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Chapter 10.  In 1800s 350,000 gray wolves roamed 48 states  1850–1900: decline due to human activity  U.S. Endangered Species Act: 1973  Only a few.

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Presentation on theme: "Chapter 10.  In 1800s 350,000 gray wolves roamed 48 states  1850–1900: decline due to human activity  U.S. Endangered Species Act: 1973  Only a few."— Presentation transcript:

1 Chapter 10

2  In 1800s 350,000 gray wolves roamed 48 states  1850–1900: decline due to human activity  U.S. Endangered Species Act: 1973  Only a few hundred wolves were left  1974 – gray wolf was placed on endangered species list  1995–1996: relocation of 41 wolves to Yellowstone Park  In 2007 Yellowstone estimated they have 171 gray wolves  2008: Gray wolf no longer protected

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4  Forest ecosystems provide ecological services far greater in value than the value of raw materials obtained from forests.  Unsustainable cutting and burning of forests, along with diseases and insects, are the chief threats to forest ecosystems. Objective 1

5  Tropical deforestation is a potentially catastrophic problem because of the vital ecological services at risk, the high rate of tropical deforestation, and its growing contribution to global warming.

6  Old-growth a.k.a primary forest  Uncut or regenerate forest that has not been disturbed by human activity or natural disaster for 200 years  Account for 36% of world’s forests  Second-growth forest  Have been disturbed by human activity or natural disaster  60% of world’s forests  Tree plantation, tree farm or commercial forest  Managed tract with uniformly aged trees  Clear cut and then replanted in a regular cycle  May supply most of the industrial wood in the future  4% of world’s forests Objective 2

7 An Old-Growth ForestAn Old-Growth Tropical Forest

8 Rotation Cycle of Cutting and Regrowth of a Monoculture Tree Plantation

9 Fig. 10-3a, p. 216

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 Objective 3  Wood for fuel  Lumber  Pulp to make paper  Mining  Livestock grazing  Recreation  Employment  Habitats

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12  Forests valued for ecological services  Nutrient cycling  Climate regulation  Erosion control  Waste treatment  Recreation  Raw materials  Forest valued for economic services  Estimated $4.7 Trillion per year  Home for 2/3 rds of the terrestrial species

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14  Increased erosion  Sediment runoff into waterways  Habitat fragmentation  Loss of biodiversity  Invasion by  Nonnative pests  Disease  Wildlife species Objective 4

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16 a.Selective Harvesting b.Clear Cutting c.Strip Cutting

17 Fig. 10-6a, p. 219

18 Fig. 10-6b, p. 219

19 Fig. 10-6c, p. 219

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23 Objective 5

24 Surface fires  Usually burn leaf litter and undergrowth  May kill seedlings and small trees  Mature trees survive  May provide food in the form of vegetation that sprouts after fire Crown fires  Extremely hot: burns whole trees  Kill wildlife  Increase soil erosion Objective 6

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26  Introduction of foreign diseases and insects  Accidental  Deliberate  Global warming  Rising temperatures  Trees more susceptible to diseases and pests  Drier forests: more fires  More greenhouse gases

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28  Deforestation  Temporary or permanent removal of large expanses of forest  Mostly in Tropical Forests  Especially in Latin America, Indonesia, and Africa  Recently there has been increase of boreal forest deforestation  Especially in Alaska, Canada, Scandinavia, and Russia Objective 7

29 Extreme Tropical Deforestation in Thailand

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31  Forest cover 30% of US land  Provide habitat for 80% of wildlife species  Forests of the eastern United States decimated between 1620 and 1920  Have grown back naturally through secondary ecological succession  Biologically simplified tree plantations that reduce biodiversity have replaced many old growth forests

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33  Tropical forests cover 6% of the earth’s land area  Majority of loss since 1950  Mature tropical forests once covered twice as much area  Brazil & Indonesia lead the world in tropical forest loss Objective 8

34 Satellite Images of Amazon Deforestation 1975 Satellite Images of Amazon Deforestation 2001

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37 Large Areas of Brazil’s Amazon Basin Are Burned

38  We can sustain forests by emphasizing the economic value of their ecological services, protecting old-growth forests, harvesting trees no faster than they are replenished, and using sustainable substitute resources. Objective 9

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40  The Smokey Bear educational campaign  Forest Service and National Advertising Council  Prescribed fires  Careful planning and monitoring  Alternative to prescribed burns = goats!  Allow fires on public lands to burn  Removes flammable underbrush and small trees  Protect structures in fire-prone areas by thinning a zone of about 200 feet and eliminate the use of flammable materials. Objective 10

41  2003 Healthy Forests Restoration Act  Allows timber companies to cut down economically valuable medium-size and large trees in 71% of the country’s national forests in return for clearing smaller, more fire-prone trees and underbrush.  The companies are not required to conduct prescribed burns after completing the thinning process.

42  Collins Pine  Owns & manages productive timberland in NE CA  Since 1993 the Scientific Certification Systems has evaluated Collins Pine timber production.  Concluded that Collin Pine consistently has not exceeded long term forest regeneration.  Forest Stewardship Council  Nonprofit  Developed list of environmentally sound practices  Certifies timber and products

43  Improve the efficiency of wood use  According to the Worldwatch Institute and forestry analyst up to 60% of the wood consumed in the Us is wasted unnecessarily.  Make tree-free paper  Paper can be made out of fiber that does not come from trees –  China = rice straw  U.S. = Kenaf (kuh-NAHF) Objective 11

44 Fast-Growing Plant: Kenaf

45  About ½ of the wood harvested each year in developed countries and ¾ of the wood harvested in developing countries is used for fuel.  Possible solutions  Establish small plantations of fast-growing fuelwood trees and shrubs  Burn wood more efficiently  Solar or wind-generated electricity  Haiti: Was once a tropical paradise but is now an ecological disaster  Now only 2% of it’s land is forest  With the trees gone, the soil has eroded away  South Korea: model for successful reforestation  Forests cover 2/3 of the land surface

46  Governments and Individuals Can Act to Reduce Tropical Deforestation  Reduce fuelwood demand  Practice small-scale sustainable agriculture and forestry in tropical forest  Debt-for-nature swaps  Conservation concessions  Use gentler logging methods  Buy certified lumber and wood products

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48  We can sustain the productivity of grasslands by controlling the number and distribution of grazing livestock (to avoid overgrazing) and restoring degraded grasslands. Objective 12

49  Important ecological services of grasslands  Soil formation  Erosion control  Nutrient cycling  Storage of atmospheric carbon dioxide in biomass  Maintenance of diversity

50  Overgrazing of rangelands  Reduces grass cover  Leads to erosion of soil by water and wind  Soil becomes compacted  Enhances invasion of plant species that cattle won’t eat

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52  Rotational grazing  Suppress growth of invasive species  Herbicides  Mechanical removal  Controlled burning  Controlled short-term trampling  Replant barren areas  Apply fertilizer  Reduce soil erosion Objective 13

53  American southwest: population surge since 1980  Land trust groups: limit land development  Reduce the harmful environmental impact of herds  Rotate cattle away from riparian areas  Use less fertilizers and pesticides  Operate ranch more economically

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55  Sustaining biodiversity will require protecting much more of the earth’s remaining undisturbed land area as parks and nature reserves. Objective 14

56 Worldwide: 1100 major national parks

57  Parks in developing countries  Greatest biodiversity  1% protected against  Illegal animal poaching  Illegal logging and mining

58  58 Major national parks in the U.S.  Biggest problem may be popularity  Noise  Congestion  Pollution  Damage or destruction to vegetation and wildlife  Repairs needed to trails and buildings

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61  Gray wolves prey on elk and push them to a higher elevation  Regrowth of aspen, cottonwoods, and willows  Increased population of riparian songbirds  Reduced the number of coyotes  Fewer attacks on cattle  Wolf pups susceptible to parvovirus carried by dogs

62  Conservationists’ goal: protect 20% of the earth’s land  Cooperation between government and private groups  Nature Conservancy  Eco-philanthropists  Developers and resource extractors opposition Objective 14

63  Large versus small reserves  The buffer zone concept  United Nations: 529 biosphere reserves in 105 countries  Habitat corridors between isolated reserves  Advantages  Disadvantages

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65  1963–1983: cleared much of the forest  1986–2006: forests grew from 26% to 51%  Goal: to reduce net carbon dioxide emissions to zero by 2021  Eight zoned megareserves  Designed to sustain around 80% of Costa Rica’s biodiversity

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67  Wilderness Act of 1964  How much of the United States is protected land?  Roadless Rule  2005: end of roadless areas within the national forest system Johnson

68  We can help sustain biodiversity by identifying severely threatened areas and protecting those with high plant diversity and those where ecosystem services are being impaired.  Sustaining biodiversity will require a global effort to rehabilitate and restore damaged ecosystems.  Humans dominate most of the earth’s land, and preserving biodiversity will require sharing as much of it as possible with other species. Objective 15

69 1) Map global ecosystems; identify species 2) Locate and protect most endangered species 3) Restore degraded ecosystems 4) Development must be biodiversity-friendly Are new laws needed?

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72  Eastern Arc Mountains of Tanzania, Africa  Highest concentration of endangered species on earth  Threatened due to  Killing of forests by farmers and loggers  Hunting  Fires

73  How to carry out most forms of ecological restoration and rehabilitation  Identify what caused the degradation  Stop the abuse  Reintroduce species, if possible  Protect from further degradation Objective 16

74 Objective 17 You know that I know that you can do this!


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