Sustaining Biodiversity: Sustaining Biodiversity: The Ecosystem ApproachThe Ecosystem Approach
Chapter 8Chapter 8
Sections 1-4Sections 1-4
Key ConceptsKey Concepts
Human impacts on biodiversityHuman impacts on biodiversity
Public lands and their use Public lands and their use
Use and management of forest resourcesUse and management of forest resources
Temperate Temperate and Tropical and Tropical DeforestationDeforestation
Problems associated with parksProblems associated with parks
Establishing and managing natural reservesEstablishing and managing natural reserves
Protecting and sustaining aquatic biodiversityProtecting and sustaining aquatic biodiversity
Importance of ecological restorationImportance of ecological restoration
Sustaining the EarthSustaining the Earth’’s biodiversitys biodiversity
Part 1
Part 2
Reintroducing Wolves to Reintroducing Wolves to Yellowstone (1995)Yellowstone (1995)
Why wolves were killedWhy wolves were killed- - 2 million killed 1850 - 1900 2 million killed 1850 - 1900 to to ““make the west safe for livestock and big-game animalsmake the west safe for livestock and big-game animals””
Wolf protection Wolf protection 1974 listed as endangered species1974 listed as endangered species
Ecological importanceEcological importance- - Keystone predator- culled Keystone predator- culled herds of bison, elk, caribou and mule deer, keep coyote pop low, …herds of bison, elk, caribou and mule deer, keep coyote pop low, …
Yellowstone controversyYellowstone controversy- - ranchers, hunters, ranchers, hunters, miners all opposedminers all opposed
Importance of biodiversityImportance of biodiversity- - ecological success- ecological success- willow & aspen re-growth in riparian areas, more beavers, elk willow & aspen re-growth in riparian areas, more beavers, elk carcasses feed grizzlies, coyote population reduced, squirrel carcasses feed grizzlies, coyote population reduced, squirrel & fox pop increase = more food for eagles & hawks& fox pop increase = more food for eagles & hawks
Fig. 8-1, p. 154
Human Impacts on BiodiversityHuman Impacts on Biodiversity Human Human ““footprintfootprint””
Disturbing the landDisturbing the land- - humans have disturbed humans have disturbed
50 - 83% of Earth50 - 83% of Earth
Destruction of wetlandsDestruction of wetlandshalf worldhalf world’’s wetlands lost in past 100 yrss wetlands lost in past 100 yrs
DeforestationDeforestation
Aquatic biodiversityAquatic biodiversity- - 27% coral reefs severely damaged- 27% coral reefs severely damaged- 75% fish are fished at or above limit75% fish are fished at or above limit
Premature extinctionsPremature extinctions- - current extinction rate likely 1,000 - 10,000 times current extinction rate likely 1,000 - 10,000 times greater than before humansgreater than before humans
Fig. 8-2, p. 155
Stepped Art
Fig. 8-3, p. 156
The Ecosystem ApproachThe Species Approach
Tactics• Protect habitat areas through
private purchase or government action
• Eliminate or reduce populations of nonnative species from protected areas
• Manage protected areas to sustain native species
• Restore degraded ecosystems
Tactics• Legally protect
endangered species
• Manage habitat
• Propagate endangered
species in captivity
• Reintroduce species
into suitable habitats
StrategyPreserve sufficient areas of habitats in different biomes and aquatic systems
Strategy
• Identify endangered species
• Protect their critical habitats
Goal
Protect populations of species in their natural habitats
Goal
Protect species frompremature extinction
Human Human Impacts on Impacts on
BiodiversityBiodiversity
Natural Capital Degradation: OrangutansNatural Capital Degradation: Orangutans
< 20,000 Organutans left- disappear at a rate >2,000 per year
Natural Capital: Scarlet Macaw Natural Capital: Scarlet Macaw
Fig. 8-5, p. 157
Types of US Public LandsTypes of US Public Lands(35% of US is public land)
Multiple-use lands:Multiple-use lands: National Forest System; Natural National Forest System; Natural Resource Lands (BLM)Resource Lands (BLM)
Moderately restricted-use lands:Moderately restricted-use lands: Natural Wildlife Refuges Natural Wildlife Refuges
Restricted-use lands:Restricted-use lands: Natural Park System; Natural Natural Park System; Natural Wilderness Preservation SystemWilderness Preservation System
What percent of U.S. land is What percent of U.S. land is federally-owned public land?federally-owned public land?
a. 35%
b. 7%
cc. 55%
d. 3%
e.e. 0%0%
Fig. 8-6b, p. 158
National parks and preserves National forests (and Xs) National wildlife refuges
US Federal Public LandsUS Federal Public Lands
Managing US Public LandsManaging US Public Lands principles of public land useprinciples of public land use
ConservationistsConservationists DevelopersDevelopersProtecting biodiversity is a primary goalProtecting biodiversity is a primary goal
No subsidies or tax breaks for use of No subsidies or tax breaks for use of resourcesresources
Public should get fair compensation for Public should get fair compensation for useuse
Users are responsible for environmental Users are responsible for environmental damagedamage
Alternative views from developers and Alternative views from developers and industryindustry
Sell public lands / resources @ less Sell public lands / resources @ less than market valuethan market value
Slash funding for regulation Slash funding for regulation
Cut old growth forests in national Cut old growth forests in national forests and replace with tree plantationsforests and replace with tree plantations
Open all public land to oil, mining, off-Open all public land to oil, mining, off-roading and commercial developmentroading and commercial development
Eliminate Nat. Park Service, mine Eliminate Nat. Park Service, mine without royalties, repeal Endangered without royalties, repeal Endangered Species Act, …Species Act, …
Which of the following is a Which of the following is a majormajor problem of U.S. national parks?problem of U.S. national parks?
a. wildfires
b. too much land area to manage
c. Popularity
d. lack of management plans
e.e. attack from vicious wildlife on attack from vicious wildlife on humanshumans
It is permissible to trap It is permissible to trap animals in most national animals in most national
wildlife refuges.wildlife refuges.a. True a. True
b. False b. False
The National Wilderness Preservation The National Wilderness Preservation System forbids the introduction of:System forbids the introduction of:
a. roads b. fishing c. camping d. sailboats e. APES students
Arctic National Wildlife RefugeArctic National Wildlife Refuge(CNN Video) (CNN Video) 2 min2 min
Types of ForestsTypes of Forests
Old-growthOld-growth- - not seriously disrupted for at least several hundred not seriously disrupted for at least several hundred yearsyears
Second-growth Second-growth - results from secondary succession - results from secondary succession
Tree plantation or tree farm Tree plantation or tree farm - - managed tract of uniformly managed tract of uniformly
aged trees of one or two species. Clear cut when commercially valuable, then aged trees of one or two species. Clear cut when commercially valuable, then replanted.replanted.
Fig. 8-7, p. 160
Support energyflow andchemical cycling
Reduce soilerosion
Absorb andrelease water
Purify water
Purify air
Influence localand regionalclimate
Storeatmosphericcarbon
Providenumerouswildlife habitats
Fuelwood
Lumber
Pulp to makepaper
Mining
Livestock grazing
Recreation
Jobs
Major Services of Forests Major Services of Forests
Forests
Natural Capital
Ecological Services
Economic Services
Ecological services of world’s forests valued at $4.7 trillion per year
Value of ecological services much greater than value of economic services
>>>Much greater than
Types of Forest ManagementTypes of Forest Management Even-aged managementEven-aged management (industry forestry) trees maintained @ (industry forestry) trees maintained @
about same age and size- simplified tree plantation- 1-2 fast-growing species about same age and size- simplified tree plantation- 1-2 fast-growing species harvested on rotation cycle.harvested on rotation cycle.EX: EX: Clear cuttingClear cuttingEX: EX: Seed tree methodSeed tree method: : In the seed-tree method, 2-12 seed trees per acre (5-30/ha) are In the seed-tree method, 2-12 seed trees per acre (5-30/ha) are left standing in order to regenerate the forest. left standing in order to regenerate the forest. EX: EX: Shelter wood methodShelter wood method: : The method's objective is to establish new forest The method's objective is to establish new forest reproduction under the shelter of the retained trees.reproduction under the shelter of the retained trees.
Rotation cycles:Rotation cycles: 25-30 years (temperate),25-30 years (temperate), 6-10 years (tropical)6-10 years (tropical)
EX: EX: Strip cuttingStrip cutting
Uneven-aged managementUneven-aged management- - variety of species w/ range of ages & variety of species w/ range of ages & sizes. Goals: biodiversity, sustainable high quality timbersizes. Goals: biodiversity, sustainable high quality timberEX: EX: Selective cuttingSelective cutting
Sustainable management Sustainable management intensive management of as little as 20% of intensive management of as little as 20% of worldworld’’s forests could meet current and future demand for commercial wood / s forests could meet current and future demand for commercial wood / fiberfiberEX: EX: Combine aspects of a number of these management techniquesCombine aspects of a number of these management techniques..
Tree Plantation Tree Plantation
Fig. 8-8, p. 160
Degradation of Forests from Degradation of Forests from Logging RoadsLogging Roads
Increased erosion and sediment runoffIncreased erosion and sediment runoff
Habitat fragmentationHabitat fragmentation
Biodiversity lossBiodiversity loss
Pathways for pests, diseases, and invasive speciesPathways for pests, diseases, and invasive species
More accessible for humansMore accessible for humans
HighwayCleared plotsfor grazing
Cleared plotsfor agriculture
Fig. 8-10b, p. 161
Degradation of Forests Degradation of Forests
Degradation Degradation from Clear-cut from Clear-cut
Logging Logging
Fig. 8-12, p. 163
Fig. 8-13, p. 163
Trade-Offs
Clear-Cutting Forests
Advantages Disadvantages
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
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
Tradeoffs of Clear-cutting Forests Tradeoffs of Clear-cutting Forests
© 2006 Brooks/Cole - Thomson Fig. 8-14, p. 164
Natural Capital Degradation
Deforestation
• Decreased soil fertility from erosion
• Runoff of eroded soil into aquatic systems
• Premature extinction of species with specialized niches
• Loss of habitat for migratory species such as birds and butterflies
• Regional climate change from extensive clearing
• Releases CO2 into atmosphere from burningand tree decay
• Accelerates flooding
Harmful Effects of Deforestation Harmful Effects of Deforestation
Deforestation has all of the following Deforestation has all of the following effects effects exceptexcept::
a. increase in soil fertility. b. regional climate change. c. flooding. d. extinction of species with specialized niches. e. increase in soil erosion.e. increase in soil erosion.
© 2006 Brooks/Cole - Thomson Fig. 8-15, p. 164
Solutions
Sustainable Forestry
• Grow more timber on long rotations
• Rely more on selective cutting and strip cutting
• No clear-cutting, seed-tree, or shelterwood cuttingon steeply sloped land
• No fragmentation of remaining large blocks of forest
• Sharply reduce road building into uncut forest areas
• Leave most standing dead trees and fallen timber for wildlife habitat and nutrient recycling
• Certify timber grown by sustainable methods
• Include ecological services of trees and forests inestimating economic value
Sustainable ForestrySustainable Forestry
Conserves biodiversity, water & soil resources
Surface and Crown Forest FiresSurface and Crown Forest Fires
Fig. 8-16, p. 166
Ground fire = underground surface fire, common in northern peat bogs
Minimizing Forest Damage from FireMinimizing Forest Damage from Fire
Prescribed burningPrescribed burning- - reduce underbrushreduce underbrush
Allow small fires in National Parks, forests & Allow small fires in National Parks, forests & wilderness to burn wilderness to burn (if people & property not threatened) (if people & property not threatened)
Defensible space- Defensible space- clear 200 feet around buildingsclear 200 feet around buildings
Effects of the Healthy Forests InitiativeEffects of the Healthy Forests InitiativeTimber Co. allowed to take large/medium trees in Nat. Forests if Timber Co. allowed to take large/medium trees in Nat. Forests if they clear away smaller, fire-prone trees- criticized by fire they clear away smaller, fire-prone trees- criticized by fire scientists (large tree most fire resistant, logging creates slash)scientists (large tree most fire resistant, logging creates slash)
Healthy Forests Initiative Healthy Forests Initiative (CNN Video) (CNN Video)
Read more about this!
Managing US National ForestsManaging US National Forests Status of US forests- Status of US forests- 30% of USA forested, more wood grown than cut30% of USA forested, more wood grown than cut
more forests now than in 1920 (old growth forests decreasing)more forests now than in 1920 (old growth forests decreasing)
Importance of national forestsImportance of national forests
Management of forestsManagement of forests
Lost revenue from timber salesLost revenue from timber sales-- timber sales from US federal land lost timber sales from US federal land lost taxpayer money in 97 of past 100 yearstaxpayer money in 97 of past 100 years
Controversies of logging national forestsControversies of logging national forests- 10x more $ and 7x more jobs - 10x more $ and 7x more jobs added to economy by using national forests for recreation, hunting & fishing added to economy by using national forests for recreation, hunting & fishing
Tree-free fibers and paper- Tree-free fibers and paper- agricultural residues, kenaf & industrial hempagricultural residues, kenaf & industrial hemp
Fig. 8-17, p. 168
Trade-Offs
Advantages Disadvantages
Logging in U.S. National Forests
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
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 ForestsLogging in U.S. National Forests
KenafKenaf
Fig. 8-18, p. 169
Holds potential to greatly reduce pressure to cut trees for paper
End Part 1
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