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Chapter 6 Sustaining Biodiversity: The Ecosystems Approach.

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1 Chapter 6 Sustaining Biodiversity: The Ecosystems Approach

2 Chapter Overview Questions  How have human activities affected the earth’s biodiversity?  How should forest resources be used, managed, and sustained globally and in the United States?  How serious is tropical deforestation, and how can we help sustain tropical forests?  How should rangeland resources be used, managed, and sustained?

3 Chapter Overview Questions (cont’d)  What problems do parks face, and how should we manage them?  How should we establish, design, protect, and manage terrestrial nature reserves?  What is wilderness, and why is it important?  What is ecological restoration, and why is it important?  What can we do to help sustain the earth’s terrestrial biodiversity?

4 Updates Online The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles.  InfoTrac: Cloud over Puerto Rico rain forest. Chicago Tribune, March 20, 2006.  InfoTrac: Can't log the forest for the trees? Roger Harris. American Scientist, March-April 2006 v94 i2 p120(2).  InfoTrac: The cry of the wild. Thomas L. Friedman. The New York Times, June 28, 2006 pA21(L).  NASA: Tropical Deforestation  Greenpeace: Eating Up the Amazon

5 Core Case Study: Reintroducing Wolves to Yellowstone  Endangered Species 1850-1900 two million wolves were destroyed. 1850-1900 two million wolves were destroyed.  Keystone Species Keeps prey away from open areas near stream banks. Keeps prey away from open areas near stream banks. Vegetation reestablishes. Vegetation reestablishes. Species diversity expands. Species diversity expands.

6 HUMAN IMPACTS ON TERRESTRIAL BIODIVERSITY  We have depleted and degraded some of the earth’s biodiversity and these threats are expected to increase.

7 Alteration of natural chemical cycles and energy flows Indirect Effects Loss of Biodiversity Climate change Human Population Size and resource use Human Activities Agriculture, industry, economic production and consumption, recreation Changes in number and distribution of species Pollution of air, water, and soil Degradation and destruction of natural ecosystems Direct Effects

8 Why Should We Care About Biodiversity?  Use Value: For the usefulness in terms of economic and ecological services.  Nonuse Value: existence, aesthetics, bequest for future generations.

9 MANAGING AND SUSTAINING FORESTS  Forests provide a number of ecological and economic services that researchers have attempted to estimate their total monetary value.

10 Support energy flow and chemical cycling Reduce soil erosion Absorb and release water Purify water and air Influence local and regional climate Store atmospheric carbon Provide numerous wildlife habitats Forests Natural Capital Fuelwood Lumber Pulp to make paper Mining Livestock grazing Recreation Jobs Economic Services Ecological Services

11 Types of Forests  Old-growth forest: uncut or regenerated forest that has not been seriously disturbed for several hundred years. 22% of world’s forest. 22% of world’s forest. Hosts many species with specialized niches. Hosts many species with specialized niches.

12 Types of Forests  Second-growth forest: a stand of trees resulting from natural secondary succession.  Tree plantation: planted stands of a particular tree species.

13 5 Clear cut Weak trees removed Seedlings planted Years of growth 30 15 25 10

14 Global Outlook: Extent of Deforestation  Human activities have reduced the earth’s forest cover by as much as half.  Losses are concentrated in developing countries.

15 Decreased soil fertility from erosion Runoff of eroded soil into aquatic systems Premature extinction of species with specialized niches Loss of habitat for native species and migratoryspecies such as birds and butterflies Regional climate change from extensive clearing Release of CO 2 into atmosphere Acceleration of flooding Natural Capital Degradation Deforestation

16 How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.  Should there be a global effort to sharply reduce the cutting of old-growth forests? a. Yes. Old-growth forests can only be saved by rapid international action and the setting aside of large reserves of the forests. a. Yes. Old-growth forests can only be saved by rapid international action and the setting aside of large reserves of the forests. b. No. Only local citizens and not global efforts led by the UN can save these forests. b. No. Only local citizens and not global efforts led by the UN can save these forests.

17 Case Study: Deforestation and the Fuelwood Crisis  Almost half the people in the developing world face a shortage of fuelwood and charcoal. In Haiti, 98% of country is deforested. In Haiti, 98% of country is deforested. MIT scientist has found a way to make charcoal from spent sugarcane. MIT scientist has found a way to make charcoal from spent sugarcane.

18 Harvesting Trees  Building roads into previously inaccessible forests paves the way for fragmentation, destruction, and degradation.

19 Old growth Highway Cleared plots for grazing Cleared plots for agriculture

20 Harvesting Trees  Trees can be harvested individually from diverse forests (selective cutting), an entire forest can be cut down (clear cutting), or portions of the forest is harvested (e.g. strip cutting).

21 (a) Selective cutting

22 (b) Clear-cutting

23 Uncut (c) Strip cutting Stream Uncut Cut 3–10 years ago Dirt road Cut 1 year ago

24 Harvesting Trees Effects of clear-cutting in the state of Washington, U.S.

25 Higher timber yields Maximum profits in shortest time Can reforest with fast- growing trees Short time to establish new stand of trees Needs less skill and planning Good for tree species needing full or moderate sunlight Disadvantages Reduces biodiversity Disrupts ecosystem processes Destroys and fragments wildlife habitats Leaves large openings Increases water pollution, flooding, and erosion on steep slopes Eliminates most recreational value Trade-Offs Clear-Cutting Forests Advantages

26 Solutions  We can use forests more sustainably by emphasizing: Economic value of ecological services. Economic value of ecological services. Harvesting trees no faster than they are replenished. Harvesting trees no faster than they are replenished. Protecting old-growth and vulnerable areas. Protecting old-growth and vulnerable areas.

27 Identify and protect forest areas high in biodiversity Grow more timber on long rotations Rely more on selective cutting and strip cutting Stop clear-cutting on steep slopes Cease logging of old-growth forests Prohibit fragmentation of remaining large blocks offorest Sharply reduce road building into uncut forest areas Leave most standing dead trees and fallen timber for wildlife habitat and nutrient recycling Certify timber grown by sustainable methods Include ecological services of forests in estimating their economic value Plant tree plantations on deforested and degraded land Shift government subsidies from harvesting trees to planting trees Sustainable Forestry Solutions

28 CASE STUDY: FOREST RESOURCES AND MANAGEMENT IN THE U.S.  U.S. forests cover more area than in 1920.  Since the 1960’s, an increasing area of old growth and diverse second-growth forests have been clear-cut. Often replace with tree farms. Often replace with tree farms. Decreases biodiversity. Decreases biodiversity. Disrupts ecosystem processes. Disrupts ecosystem processes.

29 Types and Effects of Forest Fires  Depending on their intensity, fires can benefit or harm forests. Burn away flammable ground material. Burn away flammable ground material. Release valuable mineral nutrients. Release valuable mineral nutrients.

30 Solutions: Controversy Over Fire Management  To reduce fire damage: Set controlled surface fires. Set controlled surface fires. Allow fires to burn on public lands if they don’t threaten life and property. Allow fires to burn on public lands if they don’t threaten life and property. Clear small areas around property subject to fire. Clear small areas around property subject to fire.

31 Solutions: Controversy Over Fire Management  In 2003, U.S. Congress passed the Healthy Forest Restoration Act: Allows timber companies to cut medium and large trees in 71% of the national forests. Allows timber companies to cut medium and large trees in 71% of the national forests. In return, must clear away smaller, more fire- prone trees and underbrush. In return, must clear away smaller, more fire- prone trees and underbrush. Some forest scientists believe this could increase severe fires by removing fire resistant trees and leaving highly flammable slash. Some forest scientists believe this could increase severe fires by removing fire resistant trees and leaving highly flammable slash.

32 How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.  Do you support repealing or modifying the Healthy Forests Restoration Act of 2003? a. Yes. Local officials and scientists are probably most qualified to manage their local forests. a. Yes. Local officials and scientists are probably most qualified to manage their local forests. b. No. The initiative favors the timber companies rather than effectively protecting and managing the forests. b. No. The initiative favors the timber companies rather than effectively protecting and managing the forests.

33 Controversy over Logging in U.S. National Forests  There has been an ongoing debate over whether U.S. national forests should be primarily for: Timber. Timber. Ecological services. Ecological services. Recreation. Recreation. Mix of these uses. Mix of these uses.

34 Helps meet country’s timber needs Cut areas grow back Keeps lumber and paper prices down Provides jobs in nearby communities Promotes economic growth in nearby communities Trade-Offs Provides only 4% of timber needs Ample private forest land to meet timber needs Has little effect on timber and paper prices Damages nearby rivers and fisheries Recreation in national forests provides more local jobs and income for local communities than logging Decreases recreational opportunities DisadvantagesAdvantages Logging in U.S. National Forests

35 Solutions: Reducing Demand for Harvest Trees  Tree harvesting can be reduced by wasting less wood and making paper and charcoal fuel from fibers that do not come from trees. Kenaf is a promising plant for paper production. Kenaf is a promising plant for paper production.

36 American Forests in a Globalized Economy  Timber from tree plantations in temperate and tropical countries is decreasing the need for timber production in the U.S. This could help preserve the biodiversity in the U.S. by decreasing pressure to clear-cut old- growth and second-growth forests. This could help preserve the biodiversity in the U.S. by decreasing pressure to clear-cut old- growth and second-growth forests. This may lead to private land owners to sell less profitable land to developers. This may lead to private land owners to sell less profitable land to developers. Forest management policy will play a key role. Forest management policy will play a key role.

37 CASE STUDY: TROPICAL DEFORESTATION  Large areas of ecologically and economically important tropical forests are being cleared and degraded at a fast rate.

38 CASE STUDY: TROPICAL DEFORESTATION  At least half of the world’s terrestrial plant and animal species live in tropical rain forests.  Large areas of tropical forest are burned to make way for cattle ranches and crops.

39 Why Should We Care about the Loss of Tropical Forests?  About 2,100 of the 3,000 plants identified by the National Cancer Institute as sources of cancer-fighting chemicals come from tropical forests.

40 Rauvolfia Rauvolfia sepentina, Southeast Asia Tranquilizer, high blood pressure medication

41 Foxglove Digitalis purpurea, Europe Digitalis for heart failure

42 Pacific yew Taxus brevifolia, Pacific Northwest Ovarian cancer

43 Cinchona Cinchona ledogeriana, South America Quinine for malaria treatment

44 Rosy periwinkle Cathranthus roseus, Madagascar Hodgkin's disease, lymphocytic leukemia

45 Neem tree Azadirachta indica, India Treatment of many diseases, insecticide, spermicide

46 Causes of Tropical Deforestation and Degradation  Tropical deforestation results from a number of interconnected primary and secondary causes.

47 Not valuing ecological services Exports Government policies Poverty Population growth Secondary Causes Oil drilling Mining Flooding from dams Tree plantations Cattle ranching Cash crops Settler farming Fires Logging Roads Basic Causes

48 Protect most diverse and endangered areas Educate settlers about sustainable agriculture and forestry Phase out subsidies that encourage unsustainable forest use Add subsidies that encourage sustainable forest use Protect forests with debt-for-nature swaps and conservation easements Certify sustainably grown timber Reduce illegal cutting Reduce poverty Slow population growth Restoration Reforestation Rehabilitation of degraded areas Concentrate farming and ranching on already-cleared areas Solutions Sustaining Tropical Forests Prevention

49 Kenya’s Green Belt Movement: Individuals Matter  Wangari Maathai founded the Green Belt Movement.  The main goal is to organize poor women to plant (for fuelwood) and protect millions of trees.  In 2004, awarded Nobel peace prize.

50 MANAGING AND SUSTAINING GRASSLANDS  Almost half of the world’s livestock graze on natural grasslands (rangelands) and managed grasslands (pastures).  We can sustain rangeland productivity by controlling the number and distribution of livestock and by restoring degraded rangeland.

51 MANAGING AND SUSTAINING GRASSLANDS  Overgrazing (left) occurs when too many animals graze for too long and exceed carrying capacity of a grassland area.

52 MANAGING AND SUSTAINING GRASSLANDS  Example of restored area along the San Pedro River in Arizona after 10 years of banning grazing and off-road vehicles.

53 Case Study: Grazing and Urban Development in the American West  Ranchers, ecologists, and environmentalists are joining together to preserve the grasslands on cattle ranches. Paying ranchers conservation easements (barring future owners from development). Paying ranchers conservation easements (barring future owners from development). Pressuring government to zone the land to prevent development of ecologically sensitive areas. Pressuring government to zone the land to prevent development of ecologically sensitive areas.

54 NATIONAL PARKS  Countries have established more than 1,100 national parks, but most are threatened by human activities. Local people invade park for wood, cropland, and other natural resources. Local people invade park for wood, cropland, and other natural resources. Loggers, miners, and wildlife poachers also deplete natural resources. Loggers, miners, and wildlife poachers also deplete natural resources. Many are too small to sustain large-animal species. Many are too small to sustain large-animal species. Many suffer from invasive species. Many suffer from invasive species.

55 Case Study: Stresses on U.S. National Parks  Overused due to popularity.  Inholdings (private ownership) within parks threaten natural resources.  Air pollution.

56  Suggestions for sustaining and expanding the national park system in the U.S.

57 Integrate plans for managing parks and nearby federal lands Add new parkland near threatened parks Buy private land inside parks Locate visitor parking outside parks and use shuttle buses for entering and touring heavily used parks Increase funds for park maintenance and repairs Survey wildlife in parks Raise entry fees for visitors and use funds for park management and maintenance Limit the number of visitors to crowded park areas Increase the number and pay of park rangers Encourage volunteers to give visitor lectures and tours Seek private donations for park maintenance and repairs National Parks Solutions

58 NATURE RESERVES  Ecologists call for protecting more land to help sustain biodiversity, but powerful economic and political interests oppose doing this. Currently 12% of earth’s land area is protected. Currently 12% of earth’s land area is protected. Only 5% is strictly protected from harmful human activities. Only 5% is strictly protected from harmful human activities. Conservation biologists call for full protection of at least 20% of earth’s land area representing multiple examples of all biomes. Conservation biologists call for full protection of at least 20% of earth’s land area representing multiple examples of all biomes.

59 How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.  Should at least 20% of the Earth's land area be strictly protected from economic development? a. No. Such protections would encourage people to poach and illegally extract resources from the expanded reserves. a. No. Such protections would encourage people to poach and illegally extract resources from the expanded reserves. b. Yes. The project is desperately needed to protect the Earth's biodiversity. b. Yes. The project is desperately needed to protect the Earth's biodiversity.

60 NATURE RESERVES  Large and medium-sized reserves with buffer zones help protect biodiversity and can be connected by corridors.  Costa Rica has consolidated its parks and reserves into 8 megareserves designed to sustain 80% if its biodiversity.

61 Cordillera Volcanica Central Pacific Ocean Costa Rica Caribbean Sea Nigaragua Panama La Amistad Llanuras de Tortuguero Guanacaste Arenal Bajo Tempisque Peninsula Osa Pacifico Central

62 NATURE RESERVES  A model biosphere reserve that contains a protected inner core surrounded by two buffer zones that people can use for multiple use.

63 Core area Buffer zone 1 Buffer zone 2 Biosphere Reserve Research Station Human Settlements Tourism and education center

64 NATURE RESERVES  Geographic Information System (GIS) mapping can be used to understand and manage ecosystems. Identify areas to establish and connect nature reserves in large ecoregions to prevent fragmentation. Identify areas to establish and connect nature reserves in large ecoregions to prevent fragmentation. Developers can use GIS to design housing developments with the least environmental impact. Developers can use GIS to design housing developments with the least environmental impact.

65 NATURE RESERVES  We can prevent or slow down losses of biodiversity by concentrating efforts on protecting global hot spots where significant biodiversity is under immediate threat.  Conservation biologists are helping people in communities find ways to sustain local biodiversity while providing local economic income.

66  34 hotspots identified by ecologists as important and endangered centers of biodiversity.

67 NATURE RESERVES  Wilderness is land legally set aside in a large enough area to prevent or minimize harm from human activities.  Only a small percentage of the land area of the United States has been protected as wilderness.

68 ECOLOGICAL RESTORATION  Restoration: trying to return to a condition as similar as possible to original state.  Rehabilitation: attempting to turn a degraded ecosystem back to being functional.  Replacement: replacing a degraded ecosystem with another type of ecosystem.  Creating artificial ecosystems: such as artificial wetlands for flood reduction and sewage treatment.

69 ECOLOGICAL RESTORATION  Five basic science-based principles for ecological restoration: Identify cause. Identify cause. Stop abuse by eliminating or sharply reducing factors. Stop abuse by eliminating or sharply reducing factors. Reintroduce species if necessary. Reintroduce species if necessary. Protect area form further degradation. Protect area form further degradation. Use adaptive management to monitor efforts, assess successes, and modify strategies. Use adaptive management to monitor efforts, assess successes, and modify strategies.

70 Will Restoration Encourage Further Destruction?  There is some concern that ecological restoration could promote further environmental destruction and degradation. Suggesting that any ecological harm can be undone. Suggesting that any ecological harm can be undone. Preventing ecosystem damage is far cheaper than ecological restoration. Preventing ecosystem damage is far cheaper than ecological restoration.

71 How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.  Should we mount a massive effort to restore ecosystems we have degraded even though this will be quite costly? a. No. Less expensive alternatives, such as remediation, replacement, and the creation of artificial ecosystems, should be readily considered. a. No. Less expensive alternatives, such as remediation, replacement, and the creation of artificial ecosystems, should be readily considered. b. Yes. Alternatives will probably not achieve the same biodiversity as ecological restoration. b. Yes. Alternatives will probably not achieve the same biodiversity as ecological restoration.

72 WHAT CAN WE DO?  Eight priorities for protecting biodiversity: Take immediate action to preserve world’s biological hot spots. Take immediate action to preserve world’s biological hot spots. Keep intact remaining old growth. Keep intact remaining old growth. Complete mapping of world’s biodiversity for inventory and decision making. Complete mapping of world’s biodiversity for inventory and decision making. Determine world’s marine hot spots. Determine world’s marine hot spots. Concentrate on protecting and restoring lake and river systems (most threatened ecosystems). Concentrate on protecting and restoring lake and river systems (most threatened ecosystems).

73 WHAT CAN WE DO? Ensure that the full range of the earths ecosystems are included in global conservation strategy. Ensure that the full range of the earths ecosystems are included in global conservation strategy. Make conservation profitable. Make conservation profitable. Initiate ecological restoration products to heal some of the damage done and increase share of earth’s land and water allotted to the rest of nature. Initiate ecological restoration products to heal some of the damage done and increase share of earth’s land and water allotted to the rest of nature.

74 Adopt a forest. Plant trees and take care of them. Recycle paper and buy recycled paper products. Buy sustainable wood and wood products. Choose wood substitutes such as bamboo furniture and recycled plastic outdoor furniture, decking, and fencing. Restore a nearby degraded forest or grassland. Landscape your yard with a diversity of plants natural to the area. Live in town because suburban sprawl reduces biodiversity. Sustaining Terrestrial Biodiversity What Can You Do?


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