Chapter 9 Sustaining Biodiversity: The Ecosystem Approach

1. Chapter 9 Sustaining Biodiversity: The Ecosystem Approach James MacDonald, Jackson Lundgren, HallieBrauner

2. Key Concepts • What are the major threats to forest ecosystems? • How should we manage and sustain forests? • How should we manage and sustain grasslands? • How should we manage and sustain parks and nature reserves? • How can we help to sustain terrestrial biodiversity? • How can we help to sustain aquatic biodiversity?

3. Case Study: WangariMaathai and the Green Belt Movement • Kenya’s streams were drying up, farms had displaced forests • WangariMaathai founded Green Belt Movement to organize poor women in rural Kenya to plant millions of trees • Women are paid for each seedling that survives, helping them break out of poverty

4. Forests Vary in Their Age Makeup and Origins • Old Growth Forest: uncut or regenerated primary forest • Second Growth Forest: Stand up trees resulting from secondary ecological succession • Tree Plantation (Tree Farm/ Commercial Forest): managed tract with uniformly aged trees of one or two uniform species.

5. Forest Provide Important Economic and Ecological Services • Forests remove CO2 and store it in organic compounds (biomass) • Therefore, forests stabilize the earth’s temperature and slow project climate change

6. Harvesting Trees • Clear-cutting – removing all the trees from an area • Selective cutting – intermediate-aged or mature trees in an uneven-aged forest are cut in small groups • Strip cutting – clear-cutting a strip of trees within a narrow corridor

7. Fire Can Threaten and Benefit Forest Ecosystems • Two types of fires can affect forest ecosystems • Surface fires usually burn only undergrowth and leaf litter • Burn away flammable material and help prevent more destructive fires • Free mineral nutrients in litter and undergrowth • Release seeds • Crown fires are extremely hot fire that leaps between trees • Occur in forests that haven’t experienced surface fires for several decades

8. We Have Cut Down Almost Half of the World’s Forests • Deforestation: Temporary or permanent removal of large expanses of forest for agriculture

10. Tropical Forests Are Disappearing Rapidly • Cover about 6% of earths land area (area of lower 48 states) • Once covered at least twice the area they do today. • Satellite scans indicate that large areas of tropical rainforests are being cut rapidly in South Africa , Asia and South America • Secondary tropical forests can grow on abandoned land within 15-20 years.

11. Causes of Tropical Deforestation Are Varied and Complex • Pressures of population growth and poverty push subsistence farmers and the landless into tropical forests • Government subsidies can accelerate deforestation by reducing costs of timber harvesting, cattle grazing, etc • Raising temperatures and reducing rainfall are converting tropical forests to savannas • If rates continue, 20-30% of Amazon basin will be turned into savanna in the next 50 years

12. We Can Manage Forests and Forest Fires More Sustainably • Biodiversity Researchers have called for more sustainable forest management • Smokey Bear educational campaign has educated the public, saved many lives and prevented billions of dollars in losses of trees, structures, and wildlife • Allow forests to burn, protect homes, thin forests

13. Solutions: Sustainable Forestry • Identify and protect forest areas high in biodiversity • Rely more on selective cutting and strip cutting • No clear cutting on steep slopes • No logging of old growth forests • Sharply reduce road building into uncut forest areas • Leave most standing dead trees and fallen timber for nutrient recycling • Plant tree plantations primarily on deforested and degrade plant land • Certify timber grown by sustainable methods

14. We Can Reduce the Demand for Harvested Trees • 60% of the wood consumed in the United States is wasted unnecessarily • EX: excess packaging, overuse of junk mail, inadequate paper recycling • Estimated that within 2-3 decades we could essentially eliminate the need to use trees to make paper

15. Ways to Reduce Tropical Deforestion • Debt-for-nature swap: financial incentives (foreign aid/debt relief) for countries that protect their tropical forests • Conservation concussions: governments/private organizations pay nations for agreeing to preserve natural resources

16. Overgrazed Rangelands • Rangelands – unfenced grasslands • Cattle, sheep and goats graze on about 42% of world’s grassland – this could increase to 70% by 2050 • Pastures – managed grasslands • Overgrazing – Exceeding carrying capacity • Exposes soil to erosion, increases chances of an invasive species takeover

17. Sustainably Managing Rangelands • Rotational grazing – cattle confined by portable fencing; moved around • Protecting riparian zones – thin strips of lush vegetation lining rivers and ponds

18. Threats to National Parks • More than 1,100 major national parks in more than 120 countries • Many too small to sustain large animal species • Suffer from invasions by nonnative species • U.S. National Parks • Air pollution degrades views more than 90% of the time • At least $6 billion needed for repairs

19. Case Study: Yellowstone Wolves • 1800 – at least 350,000 gray wolves in lower 48 states • Only a few hundred remain by passing of U.S. Endangered Species Act of 1973 • Keystone predator, keeping vegetation-eating herbivore populations in check • 1995 – 31 gray wolves introduced to Yellowstone • 2008 – 124 gray wolves, lower elk populations, regrowth of trees, return of beavers

20. Nature Reserves • Only 12% of earth’s land area is protected • Only 5% is strictly protected • Much of this 5% consists of ice, tundra or desert • Conservation scientists call for complete protection of at least 20% of land area • Buffer zone concept – buffer area with local people sustainably extracting resources and hired to protect the reserve from poachers

21. Case Study: Costa Rica • Established park/reserve system in mid 1970s • Included ~25% of land by 2008 • Sectioned into 8 megareserves with buffer zones • Today, largest income source is tourism (2/3 ecotourism) • One of lowest deforestation rates

22. Three Principals to Protect Ecosystems • Map the world’s terrestrial and aquatic ecosystems and create an inventory of the species contained in each of them and the ecosystem services they provide. • Locate and protect the endangered ecosystems and species, with emphasis on protecting plant biodiversity and ecosystem services. • Seek to restore as many degraded ecosystems as possible.

23. Protecting Global Diversity Hotspots is an Urgent Priority • Biodiversity Hotspots: Proposed in 1988 by environmental scientist Norton Meyers. • “Ecological Arks” • Areas rich in plant species found nowhere else and are at great risk for endangerment/extinction. • Cover 2% of the world, but contain 50% of flowering plant species and 42% of terrestrial vertebrates.

24. Restoring Damaged Ecosystems • Ecological Restoration: repairing damage caused by humans to the biodiversity and dynamics of ecosystems. • Speeding Up Repairs • Restoration • Rehabilitation • Replacement • Creating Artificial Ecosystems

25. Ecosystem Rehabilitation • 4 step strategy • Identify cause • Reduce or eliminate these factors • Reintroduce species *if necessary* • Protect area • Reconciliation Ecology • Investing , establishing and maintaining new habitats to conserve species diversity in places where humans are dominant.

26. Human Activities Destroy Aquatic Biodiversity • Humans have disrupted a large portion of coastal wetlands, reefs, mangroves, ocean bottom, and other aquatic environments. • Coastal Habitats are disappearing at 2-10x the rate of rain forests.

27. Overfishing: Gone Fishing; Fish Gone • World’s industrial fishing fleet has depleted fisheries by up to 90%. • We are overfishing the oceans by 157% of what is considered ‘sustainable’.

28. Industrial Fish Harvesting Methods • Commercial fishing fleets use GPS, SONAR, long lines, spotter aircraft, and factory ships to maximize the catch and minimize the effort spent catching • 77% of fisheries are being fished unsustainably • Bycatch including sea turtles and dolphins is thrown away, leaving animals to drown

29. Protecting Marine Biodiversity • Many people view oceans as inexhaustible resource that can absorb infinite amounts of pollution and still produce infinite seafood • Tragedy of the Commons • Marine Sanctuaries, protecting endangered and threatened species crucial to saving ocean

30. Marine Protected Areas • MPA’s are protected areas of the ocean that are off limits to most human activity • 4,000 MPA’s worldwide, 200 in US waters • MPA’s allow dredging, trawler fishing and harmful resource extraction

31. MPA’s in North America

32. Protecting the Oceans • Despite their importance less than 1% of the oceans are closed to fishing. • Less than 0.1% of the oceans are fully protected • In order to sustain marine biodiversity we must protect at least 30% of Earth’s oceans

33. Big Three Ideas of Chapter 9 (Review) • The economic values of important ecological services provided by the world’s ecosystems need to be included in the prices of goods and services • We can sustain terrestrial biodiversity by protecting threatened areas and restoring damaged ecosystems • We can sustain aquatic biodiversity by establishing protected sanctuaries, reducing water pollution and preventing overfishing