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 – 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

• 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. Habitat Alteration2. Invasive species3. Pollution4. Overharvesting5. Climate Change

1) Habitat Alteration

• Mainly by human activity• HOW?• Primary cause of reduced biodiversity.

– 85% of mammals– 85% of birds

• 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

• 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 air2. Fresh water3. Buffering systems against floods and

drought4. Reservoirs of genetic variationAnd a lot more at no cost!

And more…

• 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

• 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