biodiversity what is biodiversity? the number and variety of different species in a given area

BiodiversityBiodiversity

What is Biodiversity?What is Biodiversity?The number and variety The number and variety of different species in a of different species in a

given area.given area.

Number of Species on EarthNumber of Species on Earth

1.9 million 1.9 million knownknown species species EstimatedEstimated 9 million species exist. 9 million species exist.

May exist in remote wildernesses, deep in the May exist in remote wildernesses, deep in the oceans and even in cities. They have not been oceans and even in cities. They have not been collected and classified.collected and classified.

Levels of DiversityLevels of Diversity

Species diversitySpecies diversity- refers to the number of - refers to the number of different species in an area.different species in an area.

Ecosystem diversityEcosystem diversity- refers to the variety of - refers to the variety of habitats, communities, and ecological habitats, communities, and ecological processes within and between ecosystems.processes within and between ecosystems.

Genetic diversityGenetic diversity- refers to all the different - refers to all the different genes contained within all members of a genes contained within all members of a population.population.

Benefits of DiversityBenefits of Diversity

More species that exist, the better the More species that exist, the better the balance in an ecosystem.balance in an ecosystem.

Medical- 74% of the top 150 prescription Medical- 74% of the top 150 prescription drugs used in the US are derived from plants.drugs used in the US are derived from plants.

Food- most crops originated from a few areas Food- most crops originated from a few areas of high biodiversity.of high biodiversity.

Aesthetic or personal enjoymentAesthetic or personal enjoyment Clean air, clean water and fiber for clothing.Clean air, clean water and fiber for clothing.

Biodiversity at RiskBiodiversity at Risk

Humans are the primary cause of species Humans are the primary cause of species extinctions!!extinctions!!

LemursLemurs

90% of Lemur species face extinction.90% of Lemur species face extinction. Only found in Madagascar.Only found in Madagascar. Reason:Reason:

Illegal logging of tropical rainforests. Only 18% of Illegal logging of tropical rainforests. Only 18% of rain forest remain.rain forest remain.

Core Case Study: Core Case Study: The Passenger Pigeon - Gone The Passenger Pigeon - Gone

ForeverForever Once the most Once the most

numerous bird on earth.numerous bird on earth. In 1858, Passenger In 1858, Passenger

Pigeon hunting became Pigeon hunting became a big business.a big business.

By 1900 they became By 1900 they became extinct from over-extinct from over-harvest and habitat harvest and habitat loss.loss.

Figure 11-1Figure 11-1

SPECIES EXTINCTIONSPECIES EXTINCTION

Species can become extinct: Species can become extinct: LocallyLocally: A species is no longer found in an area : A species is no longer found in an area

it once inhabited but is still found elsewhere in it once inhabited but is still found elsewhere in the world.the world.

EcologicallyEcologically: Occurs when so few members of a : Occurs when so few members of a species are left they no longer play its ecological species are left they no longer play its ecological role.role.

Globally (biologically)Globally (biologically): Species is no longer : Species is no longer found on the earth.found on the earth.

Global ExtinctionGlobal Extinction

Some animals have become prematurely Some animals have become prematurely extinct because of human activities.extinct because of human activities.


Fig. 11-2, p. 223

Aepyornis(Madagascar)

Passenger pigeon Great auk Dodo Dusky seaside sparrow

Endangered and Threatened Species: Endangered and Threatened Species: Ecological Smoke AlarmsEcological Smoke Alarms

Endangered speciesEndangered species: so few individual : so few individual survivors that it could soon become extinct.survivors that it could soon become extinct.

Threatened speciesThreatened species: still abundant in its : still abundant in its natural range but is likely to become natural range but is likely to become endangered in the near future.endangered in the near future.


Fig. 11-3, p. 224

Hawksbill sea turtle

Giant panda Black-footed ferret

Whooping crane

Northern spotted owl

Blue whale

Mountain gorilla Florida panther

California condor

Black rhinoceros

HABITAT LOSS, DEGRADATION, HABITAT LOSS, DEGRADATION, AND FRAGMENTATIONAND FRAGMENTATION

Conservation biologists summarize the most Conservation biologists summarize the most important causes of premature extinction as important causes of premature extinction as ““HIPPOHIPPO””: : Habitat destruction, degradation, and Habitat destruction, degradation, and

fragmentationfragmentation Invasive speciesInvasive species Population growthPopulation growth PollutionPollution OverharvestOverharvest

Some species Some species have have characteristics characteristics that make them that make them vulnerable to vulnerable to ecological and ecological and biological biological extinction.extinction.

SPECIES SPECIES EXTINCTIONEXTINCTION


Fig. 11-4, p. 225

Low reproductive rate(K-strategist)

Specialized niche

Narrow distribution

Feeds at high trophic level

Fixed migratory patterns

Rare

Commercially valuable

Large territories

Characteristic

Blue whale, giant panda,rhinoceros

Blue whale, giant panda,Everglades kite

Many island species,elephant seal, desert pupfish

Bengal tiger, bald eagle,grizzly bear

Blue whale, whooping crane,sea turtles

Many island species,African violet, some orchids

Snow leopard, tiger, elephant, rhinoceros, rare plants and birds

California condor, grizzly bear, Florida panther

Examples


Scientists use measurements and models to Scientists use measurements and models to estimate extinction rates.estimate extinction rates. The International Union for the Conservation of The International Union for the Conservation of

Nature and Natural Resources (IUCN) publishes Nature and Natural Resources (IUCN) publishes an annual an annual Red ListRed List, listing the world, listing the world’’s threatened s threatened species.species.

The 2004 Red List contained 15,589 species at The 2004 Red List contained 15,589 species at risk for extinction.risk for extinction.

2014 Red list now contains 22,000 species at risk 2014 Red list now contains 22,000 species at risk for extinction.for extinction.



Percentage of various species types Percentage of various species types threatened with premature extinction from threatened with premature extinction from human activities.human activities.


Fig. 11-5, p. 225

12%Birds

Plants

Reptiles

Mammals

Fish 34% (51% of freshwater species)

25%

20%

14%

Coral ReefsCoral Reefs

60% of Earth’s coral reefs are threatened by 60% of Earth’s coral reefs are threatened by human activities: overfishing, and pollution.human activities: overfishing, and pollution.

HABITAT LOSS, DEGRADATION, HABITAT LOSS, DEGRADATION, AND FRAGMENTATIONAND FRAGMENTATION

Reduction in Reduction in ranges of four ranges of four wildlife species, wildlife species, mostly due to mostly due to habitat loss habitat loss and and overharvest.overharvest.


Fig. 11-8a, p. 230

Range 100 years ago

Indian Tiger

Range today(about 2,300 left)

Fig. 11-8b, p. 230

Range in 1700

Black Rhino

Range today(about 3,600 left)

Fig. 11-8c, p. 230

Probable range 1600

African Elephant

Range today

Fig. 11-8d, p. 230

Range today(34,000–54,000 left)

Asian or Indian Elephant

Former range

Case Study: Case Study: A Disturbing Message from the BirdsA Disturbing Message from the Birds

Human activities are causing serious declines Human activities are causing serious declines in the populations of many bird species.in the populations of many bird species.


PollutionPollution Each year pesticides:Each year pesticides:

Kill about 1/5Kill about 1/5thth of the of the U.S. honeybee U.S. honeybee colonies.colonies.

67 million birds.67 million birds. 6 -14 million fish.6 -14 million fish. Threaten 1/5Threaten 1/5thth of the of the

U.S.U.S.’’s endangered s endangered and threatened and threatened species.species.

Example of biomagnification Example of biomagnification of DDT in an aquatic food of DDT in an aquatic food chain.chain.


Fig. 11-15, p. 237

DDT in water 0.000003 ppm, or 3 ppt

DDT in fish-eating birds (ospreys)

25 ppm

DDT in large fish (needle fish) 2 ppm

DDT in small fish (minnows) 0.5 ppm

DDT in zooplankton 0.04 ppm

PROTECTING WILD SPECIES: PROTECTING WILD SPECIES: LEGAL AND ECONOMIC LEGAL AND ECONOMIC

APPROACHESAPPROACHES International treaties have helped reduce the International treaties have helped reduce the

international trade of endangered and international trade of endangered and threatened species, but enforcement is threatened species, but enforcement is difficult.difficult. One of the most powerful is the 1975 Convention One of the most powerful is the 1975 Convention

on International Trade of Endangered Species on International Trade of Endangered Species (CITES).(CITES).• Signed by 169 countries, lists 900 species that cannot Signed by 169 countries, lists 900 species that cannot

be commercially traded.be commercially traded.

Case Study: Case Study: The U.S. Endangered Species ActThe U.S. Endangered Species Act

One of the worldOne of the world’’s most far-reaching and s most far-reaching and controversial environmental laws is the 1973 controversial environmental laws is the 1973 U.S. Endangered Species Act (ESA).U.S. Endangered Species Act (ESA). ESA forbids federal agencies (besides defense ESA forbids federal agencies (besides defense

department) to carry out / fund projects that department) to carry out / fund projects that would jeopardize an endangered species.would jeopardize an endangered species.

ESA makes it illegal for Americans to engage in ESA makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect commerce associated with or hunt / kill / collect endangered or threatened species.endangered or threatened species.

Endangered SpeciesEndangered Species

Because of Because of scarcity of scarcity of inspectors, inspectors, probably no probably no more than 1/10more than 1/10thth of the illegal of the illegal wildlife trade in wildlife trade in the U.S. is the U.S. is discovered.discovered.


PROTECTING WILD SPECIES: THE PROTECTING WILD SPECIES: THE SANCTUARY APPROACHSANCTUARY APPROACH

The U.S. has set aside 544 The U.S. has set aside 544 federal refuges for wildlife, federal refuges for wildlife, but many refuges are but many refuges are suffering from environmental suffering from environmental degradation.degradation.

Pelican Island was the Pelican Island was the nationnation’’s first wildlife refuge.s first wildlife refuge.


Fig. 11-21, p. 246

• Do not buy furs, ivory products, and other materials made from endangered or threatened animal species.

• Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics.

• Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild.

• Do not buy orchids, cacti, and other plants that are taken from the wild.

• Spread the word. Talk to your friends and relatives about this problem and what they can do about it.

What Can You Do?

Protecting Species

biodiversity what is biodiversity? the number and variety of different species in a given area

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