Sustaining Biodiversity: The Ecosystem ApproachSustaining Biodiversity: The Ecosystem Approach
Chapter 6
Biodiversity - DefinedBiodiversity - Defined
• Speciation – Extinction = Biodiversity– Raw genetic material for further
evolution
SuccessionSuccession
• Highest diversity occurs when there is enough disturbance to prevent the dominant competitors from taking over, but not so much that the community is unable to develop.
Human Activities and BiodiversityHuman Activities and Biodiversity
Habitat Loss and DegradationHabitat Loss and Degradation
Greatest threat to species diversity
“HIPPO”Habitat destruction Invasive speciesPopulation (humans) growthPollutionOver-harvesting
Greatest threat to species diversity
“HIPPO”Habitat destruction Invasive speciesPopulation (humans) growthPollutionOver-harvesting
Rate = 80 million new people/year+ New York City every month+ Germany every year+ United States every 3.7 years
Biodiversity isaffected by humanpopulation sizeand resourceuse
Agriculture Industry
Economic production and consumption Recreation
Global Biodiversity StatusGlobal Biodiversity Status
Forests Grassland
Rainforests Desert
Everything
5% of our virgin forests remain uncut
2% of our native grasslands are left in their native state
15% of our redwood forests are old growth
Less than 50% of our wetlands remain
Open Season On Wetlands Destruction Begins
Menards filling wetlands for new store
Their existence being deemed less important than others…
In Puget Sound, we have lost 70% of our estuaries to farms and development
Over 800 miles of Puget Sound shorelinehas been armed withbulkheads.
Importance of BiodiversityImportance of Biodiversity
• Intrinsic value – right to exist, to have evolved means they have important roles
• Instrumental value – because of their use to us
• Existence value – knowing it exists
• Aesthetic value – wildlife viewing
• Bequest value – willing to pay for its existence
Solutions for Protecting BiodiversitySolutions for Protecting Biodiversity
Types of US Public LandsTypes of US Public Lands
• Multiple-use lands: National Forests; National Resource Lands (BLM)
• Moderately-restricted use lands: National Wildlife Refuges
• Restricted-use lands: National Park System; National Wilderness Preservation System
US Public LandsUS Public Lands
Fig. 11-6 p. 198
Managing US Public LandManaging US Public Land
Conservation biologists support:
• Biodiversity and ecological function
• No subsidies or tax breaks for use
• Public should get fair compensation
• Users held responsible for actions
Developers and Resource Extractors Support:
• Sell public land• Cut funding to
administer lands• Cut old growth
forests• Drill in the Artic
Refuge
Ecological and economic services of forests
Ecological and economic services of forests
Trade-Offs
Advantages
Helps meet country’s timber needs
Cut areas grow back
Keeps lumber and paper prices down
Provides jobs in nearby communities
Promotes economic growth in nearby communities
Disadvantages
Provides only 4% of timber needs
Ample private forest land to meet timber needs
Has little effect on timber and paper prices
Damages nearby rivers and fisheries
Recreation in national forests provides more local jobs and income for local communities than logging
Decreases recreational opportunities
Logging in U.S. National Forestsand other publicly owned lands
*
Clear cutting our forests: Advantages and Disadvantages
Trade-Offs
Clear-Cutting Forests
Advantages
Higher timber yields
Maximum economic return in shortest time
Can reforest with genetically improved fast-growing trees
Short time to establish new stand of trees
Needs less skill and planning
Best way to harvest tree plantations
Good for tree species needing full or moderate sunlight for growth
Disadvantages
Reduces biodiversity
Disrupts ecosystem processes
Destroys and fragments some wildlife habitats
Leaves moderate to large openings
Increases soil erosion
Increases sediment water pollution and flooding when done on steep slopes
Eliminates most recreational value for several decades
Sustainable ForestrySustainable Forestry
• Several methods can be used to sustain harvests and maintain biodiversity
Longer rotations will provide a morestable ecosystem and greater biodiversity
Selective logging leaves habitat,minimizing disturbance and fragmentation
Habitat fragmentation and island biogeography
Leave snags and downed logs for cavity nesting animals
Logging roads like this one have dozens of ditches, culverts and other conduits that dump pollution from clear cut and herbicide-sprayed hillsides directly into streams and rivers.
Recent efforts by the forest industry, the tribes and government agency scientists have worked to lessen theimpacts of logging roads.
Include ecologicalservices in estimatingeconomic value
Rainforests harbor the greatest gene pool in the world. The rainforest has nurtured this "pool" to become home for 170,000 of the world's 250,000 known plant species.
Tropical Deforestation: ConsequencesTropical Deforestation: Consequences
• Rapid and increasing
• Loss of biodiversity
• Loss of resources (e.g., medicines)
• Contributes to global warming
Tropical Deforestation: CausesTropical Deforestation: Causes
• Population growth• Poverty• Environmentally harmful
government subsidies (encourage poor to colonize tropical forests)
• Debts owed to developed countries• Low value of ecological services
Managing and Sustaining National ParksManaging and Sustaining National Parks
• Inadequate protection• Often too small to sustain
biodiversity• Invasions by nonnative species• Too many human visitors• Traffic jams and air pollution• Better pay for park staff
Establishing, Designing, and Managing Nature Reserves Establishing, Designing, and Managing Nature Reserves
• Include moderate to large tracts of land
• Involve government, private sector and citizens
• Biosphere reserves• Adaptive ecosystem management• Protect most important areas (“hot
spots”)• Wilderness areas
Ecological Restoration: Basic PrinciplesEcological Restoration: Basic Principles
• Mimic nature • Recreate lost niches • Rely on pioneer species • Control nonnative species• Reconnect small patches
Protecting Biodiversity in Washington StateProtecting Biodiversity in Washington State
• Governor Locke’s Executive Order• Establishment of the Washington
Biodiversity Council– Develop 30-year comprehensive prioritized
strategy to protect biodiversity– Assess existing and potential landowner
incentive program– Develop public education and a web site– By December 31, 2007
Ecosystem Planning in Washington StateEcosystem Planning in Washington State
• Mitigation “banks”• Growth Management Act Critical
Area Ordinances• CREP and CRP• Marine Protected Areas• Eco-regional Assessments for
Biodiversity