What is Biodiversity?

• Biodiversity refers to the number of different species in a given area.

• First we have to catalog all the species. Thus far the species known is about 1.7 million, most of which are insects.

• Scientists estimate that there are over 10 million total species.

A World Rich in Biodiversity

Benefits of Biodiversity

• Every species is either dependent on or depended upon by at least one other species in an ecosystem. Some relationships are not always obvious.

• Some species are so clearly critical to the functioning of an ecosystem that the are called keystone species.

Species and Population Survival

• Genetic diversity within populations is critical to species survival. Genetic diversity increases the chance of species surviving environmental changes.

• Small and isolated populations are less likely to survive such changes.

Importance of Biodiversity to Humans

Importance of Biodiversity to Humans

Saving Species

• Some regions of the world earn a majority of their income from ecotourism, a form of tourism that supports the conservation and sustainable development of ecologically unique areas.

Biodiversity at Risk

• Scientist believe that about 65 million years ago, a series of changes in the Earth’s climate and ecosystems caused the extinction of about half the species on Earth.

• The extinction of many species in a relatively short period of time is called a mass extinction.

Major Extinction Events

Species Prone to Extinction

• Species with small populations in limited areas.

• Species that migrate.

• Species with special habitat needs.

• Species exploited by humans.

AT RISK

• Endangered Species is a species that is likely to become extinct if protective measures are not taken immediately.

• Threatened Species is a species that has a declining population and that is likely to become endangered if it is not protected

How Do Humans Cause Extinctions?

Human population = extinctions

How do Humans Cause Extinctions?

• Habitat Destruction

• Fragmentation

• Invasive Exotic Species

• Harvesting, Hunting, and Poaching

• Pollution

How Do Humans Cause Extinction?

Human Cause What Happens? Example

Habitat Destruction & Fragmentation

We use land for building homes &

harvesting resources. This causes 75% of

extinctions.

Florida Panther

How Do Humans Cause Extinction?

Human Cause

What Happens? Example

Habitat Destruction & Fragmentation

We use land for building homes & harvesting resources. This causes

75% of extinctions.

Florida Panther

Invasive Exotic

Species

Species that are not native to a

particular region move in & take over

Fire ants of Southeastern

US

How Do Humans Cause Extinction?

Human Cause

What Happens? Example

Habitat Destruction & Fragmentation

We use land for building homes & harvesting resources. This causes

75% of extinctions.

Florida Panther

Invasive Exotic Species

Species that are not native to a particular region move in & take over

Fire ants of Southeastern US

Harvesting, Hunting, & Poaching

Excessive hunting & harvesting (rare

species are collected & sold). Poaching is the

illegal hunting or harvesting of species.

US – passenger pigeons & bison hunted to near

extinction.

Africa – elephants poached for ivory

tusks.

How Do Humans Cause Extinction?

Human Cause

What Happens? Example

Habitat Destruction & Fragmentation

We use land for building homes & harvesting resources. This causes

75% of extinctions.

Florida Panther

Invasive Exotic Species

Species that are not native to a particular region move in & take over

Fire ants of Southeastern US

Harvesting, Hunting, & Poaching

Excessive hunting & harvesting (rare species are collected & sold).

Poaching is the illegal hunting or harvesting of species.

US – passenger pigeons & bison hunted to near

extinction.

Africa – elephants poached for ivory tusks.

Pollution Pesticides, chemicals, drugs, etc. are entering

food webs.

DDT (pesticide) weakens bald

eagle eggs

Areas of Critical Biodiversity

Some areas of the world contain a greater diversity of species than others. Endemic species are species

that are native to and found only within a limited area.

EX:• Tropical Rain Forest – cover less than 7% of the Earth’s

land surface, but half of the world’s species live in these forests.

• Coral Reefs & Coastal Ecosystems – reefs contain the majority of marine biodiversity, provide people with food & tourism revenue, protect coasts from waves, & harbor many migrating species. 60% of reefs are threatened by humans & there are limited protection laws.

Biodiversity Hotspots• Areas with lots of endemic species but are

also threatened by human activities.

Saving Species

1. Conserving Habitats

2. Captive-Breeding Programs – breeding species in captivity with the hope of reintroducing populations to their natural habitats.

3. Preserving Genetic Material – germ plasm (any form of genetic material) stored for future recovery efforts.

4. Zoos, Aquariums, Parks, & Gardens – living museums of a small fraction of the world’s biodiversity.

Legal Protections for SpeciesUnited States

1. Endangered Species Act – US law designed to protect species in danger of becoming extinct.

A) The US Fish & Wildlife Service (USFWS) makes a list of endangered species

B) Protects the listed animals from human harm (people who harm endangered species are fined).

C) Federal government cannot do a project that may harm endangered species.

D) USFWS makes recovery plans for each endangered species.

Legal Protections for SpeciesInternational

1. International Union for the Conservation of Nature and Natural Resources (IUCN)

CITES (Convention on International Trade in Endangered Species)

Proposed a worldwide ban on the trade of ivory in

1989, decreasing elephant poaching

2. Earth Summit (UN Conference on Environment and Development)

Biodiversity Treaty that attempts to preserve biodiversity and ensure sustainable and fair use of genetic resources in all countries.

Private Conservation Efforts1. The World Wildlife Fund – encourages

the sustainable use of resources & supports wildlife protection.

2. The Nature Conservancy – helped purchase millions of hectares of habitat preserves in 29 countries.

3. Conservation International – identifies biodiversity hotspots and develop ecosystem conservation projects

4. Greenpeace International – organizes direct & sometimes confrontational actions to counter environmental threats