Bio 1 Ch 5

Bio 1 Ch 5

Biodiversity

Extinction

• Extinction - Last member of a species dies

• As species become extinct, the variety of species in the biosphere decreases

• Biodiversity - the variety of life in an area that is determined by the number of different species in that area.

• --Increases the stability of an ecosystem

• 4 types of biodiversity: Species, Genetic, Ecosystem, and functional diversity

Species diversity.

• Species diversity describes the variety of species present in a specific ecosystem and their abundance within the ecosystem.

• We have discovered 2 million species of organisms on Earth. They estimate that there are likely 7-10 million species on earth and may be as many as 100 million.

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Genetic diversity

• Genetic diversity is the variety of genes found in a population or in a species.

• Genes contain code, or instructions, called genetic information, which give rise to certain traits or characteristics.

• These traits are passed through offspring.

• Variations in these traits contribute to genetic diversity

• Species with greater genetic diversity have a better chance of survival in environmental change.

• There is a greater chance that individuals will possess favorable traits needed to survive, such as resistance to disease.

  
  

Ecosystem diversity

• Ecosystem diversity refers to Earth’s diversity of biological communities such as deserts, grasslands, forests, lakes, rivers, and wetlands

•  Ecosystems are often found within Biomes.

  
  

• Biomes - Biomes have distinct climates and certain species that are able to survive there.

  
  

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Functional Diversity

• Functional diversity is the variety of processes such as energy flow and matter cycling that occur within ecosystems.

• Concerns the variety of ecological roles organisms play in their communities and the impact these roles play on the overall ecosystem.

• Examples: Where an organism sits on a food chain, how its behaviours affect an ecosystem physically or chemically.

• An ecosystem with many species that hold similar functions will be able to withstand species loss. Whereas an ecosystem with few species that hold different function will not be able to survive as well.

The importance of biodiversity

• Direct economic value

• Indirect economic value

• Aesthetic and scientific values

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Direct economic value

• Plants and animals provide food, clothing, medicine, shelter to humans

• Protecting genetic diversity is beneficial to our future.

• We were able to create disease resistant corn because we found a distant relative of corn carrying disease-resistant genes.we

• Through genetic engineering we were able to give these genes to corn we grow today

Indirect economic value

• Green plants provide oxygen to the atmosphere and remove carbon dioxide.

• Natural processes provide drinking water

• Healthy ecosystems provide protection against floods and drought

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Aesthetic and scientific values

• Things look nice

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Threats to biodiversity

• Extinction rates

• Overexploitation

• Habitat Loss

• Fragmentation of habitat

• Pollution

• Introduced Species

Multiple Choice

When the last member of a population dies, that species has now become...

• Extinct

• Endangered

• Overexploitation

Multiple Choice

Which of the following is not a type of biodiversity?

• Species

• Climate

• Ecosystem

• Functional

Multiple Choice

The diversity of biological communities such as deserts, grasslands, forests, lakes, rivers, and wetlands is known as...

• Ecosystem diversity

• Genetic diversity

• Species diversity

• Functional diversity

Multiple Choice

The variety of genes found in a population or in a species...

• Species diversity

• Genetic diversity

• Ecosystem diversity

• Functional Diversity

Multiple Choice

Areas with distinct climates and certain species that are able to survive there.

• Ecosystems

• Biomes

• Biosphere

• Communities

Multiple Select

Biodiversity is important because of all of these except...

• Direct Economic value

• Indirect economic value

• Energy transfer

• Aesthetic and scientific values

Extinction rates

• Background extinction -  gradual process of species becoming extinct

• Ecosystems change due to the activity of other organisms, climate changes, or natural disasters.

• Due to a recent increase in the rate of extinction, scientists believe that between one third and two thirds of all plant and animals species will become extinct during the second half of this century.

• Mass extinction - an event in which a large percentage of all living species become extinct in a relatively short period of time.

Overexploitation

• Overexploitation - excessive use

• Overexploitation of certain species is increasing the current rate of extinction

• These species have economic value to humans

• Bison killed for meat and hides, ocelot habitats destroyed and hunted for furs.

Habitat Loss

• Species have to relocate when their habitat is disrupted or destroyed

• Destruction of habitat

• --Clearing of rainforests

• --Causes species to become extinct as a result of habitat loss

• Disruption of habitat

• --One species on a food web becoming affected affects many other species as well

• --One fish population declining in the ocean can cause many other species to decline as well

Fragmentation of habitat

• Habitat fragmentation - Separation of an ecosystem into small pieces of land

• Species often stay within the confines of small parcel because they are unwilling to cross human made barriers

• Smaller parcels support less species

• Reduces opportunity for individuals in one area to reproduce with individuals in another area

• --Genetic diversity decreases over time

• Dividing into parcels create edge effects

Fragmentation of habitat

• Edge effects - environmental conditions that occur along the boundaries of an ecosystem

• --Edges of ecosystems tend to have different abiotic factors

Pollution

• Pollution changes composition of soil, water, and air

• Human made substances (DDT, PCB’s, Pesticides) are released into nature, and are consumed by organisms, which builds up in their tissues.

• Biological magnification - increasing concentration of toxic substances in organisms

• --Concentration of toxic substances increases as it moves up trophic levels

Pollution

• Acid precipitation

• --Fossil fuels release sulfur dioxide into the atmosphere, and rain becomes more acidic, damaging ecosystems

• Eutrophication

• --Destroys underwater habitats

• --Eutrophication - fertilizers, animals waste, sewage, or other substances flow into waterways, causing extensive algae growth

Introduced Species

• Introduced species - Nonnative species that are either intentionally or unintentionally transported to a new habitat.

• Predators, parasites, competition keeps an ecosystem in balance

• Introduced species often reproduce in large numbers because of lack of predators and become invasive species.

• Fire ants

Conserving Biodiversity

• Natural Resources

• Protecting biodiversity

• Restoring ecosystems

Natural Resources

• Renewable resources - Replaced by natural processes faster than they are consumed

• Solar energy, plants, animals, water, air

• While they are renewable, they are not unlimited. If demand exceeds supply, they could be depleted.

• Nonrenewable Resources - Replaced by natural processes over a long period of time

• Sustainable use - using resources at a rate at which they can be replaced or recycled while preserving the long term environmental health of the biosphere

Protecting biodiversity

• Protected areas in the United states

• --National parks

• --Nature reserves

• International protected areas

• --7% of the world’s land is set aside as some type of reserve

Biodiversity hot spots

• Conservation biologists have identified locations around the world that are characterized by exceptional levels of endemic species and habitat loss

• Endemic species - Species that are only found in that specific geographic area

• Two criteria in order to be a hotspot

• --Must be at least 1500 species of vascular plants that are endemic

• --Region must have lost at least 70% of its original habitat

• Half of all plant and animal species are found in hot spots

Protecting biodiversity

• Corridors between habitat fragments

• Passageways between habitat fragments

• These areas can sustain wider variety of biodiversity

• Does not completely solve the problem for habitat destruction

• Diseases still carry from one area to the next

Restoring ecosystems

• An ecosystem can naturally restore itself following a disturbance, but biologists use 2 methods to speed a recovery process

• Bioremediation - Use of living organisms to detoxify a polluted area

• Biological augmentation - Adding natural predators to a degraded ecosystem

• --Releasing ladybugs to target aphids which destroy farm crops.

Indirect economic value

• Green plants provide oxygen to the atmosphere and remove carbon dioxide.

• Natural processes provide drinking water

• Healthy ecosystems provide protection against floods and drought