Transcript Biodiversity - Cloudfront.net

Biodiversity
A Measure of
how many
species are in
an area
Why is
Biodiversity
Important?
Why Maintain Diversity?
Ecosystem Services!
To purify our air and water
(phytoplankton)
To reduce floods (vegetation)
To generate fertile soil…
To pollinate…
To cycle nutrients…
To protect from erosion…
To control agricultural pests!
Why We Need Species?
Economic Goods!
Why We Need Species?
Sources of Food
Why We Need Species?
Sources of Medicines
Aspirin
Codeine
Why We Need Species?
Provide us with recreation
Ecotourism: giving $$ to a country
to view their environment.
Why We Need Species?
Contain genetic info that tells the
story of Earth!
# of Species?
• 1.3 million catalogued
• ≈ 8.7 ± 1.3 mill
–Undiscovered: insects, fungi,
bacteria
Threatened Species
Species has few individuals and is
near becoming endangered.
Gelada Baboon
Northern Spotted Owl
• Threatened-US ESA  Habitat loss in
Canada and No. US!
• Need old growth forest, top predators,
and are specialists.
Endangered Species
Species has fewer individuals; at risk
of becoming extinct.
White Abalone
Barred Bandicoot
Case Study: California Condor
• Scavenger bird;
eats dead
carcasses.
• 2005 = 273
individs.
• Endangered: low
birth rates, late
sexual maturity,
poaching, lead
poisoning, DDT,
and power lines.
X Ray shows bottle caps and
metal shards
Intrinsic Characteristics of E. S.
• Extremely localized/require LARGE
territory
• Low birth rates
• Island species/extreme specialists
• Low adaptability
• Late sexual maturity
Extinct Species
Species no longer exists on Earth.
1,138 documented today since 1600
Tecopa Pupfish, CA
Yangtze River Dolphin
• AKA Bajii
• Last sighting
2004
• Causes: heavy
transportation on
river,
overfishing,
dams, collision
w/ boats, H2O
pollution.
Case Study: Passenger Pigeon
• 200 yrs ago  3-5
billion
–world’s most
abundant bird
–1 flock =10 mi
wide, 100 mi
long)
• Killed for its meat
• Martha died in
1914.
Types of Extinctions
• Background
extinction: 330 species
die/yr
• Caused by
natural
selection.
• Mass Extinction:
1000’s spcs
die/yr
• Caused by
dramatic env.
change.
• 5-6 so far
• Humans causing
6th ??
Root Causes of Extinction
• Too many people!
• Weak/no laws
• High consumption rates
Humans Cause Extinction
Habitat Loss/ Habitat Fragmentation
Humans Cause Extinction
Hunting/Poaching
Humans Cause Extinction
Overfishing
Humans Cause Extinction
Capture and Sale of Exotics
2.5 million
birds
caught
illegally / yr
1 bird in
store = 10
deaths in
transit
Humans Cause Extinction
Global Warming
Humans Cause Extinction
• Introduction of Non-Native Species –
species that does not belong in area.
Cane Toad
Zebra Mussels in Great
Lakes
Iceplant at Beach
Non-Natives/Exotics
•
1.
2.
3.
4.
Cause problems w/ native
species because:
Can usually outcompete
natives
Eat same food resources
as natives
No natural predators in
new area.
Reproduce w/ no limits on
growth.
Amer. Bullfrog in
CA
Crayfish in CA