Sustaining Biodiversity: The Ecosystem Approach

1
Sustaining Biodiversity The Ecosystem Approach

• Chapter 6

2
6-1 What Are the Major Threats to Forest
Ecosystems?

• Concept 6-1 Unsustainable cutting and burning of
  forests, especially in tropical areas, is a
  potentially catastrophic problem because of the
  vital ecological services at risk and the growing
  contribution to global warming.

3
Forests Vary in Their Make-Up, Age, and Origins

• Old-growth or primary forest
• 36 of worlds forests
• Second-growth forest
• 60 of worlds forests
• Tree plantation, tree farm or commercial forest
• 4 of worlds forests
• May supply most of the industrial wood in the
  future

4
Forests Provide Important Economic and
Ecological Services (1)

• 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
• Habitats

5
Forests Provide Important Economic and
Ecological Services (2)

• Wood for fuel
• Lumber
• Pulp to make paper
• Mining
• Livestock grazing
• Recreation
• Employment

6
Unsustainable Logging is a Major Threat to Forest
Ecosystems (1)

• Increased erosion
• Sediment runoff into waterways
• Habitat fragmentation
• Loss of biodiversity

7
Unsustainable Logging is a Major Threat to Forest
Ecosystems (2)

• Invasion by
• Nonnative pests
• Disease
• Wildlife species
• Major tree harvesting methods
• Selective cutting
• Clear-cutting
• Strip cutting

8
We Have Cut Down Almost Half of the Worlds
Forests

• Deforestation
• Tropical forests
• Especially in Latin America, Indonesia, and
  Africa
• Boreal forests
• Especially in Alaska, Canada, Scandinavia, and
  Russia

9
Case Study Many Cleared Forests in the United
States Have Grown Back

• Forests of the eastern United States decimated
  between 1620 and 1920
• Grown back naturally through secondary ecological
  succession
• Biologically simplified tree plantations reduce
  biodiversity

10
Tropical Forests are Disappearing Rapidly

• Majority of loss since 1950
• Brazil and Indonesia tropical forest loss
• Role of deforestation in species extinction

11
Causes of Tropical Deforestation Are Varied and
Complex

• Primary
• Secondary

12
6-2 How Should We Manage and Sustain Forests?

• Concept 6-2 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.

13
Individuals Matter Wangari Maathari and Kenyas
Green Belt Movement

• Green Belt Movement 1977
• Self-help group of women in Kenya
• Success of tree planting
• Nobel Peace Prize 2004

14
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

15
6-3 How Should We Manage and Sustain Parks and
Natural Reserves?

• Concept 6-3 Sustaining biodiversity will require
  protecting much more of the earths remaining
  undisturbed land area as parks and nature
  reserves.

16
National Parks Face Many Environmental Threats

• Worldwide 1100 major national parks
• Parks in developing countries
• Greatest biodiversity
• 1 protected against
• Illegal animal poaching
• Illegal logging and mining

17
Case Study Stresses on U.S. Public Parks

• 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

18
Nature Reserves Occupy Only a Small Part of the
Earths Land

• Conservationists goal protect 20 of the
  earths land
• Cooperation between government and private groups
• Nature Conservancy
• Eco-philanthropists
• Developers and resource extractors opposition

19
Case Study Costa RicaA Global Conservation
Leader

• 19631983 cleared much of the forest
• 19862006 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 Ricas
  biodiversity

20
Protecting Wilderness Is an Important Way to
Preserve Biodiversity

• Pros
• Cons

21
Case Study Controversy over Wilderness
Protection in the United States

• 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

22
6-4 What is the Ecosystem Approach to Sustaining
Biodiversity?

• Concept 6-4 Sustaining terrestrial biodiversity
  will require preserving threatened areas that are
  richest in biodiversity (hotspots), mounting a
  global effort to rehabilitate and restore damaged
  ecosystems, and sharing as much of the earths
  land as possible with other species.

23
We Can Use a Four-Point Strategy to Protect
Ecosystems

• Map global ecosystems identify species
• Locate and protect most endangered species
• Restore degraded ecosystems
• Development must be biodiversity-friendly
• Are new laws needed?

24
Protecting Global Biodiversity Hot Spots Is an
Urgent Priority

• 1988 Norman Myers
• Identify biodiversity hot spots rich in plant
  species
• Not sufficient public support and funding
• Drawbacks of this approach
• May not be rich in animal diversity
• People may be displaced and/or lose access to
  important resources

25
We Can Rehabilitate and Restore Ecosystems That
We Have Damaged (1)

• Study how natural ecosystems recover
• Restoration
• Rehabilitation
• Replacement
• Creating artificial ecosystems

26
We Can Rehabilitate and Restore Ecosystems That
We Have Damaged (2)

• 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

27
Science Focus Ecological Restoration of a
Tropical Dry Forest in Costa Rica

• Guanacaste National Park restoration project
• Relinked to adjacent rain forest
• Bring in cattle and horses aid in seed
  dispersal
• Local residents actively involved

28
We Can Share Areas We Dominate With Other Species

• Win-Win Ecology How Earths Species Can Survive
  in the Midst of Human Enterprise, by Michael L.
  Rozenweig, 2003
• Reconciliation or applied ecology
• Community-based conservation
• Belize and the black howler monkeys
• Protect vital insect pollinators
• Bluebird protection with special housing boxes
• Berlin, Germany rooftop gardens
• San Francisco Golden Gate Park

29
Case Study The Blackfoot ChallengeReconciliation
Ecology in Action

• 1970s Blackfoot River Valley in Montana
  threatened by
• Poor mining, logging, and grazing practices
• Water and air pollution
• Unsustainable commercial and residential
  development
• Community meetings led to
• Weed-pulling parties
• Nesting structures for waterfowl
• Developed sustainable grazing systems

30
Concept 6-5 How Can We Protect and Sustain Marine
Biodiversity?

• Concept 6-5 We can help to sustain marine
  biodiversity by using laws and economic
  incentives to protect species, setting aside
  marine reserves to protect ecosystems, and using
  community-based integrated coastal mnagement.

31
Human Activities Are Disrupting and Degrading
Aquatic Habitats

• Major threats to marine systems
• Coastal development
• Overfishing
• Runoff of nonpoint source pollution
• Point source pollution
• Habitat destruction
• Introduction of invasive species
• Climate change from human activities
• Pollution of coastal wetlands and estuaries

32
There Are Ways to Protect and Sustain Marine
Biodiversity

• difficulties of protection
• laws and economic incentives
• marine reserves
• community-based integrated coastal management.

33
Freshwater Ecosystems Are Subject to Major Threats

• Impact of dams and canals on rivers
• Impact of flood control levees and dikes along
  rivers
• Impact of pollutants from cities and farms on
  rivers
• Impact of drained wetlands

34
Case Study- Managing River Basins

• Columbia River U.S. and Canada
• Dam system
• Pros and cons
• Snake River Washington state, U.S.
• Hydroelectric dams
• Pros and cons

35
We Can Protect Freshwater Ecosystems by
Protecting Watersheds

• Freshwater ecosystems protected through
• Laws
• Economic incentives
• Restoration efforts
• Wild rivers and scenic rivers
• Sustainable management of freshwater fishes

36
What Should Be Our Priorities?

• Concept 6-7 Sustaining the worlds biodiversity
  and ecosystem services will require mapping
  terrestrial and aquatic biodiversity, maximizing
  protection of undeveloped terrestrial and aquatic
  areas, and carrying out ecological restoration
  projects worldwide.

37
We Need to Establish Priorities for Protecting
Biodiversity

• Edward O. Wilson
• conservation strategy