1. ENVIRONMENTAL SCIENCE
CHAPTER 9: Sustaining Biodiversity: The Ecosystem Approach

2. Wangari Maathai and the Green Belt Movement
Began in Kenya in 1977
Organizes poor women in rural Kenya
50,000 members protect forests
Planted 20 million trees
Fruits
Building materials
Firewood
Similar programs in 30 African countries
2004: Nobel Peace Prize

3. 9-1 What Are Major Threats to Forest Ecosystems?
Concept 9-1 Ecologically valuable forest ecosystems are being cut and burned at unsustainable rates in many parts of the world.

4. Types of Forests Forests cover 30% of earth’s land surface
Old-growth forests
Second-growth forests
Tree plantation

5. Science Focus: Putting a Price Tag on Nature’s Ecological Services
Estimated value of earth’s ecological services
$33.2 trillion per year
$4.7 trillion per year for forests
Need to start factoring values into land use
Ecological services can be a sustainable source of ecological income

6. Harvest Methods Step one: build roads Step two: logging operations
Erosion
Invasive species
Open up for human invasion
Step two: logging operations
Selective cutting
Clear cutting
Strip cutting

7. Forests and Fires Surface fires Crown fires Burn undergrowth only
Cool fire
Ecological benefits
Crown fires
Burn the entire tree
Hot fire
Occur in forests with lack of surface fires

8. Loss of Original Forests
Deforestation
46% in 8,000 years, most since 1950
Most in tropical areas, developing countries
Estimated loss of 40% intact forests within next 20 years

9. Good News on Forests
2000–2007 net total forested area stabilized or increased
Most of the increase due to tree plantations
Net loss of terrestrial biodiversity

10. Return of Forests in the United States (1)
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

11. Return of Forests in the United States (2)
Second- and third-growth forests fairly diverse
More wood grown than cut
40% of forests in National Forest System
Some forests transformed into tree plantations

12. Tropical Forests Cover 6% of earth’s land area
Habitat for 50% of terrestrial plants and animals
Vulnerable to extinction – specialized niches
Rapid loss of 50,000–170,000 km2 per year
Some second-growth forests

13. Causes of Tropical Forest Deforestation and Degradation
Population growth and poverty
Economic reasons
Logging
Ranching
Farming
Government subsidies
Fires raise temperatures and reduce rainfall

14. 9-2 How Should We Manage and Sustain Forests?
Concept 9-2 We can sustain forests by emphasizing the economic value of their ecological services, removing government subsidies that hasten their destruction, protecting old-growth forests, harvesting trees no faster than they are replenished, and planting trees.

15. Management of Forest Fires (1)
Fire suppression in all types of forests
Increased amounts of underbrush
Increased probability of crown fires

16. Management of Forest Fires (2)
Prescribed fires
Allow some fires to burn
Thin vegetation from forests
Thin around vulnerable homes
Decrease flammability of homes

17. Science Focus: Certifying Sustainably Grown Timber
Forest Steward Council certification of forest operations
Environmentally sound practices
Sustainable yield harvest
Minimal erosion from operations
Retention of dead wood for wildlife habitat

18. Trees and Paper Many trees are cut for paper production Alternatives
Pulp from rice straw and agricultural residues (China)
Kenaf (U.S.)
Hemp

19. Ways to Reduce Tropical Deforestation
Debt-for-nature swaps
Conservation concessions
Gentler logging methods
Encourage use of wood substitutes

20. 9-3 How Should We Manage and Sustain Grasslands?
Concept 9-3 We can sustain the productivity of rangeland by controlling the number and distribution of grazing livestock and by restoring degraded grasslands.

21. Grasslands Provide important ecological services
Second most used and altered ecosystem by humans
42% grazed by cattle, sheep, and goats – rangeland (open) and pasture (fenced)
Overgrazing

22. Manage Rangelands Sustainably
Practice rotational grazing
Fence out riparian zone areas
Suppress invader plants
Herbicides
Mechanical removal
Controlled burning
Short-term trampling

23. 9-4 How Should We Manage and Sustain Parks and Nature Reserves?
Concept 9-4 We need to put more resources into sustaining existing parks and nature reserves and into protecting much more of the earth’s remaining undisturbed land area.

24. National Parks >1,100 national parks in 120 countries
Only 1% of parks in developing countries are protected
Local people invade parks to survive
Logging
Mining
Poaching

25. Problems Protecting National Parks
Illegal logging
Illegal mining
Wildlife poaching
Most parks too small to protect large animals
Invasion of nonnative species

26. Stresses on U.S. National Parks
58 major national parks
Biggest problem is popularity
Damage from nonnative species
Threatened islands of biodiversity
Need $6 billion for overdue repairs

27. Nature Reserves Occupy a Fraction of Earth
12% of earth’s land protected
Only 5% fully protected – 95% reserved for human use
Need for conservation
Minimum 20% of land in biodiversity reserves
Protection for all biomes

28. Solutions for Protection
“Ecological insurance policy”
Buffer zones around protected areas
Locals to manage reserves and buffer zones
United Nations: 531 biosphere reserves in 105 countries

29. Science Focus: Reintroducing the Gray Wolf to Yellowstone National Park
Reduced to a few hundred in lower 48 by 1973
Keystone species
Restoration proposal angered ranchers, hunters, loggers
reintroduced in Yellowstone, 124 by 2008
Positive ripple effect after reintroduction

30. Case Study: Costa Rica Superpower of biodiversity
Conserved 25% of its land, 8 megareserves
Government eliminated deforestation subsidies
Paid landowners to maintain and restore tree coverage
Boosts ecotourism

31. Protecting Wilderness Protects Biodiversity
Preserves biodiversity
Centers for evolution

32. Case Study: Controversy over Wilderness Protection in the U.S.
1964 Wilderness Act
Ten-fold increase from 1970 to 2008
4.6% of U.S. land protected, 75% of that in Alaska

33. 9-5 How Can We Help to Sustain Terrestrial Biodiversity?
Concept 9-5 We can help to sustain terrestrial biodiversity by identifying and protecting severely threatened areas (biodiversity hotspots), rehabilitating damaged ecosystems (using restoration ecology), and sharing with other species much of the land we dominate (using reconciliation ecology).

34. Three Principles to Protect Ecosystems
Map and inventory the world’s terrestrial and aquatic ecosystems
Locate and protect the most endangered ecosystems, with a focus on biodiversity
Seek to restore as many degraded ecosystems as possible

35. Protecting Global Biodiversity Hotspots
17 megadiversity countries, mostly in tropics and subtropics
Two-thirds of biodiversity
Developing countries economically poor and biodiversity rich
Protect biodiversity hotspots

36. Ecological Restoration
Rehabilitation
Replacement
Creating artificial ecosystems

37. Science-based Principles for Restoration
Identify cause of degradation
Stop abuse by reducing factors
Reintroduce species if necessary
Protect area from further degradation

38. Case Study: Ecological Restoration of Tropical Dry Forest in Costa Rica
One of world’s largest ecological restoration projects
Restore a degraded tropical dry forest and reconnect it to adjacent forests
Involve 40,000 people in the surrounding area – biocultural restoration
Ecotourism

39. Restoration Ecology
Creating new habitats to conserve species diversity in areas where people live, work, play
People learn to protect local species and ecosystems
Sustainable ecotourism
Golden Gate Park in San Francisco

40. 9-6 How Can We Help to Sustain Aquatic Biodiversity?
Concept 9-6 We can help to sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.

41. Impacts on Aquatic Ecosystems (1)
Destroyed or degraded by human activities
Coastal habitats disappearing 2-10 times faster than tropical forest
Rising sea levels will destroy coral reefs and some low islands
Ocean floor degradation 150 times larger than area clear-cut annually

42. Impacts on Aquatic Ecosystems (2)
Freshwater habitat disruption
Dams
Water withdrawals from rivers
Likely extinction
34% marine fish species
71% freshwater species
Greater than any other group of species

43. Overfishing Fishery Fishprint 157% overfishing
90% of large open-ocean fishes have disappeared since 1950

44. Case Study: Industrial Fish Harvesting Methods
Trawler fishing
Purse-seine fishing
Longlining
Drift-net fishing

45. Why Is Protection of Marine Biodiversity So Difficult?
Human aquatic ecological footprint expanding
Not visible to most people
Viewed as an inexhaustible resource
Most ocean areas outside jurisdiction of a country

46. Solutions for Marine Ecosystems
Protect endangered and threatened species
Establish protected marine sanctuaries
Marine reserves – work well and quickly
Integrated coastal management
Protect existing coastal wetlands

47. Three Big Ideas from This Chapter - #1
The economic values of the important ecological services provided by the world’s ecosystems need to be included in the prices of goods and services.

48. Three Big Ideas from This Chapter - #2
We can sustain terrestrial biodiversity by protecting severely threatened areas, restoring damaged ecosystems, and sharing with other species much of the land we dominate.

49. Three Big Ideas from This Chapter - #3
We can sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing.