Ch 13 and 14 student template ppt 2010
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Transcript of Ch 13 and 14 student template ppt 2010
Ch 13: Forests, Parks and
Landscapes
Forests are:
a. Economically important
1.
b. Ecologically important
1.
2.
3.
4.
Deforestation
1. One of the most crucial environmental
concerns of our times
2. Direct causes • a.
b.
c. in developing world = major source of fuel
Case Study:Paper and Deforestation
1. U.S. and paper:a. We (5% or world’s pop.) use 30% of paperb.
2. Global wood usea. Predicted to double by 2050b.
3. Toxic Pollution and Waste
a.
b. Pollutants: Bleaching paper:
Chlorine
c. Paper is the dominant material in solid waste!
4. Alternatives to wood in paper
a. Kenaf (from East Indies)
b. Hemp (first paper 105 A.D. - China)
One of world’s most versatile fibers.
c. Wheat, sugar cane and other agricultural straw(agricultural waste)
d. Flax (used for over 2000 yrs)
5. Recycled paper into new
a. Down from 10% (1990) to 5% today (consumer apathy)
b. Not easily marketable.
Forest Management
1. Two types of forests:a.b.
2. Most logging is on private and U.S. forest service lands
3. ________________________________for “the greatest amount of good for the greatest amount of people”
U.S.F.S. and multiple use policy:
a.
b.
c.
d.
e. conservationists call this policy
“multiple misuse”
3.Logging strategies:
a.
b.
c.
d.
e.
f.
4.Effects of clear-cutting
a. Increased..
1.
2.
3. landslides likely on steep slopes
© 2003 John Wiley and Sons Publishers
Effects of clearcutting on forest chemical cycling.
5. Forests mgmt may also include prescribed burning. (clear underbrush)
6. Plantation Forestry
a. also called
b. often planted after clearcutting
Parks and Preserves
1. General info. (10% land set aside)
a. National and State Park Service _____________________vs. Forest Service (______________________)
b. Natl. Parks managed by ________________
. Each state manages own.
c. First Natl. Park in US was Yellowstone in 1872
2. Parks and preserves as islands
a. park vs nature reserve/wilderness
1. park =
2. natl. reserve… =
b. island biogeography
1. size and diversity of habitats
affects # of species that
may be maintained there
3.Designing a preserve
a. larger, more varied habitats = better
b. Connectivity –
c.
d.
© 2003 John Wiley and Sons Publishers
Park shapes and island biogeography. Good – large
area protects many species
Small areas but over more than one area can be better insurance
Best – wildlife corridors connect
4.Conserving Wilderness
a. Wilderness = undisturbed, roadless habitat
b. U.S. Wilderness Act of 1964 “Humans can ‘visit’, not machines!”
Ch 14: Wildlife, Fisheries and Endangered Species
Managing wildlife populations
a. Maximum Sustainable Yield (MSY)
b. Minimum Viable Population (endangered species)
c. Optimum Sustainable Population
d. Carrying Capacity
Over 70% global fishes considered overfished
Fisheries
a. Wild fish harvests are declining
b. continental shelf = 95% harvesting
(upwelling, nutrients, algae)
Harmful commercial fishing techniques:
An estimated 2 billion hooks are set each year by longline fishing fleets, killing 40,000 sea turtles, over 300,000 sea birds and millions of sharks annually, to name a few.
Gillnetting
Alaskan pink salmon are evolving into smaller fish, the ones who make it through the gill nets survive to reproduce.
For every pound of shrimp caught, 10 - 20 lbs of bycatch “trawl trash” is killed and discarded!
The area of the seafloor trawled is equal to 150X the area of forests clear cut each year!
Aquaculture now accounts for about 1/3 of our seafood.
Now due to environmental problems marine aquaculture is being revisited.
© 2003 John Wiley and Sons Publishers
The world’s major fisheries.
Red = upwelling and
high production
Yellow = moderate production
Who’s being depleted?Virtually every large fish in the ocean: Including, but not limited to:
All have declined by 90% since industrialized fishing after WWII.
Fisheries in total collapse:OystersBluefin and Albacore TunaSardinesAtlantic CodAnchovies from Peru Salmon from Pacific Northwest
(Alaska is OK)
World Fisheries Congress
1992 and 1996
Every major country discusses codes of conduct/harvesting….
Established
Today: 80% of our fish must be imported:
Case Study : Local Depletion of Rock Fish
2nd Case Study – Atlantic Cod
Fish caught are getting younger and younger.
Whales and Whaling•11. Great whales and whaling
a. Subsistence vs. commercial whaling
b. heaviest losses in 20th century with high tech whaling equip
2.Commercial value
a. much less $$ than fisheries
b. but a few crucial products (whale oil)
c. __________________________established in 1946 set moratorium on commercial whaling
in 1982 (very important!)
Species depleted, in order, by commercial whalers:
*Right WhalesHumpback WhalesSperm WhalesBlue WhalesFin WhalesMinke Whales
More difficult to catch, not as valuable
Who Violates Ban?20000 have been slaughtered since the
ban in 1986
• (under guise of “scientific research”)
• – says the “rats of the sea” are responsible for crash of fisheries!
• IWC contemplating RMS
Dolphins, porpoises…
a. Commercial and accidental hunting (tuna netting)
b. cooperation and boycotting has helped establish measures
to reduce bycatch mortality
Endangered Species
• Intl. Union of Concerned Scientists (IUCC) Red List says, at risk of extinction are:
• of all known mammals• of all known birds• of all known reptiles• of all known amphibians
Natural Causes of Extinction
• Population fluctuations (if pop is very low)• Environmental Variations• Natural Catastrophes• Genetic changes (Small pops)
Human Causes of Extinction