Transcript 10-1 What Are the Major Threats to Forest Ecosystems?

Sustaining Terrestrial Biodiversity:
The Ecosystem Approach
Chapter 10
Core Case Study: Reintroducing
Gray Wolves to Yellowstone
1. How was the gray wolf species
classified and what was it’s niche to
receive this classification?
2. What was the environmental
response to the loss of the gray wolf?
3. Why was the trickle down effect to
beavers especially devastating to the
environment?
4. What were the three major concerns
about the reintroduction of the gray
wolf?
10-1 What Are the Major Threats
to Forest Ecosystems?
 Concept 10-1A Forest ecosystems provide
ecological services far greater in value than the
value of raw materials obtained from forests.
• True Value
 Concept 10-1B Unsustainable cutting and
burning of forests, along with diseases and
insects, are the chief threats to forest
ecosystems.
10-1 What Are the Major Threats
to Forest Ecosystems? (2)
 Concept 10-1C Tropical deforestation is a
potentially catastrophic problem because of the
vital ecological services at risk, the high rate of
tropical deforestation, and its growing
contribution to global warming.
Forests Vary in Their Make-Up,
Age, and Origins
 Natural and planted
forest occupy 30%
of land.
• ½ Tropical forest
• ¼ Boreal forest
 What are the two
major types of
forests based on
age and structure?
 Where are most of
the old-growth
forests?
Tree Plantation, Tree Farm, Commerical
Forest
 What is a tree
plantation?
 Generally clear cut as
soon as commercially
valuable then
replanted.
 Used for paper and
composites (pressed
wood)
 What is the negative
effect of this process?
 Where are most of the
tree plantations?
 What are the
important
ecological
and
economic
services of
forests?
True Value – monetary value of the
ecological services provided.
$4.7 Trillion per year – True
Value of Forests globally.
Fig. 10-A, p. 218
Unsustainable Logging is a Major Threat
to Forest Ecosystems Figure 10.5
 What is the environmental cost of building roads for
access and lumber removal?
What are the Major Tree Harvesting
Methods?
Clear-Cutting
 What is the positive
side to this process?
 What is the negative
side to this process?
 Why is this process
considered to be a
positive feedback
process?
 Where is this process
increasing now?
Strip Cutting
 More sustainable
variation of clearcutting.
 Natural
regeneration will
occur in a few
years then loggers
will cut the next
strip.
Fire, Insects, and Climate Change Can
Threaten Forest Ecosystems 10.9
 What are the two
types of fires?
 How are they
different?
Fires
 Fires are part of a natural cycle and not a threat
to ecosystems.
 Except when used to clear land for crops and
livestock.
• Produces pollution.
• Increases carbon dioxide in atmosphere as the
wood is oxidized.
• Loss of a carbon sink.
Fire, Insects, and Climate Change Can
Threaten Forest Ecosystems
 Explain the effects
of accidental or
deliberate
introductions of
foreign diseases
and insects and
what can be done.
 Explain the effects
of global warming
on forests.
White pine
blister rust
Sudden oak
death
Pine shoot Beech bark
disease
beetle
Hemlock woolly
adelgid
We Have Cut Down Almost Half
of the World’s Forests
 Define
Deforestation.
 Why are humans
destroying forests?
 Where is this
concentrated now?
Brazil and Indonesia Lead the World in
Tropical Forest Loss.
Brazil 1975
Brazil 2001
Endangered white monkey
in Brazilian tropical rain
forest.
World’s largest flower – the
flesh flower. 3.3 feet in
diameter and weighs 15 lbs.
Smells like rotting meat to
attract pollinators – beetles
and flies.
Fig. 10-14a, p. 224
Deforestation
Case Study: Many Cleared Forests in the
United States Have Grown Back
1. What did Bill
McKibben mean
when he said forest
re-growth was “the
great environmental
story of the U.S. and
in some ways, the
world”?
2. What are the
concerns about tree
plantations?
Causes of Tropical Deforestation
Are Varied and Complex
 1st Road is cut into the forest for logging and
settlement.
 Cut the best trees but many others fall also due
to the vines in the canopy.
 Agriculture or grazing animals until the nutrients
are gone.
 The loggers, farmers and ranchers move to the
next area of what was once tropical rain forest.
 Plantations of soybean and oil palms.
 Burning of the tropical forest responsible twice
as much CO2 as all the world’s cars and trucks.
10-2 How Should We Manage and
Sustain Forests?
 Concept 10-2 We can sustain forests by
emphasizing the economic value of their
ecological services, protecting old-growth
forests, harvesting trees no faster than they are
replenished, and using sustainable substitute
resources.
We Can Improve the Management
of Forest Fires
 The Smokey Bear
educational
campaign
• What are the
pluses?
• What are the
minuses?
 What are the steps
to reduce firerelated harm to
forests and people?
We Can Improve the Management
of Forest Fires
 2003 Healthy Forests Restoration Act
• Describe
• Pros
• Cons
How Can We Reduce the Demand for
Harvested Trees?
 Improve the efficiency of
wood use.
• 60% of wood used in the
U.S. is wasted.
• How?
 One of the primary uses for
trees is making pulp for
paper.
• How can reduce tree
usage for this product?
• China
• U.S.
Case Study: Deforestation and the
Fuelwood Crisis
 ¾ of wood cut in developing countries is used for
fuel. Firewood and charcoal made from wood.
• Heating and cooking.
 Haiti
• Once a tropical paradise; now with only 2% of
land with forests.
• Classified as one of the world’s leading “failing
states”
 How can people reduce the fuelwood crisis?
 What is the other crisis of using fuelwood
besides loss of trees?
Governments and Individuals Can Act
to Reduce Tropical Deforestation
 Ways to reduce fuelwood demand
• Practice small-scale sustainable agriculture and
forestry in tropical forest
 Debt-for-nature swaps –
 Conservation concessions –
 Use gentler logging methods –
 Roles for the consumer –
Individuals Matter: Wangari Maathari and
Kenya’s Green Belt Movement
1. What was the Green Belt Movement of 1977?
2. Nobel Peace Prize: 2004
10-3 How Should We Manage and
Sustain Grasslands?
 Concept 10-3 We can sustain the productivity
of grasslands by controlling the number and
distribution of grazing livestock and restoring
degraded grasslands.
How Should We Manage and Sustain
Grasslands?
 What are the
important ecological
services of
grasslands?
 Grasslands are the
2nd most used and
abused ecosystem.
 What is the
difference in a
rangeland and a
pasture?
Moderate Grazing, Overgrazing,
Undergrazing
 How can moderate
grazing of
rangelands be
beneficial?
 Explain how
undergrazing and
overgrazing are
both detrimental.
We Can Manage Rangelands More
Sustainably
 The point is to control
the number of grazing
animals and the
duration of their grazing
in a given area.
 Explain Rotational
grazing.
 What are riparian
zones?
We Can Manage Rangelands More
Sustainably
 There are more expensive and thus less widely
used methods to sustain rangelands
• Suppress growth of unwanted invader plants
• Replant barren areas
• Apply fertilizer
Case Study: Grazing and Urban
Development the American West
1. What has caused the population surge to the
American southwest since 1980?
2. How has the population surge helped to protect
this ecosystem?
10-4 How Should We Manage and Sustain
Parks and Natural Reserves?
 Concept 10-4 Sustaining biodiversity will
require protecting much more of the earth’s
remaining undisturbed land area as parks and
nature reserves.
National Parks Face Many Environmental
Threats
 Worldwide: 1100 major national parks
• Most too small to support a lot of large animal
species.
• Many suffer from invasions by non-native
species.
 Parks in developing countries have the greatest
biodiversity but
• Only about 1% protected against
• Illegal animal poaching
• Illegal logging and mining
Case Study: Stresses on U.S.
Public Parks
 58 Major national parks in the U.S.
• In 27 states – most in the west and Alaska.
• 3 In Florida – Everglades, Dry Tortugas, Biscayne
Bay.
 Positive
• Tourism and education.
• No resource extraction.
• Protection of threatened or endangered species.
 Negative
• Some indigenous populations were removed from
the land.
National Parks
 1st was Yellowstone National
Park in 1872 by Ulysses S.
Grant (must be established by
an act of congress).
 Newest is Great Sand Dunes
in Colorado 2004.
 Biggest problem may be
popularity.
• Great Smoky Mountains
National Park is the most
frequently visited.
State Parks
 Those near urban
areas receive
twice the traffic as
the national parks.
• What are the
problems
associated with
frequent visitors?
Science Focus: Effects of Reintroducing the
Gray Wolf to Yellowstone National Park
 The gray wolf was reintroduced to Yellowstone
and this produced ecological ripples.
1. Explain the effect on elks, grizzly bears,
scavengers, trees.
2. Explain the effect of the tree change to birds
and waterways.
3. Explain the effect on coyotes and the trickle
down effect of this change.
4. How are the wolves affected by the dogs
brought into the park by visitors?
Nature Reserves Occupy Only a Small
Part of the Earth’s Land
 Only 12% of the earth’s land is protected strickly
or partially.
 What are eco-philanthropists doing?
 What are U.S. Land Trusts groups doing?
Designing and Connecting Nature
Reserves
 Large versus small
reserves
 The buffer zone
concept
Habitat Corridors
 Habitat corridors
between isolated
reserves
• Advantages
• Disadvantages
Case Study: Costa Rica—A Global
Conservation Leader
1. What is the size of Costa
Rica?
2. Why is it considered a
superpower of
biodiversity?
3. What is the largest
source of income for
Costa Rica?
4. How has the government
aided in the development
of biodiversity in Costa
Rica?
Protecting Wilderness Is an Important
Way to Preserve Biodiversity
 Define wilderness.
 What was Teddy
Roosevelt’s
contribution
 1964 US.
Wilderness Act
 Where are most of
the U.S. wilderness
areas?
How does the U.S.
compare with other
nations in terms of
terrestrial land protected?
10-5 What is the Ecosystem Approach
to Sustaining Biodiversity?
 Concept 10-5A We can help sustain
biodiversity by identifying severely threatened
areas and protecting those with high plant
diversity and those where ecosystem services
are being impaired.
 Concept 10-5B Sustaining biodiversity will
require a global effort to rehabilitate and restore
damaged ecosystems.
10-5 What is the Ecosystem Approach
to Sustaining Biodiversity? (2)
 Concept 10-5C Humans dominate most of the
earth’s land, and preserving biodiversity will
require sharing as much of it as possible with
other species.
How Can We Protect Ecosystems
 Map ecosystems globally creating an inventory
of species in each and the services they provide.
 Locate and protect the hotspots – areas of
highest diversity with endangered or threatened
species.
 Try to restore as many degraded ecosystems as
possible.
 Make development biodiversity friendly with tax
breaks or write-offs and technical help for private
landowners who agree to help protect
endangered ecosystems.
Protecting Global Biodiversity Hot Spots
Is an Urgent Priority
 Identify biodiversity hot spots rich in endangered
species.
Endangered Centers of Terrestrial
Biodiversity
Case Study: A Biodiversity Hot Spot
in East Africa
 Eastern Arc Mountains of
Tanzania, Africa
• Highest concentration of
endangered species on earth
Threatened due to:
• Killing of forests by farmers &
loggers
• Hunting
• Fires
We Can Rehabilitate and Restore
Ecosystems That We Have Damaged
 Study how natural ecosystems recover
• Restoration
• Rehabilitation
• Replacement
• Creating artificial ecosystems
We Can Rehabilitate and Restore
Ecosystems That We Have Damaged
 How to carry out most forms of ecological
restoration and rehabilitation
• Identify what caused the degradation
• Stop the abuse
• Reintroduce species, if possible
• Protect from further degradation
Science Focus: Ecological Restoration of
a Tropical Dry Forest in Costa Rica
 Guanacaste National Park
restoration project
• World’s largest ecological
restoration project
• A small tropical dry forest that
was burned, degraded and
fragmented to be used as cattle
ranches and farms.
Will Restoration Encourage Further
Destruction?
 Preventing ecosystem damage is cheaper and
more effective than restoration.
 About 5% of the earth’s land is preserved from
the effects of human activities
We Can Share Areas We Dominate With
Other Species
 Reconciliation or applied ecology
• Conserve species diversity in areas where we live
work and play.
• Learn how to share with other species that we
dominate.
• Invent, establish and maintain new habitats.
• Community-based conservation
• Bluebird protection with special housing boxes
• Berlin, Germany: rooftop gardens
• San Francisco: Golden Gate Park
Case Study: The Blackfoot Challenge—
Reconciliation Ecology in Action
 1970s: Blackfoot River Valley in Montana
threatened by
• Poor mining, logging, and grazing practices
• Water and air pollution
• Unsustainable commercial and residential
development
 Community meetings led to:
• Weed-pulling parties
• Nesting structures for waterfowl
• Developed sustainable grazing systems