Chapter 15 Conserving Biodiversity Community and Ecosystem Ecology Fourth Edition BIOLOGY Science for Life | with Physiology Colleen Belk • Virginia Borden Maier © 2013 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc. PowerPoint Lecture prepared by Jill Feinstein Richland Community College 15.1 The Sixth Extinction  Endangered Species Act (ESA) – law passed in 1973 to protect and encourage population growth of threatened and endangered species  Biodiversity – the entire diversity of living organisms in an area  Extinction – the complete loss of a species © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Measuring Extinction Rates  History of life on earth has been punctuated with five mass extinctions. © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Measuring Extinction Rates  Is the sixth mass extinction event occurring now?  Need to know the background extinction rate  Fossils indicate that average species exists for ~1,000,000 years  Estimate of background extinction rate is 0.0001% per year © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Measuring Extinction Rates  Current rate of extinction – three times more bird and mammal species have disappeared in the last 150 years than in the previous 200 years © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – The Causes of Extinction  The most severe threats to species loss come from four general categories:  Loss or degradation of habitat  Introduction of non-native species  Overexploitation of species  Pollution © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Habitat is the place where a particular species lives and obtain resources for survival.  As human population increases, pressure on natural areas increases.  Species area curve measures the relationship between the size of a natural area and the number of species it can support.  Habitat destruction affects all ecosystems.  If worldwide habitat destruction continues at present rate, as many as 25% of world’s species could become extinct. © 2013 Pearson Education, Inc. Animation: Tropical Deforestation And The Species Area Curve Click “Go to Animation” / Click “Play” © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Predicting extinction caused by habitat destruction © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Usually human activity results in habitat fragmentation – large natural areas subdivided into smaller areas.  Large predators are threatened because they require large home ranges. © 2013 Pearson Education, Inc. Animation: Habitat Destruction And Fragmentation Click “Go to Animation” / Click “Play” © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Basic rule of biological systems: energy flows in one direction along a food in chain within an ecosystem  The sun provides energy to the producers which are feed on by the primary consumers who are feed upon by the secondary consumers. © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction - Introduced Species  Introduced species: nonnative species introduced to a new area either purposely or accidentally by human activity  Most groups of species in an area undergo coevolution.  Introduction of non-native species is often destructive because they have not evolved with local species.  Brown tree snake, introduced to Guam, caused many local bird species to go extinct. © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Overexploitation  When human use of a natural resource exceeds its reproductive rate, overexploitation occurs.  Can occur if species is highly prized by humans, which can spur illegal hunting  Can also occur if species competes with humans (i.e., wolves and ranchers) © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Pollution  The release of poisons, toxins, excess nutrients, and other waste products – pollution – is another threat to biodiversity.  Excess fertilizer runoff leads to eutrophication of waterways.  Eutrophication is the excess growth of bacteria that depletes oxygen from the water.  Carbon dioxide is another atmospheric pollutant associated with climate change. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Loss of Resources  Loss of species can lead to economic impacts for humans.  Some biological resources harvested directly include wood (lumber and fuel), shellfish (protein), and algae (gelatin).  Wild species provide biological chemicals (medicines).  Wild species have alleles that are not present in domestic species, which can increase vigor of domesticated species.  Wild species can contribute other means of combating pests (biological control). © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Predation, Mutualism, and Competition Derailed  Species interact with one another and their environment in complex ways, not just a simple food chain, but instead as a food web. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Mutualism: How Bees Feed the World  Mutualism – relationship in which both species benefit from their interaction, for example:  Cleaner fish  Fungal mycorrhizae  Ants and acacia trees  Bees are primary pollinators of many wild plants  Wild bees pollinate 80% of agricultural crops in U.S.  Bee populations are falling due to “colony collapse disorder”  Humans benefit from mutualism, and will lose if bees go extinct  Commensalism is a relationship where one species benefits and the other is unaffected. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Predation: How Songbirds May Save Forests  Predator – species that survives by eating other species  Songbirds consume many insects.  Most insects eaten by songbirds consume plants.  Songbirds help to sustain forests.  As songbird numbers decline, damage to forests increases. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life  A leading cause of food illness in the U.S. is caused by Salmonella enteritidis.  About 2 million Americans infected each year.  About 400 die each year as a result of infection.  Most common source of infection is eggs.  S. enteritidis contaminates egg when it forms in the hen. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life  Competitive exclusion is the use of food and space resources, making it impossible for another species to establish itself.  On this principle, chickens are deliberately infected with harmless bacteria.  Harmless bacteria establish and prevent S. enteritidis from living in chicken’s gut thus decreasing the number of eggs infected with S. enteritidis. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life  Competition between species can have consequences for humans as well.  Mosquitos, snails, and tadpoles compete for the same resources in ponds.  When populations of snails and tadpoles decrease, mosquitoes increase.  This is potentially serious because mosquitoes can spread malaria, West Nile virus, and yellow fever. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Keystone Species: How Wolves Feed Beavers  Keystone species are key figures in determining the food web of an ecosystem.  Wolves were eradicated from Yellowstone Park in the 1920s.  With wolves gone, biologists noted declines in aspen, cottonwood, and willow trees.  Trees declined due to predation by elk.  Trees are crucial for beavers, songbirds, and fish.  With reintroduction of wolves, trees and other species rebounded. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction –Keystone Species: How Wolves Feed Beavers © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Disrupted Energy and Chemical Flows  An ecosystem is defined as all of the organisms in a given area, along with their non-biological enivornment.  Energy flow - only a small portion (~10%) of the energy in one level of a trophic pyramid can be converted to biomass at the next level  Diversity also affects energy flow, such as in more diverse grasslands, more biomass is produced © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Disrupted Energy and Chemical Flows  Nutrient cycling – nutrients that pass through a food web rarely leave the system © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Disrupted Energy and Chemical Flows  The soil community has an important role in nutrient cycling.  Decomposers return nutrients back in to the soil for use by plants.  Introduction of non-native earthworms in NE U.S. had dramatic impact on forest plants.  Non-native worms changed the soil community. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Psychological Effects  Our experience with nature has strong psychological effects.  Dental patients viewing landscapes showed a decrease in blood pressure.  Hospital patients who could view trees recovered from surgery more quickly.  Instinctive desire to commune with nature is called biophilia.  Loss of biodiversity could make human experience less pleasant. © 2013 Pearson Education, Inc. 15.3 Saving Species – Protecting Habitat  Less than 2% of the earth’s surface contains up to 50% of the earth’s mammal, bird, reptile, and plant species. These areas are biodiversity hotspots. © 2013 Pearson Education, Inc. 15.3 Saving Species – Protecting Habitat  Converting wild areas to agricultural production is a major cause of habitat destruction.  Ways to decrease the rate of habitat destruction:  Altering our consumption patterns can help decrease habitat destruction.  Eating low on the food chain (less meat and dairy) makes a difference.  Increased financial aid to developing countries can also help.  So can slowing human population growth rate. © 2013 Pearson Education, Inc. 15.3 Saving Species – Protection From Environmental Disasters  A large population provides group protection from environmental disaster.  A species with a slow growth rate is at greater risk if its numbers diminish.  The longer a population remains small, the greater its risk. © 2013 Pearson Education, Inc. 15.3 Saving Species – An Overview of Conservation Genetics  Genetic variability is the sum of all of the alleles and their distribution within the species.  Loss of genetic variability is a two-fold problem.  Low genetic variability leads to low fitness, and is more likely to express harmful mutant alleles.  Rapid loss of genetic variability can lead to extinction due to the low fitness of individuals. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  The importance of genetic variability  When individuals are heterozygotic for many genes, the overall effect is greater fitness. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  Heterozygotes can avoid deleterious effects of recessive alleles. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  In a small population, individuals are more likely to be related to their mates.  Result can be inbreeding depression, a decline in heterozygotes.  Because of this, cheetahs have poor quality sperm and low rate of cub survival.  In humans, children of first cousins have lower rates of heterozygosity and higher rates of infant mortality. © 2013 Pearson Education, Inc. 15.3 Saving Species - A Closer Look: Conservation Genetics  Small populations lose their genetic variability due to genetic drift. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  The consequences of low genetic variability in a population  A small population can become stuck in a cycle that leads to extinction.  This is called the extinction vortex © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  Irish potato is a human example of the potentially disastrous effects of low genetic diversity.  In 1850s, Irish potato crop had very low genetic diversity  Fungus that causes potato blight arrived in Ireland; plants rotted in fields  Because of crop failure, nearly 1 million Irish died of starvation and disease © 2013 Pearson Education, Inc. 15.4 Protecting Biodiversity Versus Meeting Human Needs  The protection of endangered species sometimes has effects on human livelihood.  Farmers were unable to use water for irrigation because diversion of water would have disrupted fish populations.  Endangered Species Act has helped save American alligators, peregrine falcons, and bald eagles. © 2013 Pearson Education, Inc. 15.4 Protecting Biodiversity Versus Meeting Human Needs © 2013 Pearson Education, Inc. Unit V Homework Ecology Introduction In previous chapters, we learned that life is very diverse. Organisms range from single cells to multicelled. Some organisms cannot even be seen with the naked eye. Is diversity increasing or decreasing? In the future, will we have more organisms? Does our population play a role in the lives of other organisms? Should we be considered if an organism goes extinct? The following exploratory activity will help you understand threats to organisms, what is being done to save them, and how organisms are classified. Materials Computer with internet access Directions 1. Go to: http://www.redlist.org/ or copy and paste the address into your web browser. 2. In the search term, box type in the word Ivory-billed Woodpecker . 3. Click on the scientific name for Ivory-billed Woodpecker. 4. Read the information and answer the following questions. Questions 1 – 20 are short answer questions and should be answered in a few words. Total: 80 points Type all answers directly in the data sheet text boxes and upload the data sheet as a .doc, .docx, or .rtf file with your last name and student number when finished. You may need to adjust the textbox size to display all text. 1. In your own words, explain the purpose of the IUCN Red List. (4 points) 2. What is the scientific name for the Ivory-billed Woodpecker? (4 points) 3. Are there any similar species? If so, name them. (4 points) 4. In your own words state where are Ivory-billed Woodpeckers found. (4 points) 5. What is the current status of the Ivory-billed Woodpecker? What was it before the year 2000? (4 points) 6. What is the population trend? (4 points) 7. How many mature Ivory-billed Woodpeckers are estimated to exist? How many sub-populations? (4 points) 8. In your own words describe the habitat that Ivory-billed Woodpeckers require. (4 points) 9. Look at the range map linked in the Ivory-billed Woodpecker IUCN page. How many U.S. states does the bird's range include? (4 points) 10. In which Kingdom is the Ivory-billed Woodpecker classified? (4 points) 11. In which Phylum is the Ivory-billed Woodpecker classified? (4 points) 12. In which Class is the Ivory-billed Woodpecker classified? (4 points) 13. In which Order is the Ivory-billed Woodpecker classified? (4 points) 14. In which Family is the Ivory-billed Woodpecker classified? (4 points) 15. What is the most significant threat to Ivory-billed Woodpeckers. (4 points) 16. Describe in your own words what (if anything) is currently being done to protect the species. (4 points) 17. What is the primary food source for this species? (4 points) 18. With such low population numbers, why might genetic diversity be a concern? (4 points) 19. Do you feel that it is worth it to save this species? Explain why or why not. (4 points) 20. In your opinion, can this species be saved or is it too late? Briefly explain your answer. (4 points) Question 21 is an extended response question. Your response should be at least 100 words in length. Total: 20 points 21. Considering what you have learned from this activity and the textbook chapters, explain your thoughts about the following statement: "Humans rely on other organisms for survival; however, other organisms would be better off without humans." Take a stand and argue for or against this statement. Chapter 16 Where Do You Live? Climate and Biomes Fourth Edition BIOLOGY Science for Life | with Physiology Colleen Belk • Virginia Borden Maier © 2013 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc. PowerPoint Lecture prepared by Jill Feinstein Richland Community College 16.1 Global and Regional Climate  Climate – the average conditions of a place measured over many years  Climate is different from weather, which is current conditions in terms of temperature, cloud cover, and precipitation.  Precipitation is rain or snowfall. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate  Generally, temperatures are warmer near the tropics than near the poles.  Temperatures are usually warmer at low altitudes.  Generally, there is more seasonality nearer to the poles.  Water tends to mediate temperature swings.  Rain and snowfall patterns are more variable than temperature patterns. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate  Seasonality and precipitation are influenced by geographical factors. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate  Average temperature of any place on earth is determined by the total amount of solar irradiance received on an annual basis. This can vary because of:  Earth’s spherical shape – more irradiance at equator © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate  Solar irradiance can also vary because of:  Earth’s axial tilt – 23.5º causes annual variation in solar irradiance © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate – A Closer Look: Temperature and Precipitation Patterns  Distribution of precipitation on Earth’s surface  Rain and snowfall patterns are primarily caused by sun’s energy.  Rate of evaporation depends on temperature – the rate is high at high temperatures and low at low temperatures.  At low evaporation rates, water droplets clump together. Groups of droplets form clouds.  As temperatures decrease, cloud droplets form drops and fall, or drops can freeze. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate – An Overview: Global Temperature and Precipitation Patterns  The water cycle is the relationship between liquid water, water vapor, and rainfall. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate – An Overview: Global Temperature and Precipitation Patterns  Rainfall patterns result from global wind patterns. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate – An Overview: Global Temperature and Precipitation Patterns  Average daily amount of solar irradiance varies by location.  In Northern Hemisphere, summer solstice is longest day of year.  The closer a region is to a pole, the greater the variance in day length.  Chicago varies by 6 hours, Fairbanks by 18 hours winter to summer  Large day length changes explain why there are more extreme seasonal temperatures nearer to the poles. © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate – A Closer Look: Temperature and Precipitation Patterns  Local factors that influence temperatures:  Altitude  Proximity of a large body of water  Characteristics of land’s surface and vegetation © 2013 Pearson Education, Inc. 16.1 Global and Regional Climate – A Closer Look: Temperature and Precipitation Patterns  The moderating influence of water © 2013 Pearson Education, Inc. Animation: Tropical Atmospheric Circulation and Global Climate Click “Go to Animation” / Click “Play” © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes  Biome  primary vegetation type  Four basic biome categories:     Forest Grassland Desert Tundra © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Forests and Shrublands  Forests – vegetation communities dominated by trees and other woody plants  Forests account for  1/3 of earth’s land mass.  They contain  70% of earth’s biomass.  Three general types:  Tropical – at or near equator  Temperate – from 23º to 50º north and south of equator  Boreal – close to the poles © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Tropical Forests  Tropical forests have high rates of biodiversity. As many as 750 tree species per hectare (10,000 m2)  High levels of solar energy and rainfall enable tall tree growth  Facilitates life in canopy  Also high rates of decomposition  Dead matter quickly reabsorbed which leaves very little in the soil  Deforestation for agriculture endangers thousands of organisms. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Temperate Forests  Temperate forests have favorable water and sunlight for growing season, but not during winter months.  Evolution of deciduous habit – trees drop their leaves during winter.  During spring, trees begin to re-leaf.  Plants of forest floor have rapid growth and blooming period to take advantage of sunlight. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Temperate Forests  The understory of temperate forests contains the forest floor and shrub layer that is missing from tropical forest.  Succession is the progressive replacement of different suites of species over time. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Boreal Forests  Largest biome on earth found in North America, Asia, and northern Europe  Dominated by conifers (pines, spruce, etc.)  Adapted for long, cold winters and moist summers  Evergreen lifestyle allows for photosynthesis earlier than deciduous plants. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Chaparral  Dominated by woody plants, but not a forest.  Adapted to regular burning cycle, many species have seeds that germinate only after exposure to high heat.  Found in Mediterranean, southern California, South Africa, and South West Australia  Because of urbanization this is one of the most threatened biomes on earth. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Grasslands  Dominated by non-woody grasses with few trees or shrubs. Found in areas without enough rain to support trees. Divided into tropical and temperate types:  Tropical grasslands  savannahs  Temperate grasslands  prairies and steppes  Grazing further favors grasses and plants that grow from base as grazers eat tips of plants.  Grasslands are typically maintained by periodic burning.  Desertification occurs when there is an introduction of large number of grazing cattle, which changes the grassland to bare, sandy soil. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Desert  Areas where rainfall is less than 50 cm/year  Generally found at 30º N and S of Equator  Temperatures can fluctuate – deserts can become very cold.  Typical plant adaptations include waxy coating, spines, column-like form, and water storage in stem. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Tundra  Plant growth only sustained for 50 – 60 days/year  Underlain by permafrost, an icy mud impedes water drainage and tree growth.  Plants are typically ground hugging, due to high winds and low temperatures.  Supports a number of grazing mammals such as caribou and musk oxen  With climate change, some areas of tundra are converting to boreal forest. © 2013 Pearson Education, Inc. 16.2 Terrestrial Biomes – Tundra  Because of the long winters, birds in the tundra perform migration to warmer climates such as South America. © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Freshwater  Freshwater characterized by low concentration of salts (less than 0.1%)  Three general types:  Lakes and ponds  Streams and rivers  Wetlands © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Freshwater  Lakes and ponds – bodies of water that are surrounded by land  Some ponds dry up seasonally – often important habitats for frogs, salamanders  Seasonal changes in air temperature cause winds that promote “turnover” in lakes and ponds. © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Freshwater  Lakes and ponds  Eutrophication occurs when too many nutrients are introduced, causing large amount of algae to grow.  The algae then consume most of the oxygen in the water and suffocate the native fish.  This can occur because of fertilizer run off.  Acid rain threatens lakes and Ponds by increasing the acidity of the water and killing off sensitive species. © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Freshwater  Rivers and streams – bodies of water flowing in one direction  Headwater – water is cold, clear, and fast-flowing  Middle reaches – water warms, can sustain algal growth that provides food for greater diversity of animals  Mouth – where river flows into another body of water, speed slower, more sediments in water, reducing light levels © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Freshwater  Wetlands – areas of standing water that support growth of above water plants  Support large numbers of species, like tropical forests  By slowing water, help to control flooding  Also filter toxins and sediments from water  In U.S., over 50% of wetlands have been lost or degraded. © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Saltwater  Saltwater, or marine, biomes account for nearly 75% of earth’s surface.  Typically divided into three categories:  Oceans  Coral reefs  Estuaries © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Saltwater  Open ocean is about 2/3 of earth’s surface, but it is the least known biome.  50% of oxygen in atmosphere is generated by photosynthetic algae in open ocean.  Open ocean also generates most freshwater through evaporation.  Species diversity in open ocean has declined by 50% in last 50 years due to overexploitation.  Intertidal zones contain unique habitats due to the changing of the tides. © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Saltwater  Coral Reefs  Habitat is not geological – it is formed from the skeleton of coral animals  Found in warm, well lit tropical waters  Most diverse aquatic habitat – as many species per area as tropical forest  Sensitive to environmental change © 2013 Pearson Education, Inc. 16.3 Aquatic Biomes – Saltwater  Estuaries  Zone where freshwater river drains into salty oceans  Provided habitat for 75% of commercial fish populations, and rich source of shellfish  Salt marsh vegetation provides a buffer that resists erosion and stabilizes shoreline.  Estuaries are currently threatened by human activity, including habitat loss and eutrophication. © 2013 Pearson Education, Inc. 16.4 Human Habitats  Humans have modified 50% of earth’s surface.  Half of the human population live in cities. © 2013 Pearson Education, Inc. 16.4 Human Habitats – Energy and Natural Resources  Energy use  Developed countries use a large amount of fossil fuels.  For most people, energy used is not taken from bioregion, thus people don’t feel environmental impacts. © 2013 Pearson Education, Inc. 16.4 Human Habitats – Energy and Natural Resources  Natural resources  Human settlements require raw materials to sustain life – food, shelter, water, etc.  Ecological footprint – the amount of land required to support human activity  For city of London, ecological footprint was 239 times size of city.  This is twice the land area of the whole United Kingdom.  London is not unique in resource consumption. © 2013 Pearson Education, Inc. 16.4 Human Habitats – Waste Production  Wastewater  Developed world cities have treatment plants to deal with wastewater from many sources.  Plants remove semisolid waste, use chemicals to kill organisms and discharge water.  Disposal of sludge (semisolid waste) is problematic.  Urban areas in undeveloped countries typically have antiquated and inadequate sewer systems, and water treatment is not available. © 2013 Pearson Education, Inc. 16.4 Human Habitats – Waste Production  Garbage and recycling  In developed world, most solid waste (garbage) is disposed of in sanitary landfills.  Landfill space is becoming limited and farther from cities.  Even with recycling, household production of waste is increasing.  In underdeveloped countries, waste is generally disposed of in large open dumps. © 2013 Pearson Education, Inc. 16.4 Human Habitats – Waste Production  Air pollution  Reliance on fossil fuels means that urban areas produce large amounts of gaseous waste.  Byproducts include carbon dioxide, nitrogen oxide, sulfur oxide, and particulates.  Bioaccumulation is the process that concentrates small amounts of pollutants to dangerous levels.  Problematic in both developed and developing world © 2013 Pearson Education, Inc. 16.4 Human Habitats – Waste Production  Air pollution  In U.S., number of miles driven per household has doubled in last 25 years.  Human impacts on biomes can be severe, but with planning, can be mitigated.  In U.S., Clean Air Act and Clean Water Act have greatly reduced pollution, and helped habitats to recover.  Many cities around the world are engaging in planning to make their communities sustainable. © 2013 Pearson Education, Inc. Chapter 15 Conserving Biodiversity Community and Ecosystem Ecology Fourth Edition BIOLOGY Science for Life | with Physiology Colleen Belk • Virginia Borden Maier © 2013 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc. PowerPoint Lecture prepared by Jill Feinstein Richland Community College 15.1 The Sixth Extinction  Endangered Species Act (ESA) – law passed in 1973 to protect and encourage population growth of threatened and endangered species  Biodiversity – the entire diversity of living organisms in an area  Extinction – the complete loss of a species © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Measuring Extinction Rates  History of life on earth has been punctuated with five mass extinctions. © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Measuring Extinction Rates  Is the sixth mass extinction event occurring now?  Need to know the background extinction rate  Fossils indicate that average species exists for ~1,000,000 years  Estimate of background extinction rate is 0.0001% per year © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Measuring Extinction Rates  Current rate of extinction – three times more bird and mammal species have disappeared in the last 150 years than in the previous 200 years © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – The Causes of Extinction  The most severe threats to species loss come from four general categories:  Loss or degradation of habitat  Introduction of non-native species  Overexploitation of species  Pollution © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Habitat is the place where a particular species lives and obtain resources for survival.  As human population increases, pressure on natural areas increases.  Species area curve measures the relationship between the size of a natural area and the number of species it can support.  Habitat destruction affects all ecosystems.  If worldwide habitat destruction continues at present rate, as many as 25% of world’s species could become extinct. © 2013 Pearson Education, Inc. Animation: Tropical Deforestation And The Species Area Curve Click “Go to Animation” / Click “Play” © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Predicting extinction caused by habitat destruction © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Usually human activity results in habitat fragmentation – large natural areas subdivided into smaller areas.  Large predators are threatened because they require large home ranges. © 2013 Pearson Education, Inc. Animation: Habitat Destruction And Fragmentation Click “Go to Animation” / Click “Play” © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Habitat Destruction and Fragmentation  Basic rule of biological systems: energy flows in one direction along a food in chain within an ecosystem  The sun provides energy to the producers which are feed on by the primary consumers who are feed upon by the secondary consumers. © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction - Introduced Species  Introduced species: nonnative species introduced to a new area either purposely or accidentally by human activity  Most groups of species in an area undergo coevolution.  Introduction of non-native species is often destructive because they have not evolved with local species.  Brown tree snake, introduced to Guam, caused many local bird species to go extinct. © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Overexploitation  When human use of a natural resource exceeds its reproductive rate, overexploitation occurs.  Can occur if species is highly prized by humans, which can spur illegal hunting  Can also occur if species competes with humans (i.e., wolves and ranchers) © 2013 Pearson Education, Inc. 15.1 The Sixth Extinction – Pollution  The release of poisons, toxins, excess nutrients, and other waste products – pollution – is another threat to biodiversity.  Excess fertilizer runoff leads to eutrophication of waterways.  Eutrophication is the excess growth of bacteria that depletes oxygen from the water.  Carbon dioxide is another atmospheric pollutant associated with climate change. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Loss of Resources  Loss of species can lead to economic impacts for humans.  Some biological resources harvested directly include wood (lumber and fuel), shellfish (protein), and algae (gelatin).  Wild species provide biological chemicals (medicines).  Wild species have alleles that are not present in domestic species, which can increase vigor of domesticated species.  Wild species can contribute other means of combating pests (biological control). © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Predation, Mutualism, and Competition Derailed  Species interact with one another and their environment in complex ways, not just a simple food chain, but instead as a food web. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Mutualism: How Bees Feed the World  Mutualism – relationship in which both species benefit from their interaction, for example:  Cleaner fish  Fungal mycorrhizae  Ants and acacia trees  Bees are primary pollinators of many wild plants  Wild bees pollinate 80% of agricultural crops in U.S.  Bee populations are falling due to “colony collapse disorder”  Humans benefit from mutualism, and will lose if bees go extinct  Commensalism is a relationship where one species benefits and the other is unaffected. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Predation: How Songbirds May Save Forests  Predator – species that survives by eating other species  Songbirds consume many insects.  Most insects eaten by songbirds consume plants.  Songbirds help to sustain forests.  As songbird numbers decline, damage to forests increases. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life  A leading cause of food illness in the U.S. is caused by Salmonella enteritidis.  About 2 million Americans infected each year.  About 400 die each year as a result of infection.  Most common source of infection is eggs.  S. enteritidis contaminates egg when it forms in the hen. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life  Competitive exclusion is the use of food and space resources, making it impossible for another species to establish itself.  On this principle, chickens are deliberately infected with harmless bacteria.  Harmless bacteria establish and prevent S. enteritidis from living in chicken’s gut thus decreasing the number of eggs infected with S. enteritidis. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Competition: How a Deliberately Infected Chicken Could Save a Life  Competition between species can have consequences for humans as well.  Mosquitos, snails, and tadpoles compete for the same resources in ponds.  When populations of snails and tadpoles decrease, mosquitoes increase.  This is potentially serious because mosquitoes can spread malaria, West Nile virus, and yellow fever. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Keystone Species: How Wolves Feed Beavers  Keystone species are key figures in determining the food web of an ecosystem.  Wolves were eradicated from Yellowstone Park in the 1920s.  With wolves gone, biologists noted declines in aspen, cottonwood, and willow trees.  Trees declined due to predation by elk.  Trees are crucial for beavers, songbirds, and fish.  With reintroduction of wolves, trees and other species rebounded. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction –Keystone Species: How Wolves Feed Beavers © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Disrupted Energy and Chemical Flows  An ecosystem is defined as all of the organisms in a given area, along with their non-biological enivornment.  Energy flow - only a small portion (~10%) of the energy in one level of a trophic pyramid can be converted to biomass at the next level  Diversity also affects energy flow, such as in more diverse grasslands, more biomass is produced © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Disrupted Energy and Chemical Flows  Nutrient cycling – nutrients that pass through a food web rarely leave the system © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Disrupted Energy and Chemical Flows  The soil community has an important role in nutrient cycling.  Decomposers return nutrients back in to the soil for use by plants.  Introduction of non-native earthworms in NE U.S. had dramatic impact on forest plants.  Non-native worms changed the soil community. © 2013 Pearson Education, Inc. 15.2 The Consequences of Extinction – Psychological Effects  Our experience with nature has strong psychological effects.  Dental patients viewing landscapes showed a decrease in blood pressure.  Hospital patients who could view trees recovered from surgery more quickly.  Instinctive desire to commune with nature is called biophilia.  Loss of biodiversity could make human experience less pleasant. © 2013 Pearson Education, Inc. 15.3 Saving Species – Protecting Habitat  Less than 2% of the earth’s surface contains up to 50% of the earth’s mammal, bird, reptile, and plant species. These areas are biodiversity hotspots. © 2013 Pearson Education, Inc. 15.3 Saving Species – Protecting Habitat  Converting wild areas to agricultural production is a major cause of habitat destruction.  Ways to decrease the rate of habitat destruction:  Altering our consumption patterns can help decrease habitat destruction.  Eating low on the food chain (less meat and dairy) makes a difference.  Increased financial aid to developing countries can also help.  So can slowing human population growth rate. © 2013 Pearson Education, Inc. 15.3 Saving Species – Protection From Environmental Disasters  A large population provides group protection from environmental disaster.  A species with a slow growth rate is at greater risk if its numbers diminish.  The longer a population remains small, the greater its risk. © 2013 Pearson Education, Inc. 15.3 Saving Species – An Overview of Conservation Genetics  Genetic variability is the sum of all of the alleles and their distribution within the species.  Loss of genetic variability is a two-fold problem.  Low genetic variability leads to low fitness, and is more likely to express harmful mutant alleles.  Rapid loss of genetic variability can lead to extinction due to the low fitness of individuals. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  The importance of genetic variability  When individuals are heterozygotic for many genes, the overall effect is greater fitness. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  Heterozygotes can avoid deleterious effects of recessive alleles. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  In a small population, individuals are more likely to be related to their mates.  Result can be inbreeding depression, a decline in heterozygotes.  Because of this, cheetahs have poor quality sperm and low rate of cub survival.  In humans, children of first cousins have lower rates of heterozygosity and higher rates of infant mortality. © 2013 Pearson Education, Inc. 15.3 Saving Species - A Closer Look: Conservation Genetics  Small populations lose their genetic variability due to genetic drift. © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  The consequences of low genetic variability in a population  A small population can become stuck in a cycle that leads to extinction.  This is called the extinction vortex © 2013 Pearson Education, Inc. 15.3 Saving Species – A Closer Look: Conservation Genetics  Irish potato is a human example of the potentially disastrous effects of low genetic diversity.  In 1850s, Irish potato crop had very low genetic diversity  Fungus that causes potato blight arrived in Ireland; plants rotted in fields  Because of crop failure, nearly 1 million Irish died of starvation and disease © 2013 Pearson Education, Inc. 15.4 Protecting Biodiversity Versus Meeting Human Needs  The protection of endangered species sometimes has effects on human livelihood.  Farmers were unable to use water for irrigation because diversion of water would have disrupted fish populations.  Endangered Species Act has helped save American alligators, peregrine falcons, and bald eagles. © 2013 Pearson Education, Inc. 15.4 Protecting Biodiversity Versus Meeting Human Needs © 2013 Pearson Education, Inc. Unit V Homework Ecology Introduction In previous chapters, we learned that life is very diverse. Organisms range from single cells to multicelled. Some organisms cannot even be seen with the naked eye. Is diversity increasing or decreasing? In the future, will we have more organisms? Does our population play a role in the lives of other organisms? Should we be considered if an organism goes extinct? The following exploratory activity will help you understand threats to organisms, what is being done to save them, and how organisms are classified. Materials Computer with internet access Directions 1. Go to: http://www.redlist.org/ or copy and paste the address into your web browser. 2. In the search term, box type in the word Ivory-billed Woodpecker . 3. Click on the scientific name for Ivory-billed Woodpecker. 4. Read the information and answer the following questions. Questions 1 – 20 are short answer questions and should be answered in a few words. Total: 80 points Type all answers directly in the data sheet text boxes and upload the data sheet as a .doc, .docx, or .rtf file with your last name and student number when finished. You may need to adjust the textbox size to display all text. 1. In your own words, explain the purpose of the IUCN Red List. (4 points) 2. What is the scientific name for the Ivory-billed Woodpecker? (4 points) 3. Are there any similar species? If so, name them. (4 points) 4. In your own words state where are Ivory-billed Woodpeckers found. (4 points) 5. What is the current status of the Ivory-billed Woodpecker? What was it before the year 2000? (4 points) 6. What is the population trend? (4 points) 7. How many mature Ivory-billed Woodpeckers are estimated to exist? How many sub-populations? (4 points) 8. In your own words describe the habitat that Ivory-billed Woodpeckers require. (4 points) 9. Look at the range map linked in the Ivory-billed Woodpecker IUCN page. How many U.S. states does the bird's range include? (4 points) 10. In which Kingdom is the Ivory-billed Woodpecker classified? (4 points) 11. In which Phylum is the Ivory-billed Woodpecker classified? (4 points) 12. In which Class is the Ivory-billed Woodpecker classified? (4 points) 13. In which Order is the Ivory-billed Woodpecker classified? (4 points) 14. In which Family is the Ivory-billed Woodpecker classified? (4 points) 15. What is the most significant threat to Ivory-billed Woodpeckers. (4 points) 16. Describe in your own words what (if anything) is currently being done to protect the species. (4 points) 17. What is the primary food source for this species? (4 points) 18. With such low population numbers, why might genetic diversity be a concern? (4 points) 19. Do you feel that it is worth it to save this species? Explain why or why not. (4 points) 20. In your opinion, can this species be saved or is it too late? Briefly explain your answer. (4 points) Question 21 is an extended response question. Your response should be at least 100 words in length. Total: 20 points 21. Considering what you have learned from this activity and the textbook chapters, explain your thoughts about the following statement: "Humans rely on other organisms for survival; however, other organisms would be better off without humans." Take a stand and argue for or against this statement.
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