Chapter 5

Conserving Life

Biodiversity

•      Biodiversity is the variety of life in an ecosystem

•      Biodiversity is measured by the number of species that live in an area

•      Biodiversity tends to increase in warmer, moister climates such as tropical regions

Importance of Biodiversity

•      People find beauty and pleasure in nature’s biodiversity

•      Hundreds of species help feed the human population

•      Helps improve food crops

Importance of Biodiversity

•      Provides people with useful materials

•      Ex:  wood to build furniture and buildings

•      Ex:  Cotton, flax and wool to make cloth

•      Ex:  Plants to make medicines

Importance of Biodiversity

•      Allows for stability in an ecosystem

•      Loss of biodiversity can weaken an ecosystem

–   You take out a food source for an item, or a predator to keep a population under control

•      Biodiversity on a farm helps prevent disease and reduces the need for pesticides

–   Crops better at resisting disease

Reduction of Biodiversity

•      An extinct species is a species that was once present on Earth but has died out

•      Extinction can be caused by competition from other species or other changes in the environment

•      Rate of extinction appears to be rising

 

Reduction of Biodiversity

•      An endangered species is a species in danger of becoming extinct

•      A threatened species is a species likely to become endangered in the near future

 

Reduction of Biodiversity

•      Habitat loss is a major reason why species become endangered or threatened

•      When people alter an ecosystem, habitats of some species may become smaller or disappear completely

•      Ex: The Lake Erie snake                              is classified as threatened                      because of development                              of some areas has caused                     habitat loss

Reduction of Biodiversity

•      Biodiversity can be reduced when a habitat is divided

•      Some large animals require spacious hunting territories

•      Small habitat areas make it difficult for species to recover from disaster

Reduction of Biodiversity

•      Introduced species are species that move into an ecosystem as a result of human actions

–   Morning glory

•      Introduced species often have no competitors or predators in a new area

•      They can crowd out or consume the native species (original organisms)        in an ecosystem

–    The tamarisk in S. Utah

Pollution

•      Biodiversity is affected by pollution of land, water or air

•      Soil contaminated with old, chemicals, or other pollutants can harm plants

Pollution

•      Water-dwelling organisms are easily harmed by pesticides, chemicals, and other pollutants

•      Water pollutants come from factories, ships or runoff from roads, lawns and farms.

•      Waterways can be polluted when people dispose of waste improperly

Pollution

•      When sulfur dioxide and nitrogen oxide combine with water vapor in the air, they form pollution called acid rain

•      Acid rain washes calcium and other nutrients from the soil

•      Acid rain harms                                        fish and other                                  organisms that                                          live in lakes and                                 streams

Pollution

•      The ozone layer prevents damaging amounts of UV                                 radiation from                                   reaching Earth’s                                  surface

–   Some pollution can                                   destroy the ozone

Global Warming

Conservation Biology

•      Conservation Biology is the study of methods for protecting biodiversity

•      Conservation plans have two goals

–   Protect a species from harm

–   Protect a species’ habitat

Conservation Plans

•      The US Endangered Species Act of 1973 protects a species and its habitat

•      Nature preserves such as national parks and wildlife areas protect habitats

•      Wildlife corridors link small protected areas together to allow animals to move from one preserve to another without crossing areas inhabited by humans

 

Conservation Plans

•      Habitat restoration occurs when people take action to bring a habitat back to a healthy condition

•      Park rangers, guards and volunteers often manage wildlife areas

•      Some wildlife preserves allow no visitors

•      Selling fishing and hunting licenses provides funds and protects populations from overhunting

Conservation Plans

•      Captive populations are populations           of organisms that are cared for by     humans

•      When ready, these organisms are       placed in reintroduction programs

–   They return captive populations           to their natural habitats

•      Reintroduction programs only succeed if factors that caused the species to become extinct are removed

•      Plants can also be reintroduced into their natural habitats

Conservation Plans

•      Seeds of many endangered plants are stored in seed banks

•      Reintroductions are most successful when wild organisms are relocated to new areas of suitable habitat