What is Biodiversity Biodiversity refers to the number

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

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? • • • Habitat Destruction Fragmentation Invasive Exotic Species Harvesting, Hunting, and Poaching Pollution

How Do Humans Cause Extinction? Human Cause What Happens? Habitat We use land for Destruction & building homes & Fragmentation harvesting resources. This causes 75% of extinctions. Example Florida Panther Polar Bear

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 Polar Bear Invasive Exotic Species that are not Stink bugs native to a Zebra Mussels particular region Kudza move in & take over

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 Polar Bear Invasive Exotic Species that are not native to a particular region move in & take over Stink bugs Zebra Mussels Kudza Harvesting, Hunting, & Poaching Excessive hunting & US – passenger harvesting (rare pigeons & bison species are collected & hunted to near sold). Poaching is the extinction. illegal hunting or Africa – elephants harvesting of species. 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 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