BIODIVERSITY

Objectives:

Loss of biodiversity due to continued agricultural expansion, pollution, climate change and infrastructure development

• Explain biodiversity and its importance.

• Relate various threats to the loss of biodiversity.

Biodiversity: the number of different species that live in a certain area.

Biological Diversity

• Biodiversity increases as you move toward the equator. Two-thirds of all the species on Earth are found in tropical regions: tropical rain forests, coral reefs, and large tropical lakes.

• Biodiversity has great importance not only to nature, but to people as well.

Importance of Biodiversity to Nature• Living things are interdependent (living things can be niches for

other living things).• Populations are adapted to live together in communities. • Biodiversity can bring stability to an ecosystem (ecosystems

are stable if their biodiversity is maintained).

Importance of Biodiversity to People• Humans depend on other organisms for their needs (only a few

species of plants and animals supply the major portion of the food eaten by the human population.

• Biodiversity could help breeders produce additional food crops.• Biodiversity can be used to improve people’s health since living

things supply the world pharmacy.

Loss of BiodiversityExtinction: the disappearance of a species when the last of its members dies.

Background Extinction: Natural extinction that occurs in nature (one out of ten species loss per year). Endangered Species: When a species numbers become so low that extinction is possible.

Threatened Species: A species that is likely to become endangered.

Mexican walking fishGlass frog

• Habitat loss• Habitat fragmentation• Habitat degradation• Pollution (Air, land, water)• Edge and Size• Exotic species

Habitat loss: loss of habitat due to deforestation or human disturbances.

Threats to Biodiversity

Habitat fragmentation: Separation of wild life areas from other wild life.

Habitat fragmentation has been found to contribute to:• increased extinction of local species.• changes in overall biodiversity.

• disruption of ecological processes.

• new opportunities for invasions by unwanted or exotic species.

• increased risk of fire.

Habitat degradation: the damage to a habitat by pollution (air, land, and water).

Air pollution: is caused by pollutants that enter the atmosphere through forest fires, volcanic eruptions, and burning of fossil fuels.

Burning of fossil fuels produces sulfur dioxide. When sulfur dioxide combines with water vapor in the air it form acid droplets.

Acid rain causes:• loss of nutrients from the soil.• damage to plant tissue and interferes with plant growth.• degradation of lake ecosystems.

Land Pollution: is caused by solid waste (cans, bottles, paper, plastic, metals, dirt, and spoiled food that people throw away every day).

1,000 10,000 100,000 1,000,000 100,000,000

Magnification of DDT Concentration

Producer Large FishSmall FishZooplankton Fish-Eating Bird

Water PollutionWater pollution: degrades aquatic habitats in streams, rivers, lakes and oceans.

Edge and sizeEdge: where one habitat or ecosystem meets another.

Edge Effects: The different conditions along the boundaries of an ecosystem.

Exotic SpeciesInvasive species: Non-native plants and animals that adversely affect the habitat they invade (these species can cause problems to the native species).

Kudzu Zebra mussels