Transcript Biodiversity and Conservation Biology

Biodiversity and
Conservation Biology
EB
Lecture 8
2008 Spring
Case study
• Siberian Tiger
Siberian Tiger
Found
• Before 20th century
– Large region
• Turkey to Russia to Indonesia
• Lived with by locals
• After 20th century
– Small tracks of forest in the far reaches of Russia
– Number down to a little as 20
– Now near 1000
Siberian Tiger
• What led to the drop in number of this
species?
• What of other species?
• Mass extinction event happening now..
Biodiversity
• The sum of all the organisms in a given
area
• But, it can vary according to the
biologist and situation…
Species
• Species richness - refers to the number
of species in a given area.
– Density of species
– Richness of Species
• New Species are born via speciation
• Species die due to extinction
Sub-species
• What is a sub-species?
• Either you are pregnant or you are not!
• Differ in some aspect
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Height
Coloration
Size
But are still able to mate and generate viable
fertile offspring.
Genetic Diversity
• Everyone differs from others in their
DNA to some degree (except?)
• So there is genetic diversity present in
all species and populations
• Genetic Diversity provides the raw
material for evolution - survival of the
fittest.
Genetic Diversity..
• More genetic diversity = more flexibility to
adapt to environmental changes
• Less genetic diversity = depressed genetic
diversity = less chance of survival
• Inbreeding = mating between genetically
related individuals = less fitness = more
diseases surface.
• How? Give examples in humans. In aminals?
Ecosystem Diversity
• Above the species level
• Refers to the number and variety of
ecosystems
• Again density of types in important here
too…
– Same area of land but with differing
biodiversity and ecosystems.
How much biodiversity
• Hard concept to measure
• We have documented about 2 million
species today
• Estimated that there are a total of 2 to
100 million altogether!!!!!
• Where are they all?
Insects rule
• Insects account for most of the known
types
• Followed by Protists
• And Fungi
• And Arachnids
• We may find many more bacterial
species and other smaller life forms…
Species Richness and
location
• As one approaches the equator the
levels of species richness increases
greatly. Why?
• Plant growth rate?
• Glaciation?
Extinction
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Lost for ever, and ever, and ever…
Loss of a local population = extirpation
Many species are extinct now
99% of species that ever lived are gone.
On going process, with one species lost
for every 1 to 10 million in existence
• Background rate = above number…
Extinction..
• Rapid loss of species = Mass extinction
• 5 mass extinction events in the last half
a billion years.
• About half the species die on Earth
• Fifth of these killed the dinosaurs
• Latest one (6th)is caused by man and
will effect man!!!!!!!!!!!!!!
Extinction...
• Many species have gone extinct recently,
including,
• Tigers
• 8 sub-species existed
• 3 are extinct
• 5 are tittering on the edge….
YOUR HELP AND UNDERSTANDING IS
NEEDED
Biodiversity has another
parameter too…
• Species numbers are one measure
• The other is population numbers of
each species
• They are mostly on the decline
• Which species are on the rise?
• By one such measure there has been a
40% reduction in numbers of many
species.
Biodiversity loss by…
1.
2.
3.
4.
5.
Habitat Alteration
Invasive species
Pollution
Overharvesting
Climate Change
1) Habitat Alteration
• Mainly by human activity
• HOW?
• Primary cause of reduced biodiversity.
– 85% of mammals
– 85% of birds
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GONE FOREVER
45% of forests are lost
50% of mangroves
10% of coral reefs
2) Invasive species
• Introduction of non-native species
– Accidental
• Examples
– Intentional
• Examples
– Economic damage can be tremendous
– Most perish but some thrive!!!!!
3) Pollution
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Not as devastating as the previous two
Air pollution
Water pollution
Soil pollution
Mostly man made…
4) Overharvesting
• This factor is dependent upon the life
style of the hunted
• Organisms few in number and with long
reproductive cycles and few offspring
are at risk!!!
• Siberian Tigers fit this model…
5) Climate Change
• Man’s activity and use of fossil fuels is
having an effect on the environment
• Rising temperatures
• Changing weather patterns
• Air and ocean currents
• Ice shelves
• Plant growth and deserification
You and Me My wife
• Population growth
• Consumption
– These two forces are responsible for the
increase in loss of biodiversity
WHY CARE!
Does it matter, if just humans and their
food supply remain?
Free of Charge
•
The various ecosystems provide us
with;
1. Clean air
2. Fresh water
3. Buffering systems against floods and
drought
4. Reservoirs of genetic variation
And a lot more at no cost!
And more…
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Drugs - treat ulcers
Medicines - anticancer compounds
Tourism - ecotourism
Better solutions - better sweeteners
• Biophilia - the connection to nature!
Conservation Biology
Conservation Biology
• - that branch of biology devoted to
understanding the
• factors, forces, and processes
• that influence
• the loss, protection, and restoration
• of biological diversity
Tools
• Regulations
– Endangered Species Act (ESA) USA
– Passed in 1973
– Stops habitat destruction of endangered
species
– Spotted Owl
– California Condor
Zoos
• Captive breeding programs designed to
rear healthy at risk species and
introduction back to natural habitat.
• Slow
• Single species approach
International treaties
• CITES
– Convention on International Trade in Endangered
Species of wild fauna and flora
– Protecting the high-land gorillas
• Convention on Biological Diversity
– Promotes biodiversity by conserving biodiversity
– 188 nations signed, but not US
Umbrella Species
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Take likable species - like panda
Have the public relate to it
Protect its vast habitat
Also end up protecting many other
species in that protected habitat.
Biodiversity Hotspots
• This list includes 34 of the highest
density hotspots and aims to use the
limited resources to protect these first.
Community-based
conservation
• Educate and involve the locals
• Share revenues or promote locally
grown products, or tourist revenues
• Basis of modern ecotourism