600 likes | 858 Vues
Sustaining Terrestrial Biodiversity: The Ecosystem Approach. Chapter 10. Core Case Study: Reintroducing Gray Wolves to Yellowstone. How was the gray wolf species classified and what was it’s niche to receive this classification?
E N D
Sustaining Terrestrial Biodiversity: The Ecosystem Approach Chapter 10
Core Case Study: Reintroducing Gray Wolves to Yellowstone • How was the gray wolf species classified and what was it’s niche to receive this classification? • What was the environmental response to the loss of the gray wolf? • Why was the trickle down effect to beavers especially devastating to the environment? • What were the three major concerns about the reintroduction of the gray wolf?
10-1 What Are the Major Threats to Forest Ecosystems? • Concept 10-1A Forest ecosystems provide ecological services far greater in value than the value of raw materials obtained from forests. • True Value • Concept 10-1B Unsustainable cutting and burning of forests, along with diseases and insects, are the chief threats to forest ecosystems.
10-1 What Are the Major Threats to Forest Ecosystems? (2) • Concept 10-1C 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.
Forests Vary in Their Make-Up, Age, and Origins • Natural and planted forest occupy 30% of land. • ½ Tropical forest • ¼ Boreal forest • What are the two major types of forests based on age and structure? • Where are most of the old-growth forests?
Tree Plantation, Tree Farm, Commerical Forest • What is a tree plantation? • Generally clear cut as soon as commercially valuable then replanted. • Used for paper and composites (pressed wood) • What is the negative effect of this process? • Where are most of the tree plantations?
What are the important ecological and economic services of forests?
True Value – monetary value of the ecological services provided. $4.7 Trillion per year – True Value of Forests globally. Fig. 10-A, p. 218
Unsustainable Logging is a Major Threat to Forest Ecosystems Figure 10.5 • What is the environmental cost of building roads for access and lumber removal?
Clear-Cutting • What is the positive side to this process? • What is the negative side to this process? • Why is this process considered to be a positive feedback process? • Where is this process increasing now?
Strip Cutting • More sustainable variation of clear-cutting. • Natural regeneration will occur in a few years then loggers will cut the next strip.
Fire, Insects, and Climate Change Can Threaten Forest Ecosystems 10.9 • What are the two types of fires? • How are they different?
Fires • Fires are part of a natural cycle and not a threat to ecosystems. • Except when used to clear land for crops and livestock. • Produces pollution. • Increases carbon dioxide in atmosphere as the wood is oxidized. • Loss of a carbon sink.
Fire, Insects, and Climate Change Can Threaten Forest Ecosystems Beech bark disease White pine blister rust Pine shoot beetle • Explain the effects of accidental or deliberate introductions of foreign diseases and insects and what can be done. • Explain the effects of global warming on forests. Sudden oak death Hemlock woolly adelgid
We Have Cut Down Almost Half of the World’s Forests • Define Deforestation. • Why are humans destroying forests? • Where is this concentrated now?
Brazil and Indonesia Lead the World in Tropical Forest Loss. Brazil 1975 Brazil 2001
World’s largest flower – the flesh flower. 3.3 feet in diameter and weighs 15 lbs. Smells like rotting meat to attract pollinators – beetles and flies. Endangered white monkey in Brazilian tropical rain forest. Fig. 10-14a, p. 224
Case Study: Many Cleared Forests in the United States Have Grown Back • What did Bill McKibben mean when he said forest re-growth was “the great environmental story of the U.S. and in some ways, the world”? • What are the concerns about tree plantations?
Causes of Tropical Deforestation Are Varied and Complex • 1st Road is cut into the forest for logging and settlement. • Cut the best trees but many others fall also due to the vines in the canopy. • Agriculture or grazing animals until the nutrients are gone. • The loggers, farmers and ranchers move to the next area of what was once tropical rain forest. • Plantations of soybean and oil palms. • Burning of the tropical forest responsible twice as much CO2 as all the world’s cars and trucks.
10-2 How Should We Manage and Sustain Forests? • Concept 10-2 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.
We Can Improve the Management of Forest Fires • The Smokey Bear educational campaign • What are the pluses? • What are the minuses? • What are the steps to reduce fire-related harm to forests and people?
We Can Improve the Management of Forest Fires • 2003 Healthy Forests Restoration Act • Describe • Pros • Cons
How Can We Reduce the Demand for Harvested Trees? • Improve the efficiency of wood use. • 60% of wood used in the U.S. is wasted. • How? • One of the primary uses for trees is making pulp for paper. • How can reduce tree usage for this product? • China • U.S.
Case Study: Deforestation and the Fuelwood Crisis • ¾ of wood cut in developing countries is used for fuel. Firewood and charcoal made from wood. • Heating and cooking. • Haiti • Once a tropical paradise; now with only 2% of land with forests. • Classified as one of the world’s leading “failing states” • How can people reduce the fuelwood crisis? • What is the other crisis of using fuelwood besides loss of trees?
Governments and Individuals Can Act to Reduce Tropical Deforestation • Ways to reduce fuelwood demand • Practice small-scale sustainable agriculture and forestry in tropical forest • Debt-for-nature swaps – • Conservation concessions – • Use gentler logging methods – • Roles for the consumer –
Individuals Matter: Wangari Maathari and Kenya’s Green Belt Movement • What was the Green Belt Movement of 1977? • Nobel Peace Prize: 2004
10-3 How Should We Manage and Sustain Grasslands? • Concept 10-3 We can sustain the productivity of grasslands by controlling the number and distribution of grazing livestock and restoring degraded grasslands.
How Should We Manage and Sustain Grasslands? • What are the important ecological services of grasslands? • Grasslands are the 2nd most used and abused ecosystem.
Moderate Grazing, Overgrazing, Undergrazing • How can moderate grazing of rangelands be beneficial? • Explain how undergrazing and overgrazing are both detrimental.
We Can Manage Rangelands More Sustainably • The point is to control the number of grazing animals and the duration of their grazing in a given area. • Explain Rotational grazing. • What are riparian zones?
We Can Manage Rangelands More Sustainably • There are more expensive and thus less widely used methods to sustain rangelands • Suppress growth of unwanted invader plants • Replant barren areas • Apply fertilizer
Case Study: Grazing and Urban Development the American West • What has caused the population surge to the American southwest since 1980? • How has the population surge helped to protect this ecosystem?
10-4 How Should We Manage and Sustain Parks and Natural Reserves? • Concept 10-4 Sustaining biodiversity will require protecting much more of the earth’s remaining undisturbed land area as parks and nature reserves.
National Parks Face Many Environmental Threats • Worldwide: 1100 major national parks • Most too small to support a lot of large animal species. • Many suffer from invasions by non-native species. • Parks in developing countries have the greatest biodiversity but • Only about 1% protected against • Illegal animal poaching • Illegal logging and mining
Case Study: Stresses on U.S. Public Parks • 58 Major national parks in the U.S. • In 27 states – most in the west and Alaska. • 3 In Florida – Everglades, Dry Tortugas, Biscayne Bay. • Positive • Tourism and education. • No resource extraction. • Protection of threatened or endangered species. • Negative • Some indigenous populations were removed from the land.
National Parks • 1st was Yellowstone National Park in 1872 by Ulysses S. Grant (must be established by an act of congress). • Newest is Great Sand Dunes in Colorado 2004. • Biggest problem may be popularity. • Great Smoky Mountains National Park is the most frequently visited.
State Parks • Those near urban areas receive twice the traffic as the national parks. • What are the problems associated with frequent visitors?
Science Focus: Effects of Reintroducing the Gray Wolf to Yellowstone National Park • The gray wolf was reintroduced to Yellowstone and this produced ecological ripples. • Explain the effect on elks, grizzly bears, scavengers, trees. • Explain the effect of the tree change to birds and waterways. • Explain the effect on coyotes and the trickle down effect of this change. • How are the wolves affected by the dogs brought into the park by visitors?
Nature Reserves Occupy Only a Small Part of the Earth’s Land • Only 12% of the earth’s land is protected strickly or partially. • What are eco-philanthropists doing? • What are U.S. Land Trusts groups doing?
Designing and Connecting Nature Reserves • Large versus small reserves • The buffer zone concept
Habitat Corridors • Habitat corridors between isolated reserves • Advantages • Disadvantages
Case Study: Costa Rica—A Global Conservation Leader • What is the size of Costa Rica? • Why is it considered a superpower of biodiversity? • What is the largest source of income for Costa Rica? • How has the government aided in the development of biodiversity in Costa Rica?
Protecting Wilderness Is an Important Way to Preserve Biodiversity • Define wilderness. • What was Teddy Roosevelt’s contribution • 1964 US. Wilderness Act • Where are most of the U.S. wilderness areas? How does the U.S. compare with other nations in terms of terrestrial land protected?
10-5 What is the Ecosystem Approach to Sustaining Biodiversity? • Concept 10-5A 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. • Concept 10-5B Sustaining biodiversity will require a global effort to rehabilitate and restore damaged ecosystems.
10-5 What is the Ecosystem Approach to Sustaining Biodiversity? (2) • Concept 10-5C Humans dominate most of the earth’s land, and preserving biodiversity will require sharing as much of it as possible with other species.
How Can We Protect Ecosystems • Map ecosystems globally creating an inventory of species in each and the services they provide. • Locate and protect the hotspots – areas of highest diversity with endangered or threatened species. • Try to restore as many degraded ecosystems as possible. • Make development biodiversity friendly with tax breaks or write-offs and technical help for private landowners who agree to help protect endangered ecosystems.