Chapter 9///environmental science

8/13/2019 Chapter 9///environmental science

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ENVIRONMENTALSCIENCE

CHAPTER 9:

Sustaining Biodiversity:The Ecosystem Approach


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Wangari Maathai and the GreenBelt Movement

Began in Kenya in 1977

Organizes poor women in rural Kenya

50,000 members protect forests Planted 20 million trees

Fruits

Building materials Firewood

Similar programs in 30 African countries

2004: Nobel Peace Prize


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9-1 What Are Major Threats to

Forest Ecosystems?

Concept 9-1 Ecologically valuable

forest ecosystems are being cut and

burned at unsustainable rates inmany parts of the world.


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Types of Forests

Forests cover 30% of earths land

surface

Old-growth forests Second-growth forests

Tree plantation


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Fig. 9-2, p. 180


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Fig. 9-3, p. 180


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Years of growth

Weak trees

removed

Seedlings

planted

Clear cut

30 yrs

25 yrs

5 yrs 10 yrs

15 yrs

Fig. 9-3, p. 180


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9/113Fig. 9-4, p. 181


10/113Fig. 9-4, p. 181

Natural Capital

Fuelwood

Lumber

Pulp to make

paper

Mining

Livestockgrazing

Recreation

Jobs

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

Provide numerous wildlife habitats

EcologicalServices EconomicServices

Forests


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Science Focus: Putting a Price Tagon Natures Ecological Services

Estimated value of earths ecological

services

$33.2 trillion per year $4.7 trillion per year for forests

Need to start factoring values into land

use Ecological services can be a

sustainable source of ecological income


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Harvest Methods

Step one: build roads

Erosion

Invasive species Open up for human invasion

Step two: logging operations

Selective cutting

Clear cutting

Strip cutting


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Cleared plotsfor agriculture

New highway

Old growth

HighwayCleared plotsfor grazing

Fig. 9-5, p. 182


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17/113Fig. 9-6, p. 182


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Clear

stream

(a) Selective cutting

Fig. 9-6, p. 182


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Fig. 9-6, p. 182


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Fig. 9-6, p. 182


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Cut 1

year ago

(c) Strip cuttingUncut

Clear

stream

Uncut

Cut 310

years ago

Dirt road

Fig. 9-6, p. 182

( ) S l ti tti


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Stepped Art

(b) Clear-cutting

Muddy

stream

Uncut

Cut 1 year ago

Dirt road

Cut 310 years ago

Uncut

Clear stream

(a) Selective cutting

(c) Strip cutting

Clear stream

Fig. 9-6, p. 182


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Fig. 9-7, p. 182


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Forests and Fires

Surface fires

Burn undergrowth only

Cool fire Ecological benefits

Crown fires

Burn the entire tree

Hot fire

Occur in forests with lack of surface fires


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Fig. 9-8, p. 183


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Loss of Original Forests

Deforestation

46% in 8,000 years, most since 1950

Most in tropical areas, developingcountries

Estimated loss of 40% intact forests

within next 20 years


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Fig. 9-9, p. 184


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Fig. 9-10, p. 184


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Good News on Forests

20002007 net total forested areastabilized or increased

Most of the increase due to treeplantations

Net loss of terrestrial biodiversity


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Return of Forests in the UnitedStates (1)

U.S. forests

Cover ~30% of land

Contain ~80% of wildlife species Supply ~67% of nations surface water

Forest cover greater now than in

1920 Secondary succession


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Return of Forests in the UnitedStates (2)

Second- and third-growth forestsfairly diverse

More wood grown than cut 40% of forests in National Forest

System

Some forests transformed into treeplantations


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Tropical Forests

Cover 6% of earths land area

Habitat for 50% of terrestrial plants

and animals Vulnerable to extinctionspecialized

niches

Rapid loss of 50,000170,000 km2per year

Some second-growth forests


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Causes of Tropical ForestDeforestation and Degradation

Population growth and poverty

Economic reasons

Logging Ranching

Farming

Government subsidies

Fires raise temperatures and reducerainfall


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Fig. 9-11, p. 186


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Fig. 9-11, p. 186

Natural Capital Degradation

Not valuing ecological services

Crop and timber exports

Government policies

Poverty

Population growth

Roads

Fires

Settler farming

Cash crops

Cattle ranching

Logging

Tree plantations

Basic Causes Secondary Causes

Settler

farming

Cattle

ranching

Tree

plantations

Cash crops

Logging

RoadsFires

Major Causes of the Destruction and Degradation of Tropical Forests


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Fig. 9-12, p. 187


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9-2 How Should We Manage

and Sustain Forests?

Concept 9-2 We can sustain forests

by emphasizing the economic value

of their ecological services, removing

government subsidies that hasten

their destruction, protecting old-

growth forests, harvesting trees nofaster than they are replenished, and

planting trees.


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Fig. 9-13, p. 188


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Management of Forest Fires (1)

Fire suppression in all types of forests

Increased amounts of underbrush

Increased probability of crown fires


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Management of Forest Fires (2)

Prescribed fires

Allow some fires to burn

Thin vegetation from forests Thin around vulnerable homes

Decrease flammability of homes


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Fig. 9-14, p. 189

W t R d T i l


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Ways to Reduce TropicalDeforestation

Debt-for-nature swaps

Conservation concessions

Gentler logging methods Encourage use of wood substitutes


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Fig. 9-15, p. 190

Solutions


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Fig. 9-15, p. 190

Sustaining Tropical Forests

Protect the most diverse and

endangered areas

Educate settlers about

sustainable agriculture and

forestry

Subsidize only sustainable

forest use

Protect forests with

debt-for-nature swaps and

conservation concessions

Certify sustainably grown

timber

Reduce poverty

Slow population growth

Encourage regrowth

through secondary

succession

Rehabilitate degraded

areas

Concentrate farming

and ranching in

already-cleared areas

Prevention

Solutions

Restoration

9 3 H Sh ld W M


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9-3 How Should We Manage

and Sustain Grasslands?

Concept 9-3 We can sustain the

productivity of rangeland by

controlling the number and

distribution of grazing livestock and

by restoring degraded grasslands.


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Grasslands

Provide important ecological services

Second most used and altered

ecosystem by humans 42% grazed by cattle, sheep, and

goatsrangeland(open) and

pasture (fenced) Overgrazing


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Fig. 9-16, p. 191

Manage Rangelands


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Manage RangelandsSustainably

Practice rotational grazing

Fence out riparian zoneareas

Suppress invader plants Herbicides

Mechanical removal

Controlled burning

Short-term trampling


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Fig. 9-17, p. 191


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Fig. 9-17, p. 191

9 4 H Sh ld W M d


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9-4 How Should We Manage and

Sustain Parks and Nature Reserves?

Concept 9-4 We need to put more

resources into sustaining existing

parks and nature reserves and into

protecting much more of the earths

remaining undisturbed land area.


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Problems Protecting National


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Problems Protecting NationalParks

Illegal logging

Illegal mining

Wildlife poaching Most parks too small to protect large

animals

Invasion of nonnative species


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Stresses on U.S. National Parks

58 major national parks

Biggest problem is popularity

Damage from nonnative species Threatened islands of biodiversity

Need $6 billion for overdue repairs

Nature Reserves Occupy a


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Nature Reserves Occupy aFraction of Earth

12% of earths land protected

Only 5% fully protected95%

reserved for human use Need for conservation

Minimum 20% of land in biodiversity

reserves Protection for all biomes


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Solutions for Protection

Ecological insurance policy

Buffer zones around protected areas

Locals to manage reserves and bufferzones

United Nations: 531 biosphere

reserves in 105 countries

Science Focus: Reintroducing the Gray


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Science Focus: Reintroducing the GrayWolf to Yellowstone National Park

Reduced to a few hundred in lower 48 by1973

Keystone species

Restoration proposal angered ranchers,hunters, loggers

1995 - reintroduced in Yellowstone, 124 by2008

Positive ripple effect after reintroduction


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Fig. 9-B, p. 193


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Case Study: Costa Rica

Superpower of biodiversity

Conserved 25% of its land, 8

megareserves Government eliminated deforestation

subsidies

Paid landowners to maintain andrestore tree coverage

Boosts ecotourism


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Fig. 9-18, p. 194


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Fig. 9-18, p. 194

Caribbean SeaNicaragua

Panama

CostaRica

Buffer zone

National parkland

Pacif ic Ocean

Protecting Wilderness Protects


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Protecting Wilderness ProtectsBiodiversity

Wilderness

Preserves biodiversity

Centers for evolution

Case Study: Controversy over


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Case Study: Controversy overWilderness Protection in the U.S.

1964 Wilderness Act

Ten-fold increase from 1970 to 2008

4.6% of U.S. land protected, 75% ofthat in Alaska

9-5 How Can We Help to


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Sustain Terrestrial Biodiversity?

Concept 9-5 We can help to sustain

terrestrial biodiversity by identifying

and protecting severely threatened

areas (biodiversity hotspots),

rehabilitating damaged ecosystems

(using restoration ecology), and

sharing with other species much of

the land we dominate (using

reconciliation ecology).

Three Principles to Protect


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Three Principles to ProtectEcosystems

1. Map and inventory the worldsterrestrial and aquatic ecosystems

2. Locate and protect the mostendangered ecosystems, with afocus on biodiversity

3. Seek to restore as many degradedecosystems as possible

Protecting Global Biodiversity


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Protecting Global BiodiversityHotspots

17 megadiversity countries, mostly intropics and subtropics

Two-thirds of biodiversity

Developing countries economicallypoor and biodiversity rich

Protect biodiversity hotspots


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Fig. 9-19, p. 196


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Supplement 4, Fig. 2, p. S16


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Science-based Principles for


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Science based Principles forRestoration

Identify cause of degradation

Stop abuse by reducing factors

Reintroduce species if necessary Protect area from further degradation

Case Study: Ecological Restoration


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Case Study: Ecological Restorationof Tropical Dry Forest in Costa Rica

One of worlds largest ecological

restoration projects

Restore a degraded tropical dry forestand reconnect it to adjacent forests

Involve 40,000 people in the

surrounding areabioculturalrestoration

Ecotourism


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Restoration Ecology

Creating new habitats to conservespecies diversity in areas wherepeople live, work, play

People learn to protect local speciesand ecosystems

Sustainable ecotourism Golden Gate Park in San Francisco


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Fig. 9-20, p. 198



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9 6 How Can We Help to

Sustain Aquatic Biodiversity?

Concept 9-6 We can help to sustain

aquatic biodiversity by establishing

protected sanctuaries, managing

coastal development, reducing water

pollution, and preventing overfishing.

Impacts on Aquatic Ecosystems


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Impacts on Aquatic Ecosystems(1)

Destroyed or degraded by humanactivities

Coastal habitats disappearing 2-10times faster than tropical forest

Rising sea levels will destroy coral

reefs and some low islands Ocean floor degradation 150 times

larger than area clear-cut annually

Impacts on Aquatic Ecosystems


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Impacts on Aquatic Ecosystems(2)

Freshwater habitat disruption

Dams

Water withdrawals from rivers

Likely extinction

34% marine fish species

71% freshwater species Greater than any other group of species


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Fig. 9-21, p. 199


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Fig. 9-21, p. 199

O fi hi


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Overfishing

Fishery

Fishprint

157% overfishing 90% of large open-ocean fishes have

disappeared since 1950


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Fig. 9-22, p. 200

Case Study: Industrial Fish


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Case Study: Industrial FishHarvesting Methods

Trawler fishing

Purse-seine fishing

Longlining Drift-net fishing


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Fig. 9-23, p. 201


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Fig. 9-23, p. 201

Float

Trawler

fishing

Drift-net fishing

Purse-seine fishing

Sonar

Long line fishing

lines with

hooks

Fish farming

in cageSpotter airplane

Deep sea

aquaculture cage Fish caught

by gills

Buoy


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Fish farming

in cage Spotter airplane

Trawler

fishing

Sonar Purse-seine

fishing

Long line

fishing

lines with

hooks

Deep sea

aquaculture cage

Drift-net fishing

Float Buoy

Fish caught

by gills Stepped ArtFig. 9-23, p. 201

Why Is Protection of Marine


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yBiodiversity So Difficult?

Human aquatic ecological footprintexpanding

Not visible to most people Viewed as an inexhaustible resource

Most ocean areas outside jurisdiction

of a country

Solutions for Marine


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Ecosystems

Protect endangered and threatenedspecies

Establish protected marinesanctuaries

Marine reserveswork well and

quickly Integrated coastal management

Protect existing coastal wetlands


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Fig. 9-24, p. 202

Solutions


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Fig. 9-24, p. 202

Managing Fisheries

Fishery Regulations

Set catch limits well below the

maximum sustainable yield

Improve monitoring and

enforcement of regulations

Economic Approaches

Sharply reduce or eliminate

fishing subsidies

Charge fees for harvesting fish

and shellfish from publiclyowned offshore waters

Certify sustainable fisheries

Protect Areas

Establish no-fishing areas

Establish more marine

protected areas

Rely more on integrated

coastal management

Consumer Information

Label sustainably harvested

fish

Publicize overfished and

threatened species

Bycatch

Dump ballast water far at

sea and replace with

deep-sea water

Filter organisms from ship

ballast water

Kill organisms in ship

ballast water

Nonnative Invasions

Depend more on

herbivorous fish species

Control pollution more

strictly

Restrict coastal locations

for fish farms

Aquaculture

Ban throwing edible and

marketable fish back into

the sea

Use net escape devices for

seabirds and sea turtles

Use wide-meshed nets to

allow escape of smaller fish

Three Big Ideas from This


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gChapter - #1

The economic values of the importantecological services provided by theworlds ecosystems need to be

included in the prices of goods andservices.



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gChapter - #2

We can sustain terrestrial biodiversityby protecting severely threatenedareas, restoring damagedecosystems, and sharing with otherspecies much of the land wedominate.



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gChapter - #3

We can sustain aquatic biodiversitybyestablishing protected sanctuaries,managing coastal development,

reducing water pollution, andpreventing overfishing.

Animation: Ocean Provinces


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Animation: Ocean Provinces

PLAYANIMATION

Animation: Humans Affect
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/ocean_zones.htmlhttp://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/ocean_zones.htmlhttp://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/ocean_zones.html


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Biodiversity

PLAYANIMATION

Animation: Habitat Loss and
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Fragmentation

PLAYANIMATION
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Animation: Succession


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Animation: Succession

PLAYANIMATION

Animation: Hubbard Brook
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Experiment

PLAYANIMATION

Animation: Effects of Air Pollution
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in Forests

PLAYANIMATION

Animation: Effects of
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Deforestation

PLAYANIMATION
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Animation: Resources Depletion


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and Degradation

PLAYANIMATION

Animation: Species Diversity By
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Latitude

PLAYANIMATION

Video: Easter Island
http://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/species_by_latitude.htmlhttp://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/species_by_latitude.htmlhttp://localhost/var/www/apps/conversion/tmp/scratch_3/Animations/species_by_latitude.html


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Video: Easter Island

PLAYVIDEO

Video: New Species Found
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Video: New Species Found

PLAYVIDEO

Video: Bachelor Pad at the Zoo
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Video: Bachelor Pad at the Zoo

PLAYVIDEO

Video: Desertification in China
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Video: Desertification in China

PLAYVIDEO

Video: U.S. Forests
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Video: U.S. Forests

PLAYVIDEO

Video: Marine Sanctuary
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Video: Marine Sanctuary

PLAYVIDEO

Video: Sea Turtle Release
http://localhost/var/www/apps/conversion/tmp/scratch_3/Videos/Marine_Sanctuary.movhttp://localhost/var/www/apps/conversion/tmp/scratch_3/Videos/Marine_Sanctuary.movhttp://localhost/var/www/apps/conversion/tmp/scratch_3/Videos/Marine_Sanctuary.mov


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Video: Sea Turtle Release

PLAY
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Chapter 9///environmental science