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Chapter 38 Introduction Conservation Biology Over the past century, wild tiger populations have been reduced from about 100,000 to 3,200. Tigers are threatened by – declining habitat, – poaching, and – human populations encroaching into their habitat. PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey Lecture by Edward J. Zalisko © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. Figure 38.0_1 Figure 38.0_2 Chapter 38: Big Ideas The Loss of Biodiversity Conservation Biology and Restoration Ecology 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes THE LOSS OF BIODIVERSITY Biodiversity has three levels: 1. ecosystem diversity, 2. species diversity, and 3. genetic diversity. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. 1 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes Figure 38.1A As natural ecosystems are lost, so are essential services, including – productivity of natural environments for human food supplies and – the purification of water used by cities. Video: Coral Reef © 2012 Pearson Education, Inc. At present, scientists have described and formally named about 1.8 million species. – It is difficult to estimate species loss. – Species loss may be 1,000 times higher than at any time in the past 100,000 years. – Extirpation is the loss of a single population of a species. Figure 38.1B 100% Percentage of species assessed 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes 80% 60% 40% 20% – Extinction is the irreversible loss of all populations of a species. 0% Mammals (N 4,653) Lowest risk Birds (N 9,933) Amphibians (N 4,688) Near threatened Freshwater fishes (N 2,689) Threatened Reptiles (N 1,429) Extinct © 2012 Pearson Education, Inc. 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes Figure 38.1C Because of the network of community interactions among populations of different species within an ecosystem, – the loss of one species – can negatively affect the species richness of an ecosystem. © 2012 Pearson Education, Inc. 2 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes Figure 38.1D Genetic diversity of a species is reduced if – local populations are lost and – the total number of individuals declines. © 2012 Pearson Education, Inc. 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Figure 38.2A Human alteration of habitats poses the greatest threat to biodiversity. Habitation alteration is caused by – agriculture, – urban development, – forestry, – mining, and – environmental pollution. © 2012 Pearson Education, Inc. 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Figure 38.2B Invasive species rank second behind habitat destruction as a threat to biodiversity. Invasive species – compete with native species, – prey on native species, and – parasitize native species. © 2012 Pearson Education, Inc. 3 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Figure 38.2C Overexploitation is the third major threat to biodiversity. Overharvesting has threatened – rare trees, – reduced populations of tigers, Galápagos tortoises, whales, and rhinoceroses, and – depleted wild populations of game fish. © 2012 Pearson Education, Inc. 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Figure 38.2D Human activities produce diverse pollutants that may affect ecosystems far from their source. – The water cycle transfers pollutants from terrestrial to aquatic ecosystems. – The release of chemicals into the atmosphere promoted the thinning of the ozone layer. Biological magnification concentrates synthetic toxins that cannot be degraded by microorganisms. © 2012 Pearson Education, Inc. Figure 38.2E 38.3 CONNECTION: Rapid warming is changing the global climate Concentration of PCBs Herring gull eggs 124 ppm Lake trout 4.83 ppm Smelt 1.04 ppm The scientific debate about global warming is over. Increased global temperatures caused by rising concentrations of greenhouse gases are changing climate patterns with grave consequences. – Global temperature has risen 0.8°C in the last 100 years. – 0.6°C of that increase occurred in the last three decades. – 2 to 4.5°C increases are likely by the end of the 21st century. – Temperature increases are not distributed evenly. – Precipitation patterns are changing too. Zooplankton 0.123 ppm Phytoplankton 0.025 ppm © 2012 Pearson Education, Inc. 4 Figure 38.3A 4.1 Figure 38.3B 4 2 1 0.5 Figure 38.3B_1 0.2 1938 0.2 0.5 1 2 4 1981 2005 4.1 Figure 38.3B_2 1938 Figure 38.3B_3 1981 38.4 CONNECTION: Human activities are responsible for rising concentrations of greenhouse gases Much of the rapid warming is the result of burning fossil fuels. – Atmospheric CO2 did not exceed 300 ppm for 650,000 years. – The preindustrial concentration was below 300 ppm. – Atmospheric CO2 is approximately 385 ppm today. – High levels of methane and nitrous oxide also trap heat. 2005 © 2012 Pearson Education, Inc. 5 Figure 38.4A Figure 38.4B 2,000 Photosynthesis Nitrous Oxide (N2O) Methane (CH4) 350 Atmosphere 1,800 Carbon Dioxide (CO2) 1,600 1,400 1,200 300 1,000 CH4 (parts per billion) CO2 (ppm), N2O (parts per billion) 400 Respiration Combustion of fossil fuels Ocean 800 250 600 0 500 1000 Year 1500 2000 38.5 Global climate change affects biomes, ecosystems, communities, and populations Figure 38.5A Climate change in western North America has spawned catastrophic wildfires. © 2012 Pearson Education, Inc. 38.5 Global climate change affects biomes, ecosystems, communities, and populations Figure 38.5B The greatest impact of global climate change is affecting organisms that live at – high latitudes and – high elevations. © 2012 Pearson Education, Inc. 6 38.5 Global climate change affects biomes, ecosystems, communities, and populations 38.5 Global climate change affects biomes, ecosystems, communities, and populations Warming oceans threaten coral reef communities. Climate change has also Earlier arrival of warm temperatures in the spring is disturbing ecological communities. – Birds and frogs have begun their breeding periods earlier. – increased the range of disease-carrying mosquitoes and – enabled bark beetles to reproduce faster, promoting the destruction of millions of acres of conifers in western North America. – Migratory birds may experience mismatches, arriving after peak food availability has already passed. © 2012 Pearson Education, Inc. © 2012 Pearson Education, Inc. 38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection 38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection Phenotypic plasticity In Europe, the great tit bird – has minimized the impact of global climate change on some species, and – has shifted its breeding season earlier, in an example of directional selection, – cases of microevolutionary changes have been observed. – favoring individuals that lay their eggs sooner, and – The rapidity of the environmental changes makes it unlikely that evolutionary processes will save many species from extinction. © 2012 Pearson Education, Inc. Figure 38.6A – better matching the earlier emergence of caterpillars. © 2012 Pearson Education, Inc. 38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection In the Yukon Territory of Canada, – where the spring temperatures have increased by about 2°C, – red squirrels have begun breeding earlier in the spring. © 2012 Pearson Education, Inc. 7 Figure 38.6B CONSERVATION BIOLOGY AND RESTORATION ECOLOGY © 2012 Pearson Education, Inc. 38.7 Protecting endangered populations is one goal of conservation biology 38.7 Protecting endangered populations is one goal of conservation biology Conservation biology is a goal-driven science that seeks to The black-footed ferret in the United States – understand and – is one of three ferret species worldwide and the only ferret found in North America, – counter the rapid loss of biodiversity. – was reduced to just 18 individuals, Some conservation biologists direct their efforts at – protecting populations and – has been bred in captivity, and – was reintroduced into the wild. – increasing endangered populations. – Threats posed by human activities are also assessed. © 2012 Pearson Education, Inc. Figure 38.7A © 2012 Pearson Education, Inc. 38.7 Protecting endangered populations is one goal of conservation biology In Hawaii, the silversword plants once abundant on the cinder cone of the volcano Mauna Kea – were bred in greenhouses and – reintroduced to reestablish wild populations. © 2012 Pearson Education, Inc. 8 Figure 38.7B 38.8 Sustaining ecosystems and landscapes is a conservation priority Conservation efforts are increasingly aimed at sustaining – ecosystems and – landscapes, a regional assemblage of interacting ecosystems. Landscape ecology is the application of ecological principles to the study of the structure and dynamics of a collection of ecosystems. © 2012 Pearson Education, Inc. Figure 38.8A 38.8 Sustaining ecosystems and landscapes is a conservation priority Edges between ecosystems have distinct sets of features and species. The increased frequency and abruptness of edges caused by human activities can increase species loss. Movement corridors connecting isolated habitats may be helpful to fragmented populations. © 2012 Pearson Education, Inc. Figure 38.8B Figure 38.8C 9 38.9 Establishing protected areas slows the loss of biodiversity 38.9 Establishing protected areas slows the loss of biodiversity To establish parks, wilderness areas, and other legally protected reserves, conservation biologists are applying their understanding of Choosing locations for protection often focuses on biodiversity hot spots, relatively small areas with – population, – ecosystem, and – a large number of endangered and threatened species, and – an exceptional concentration of endemic species, those that are found nowhere else. – landscape dynamics. © 2012 Pearson Education, Inc. Figure 38.9A © 2012 Pearson Education, Inc. 38.9 Establishing protected areas slows the loss of biodiversity Migratory species pose a special problem for conservationists. – Monarch butterflies occupy many areas. Equator – Sea turtles travel great distances. © 2012 Pearson Education, Inc. Figure 38.9B Figure 38.9_UN 10 38.10 Zoned reserves are an attempt to reverse ecosystem disruption Figure 38.10A NICARAGUA Zoned reserves are undisturbed wildlands surrounded by buffer zones of compatible economic development. COSTA RICA Costa Rica has established many zoned reserves. Ecotourism PANAMA – is travel to natural areas for tourism and recreation and – has become an important source of revenue for conservation efforts. National Parks and Reserves © 2012 Pearson Education, Inc. Figure 38.10B 38.11 CONNECTION: The Yellowstone to Yukon Conservation Initiative seeks to preserve biodiversity by connecting protected areas The Yellowstone to Yukon Conservation Initiative – created a string of parks and reserves in a 3,200-km wildlife corridor, – extends from Alaska south across Canada to northern Wyoming, – included the reintroduction of wolf populations, considered a keystone species in this region, and – sparked angry protests from some ranchers. © 2012 Pearson Education, Inc. Figure 38.11A Figure 38.11A_1 YUKON TERRITORY NORTHWEST TERRITORIES Whitehorse YUKON TERRITORY NORTHWEST TERRITORIES ALBERTA Whitehorse PACIFIC OCEAN BRITISH COLUMBIA Calgary Vancouver MONTANA ALBERTA Spokane WASHINGTON Bozeman Jackson OREGON IDAHO WYOMING 11 Figure 38.11A_2 PACIFIC OCEAN Figure 38.11B BRITISH COLUMBIA Calgary Vancouver MONTANA Spokane WASHINGTON Bozeman Jackson OREGON IDAHO WYOMING Figure 38.11C 38.12 CONNECTION: The study of how to restore degraded habitats is a developing science Restoration ecology uses ecological principles to restore degraded areas to their natural state, a process that may include – detoxifying polluted ecosystems, – replanting native vegetation, and – returning waterways to their natural course. © 2012 Pearson Education, Inc. 38.12 CONNECTION: The study of how to restore degraded habitats is a developing science Large-scale restoration projects attempt to restore damaged landscapes. Figure 38.12A Widened canal Water control structure remaining The Kissimmee River Restoration Project in Florida is Water control structure removed Phase 1 River channel completed restored Canal backfilled Water control structure to be removed in Kissimmee Phase 2 River Floodplain – restoring river flow and wetlands and – improving wildlife habitat. FLORIDA 0 Miles 10 © 2012 Pearson Education, Inc. 12 Figure 38.12B 38.13 Sustainable development is an ultimate goal Sustainable development – seeks to improve the human condition while conserving biodiversity, – depends on increasing and applying ecological knowledge, and – values our linkages to the biosphere. Former canal © 2012 Pearson Education, Inc. 38.13 Sustainable development is an ultimate goal Figure 38.13 We are most likely to – save what we appreciate and – appreciate what we understand. Now is the time to – aggressively pursue more knowledge about life and – work toward long-term sustainability. © 2012 Pearson Education, Inc. You should now be able to You should now be able to 1. Describe the three components of biodiversity. 6. Describe the goals of landscape ecology. Describe the significance of edges and movement corridors in maintaining biodiversity. 2. Describe the greatest current threats to biodiversity, providing examples of each. 3. Describe the process of biological magnification. 4. Describe the causes and consequences of global warming. 5. Explain why the efforts to save the black-footed ferret and silversword plant from extinction are a good model for future conservation efforts. © 2012 Pearson Education, Inc. 7. Describe the significance of biodiversity hotspots. 8. Explain how zoned reserves are being used to protect ecosystems. 9. Describe the goals of the Yukon to Yellowstone Initiative. © 2012 Pearson Education, Inc. 13 Figure 38.UN01 You should now be able to 10. Describe the goals and methods of restoration ecology. Ecosystem diversity 11. Explain why sustainable development should be the ultimate goal for the long-term maintenance of human societies and the ecosystems that support them. Species diversity Genetic diversity © 2012 Pearson Education, Inc. Figure 38.UN02 Conservation biology seeks to conserve may involve ecosystems and landscapes (a) may be protected in attempt to restore nature reserves restoration projects which uses (c) ATLANTIC OCEAN may be to FLORIDA (d) which support GULF OF MEXICO detoxify or replenish degraded ecosystems sustainable development 14