Transcript Protected Areas

Sustaining Biodiversity:
The Ecosystem Approach
Chapter 9
Types of Forests

Old-growth- not seriously disrupted for at least several hundred
years

Second-growth - results from secondary succession

Tree plantation or tree farm - managed tract of uniformly
aged trees of one or two species. Clear cut when commercially valuable, then
replanted.
Major Services of Forests
Natural Capital
Ecological
services of
world’s
forests
valued at
$4.7
trillion per
year
Forests
Ecological
Services
Support energy
flow and
chemical cycling
>>>
Much greater than
Economic
Services
Fuelwood
Lumber
Reduce soil
erosion
Absorb and
release water
Pulp to make
paper
Value of
ecological
services much
greater than
value of
economic
services
Purify water
Purify air
Mining
Influence local
and regional
climate
Livestock grazing
Store
atmospheric
carbon
Recreation
Provide
numerous
wildlife habitats
Jobs
Fig. 9-4, p. 181
Types of Forest Management

Even-aged management (= industry forestry) trees maintained @
about same age and size- simplified tree plantation- 1-2 fast-growing species
harvested on rotation cycle

Rotation cycles:

Uneven-aged management- variety of species w/ range of ages
- 25-30 years (temperate), 6-10 years (tropical)
& sizes. Goals: biodiversity, sustainable high quality timber

Sustainable management intensive management of as little as
20% of world’s forests could meet current and future demand for commercial
wood / fiber
Tree Plantation
Management Strategies: Rotation Cycles
Weak trees
removed
Seedlings
planted
Clear
cut
25
15
10
30
Years of growth
5
Growth faster in tropical countries (6-10 years)
Degradation of Forests from
Logging Roads

Increased erosion and sediment runoff

Habitat fragmentation

Biodiversity loss

Pathways for pests, diseases, and invasive species

More accessible for humans
Degradation of Forests
Highway
Old growth
Degradation of Forests
Cleared plots
for grazing
Cleared plots
for agriculture
Highway
Degradation
from Clear-cut
Logging
Tradeoffs of Clear-cutting Forests
Trade-Offs
Clear-Cutting Forests
Advantages
Disadvantages
Higher timber yields
Reduces biodiversity
Maximum economic return
in shortest time
Disrupts ecosystem processes
Can reforest with genetically
improved fast-growing trees
Destroys and fragments some
wildlife habitats
Leaves moderate to large openings
Short time to establish new
stand of trees
Needs less skill and planning
Increases soil erosion
Increases sediment water pollution and
flooding when done on steep slopes
Best way to harvest tree plantations
Good for tree species needing
full or moderate sunlight for growth
Eliminates most recreational value for
several decades
Harmful Effects of Deforestation
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 burning
and tree decay
• Accelerates flooding
© 2006 Brooks/Cole - Thomson
Global Outlook: Extent of
Deforestation

Extensive deforestation by humans over past 8,000
years (20 - 50% reduction)

Deforestation continues

Some reforestation in North America and Europe.
However, tree plantation ≠ old growth forest

Some regrown tropical forests show increased tree
cover
Protecting Tropical Forests
Solutions
Sustaining Tropical Forests
Prevention
Protect most diverse and endangered areas
Restoration
Reforestation
Educate settlers about sustainable
agriculture and forestry
Phase out subsidies that encourage
unsustainable forest use
Add subsidies that encourage
sustainable forest use
Rehabilitation of degraded areas
Protect forests with debt-for-nature swaps,
conservation easements, and conservation
concessions
Certify sustainably grown timber
Reduce illegal cutting
Reduce poverty
Slow population growth
Concentrate farming and ranching on
already-cleared areas
World’s Forests

Deforestation

Economic value of forests: value of ecological services could be as
high as $4.7 trillion / year. Value of ecological services >>> economic value

Should we make economic estimates?
”Our economic system has been constructed under the premise that natural
services are free.” Profits are short term, services long-term

Sustainable management of forests

Certifying sustainably grown timber 2002 Mitsubishi agreed to
certify practices as sustainable (Home Depot & Lowes sell only certified wood)
Sustainable Forestry
Solutions
Sustainable Forestry
• Grow more timber on long rotations
• Rely more on selective cutting and strip cutting
• No clear-cutting, seed-tree, or shelterwood cutting
on 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 in
estimating economic value
© 2006 Brooks/Cole - Thomson
Conserves
biodiversity,
water & soil
resources
US Forests

Reforestation

Old-growth forests still decline

Forest fires: surface, crown, and ground
Surface and Crown Forest Fires
Ground fire = underground surface fire, common in northern peat bogs
Minimizing Forest Damage from Fire

Prescribed burning- reduce underbrush

Allow small fires in National Parks, forests &
wilderness to burn (if people & property not threatened)

Defensible space- clear 200 feet around buildings

Effects of the Healthy Forests Initiative
Timber Co. allowed to take large/medium trees in Nat. Forests if
they clear away smaller, fire-prone trees- criticized by fire
scientists (large tree most fire resistant, logging creates slash)
Reintroducing Wolves to
Yellowstone (1995)

Why wolves were killed-
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Wolf protection 1974 listed as endangered species
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Ecological importance- Keystone predator- culled
2 million killed 1850 - 1900
to “make the west safe for livestock and big-game animals”
herds of bison, elk, caribou and mule deer, keep coyote pop low, …

Yellowstone controversy- ranchers, hunters,
miners all opposed

Importance of biodiversity- ecological successwillow & aspen re-growth in riparian areas, more beavers, elk
carcasses feed grizzlies, coyote population reduced, squirrel
& fox pop increase = more food for eagles & hawks
Establishing, Designing, Protecting
Nature Reserves

Currently 12% of earth’s land is “protected”

Include large to moderate tracts of land

Preserve biodiversity

Involve government, businesses, and private groups
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Buffer zone concept: biosphere reserves
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Costa Rica’s accomplishments
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Adaptive ecosystem management
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Emergency action and biodiversity hot spots
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Wilderness
Biosphere Reserve
Biosphere Reserve
Core area
Buffer zone 1
Buffer zone 2
Tourism and
education center
Human
settlements
Research
station
Fig. 8-23, p. 174
Biodiversity Hot Spots
Fig. 8-26, p. 176
Types of US Public Lands
(35% of US is public land)

Multiple-use lands: National Forest System; Natural
Resource Lands (BLM)

Moderately restricted-use lands: Natural Wildlife Refuges

Restricted-use lands: Natural Park System; Natural
Wilderness Preservation System
US Federal Public Lands
National parks and preserves
National forests
(and Xs) National wildlife refuges
Fig. 8-6b, p. 158
Logging in U.S. National Forests
Trade-Offs
Logging in U.S. National Forests
Advantages
Disadvantages
Helps meet country’s timber needs
Provides only 4% of timber needs
Cut areas grow back
Ample private forest land to meet
timber needs
Keeps lumber and paper prices down
Has little effect on timber and paper
prices
Damages nearby rivers and fisheries
Provides jobs in nearby communities
Promotes economic growth
in nearby communities
*Recreation in national forests provides
more local jobs and income for local
communities than logging
Decreases recreational opportunities
Kenaf
Holds potential to
greatly reduce
pressure to cut trees
for paper
Ecological Restoration
= “process of repairing damage caused by humans to the biodiversity &
dynamics of natural ecosystems”

Restoration, rehabilitation and replacement

Creating artificial ecosystems
4 Principles of Ecological Restoration:
1.
Mimic nature
2.
Recreate important ecological niches
3.
Rely on pioneer, keystone and foundational species and natural ecological
succession
4.
Control or remove nonnative species

Accomplishments in Costa Rica
Restoration of a Stream Bank
Area restored in 10 years after banning grazing and off-road vehicles.
Major Human Impacts on Aquatic
Biodiversity

Loss and degradation of habitat is greatest threat

Damage to coral reefs and other habitats

Dredging / trawler operations destroy bottom habitats

Overfishing

Premature extinction
Degradation of the Ocean Floor
Fig. 8-29, p. 179
Protecting and Sustaining Marine
Biodiversity

Protecting endangered and threatened species

Establish large and unpolluted protected areas- marine reserves work.

Integrated coastal management

Protect wetlands

Prevent overfishing

Regulate and prevent pollution
Managing Fisheries
Solutions
Managing Fisheries
Fishery Regulations
Set catch limits well below the maximum
sustainable yield
Bycatch
Improve monitoring and enforcement of
regulations
Use net escape devices for seabirds and sea turtles
Economic Approaches
Sharply reduce or eliminate fishing subsidies
Use wide-meshed nets to allow escape of smaller
fish
Ban throwing edible and marketable fish back into
the sea
Aquaculture
Charge fees for harvesting fish
and shellfish from publicly owned
offshore waters
Restrict coastal locations for fish farms
Certify sustainable fisheries
Depend more on herbivorous fish species
Protected Areas
Establish no-fishing areas
Nonative Invasions
Establish more marine protected areas
Filter organisms from ship ballast water
Rely more on integrated coastal management
Dump ballast water far at sea and
replace with deep-sea water
Consumer Information
Label sustainably harvested fish
Publicize overfished and
Control pollution more strictly
Kill organisms in ship ballast water
Fig. 8-30, p. 181