Chapter 38. Conservation Biology. Lecture by Edward J. Zalisko

Transcription

1 Chapter 38 Conservation Biology PowerPoint Lectures for Campbell Biology: Concepts & Connections, Seventh Edition Reece, Taylor, Simon, and Dickey 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko

2 Introduction 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.

3 Figure 38.0_1 Chapter 38: Big Ideas The Loss of Biodiversity Conservation Biology and Restoration Ecology

4 Figure 38.0_2

5 THE LOSS OF BIODIVERSITY

6 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes Biodiversity has three levels: 1. ecosystem diversity, 2. species diversity, and 3. genetic diversity.

7 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes 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.

8 Figure 38.1A

9 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes 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. Extinction is the irreversible loss of all populations of a species.

10 Figure 38.1B Percentage of species assessed 10 0% 80 % 60 % 40 % 20 % 0% Mam mals (N = 4,653) Lowest risk Birds (N = 9,933) Amph ibians (N = 4,688) Near threatened Fresh water fishes (N = 2,689) Threatened Reptil es= (N 1,429) Extinct

11 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes 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.

12 Figure 38.1C

13 38.1 Loss of biodiversity includes the loss of ecosystems, species, and genes Genetic diversity of a species is reduced if local populations are lost and the total number of individuals declines.

14 Figure 38.1D

15 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity Human alteration of habitats poses the greatest threat to biodiversity. Habitation alteration is caused by agriculture, urban development, forestry, mining, and environmental pollution.

16 Figure 38.2A

17 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity 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.

18 Figure 38.2B

19 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity 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.

20 Figure 38.2C

21 38.2 CONNECTION: Habitat loss, invasive species, overharvesting, pollution, and climate change are major threats to biodiversity 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.

22 Figure 38.2D

23 Figure 38.2E Concentration of PCBs Herring gull eggs 124 ppm Lake trout 4.83 ppm Smelt 1.04 ppm Zooplankton ppm Phytoplankton ppm

24 38.3 CONNECTION: Rapid warming is changing the global climate 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.

25 Figure 38.3A

26 Figure 38.3B

27 Figure 38.3B_1 1938

28 Figure 38.3B_2 1981

29 Figure 38.3B_3 2005

30 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.

31 Figure 38.4A 400 2,000 Carbon Dioxide (CO2) Nitrous Oxide (N2O) Methane (CH4) CO2 (ppm), N2O (parts per billion) 350 1,600 1,400 1, , Year CH4 (parts per billion) 1,800

32 Figure 38.4B Photosynthesis Atmosphere Respiration Combustion of fossil fuels Ocean

33 38.5 Global climate change affects biomes, ecosystems, communities, and populations Climate change in western North America has spawned catastrophic wildfires.

34 Figure 38.5A

35 38.5 Global climate change affects biomes, ecosystems, communities, and populations The greatest impact of global climate change is affecting organisms that live at high latitudes and high elevations.

36 Figure 38.5B

37 38.5 Global climate change affects biomes, ecosystems, communities, and populations Warming oceans threaten coral reef communities. Earlier arrival of warm temperatures in the spring is disturbing ecological communities. Birds and frogs have begun their breeding periods earlier. Migratory birds may experience mismatches, arriving after peak food availability has already passed.

38 38.5 Global climate change affects biomes, ecosystems, communities, and populations Climate change has also 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.

39 38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection Phenotypic plasticity has minimized the impact of global climate change on some species, and cases of microevolutionary changes have been observed. The rapidity of the environmental changes makes it unlikely that evolutionary processes will save many species from extinction.

40 38.6 EVOLUTION CONNECTION: Climate change is an agent of natural selection In Europe, the great tit bird has shifted its breeding season earlier, in an example of directional selection, favoring individuals that lay their eggs sooner, and better matching the earlier emergence of caterpillars.

41 Figure 38.6A

42 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.

43 Figure 38.6B

44 CONSERVATION BIOLOGY AND RESTORATION ECOLOGY

45 38.7 Protecting endangered populations is one goal of conservation biology Conservation biology is a goal-driven science that seeks to understand and counter the rapid loss of biodiversity. Some conservation biologists direct their efforts at protecting populations and increasing endangered populations. Threats posed by human activities are also assessed.

46 38.7 Protecting endangered populations is one goal of conservation biology The black-footed ferret in the United States is one of three ferret species worldwide and the only ferret found in North America, was reduced to just 18 individuals, has been bred in captivity, and was reintroduced into the wild.

47 Figure 38.7A

48 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.

49 Figure 38.7B

50 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.

51 Figure 38.8A

52 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.

53 Figure 38.8B

54 Figure 38.8C

55 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 population, ecosystem, and landscape dynamics.

56 38.9 Establishing protected areas slows the loss of biodiversity Choosing locations for protection often focuses on biodiversity hot spots, relatively small areas with a large number of endangered and threatened species, and an exceptional concentration of endemic species, those that are found nowhere else.

57 Figure 38.9A Equator

58 38.9 Establishing protected areas slows the loss of biodiversity Migratory species pose a special problem for conservationists. Monarch butterflies occupy many areas. Sea turtles travel great distances.

59 Figure 38.9B

60 Figure 38.9_UN

61 38.10 Zoned reserves are an attempt to reverse ecosystem disruption Zoned reserves are undisturbed wildlands surrounded by buffer zones of compatible economic development. Costa Rica has established many zoned reserves. Ecotourism is travel to natural areas for tourism and recreation and has become an important source of revenue for conservation efforts.

62 Figure 38.10A NICARAGUA COSTA RICA PANAMA National Parks and Reserves

63 Figure 38.10B

64 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.

65 Figure 38.11A IN ZIE TA EN OUN M CK MA YUKON TERRITORY NORTHWEST TERRITORIES S Whitehorse ALBERTA RO Y CK I BI I M TA TA LU UN CO MO A NS BRITISH COLUMBI A UN O M S N PACIFIC OCEAN Calgary Vancouver MONTANA Spokane WASHING TON Bozeman Jackson OREGON IDAHO WYOMING

66 Figure 38.11A_1 MA N ZIE TAI EN UN CK MO YUKON TERRITORY NORTHWEST TERRITORIES Whitehorse S Y CK RO U MO ALBERTA NS AI NT

67 Figure 38.11A_2 CK Y Calga ry IN TA A NS UN MBI TAI O M LU OUN CO M BRITISH COLUMBIA RO PACIFIC OCEAN S Vanco uver MONTANA Spokane WASHINGTON Boze man ORE GON IDAHO Jacks on WYOMING

68 Figure 38.11B

69 Figure 38.11C

70 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.

71 38.12 CONNECTION: The study of how to restore degraded habitats is a developing science Large-scale restoration projects attempt to restore damaged landscapes. The Kissimmee River Restoration Project in Florida is restoring river flow and wetlands and improving wildlife habitat.

72 Figure 38.12A Widened canal Water control structure remaining im Kiss Water control structure removed Phase 1 River channel completed restored Canal backfilled m ee Water control Ri structure to ve be removed in Kissimmee Phase 2 River Floodplain r FLORID A 0 Miles 1 0

73 Figure 38.12B Former canal

74 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.

75 38.13 Sustainable development is an ultimate goal 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.

76 Figure 38.13

77 Figure 38.UN01 Ecosystem diversity Species diversity Genetic diversity

78 Figure 38.UN02 Conservation biology seeks to conserve may involve ecosystems and landscapes (a) may be protected in attempt to restore nature reserve s restoration projects which uses (c) ATLANTIC OCEAN may be to FLORIDA (d) GULF OF MEXICO which support sustain able develo detoxify or replenish degraded ecosystems