Preserving Earth’s

Biological Diversity

Chapter 17

Biological Diversity

Biodiversity

Species Richness

Genetic Diversity

Biological Diversity

Biodiversity

Species Richness

Genetic Diversity

Ecosystem Diversity

Biological Diversity

Why We Need Organisms

• Ecosystem Services and Species Richness

Maintains smaller fish populations by eating gar

Digs underwater holes used by other aquatic organisms

Gator trails clear out aquatic vegetation

Nests eventually become small islands of trees

Biological Diversity

Why We Need Organisms

• Ecosystem Services and Species Richness

• Genetic Reserves• Scientific Importance of Genetic Diversity• Medicinal, Agricultural, and Industrial Importance of Organisms

Biological Diversity

Why We Need Organisms

• Ecosystem Services and Species Richness

• Genetic Reserves• Scientific Importance of Genetic Diversity• Medicinal, Agricultural, and Industrial Importance of Organisms• Aesthetic, Ethical, and Spiritual Value of Organisms (intrinsic value)

Endangered and Extinct Species

Background Extinction vs. Mass Extinction

Continuous, slow rate of extinction over millions of years

Numerous species disappear over geologically short time frame.

Endangered and Extinct SpeciesEndangered and extinct species

Confirmed observation in Arkansas in April 2005

Endangered and Extinct Species

Endangered and Threatened Species

Could become extinct soon.

Population declining very fast.

Endangered and Extinct Species

Characteristics of Endangered Species:

• Extremely small range

• Requiring large territories

• Living on islands

• Low reproductive success

• Specialized breeding areas

• Specialized feeding habits

Tiburon mariposa lily

California condor

Hawaii ‘O’ o

Blue whale

Green sea turtle

Giant panda

Endangered and Extinct Species

Common problem: habitat fragmentation

Endangered and Extinct Species

Human Causes of Species Endangerment

#1 cause: Habitat Destruction, Fragmentation, and Degradation

Endangered and Extinct Species

Earth’s Biodiversity Hotspots

Endangered and Extinct Species

Human Causes of Species Endangerment:

Invasive

Species

Endangered and Extinct Species

Human Causes of Species Endangerment:

Pollution

• Acid rain

• Ozone depletion (leading to increased UV radiation

• Climate change due to CO2 increases

Endangered and Extinct Species

Human Causes of Species Endangerment:

Overexploitation, poaching

Endangered and Extinct SpeciesCase-in-Point: Disappearing Frogs•In the US, 38% of amphibian

species are declining

•No single factor has been

determined•Many deformities have been observed

Conservation Biology

• Preservation – keeping resources/areas in a pristine state; not using them at all.

• Conservation – the sensible and careful management (use) of natural resources:

• In situ conservation – maintaining biodiversity in the wild

• Ex situ conservation – human-controlled settings; captive breeding, zoos

Conservation Policies and Laws

Endangered Species Act - 1973

Conservation Policies and Laws

Endangered Species

Act: critical habitats,

management plans

for each species

1982, 1985, 1988

Science vs private

interest

Conservation Policies and Laws

International Conservation Policies and Laws

• Most important: CITES (Convention on International Trade in Endangered Species of Wild Flora and Fauna)

• 1975 to ban international trade of endangered animals & parts (tusks, skins)

Conservation BiologyProtecting Habitats

Conservation Policies and Laws

Habitat Conservation Plans

• 1982 amendment to ESA

• Landowner allowed to set aside land for endangered species, but develop other land with those species

Conservation Biology

Restoring Damaged or Destroyed Habitats

Beginning of prairie restoration in 1935

Conservation Biology

Restoring Damaged or Destroyed Habitats

Same area in 2004

Conservation Biology

Zoos, Aquaria, Botanical Gardens, and Seed Banks

Conservation Biology

Zoos, Aquaria, Botanical Gardens, and Seed Banks

Ultimate goal is to reintroduce endangered species back to their natural habitats

Conservation Biology

Zoos, Aquaria, Botanical Gardens, and Seed Banks

Establishing seed banks

Conservation Biology

Conservation Organizations

Many work with state & federal agencies and private landowners to promote conservation.

Wildlife Management

Differs from conservation biology in that wildlife managers focus more often on common organisms

and manage those species primarily for human benefits

Wildlife Management

Management of Migratory Animals

Example of artic snow geese impact

Wildlife Management

Management of Aquatic Organisms

• Freshwater fisheries primarily managed by state fishing regulations

• Ocean fisheries commonly viewed as common property

this has lead many species close to commercial extinction

What Can We Do About Declining Biological Diversity?

• Increase Public Awareness

• Support Research in Conservation Biology

• Support the Establishment of an International System of Parks

• Control Pollution

• Provide Economic Incentives to Landowners and Other Local People

Endangered and Extinct Species

Where is Declining Biological Diversity the Greatest Problem?

• In US: Hawaii and California

• Worldwide: Tropical rain forests