Ch. 5 Biodiversity and Conservation
Dec 30, 2015
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
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