Ch. 5 Biodiversity and Conservation Biodiversity and Conservation

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

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 1.Genetic Diversity

2.Species Diversity - the number and relative abundance of species in an area TeosinteMaize

3.Ecosystem Diversity - the variety of ecosystems in a region or the biosphere

3.Ecosystem Diversity

B. Importance of Biodiversity - biodiversity provides direct and indirect value to humans

1.Direct Economic Value - plants and animals provide food, clothing, energy, medicine, shelter

1.Direct Economic Value - also provide sources for new medicines, crops, useful genes

1.Direct Economic Value - also provide sources for new medicines, crops, useful genes

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 - Their true value is realized when they are lost.

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 - 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 Cambrian Proterozoic eon Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene Number of families ( ) Number of taxonomic families Extinction rate Cretaceous mass extinction Permian mass extinction Millions of years ago Extinction rate ( ) PaleozoicMesozoic ,500 1,500 1, ,000 Ceno- zoic

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. 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 - Today’s high extinction rate is human caused. ~ 1,000 times the background extinction rate.

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

2.Habitat Loss - deforestation, urbanization, expanding agriculture

3.Habitat Fragmentation -Dividing habitats into smaller parcels reduces species diversity. -Populations become isolated reducing genetic diversity.

4.Pollution - Biomagnification

4.Pollution - Acid Precipitation

4.Pollution - Eutrophication

4.Pollution - Eutrophication

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.

5.Introduced Species - Exotic species lack natural enemies. - can outcompete native species Kudzu overgrowing a house in S. Carolina.

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.

5.Introduced Species Burmese Python Red Lion Fish Cane Toad

III.Conserving Biodiversity A.Natural Resources - As human population grows, demand for resources increases. - Consumption is higher in industrial nations. - As developing countries become more industrialized, consumption rates increase.

On average, one American consumes as much energy as: 2Japanese 6Mexicans 13Chinese 31Indians 128Bangladeshis 307Tanzanians 370Ethiopians

Ecological Footprint in Relation to Available Ecological Capacity New Zealand Australia Canada Sweden World China India Available ecological capacity (ha per person) Spain UK Japan Germany Netherlands Norway USA Ecological footprint (ha per person)

1.Renewable Resources - replaced by natural processes faster than they are consumed - sunlight, timber, clean air and water

2.Nonrenewable Resources - limited supply, replaced by nature very slowly - fossil fuels, minerals, old-growth forest

3.Sustainable Use - rate of resource consumption equals replacement rate

B.Protecting Biodiversity 1.U.S. Protected Areas - National Parks, Wildlife Refuges, Wilderness Areas, etc.

2.International Protected Areas - Biosphere Reserves, World Heritage Sites, National Parks ~ 7% of world’s land Nanda Devi Biosphere Reserve, Uttarakhand, India

2.International Protected Areas - Biosphere Reserves, World Heritage Sites, National Parks ~ 7% of world’s land Biosphere Reserves

3.Biodiversity Hot Spots - regions of exceptional diversity

3.Biodiversity Hot Spots - regions of exceptional diversity - 34 areas recognized internationally - contain >1500 species of endemic plants and 70% of habitat lost

4.Habitat Corridors - connect fragmented habitats - increases species and genetic diversity ‘Toad Tunnel’ in England ‘Wildlife Bridge’ in Netherlands ‘Migration Corridor’ for herptofauna

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 - 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 End