploitation - over hunting or harvesting- especially the ‘charismatic

megafauna’ (panda, rhinos, tigers, California condor)

- As the species becomes increasingly rare, its value goes up.

Northern White Rhino, only 7 survive in the wild

Northern White Rhino, only 7 survive in the wild

2.Habitat Loss 2.Habitat Loss - deforestation, urbanization,

expanding agriculture

3.Habitat Fragmentation 3.Habitat Fragmentation - Dividing habitats into smaller

parcels reduces species diversity.- Populations become isolated

reducing genetic diversity.

4.Pollution 4.Pollution - Biomagnification

4.Pollution 4.Pollution - Acid Precipitation

4.Pollution 4.Pollution - Eutrophication

4.Pollution 4.Pollution - Eutrophication

5. Introduced Species 5. Introduced Species

5. Introduced Species 5. Introduced Species - Exotic species lack natural enemies.- can outcompete native species

In 1859, an Australian farmer introduced 24 grey rabbits to remind him of home. By the 1930’s the rabbit population increased to 600 million. In 1950 Myxomatosis virus was introduced, las in this government dug water hole and the population was reduced to “only” 100 million.

In 1859, an Australian farmer introduced 24 grey rabbits to remind him of home. By the 1930’s the rabbit population increased to 600 million. In 1950 Myxomatosis virus was introduced, las in this government dug water hole and the population was reduced to “only” 100 million.

5. Introduced Species 5. Introduced Species - Exotic species lack natural enemies.- can outcompete native species

Kudzu overgrowing a house in S. Carolina.

5. Introduced Species 5. Introduced Species - Exotic species lack natural enemies.- can outcompete native species

Asian or Silver Carp, some over 100 pounds,

were originally imported from China to clear algae

from catfish ponds. Flooding allowed some

into the Mississippi River and its tributaries where

populations have exploded.

Asian or Silver Carp, some over 100 pounds,

were originally imported from China to clear algae

from catfish ponds. Flooding allowed some

into the Mississippi River and its tributaries where

populations have exploded.

5. Introduced Species 5. Introduced Species

Burmese Python

Red Lion Fish

Cane Toad

III. Conserving

Biodiversity III. Conserving

Biodiversity A. Natural Resources

- As human population grows, demand for resources increases.- Consumption is higher inindustrial nations.- As developing countries become more industrialized, consumption rates increase.

On average, one American consumes as much energy as:

2 Japanese 6 Mexicans 13 Chinese 31 Indians 128 Bangladeshis 307 Tanzanians 370 Ethiopians

Ecological Footprint in Relation to Available Ecological Capacity

Ecological Footprint in Relation to Available Ecological Capacity

16

14

12

10

8

6

4

2

00 2 4 6 8 10 12 14 16

New Zealand

AustraliaCanada

Sweden

World

ChinaIndia

Available ecological capacity (ha per person)

Spain

UK

Japan

Germany

NetherlandsNorway

USA

Eco

logic

al fo

otp

rint

(ha p

er

pers

on)

1.Renewable Resources1.Renewable Resources- replaced by natural processes

faster than they are consumed- sunlight, timber, clean air and

water

2.Nonrenewable Resources

2.Nonrenewable Resources- limited supply, replaced by nature

very slowly- fossil fuels, minerals, old-growth

forest

3.Sustainable Use3.Sustainable Use- rate of resource consumption

equals replacement rate

B. Protecting Biodiversity

B. Protecting Biodiversity1. U.S. Protected Areas

- National Parks, Wildlife Refuges, Wilderness Areas, etc.

2. International Protected Areas

2. International Protected Areas- Biosphere Reserves, World

Heritage Sites, National Parks~ 7% of world’s land

Nanda Devi Biosphere Reserve, Uttarakhand, IndiaNanda Devi Biosphere Reserve, Uttarakhand, India

2. International Protected Areas

2. International Protected Areas- Biosphere Reserves, World

Heritage Sites, National Parks~ 7% of world’s land

Biosphere ReservesBiosphere Reserves

3.Biodiversity Hot Spots3.Biodiversity Hot Spots- regions of exceptional diversity

3.Biodiversity Hot Spots3.Biodiversity Hot Spots- regions of exceptional diversity- 34 areas recognized internationally- contain >1500 species of endemic

plants and 70% of habitat lost

4.Habitat Corridors4.Habitat Corridors- connect fragmented habitats- increases species and genetic

diversity

‘Toad Tunnel’ in England

‘Toad Tunnel’ in England

‘Wildlife Bridge’ in Netherlands

‘Wildlife Bridge’ in Netherlands

‘Migration Corridor’ for herptofauna

‘Migration Corridor’ for herptofauna

C.Restoring Ecosystems

C.Restoring Ecosystems- speeding up a damaged

ecosystem’s recovery

Bioremediation- Bacteria and plants have been used

to remove or immobilize pollutants.

D.Legally Protecting Biodiversity

D.Legally Protecting Biodiversity- Endangered Species Act (1973)

protects endangered species in U.S.

- CITES (Convention on International Trade in Endangered Species of Wild Flora and Fauna (1975)

The

The

End

End