Sustaining Biodiversity: The Ecosystem Approach

1. Sustaining Biodiversity: The Ecosystem Approach Chapter 8

2. North American Gray Wolf • Reduced to a few hundred • Keystone species • Restoration proposal angered ranchers, hungers, loggers • 1995, reintroduced in Yellowstone, 136 by 2007 • Positive ripple effect after reintroduction

3. 8-1 How Are We Affecting the Earth’s Biodiversity and Why Should We Protect It? • Concept 8-1A We are degrading and destroying biodiversity in many parts of the world and these threats are increasing. • Concept 8-1B We should protect biodiversity because it exists and because of its usefulness to us and other species.

4. Loss of Biodiversity • Earth’s biodiversity depleted and degraded • Wetlands, grasslands & forests • 83% land surface disturbed • Antarctica & Greenland

5. Loss of Biodiversity • Degradation of aquatic biodiversity • 50% wetlands (globally) • 15-35% coral reefs destroyed and damaged • Ecological fishprintunsustainable • 200 commercially valuable fish overfished or at their sustainable yield • 29% collapsed, w/90% in decline • Need >2.5x current ocean area • Japan, Indonesia and China

6. Lake Victoria • Lake Victoria has lost their endemic fish species to large introduced predatory fish.

7. Lake Victoria • Reasons for loss of biodiversity: • Introduction of Nile perch. • Algal blooms from nutrient runoff. • Invasion of water hyacinth has blocked sunlight and deprived oxygen. • Nile perch is in decline because it has eaten its own food supply.

8. Why Protect Biodiversity • Intrinsic value • Value regardless of use to us • Instrumental value • Use Value: Usefulness in terms of economic and ecological services. (farms, crops, fisheries) • Nonuse values • Existence • Aesthetic • Bequest

9. Endangered Orangutans

10. 8-2 Managing and Sustaining Forests • Concept 8-2 We can sustain forests by recognizing the economic value of their ecological services, protecting old-growth forests, harvesting trees no faster than they are replenished, and making most paper from fast-growing plants and agricultural residues instead of trees.

11. Forest Services • Forests 30% of earth’s land surface – • mostly in the mountains

12. Types of Forests • Old-growth forests • (primary, ancient, primeval, frontier) diverse • 150-500+ yrs old • 22% of forests • Second-growth forests • Secondary succession • Tree plantation • Managed, uniform, clear cut, economical, depletes nutrients

13. Short Rotation Cycle Forestry

14. Loss of Original Forests • DEFORESTATION – temporary & permanent • 46% in 8,000 years, most since 1950 • Most in tropical areas, developing countries • Crops and cattle • Latin America, Indonesia, Africa • Estimated loss of 40% intact forests within next 20 years • Clearing is exponential (0.3-0.8%)

15. Video: U.S. Forests Videos/US_Forests.mov

16. Roads and Forests • Fragmentation, destruction, and degradation.

17. Natural Capital Degradation: Deforestation Fig. 8-6, p. 155

18. Putting a Price Tag on Nature’s Ecological Services The long-term health of an economy cannot be separated from the health of the natural systems that support it. • Estimated value of earth’s ecological services • $33.2 trillion per year • $4.7 trillion per year for forests • What services do we need to start factoring into land use?

19. Good News on Forests • 2000–2005 net total forested area stabilized or increased • N. America, Europe, India, China, Turkey & Vietnam • Most due to tree plantations • Some secondary succession (cropland & cleared forests) • BENEFIT • Wood needs, decreased erosion & nutrient loss, CO2 • LOSS • Decreased biodiversity & nutrients

20. Return of Forests in the United States • U.S. forests • Cover ~30% of land • Contain ~80% of wildlife species • Supply ~67% of nation’s surface water • Forest cover greater now than in 1920 • Secondary succession

21. Return of Forests in the United States • Second- and third-growth forests fairly diverse • More wood grown than cut annually • 40% of forests in National Forest System • 155 National Forests • LOSS: transformed into tree plantations • Julia Hill – “Butterfly” – two years on a platform of California redwood tree

22. Controversy over the National Forests • Forest service mandate • Principle of sustainable yield • Harvest at replenishing rate • Principle of multiple use • Recreation, hunting & fishing in forests = 10x timber revenue • Timber companies push for tree cutting to be primary goal • Subsidized by taxpayers money • Timber sales have lost money 97 out of last 100 yrs (cost of roads, timber prep, admin, etc)

23. Harvest Methods • Step one – build roads • Erosion • Invasive species • Open up for human invasion • DISQUALIFY LAND FOR PROTECTION AS WILDERNESS • Step two – logging operations • Selective cutting • Strip cutting • Clear cutting

24. Forest Harvesting Methods

25. Clear-cut Logging Fig. 8-9, p. 157

26. Trade-offs: Clear-cutting Forests Fig. 8-10, p. 157

27. Forests and Fires • Surface fires • Burn undergrowth only • Cool fire • Ecological benefits – • remove flammables, release minerals & seeds (lodgepole), stimulate germination (sequoia/jack pine), control pathogens, post-fire food (deer, moose, elk, quail, etc) • Crown fires • Burn the entire tree, hot fire • Occur in forests with lack of surface fires (buildup) • Flames leap, are rapid, destructive, kill & erode

28. Management of Forest Fires • Fire suppression in all types of forests • Smokey Bear • Some forests naturally fire adapted • Not all fires are bad • Prescribed fires • Native Americans

29. Management of Forest Fires Restoration of fire’s natural role: • Allow fires to burn • 60 m buffer zone around homes (thinning) • Healthy Forests Restoration Act, 2003 • Allows timber companies to cut med-large trees in return for clearing • Exempts thinning projects from environmental review • Paid for by taxpayers – may increase damage

30. Forest Fires • Forest fires have increased – past 15 yrs • Drying from climate change • Increases climate change

31. Certifying Sustainably Grown Timber • Forest Steward Council certification of forest operations • Scientific Certification Systems (SCS) • Environmentally sound practices • Sustainable yield harvest • Minimal erosion from operations • Retention of dead wood for wildlife habitat • Steward of land and water • 2005 – only 6% certified • Sweden, Poland, US, Canada

32. Solutions: Sustainable Forestry Fig. 8-12, p. 159

33. Trees and Paper • Many trees are cut for paper production • Alternatives • Pulp from rice straw and agricultural residues (China) • Kenaf (U.S.) • More paper pulp/land area • Require fewer pesticides and herbicides http://www.environmentalpaper.org/PAPER-statistics.html

34. How Serious Is Tropical Deforestation and How Can It Be Reduced? • Concept 8-3 We can reduce tropical deforestation by protecting large forest areas, teaching settlers about sustainable agriculture and forestry, using government subsidies that encourage sustainable forest use, reducing poverty, and slowing population growth.

35. Tropical Forests • Cover 6% of earth’s land area (size of US) • Lost 50% since 1950 • Habitat for 50% of terrestrial plants and animals • Diversity increases pole to equator • Vulnerable to extinction – specialized niches • Rapid loss of 50,000–170,000 km2 per year • Imazon (2004) - land occupation/deforestation = 47%

36. Burning of a Tropical Forest • Accounts for ¾ greenhouse gas emissions. Fig. 8-14, p. 160

37. Destruction of Tropical Forests

38. Causes of Tropical Forest Deforestation and Degradation • Population growth and poverty • Subsistence farming & poor search for land • Government subsidies • Reducing cost of harvest and grazing • Gov. gives title to land-clearers to reduce poverty but don’t teach sustainability (Ind, Mex, Brazil) • International lending agencies encourage development • Roads, soybeans, coffee, mines, logging, oil, dams • Africa, Latin America

39. Effects of Tropical Deforestation • Fragmentation of remaining patches • Roads, erosion, toppling • Remaining forests get drier and may burn • Degrades biodiversity • CO2 to the atmosphere • Accelerates climate change • Converts forest to savannah

40. Animation: Effects of Deforestation Animations/effects_deforestation.html

41. How to Protect Tropical Forests • Teach settlers to practice small-scale sustainable agriculture • Harvest renewable resources from the forests • Debt-for-nature swaps • Foreign aid & debt relief to be stewards • Conservation concessions • Gov & NPOs give $ • Gentler logging methods

42. Solutions: Sustaining Tropical Forests Fig. 8-16, p. 162

43. Wangari Maathai and Kenya’s Green Belt Movement • Backyard small tree nursery • Organized poor women • Women paid for each surviving seedling planted • Breaks cycle of poverty • Reduces environmental degradation • People walk less distance to get fuelwood • Sparked projects in 30+ African countries

44. How Should We Manage and Sustain Grasslands? • Concept 8-4 We can sustain the productivity of rangeland by controlling the number and distribution of livestock and by restoring degraded rangeland.

45. Grasslands • Ecological services • Soil formation, erosion control, nutrient cycling, carbon storage, maintaining biodiversity • Second most used and altered ecosystem by humans • Rangeland - unfenced (temperate/tropical) forage land • 42% grazed by cattle, sheep, and goats • Pasture – fenced, managed, sometimes planted • Grow from the bottom – tops dispensable

46. Grasslands

47. Grasslands • Overgrazing – over carrying capacity • Erosion/compaction, • Invasives (sagebrush, mesquite, cactus, cheatgrass and salt cedar) • loss of productivity

48. Video: Desertification in China Videos/Desertification_in_China.mov

49. Manage Rangelands Sustainably • Practice rotational grazing • Move fences and confine animals • Fence out riparian zoneareas

50. Manage Rangelands Sustainably • Suppress invader plants • Expensive – herbicides, uproot, trample • Replant barren soil with seeds • Expensive – seeds and fertilizer • Employ controlled burns to control exotic vegetation