7 Biodiversity and Conservation
CHAPTER
7
Biodiversity and Conservation
Saving the Siberian Tiger • Siberian tigers are one of five remaining tiger subspecies. • In the early 20th century, hunting and habitat loss reduced the wild population to just 20–30 animals. • Conservation efforts have helped the wild population rebound to 450–500 today.
Talk About It What are the benefits of wildlife conservation? Are there drawbacks?
Lesson 7.1 Our Planet of Life
Lesson 7.1 Our Planet of Life
Biodiversity • Describes the variety of life across all levels of ecological organization • Includes three types: • Genetic diversity: Differences in DNA among individuals • Species diversity: Variety of species in a given area • Ecosystem diversity: Variety of habitats, ecosystems, communities
There are more known species of insects than any other form of life. Among known insect species, 4% are beetles.
Lesson 7.1 Our Planet of Life
Classification • Taxonomists classify species based on physical appearance and genetic makeup. • Species are placed into a hierarchy of taxonomic groups: • • • • • • •
Genus Family Order Class Phylum Kingdom Domain
• Taxonomic groups reflect evolutionary relationships among species. • Below the species level, organisms may fall into subspecies—populations with genetically based characteristics that differ area to area.
Genetic Diversity
Species Diversity
Ecosystem Diversity
Lesson 7.1 Our Planet of Life
Biodiversity Distribution • There are likely between 5 and 30 million species on Earth. • Species can be difficult to find and identify. • Species are not evenly distributed globally, among taxonomic groups, or within a given geographic area. Did You Know? In general, biodiversity increases toward the equator. Orangutan in an Indonesian rain forest
1
Lesson 7.1 Our Planet of Life
Lesson 7.1 Our Planet of Life
Ecosystem Services
Other Benefits of Biodiversity
• Intact environments provide ecosystem services, such as water purification and pest control. • High biodiversity increases stability of communities and ecosystems, enabling them to perform services. • Stable ecosystems are resistant and resilient. • Resistant: Resist environmental change without losing function • Resilient: Affected by change, but bounce back and regain function
• Agriculture: Wild strains are crossbred with related crops to transfer beneficial traits.
The yew tree, an original source of Taxol, a cancer-fighting drug Did You Know? Of the 150 most prescribed drugs in the United States, 118 originated in nature.
• Medicine: Organisms contain compounds that are useful for treating disease. • Ecotourism: Environmentally responsible tourism is a source of income for many nations.
Wetlands in Loxahatchee National Wildlife Refuge, Loxahatchee, Florida
Practical Uses of Species • • •
•
Many species have practical uses for humans today. Over 40% of all prescription drugs in the United States were developed from plants and animals. Diseases such as cancer, heart attack, and strokes, all of which are fatal, are all treated with drugs developed by endangered plants and animals. • You have about a 25% chance of getting cancer, 50% chance of having a heart attack and about a 33% chance of having a stroke! Additionally, since we rely on plants an animals for food, the loss of biodiversity will affect the amount of overall food that is available for us to eat! • And, the lack of biodiversity will make the chance of our food supply becoming more at risk to disease and pestilence even greater!
Lesson 7.2 Extinction and Biodiversity Loss
Natural Biodiversity Loss • Background extinctions: Naturally occurring extinctions, occurring one species at a time • Mass extinctions: Events when extinction rates far exceed the normal background rate • There have been five mass extinctions in Earth’s history. • Each time, more than 1/5 of all families and 1/2 of all species have gone extinct. Dinosaur extinctions were part of a mass extinction.
Lesson 7.2 Extinction and Biodiversity Loss
Biodiversity losses caused by humans are common in our history. Hunting and forest cutting drove the passenger pigeon—once North America’s most numerous bird—into extinction.
Lesson 7.2 Extinction and Biodiversity Loss
Biodiversity at Risk • The current extinction rate is 100 to 1000 times greater than the natural background rate. • In 2009, 1321 species in the U.S. were classified as endangered or threatened. • Endangered: At serious risk of extinction • Threatened: Likely to become endangered soon through all or part of its range Giant panda, an endangered species Did You Know? The Living Planet Index fell nearly 30% between 1970 and 2005.
• Living Planet Index: Summarizes global population trends for certain terrestrial, freshwater, and marine species
2
Lesson 7.2 Extinction and Biodiversity Loss
Lesson 7.2 Extinction and Biodiversity Loss
Causes of Biodiversity Loss • Habitat change and loss • Invasive species • Pollution • Overharvesting Siberian tiger
Habitat Change and Loss • Greatest cause of biodiversity loss • Organisms, adapted to their habitat, decline in population when the habitat changes. • Habitat fragmentation: Patches of suitable habitat surrounded by unsuitable habitat • In general, larger habitat fragments can support greater biodiversity than smaller fragments. Did You Know? Habitat change or destruction is the primary cause of population decline in more than 80% of threatened birds and mammals.
Lesson 7.2 Extinction and Biodiversity Loss
Lesson 7.2 Extinction and Biodiversity Loss
Invasive Species, Pollution, and Overharvesting
Climate Change • Increasingly becoming a factor in biodiversity loss • Unlike the other factors, climate change will have a potentially global effect on biodiversity.
• Invasive species can out-compete and displace native species. • Harmful chemicals and materials that make their way into habitats can poison people and wildlife.
Did You Know? Scientists predict that a 1.5–2.5°C global temperature increase could put 20–30% of plant and animal species at increased risk of extinction.
An example is the melaleuca tree, which was brought to Everglades in the early 1900s. It is now spreading at a rate of about 50 acres a day, wiping out species that depend on that wetland ecosystem.
• Occasionally, species can be driven toward extinction by hunting or overharvesting by humans. Examples include Siberian tigers and passenger pigeons.
Once common in North America, the passenger pigeon is now extinct.
Lesson 7.3 Protecting Biodiversity
Lesson 7.3 Protecting Biodiversity
The Endangered Species Act Just 2.3% of the planet’s land surface is home to 50% of the world’s plant species and 42% of its vertebrate animal species.
• U.S. law that protects biodiversity, passed in 1973 • Has three major parts: • Forbids governments and citizens from harming listed species and habitats • Forbids trade in products made from listed species • Requires U.S. Fish and Wildlife Service to maintain official list of endangered and threatened species, and to develop recovery plan for each listed species Did You Know? In part because of the Endangered Species Act, 40% of populations that were once declining in the U.S. are now stable.
3
Developers vs. Environmentalists? • The Endangered Species Act is extremely controversial with developers (builders). • This is because the builders want to make money by clearing land and are often prevented from doing so by the Endangered Species Act. • Also, a lot of people who work in construction or who would have benefited from the jobs become upset about the loss of jobs/income. • In the end, most controversies end in a compromise, where the needs of the community and the needs of the environment are balanced. • Although there are many lawsuits over the Endangered Species Act, most get settled and never go to trial.
International Cooperation • Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES, 1975): Bans international trade in body parts of endangered species. • Convention on Biological Diversity (1992): International treaty to conserve biodiversity and ensure its responsible use and distribution Ivory products, made from elephant tusks
Captive-Breeding Programs
Lesson 7.3 Protecting Biodiversity
Single-Species Approaches to Conservation • Captive breeding programs: Raising and breeding organisms in controlled conditions, such as zoos or aquariums • Species Survival Plan: Program to save individual species, includes captive breeding, education, and research • Cloning: Inserting DNA from an endangered species into a cultured egg cell; process involves implanting eggs into mothers of closely related species
Majete Wildlife Reserve, Malawi Did You Know? The Species Survival Plan for the golden lion tamarin started with only 91 individuals. As of 2007, there were nearly 500 tamarins in zoos, and 150 reintroduced into the wild.
Captive-Breeding Programs Benefits and Risks •
•
The benefits of captive-breeding programs are that it can work to save a single species. • This often works best when there are very few members of the species left and they reproduce very slowly or rarely. The risks are that this is very expensive, and by placing all of the organisms together in 1 place, they could all be killed by a disease. • Additionally, if it does not work, most likely there will be no members of the species left at all. • And, if it does work, the animals may not learn the skills they need to survive in the wild while being raised by humans in a zoo.
Lesson 7.3 Protecting Biodiversity
• Captive-Breeding is when scientists capture wild organisms and try and get them to breed in captivity in order to increase their overall number. • This is typically done at zoos and wild animal parks • An example of a successful captive breeding program is the California Condor. • In 1986, there were only 9 condors left (there once were millions of them ranging from California to Florida). By 1998, there were 93 condors in zoos and 39 that had been released back into the wild! • Another example is the panda, where there are now more than 1,000 pandas saved as a result of captive-breeding.
Germ-Plasm Banks • Germ-plasm banks store DNA (either seeds or sperm and eggs) from organisms for future use. • The goal is to preserve the DNA of an organism until a time in the future when science is able to recover the species and reproduce it.
4
Botanical Gardens •
• •
• The benefits of Botanical Gardens are that they protect a large number of plants around the world. • Additionally, botanical gardens are not too expensive as they are often sustained by the fees people pay to visit them. • The risks are that by placing all the plants together, pests and diseases could easily spread throughout the garden and kill off large numbers of plants very quickly. • Also, many plants require other animals in the ecosystem to help reproduce (such as bees and animals) which most likely aren’t present in the botanical garden. Without those other animals, the plants will not reproduce and may die. • Finally, there are far more plants that are at risk of going extinct than can ever be supported in botanical gardens (most likely there are more than 1 million different plant species on the planet).
Around the world, more than 90,000 different plants are preserved in botanical gardens. These can range from greenhouses to large open fields of plants. As a result, they store protect a large amount of biodiversity and can be used for research.
Lesson 7.3 Protecting Biodiversity
Lesson 7.3 Protecting Biodiversity
Biodiversity Hotspots • The “hotspot approach” focuses attention on areas where the greatest number of species can be protected with the least effort. • At least 1500 plant species found nowhere else in the world
• The 34 biodiversity hotspots are home to 50% of Earth’s plant species and 42% of terrestrial vertebrate species.
Economic Approaches to Conservation • Many conservation efforts today attempt to balance protection of land and wildlife with the economic interests of local people:
• Hotspots have:
• Already lost 70% of their habitat as a result of human activity
Botanical Gardens-Benefits & Risks
Northern Pintail ducks, Honshu, Japan Japan is one of the world’s biodiversity hotspots.
• Debt-for-nature swap: Conservation organizations raise money to pay off a nation’s debt in return for improved conservation measures. • Conservation concession: Conservation organizations buy the rights to conserve resources, instead of harvesting them.
Lesson 7.3 Protecting Biodiversity
Wildlife Corridors • Connect habitat fragments enabling once-isolated populations to interbreed • Interbreeding increases genetic diversity. • Conservation biologists hope that a planned 250-km long corridor in Australia will enable the endangered southern cassowary to recover from population declines.
5
7
Biodiversity and Conservation
Saving the Siberian Tiger • Siberian tigers are one of five remaining tiger subspecies. • In the early 20th century, hunting and habitat loss reduced the wild population to just 20–30 animals. • Conservation efforts have helped the wild population rebound to 450–500 today.
Talk About It What are the benefits of wildlife conservation? Are there drawbacks?
Lesson 7.1 Our Planet of Life
Lesson 7.1 Our Planet of Life
Biodiversity • Describes the variety of life across all levels of ecological organization • Includes three types: • Genetic diversity: Differences in DNA among individuals • Species diversity: Variety of species in a given area • Ecosystem diversity: Variety of habitats, ecosystems, communities
There are more known species of insects than any other form of life. Among known insect species, 4% are beetles.
Lesson 7.1 Our Planet of Life
Classification • Taxonomists classify species based on physical appearance and genetic makeup. • Species are placed into a hierarchy of taxonomic groups: • • • • • • •
Genus Family Order Class Phylum Kingdom Domain
• Taxonomic groups reflect evolutionary relationships among species. • Below the species level, organisms may fall into subspecies—populations with genetically based characteristics that differ area to area.
Genetic Diversity
Species Diversity
Ecosystem Diversity
Lesson 7.1 Our Planet of Life
Biodiversity Distribution • There are likely between 5 and 30 million species on Earth. • Species can be difficult to find and identify. • Species are not evenly distributed globally, among taxonomic groups, or within a given geographic area. Did You Know? In general, biodiversity increases toward the equator. Orangutan in an Indonesian rain forest
1
Lesson 7.1 Our Planet of Life
Lesson 7.1 Our Planet of Life
Ecosystem Services
Other Benefits of Biodiversity
• Intact environments provide ecosystem services, such as water purification and pest control. • High biodiversity increases stability of communities and ecosystems, enabling them to perform services. • Stable ecosystems are resistant and resilient. • Resistant: Resist environmental change without losing function • Resilient: Affected by change, but bounce back and regain function
• Agriculture: Wild strains are crossbred with related crops to transfer beneficial traits.
The yew tree, an original source of Taxol, a cancer-fighting drug Did You Know? Of the 150 most prescribed drugs in the United States, 118 originated in nature.
• Medicine: Organisms contain compounds that are useful for treating disease. • Ecotourism: Environmentally responsible tourism is a source of income for many nations.
Wetlands in Loxahatchee National Wildlife Refuge, Loxahatchee, Florida
Practical Uses of Species • • •
•
Many species have practical uses for humans today. Over 40% of all prescription drugs in the United States were developed from plants and animals. Diseases such as cancer, heart attack, and strokes, all of which are fatal, are all treated with drugs developed by endangered plants and animals. • You have about a 25% chance of getting cancer, 50% chance of having a heart attack and about a 33% chance of having a stroke! Additionally, since we rely on plants an animals for food, the loss of biodiversity will affect the amount of overall food that is available for us to eat! • And, the lack of biodiversity will make the chance of our food supply becoming more at risk to disease and pestilence even greater!
Lesson 7.2 Extinction and Biodiversity Loss
Natural Biodiversity Loss • Background extinctions: Naturally occurring extinctions, occurring one species at a time • Mass extinctions: Events when extinction rates far exceed the normal background rate • There have been five mass extinctions in Earth’s history. • Each time, more than 1/5 of all families and 1/2 of all species have gone extinct. Dinosaur extinctions were part of a mass extinction.
Lesson 7.2 Extinction and Biodiversity Loss
Biodiversity losses caused by humans are common in our history. Hunting and forest cutting drove the passenger pigeon—once North America’s most numerous bird—into extinction.
Lesson 7.2 Extinction and Biodiversity Loss
Biodiversity at Risk • The current extinction rate is 100 to 1000 times greater than the natural background rate. • In 2009, 1321 species in the U.S. were classified as endangered or threatened. • Endangered: At serious risk of extinction • Threatened: Likely to become endangered soon through all or part of its range Giant panda, an endangered species Did You Know? The Living Planet Index fell nearly 30% between 1970 and 2005.
• Living Planet Index: Summarizes global population trends for certain terrestrial, freshwater, and marine species
2
Lesson 7.2 Extinction and Biodiversity Loss
Lesson 7.2 Extinction and Biodiversity Loss
Causes of Biodiversity Loss • Habitat change and loss • Invasive species • Pollution • Overharvesting Siberian tiger
Habitat Change and Loss • Greatest cause of biodiversity loss • Organisms, adapted to their habitat, decline in population when the habitat changes. • Habitat fragmentation: Patches of suitable habitat surrounded by unsuitable habitat • In general, larger habitat fragments can support greater biodiversity than smaller fragments. Did You Know? Habitat change or destruction is the primary cause of population decline in more than 80% of threatened birds and mammals.
Lesson 7.2 Extinction and Biodiversity Loss
Lesson 7.2 Extinction and Biodiversity Loss
Invasive Species, Pollution, and Overharvesting
Climate Change • Increasingly becoming a factor in biodiversity loss • Unlike the other factors, climate change will have a potentially global effect on biodiversity.
• Invasive species can out-compete and displace native species. • Harmful chemicals and materials that make their way into habitats can poison people and wildlife.
Did You Know? Scientists predict that a 1.5–2.5°C global temperature increase could put 20–30% of plant and animal species at increased risk of extinction.
An example is the melaleuca tree, which was brought to Everglades in the early 1900s. It is now spreading at a rate of about 50 acres a day, wiping out species that depend on that wetland ecosystem.
• Occasionally, species can be driven toward extinction by hunting or overharvesting by humans. Examples include Siberian tigers and passenger pigeons.
Once common in North America, the passenger pigeon is now extinct.
Lesson 7.3 Protecting Biodiversity
Lesson 7.3 Protecting Biodiversity
The Endangered Species Act Just 2.3% of the planet’s land surface is home to 50% of the world’s plant species and 42% of its vertebrate animal species.
• U.S. law that protects biodiversity, passed in 1973 • Has three major parts: • Forbids governments and citizens from harming listed species and habitats • Forbids trade in products made from listed species • Requires U.S. Fish and Wildlife Service to maintain official list of endangered and threatened species, and to develop recovery plan for each listed species Did You Know? In part because of the Endangered Species Act, 40% of populations that were once declining in the U.S. are now stable.
3
Developers vs. Environmentalists? • The Endangered Species Act is extremely controversial with developers (builders). • This is because the builders want to make money by clearing land and are often prevented from doing so by the Endangered Species Act. • Also, a lot of people who work in construction or who would have benefited from the jobs become upset about the loss of jobs/income. • In the end, most controversies end in a compromise, where the needs of the community and the needs of the environment are balanced. • Although there are many lawsuits over the Endangered Species Act, most get settled and never go to trial.
International Cooperation • Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES, 1975): Bans international trade in body parts of endangered species. • Convention on Biological Diversity (1992): International treaty to conserve biodiversity and ensure its responsible use and distribution Ivory products, made from elephant tusks
Captive-Breeding Programs
Lesson 7.3 Protecting Biodiversity
Single-Species Approaches to Conservation • Captive breeding programs: Raising and breeding organisms in controlled conditions, such as zoos or aquariums • Species Survival Plan: Program to save individual species, includes captive breeding, education, and research • Cloning: Inserting DNA from an endangered species into a cultured egg cell; process involves implanting eggs into mothers of closely related species
Majete Wildlife Reserve, Malawi Did You Know? The Species Survival Plan for the golden lion tamarin started with only 91 individuals. As of 2007, there were nearly 500 tamarins in zoos, and 150 reintroduced into the wild.
Captive-Breeding Programs Benefits and Risks •
•
The benefits of captive-breeding programs are that it can work to save a single species. • This often works best when there are very few members of the species left and they reproduce very slowly or rarely. The risks are that this is very expensive, and by placing all of the organisms together in 1 place, they could all be killed by a disease. • Additionally, if it does not work, most likely there will be no members of the species left at all. • And, if it does work, the animals may not learn the skills they need to survive in the wild while being raised by humans in a zoo.
Lesson 7.3 Protecting Biodiversity
• Captive-Breeding is when scientists capture wild organisms and try and get them to breed in captivity in order to increase their overall number. • This is typically done at zoos and wild animal parks • An example of a successful captive breeding program is the California Condor. • In 1986, there were only 9 condors left (there once were millions of them ranging from California to Florida). By 1998, there were 93 condors in zoos and 39 that had been released back into the wild! • Another example is the panda, where there are now more than 1,000 pandas saved as a result of captive-breeding.
Germ-Plasm Banks • Germ-plasm banks store DNA (either seeds or sperm and eggs) from organisms for future use. • The goal is to preserve the DNA of an organism until a time in the future when science is able to recover the species and reproduce it.
4
Botanical Gardens •
• •
• The benefits of Botanical Gardens are that they protect a large number of plants around the world. • Additionally, botanical gardens are not too expensive as they are often sustained by the fees people pay to visit them. • The risks are that by placing all the plants together, pests and diseases could easily spread throughout the garden and kill off large numbers of plants very quickly. • Also, many plants require other animals in the ecosystem to help reproduce (such as bees and animals) which most likely aren’t present in the botanical garden. Without those other animals, the plants will not reproduce and may die. • Finally, there are far more plants that are at risk of going extinct than can ever be supported in botanical gardens (most likely there are more than 1 million different plant species on the planet).
Around the world, more than 90,000 different plants are preserved in botanical gardens. These can range from greenhouses to large open fields of plants. As a result, they store protect a large amount of biodiversity and can be used for research.
Lesson 7.3 Protecting Biodiversity
Lesson 7.3 Protecting Biodiversity
Biodiversity Hotspots • The “hotspot approach” focuses attention on areas where the greatest number of species can be protected with the least effort. • At least 1500 plant species found nowhere else in the world
• The 34 biodiversity hotspots are home to 50% of Earth’s plant species and 42% of terrestrial vertebrate species.
Economic Approaches to Conservation • Many conservation efforts today attempt to balance protection of land and wildlife with the economic interests of local people:
• Hotspots have:
• Already lost 70% of their habitat as a result of human activity
Botanical Gardens-Benefits & Risks
Northern Pintail ducks, Honshu, Japan Japan is one of the world’s biodiversity hotspots.
• Debt-for-nature swap: Conservation organizations raise money to pay off a nation’s debt in return for improved conservation measures. • Conservation concession: Conservation organizations buy the rights to conserve resources, instead of harvesting them.
Lesson 7.3 Protecting Biodiversity
Wildlife Corridors • Connect habitat fragments enabling once-isolated populations to interbreed • Interbreeding increases genetic diversity. • Conservation biologists hope that a planned 250-km long corridor in Australia will enable the endangered southern cassowary to recover from population declines.
5
