Transcript File

Sustaining Terrestrial Biodiversity:
Managing and Protecting Ecosystems
Chapter 10
Core Case Study: Reintroducing
Gray Wolves to Yellowstone
 1850–1900: decline of wolves due to
human activity
(shooting, trapping and poisoning to make
safe for grazing livestock);
 U.S. Endangered Species Act: 1973
 1987- proposal to reintroduce gray wolf to
Yellowstone to help control the increase
in herds of grazers, coyotes
 1995–1996: relocation of gray wolves to
Yellowstone Park from Canada
 2008: Gray wolf no longer protected
Ch. 10 Key Concepts
 Human impact on earth’s biodiversity
 Types and uses of US public lands
 Forests and forest management
 Implications of deforestation
 Management of parks
 Establishment and management of nature
preserves
 Importance of ecological restoration
Human Impacts on Terrestrial Biodiversity
- Middle stages of
succession
- Moderate environmental
disturbances
- Small changes in
envtl.conditions
- Physically diverse habitat
- Evolution
-Extreme envtl. Conditions
- Large envtl. Disturbances
- Intense envtl. Stress
- Severe shortages of key
resources
- Nonative species
introductions
- Geographic isolation
Factors that tend to increase or
decrease biodiversity
Human Population
Size and resource use
Natural Capital
Degradation
Human Activities
Agriculture, industry, economic
production and consumption, recreation
Direct Effects
Degradation and destruction
of natural ecosystems
Changes in number and
distribution of species
Alteration of natural chemical
cycles and energy flows
Pollution of air, water,
and soil
Indirect Effects
Loss of
Climate
biodiversity
change
Major
connections
between
human
activities and
earth’s
biodiversity.
Arctic Circle
60°
EUROPE
NORTH
AMERICA
30°N
Tropic of Cancer
Pacific
Ocean
0° 150° 120° 90°
Tropic of Capricorn
ASIA
Atlantic
Ocean
AFRICA
30°W
SOUTH
AMERICA
0°
Pacific
Ocean
60°E
90°
150°
Indian
AUSTRALIA
Ocean
30°S
Antarctic Circle
60°
ANTARCTICA
Critical and endangered
Projected Status of Biodiversity
1998–2018
Threatened
Stable or intact
Why should we care???
Importance of Biodiversity
 Intrinsic value (Existence value)- because they
exist, regardless of their use to us!
 Instrumental value- because of their usefulness to
us
 Aesthetic value- appreciation of the beauty
 Bequest value- appreciation of protection for future
generations
The Species Approach
Goal
The Ecosystem Approach
Goal
Protect species from
premature extinction
Protect populations of
species in their natural
habitats
Strategies
Strategy
• Identify
endangered
species
• Protect their critical
habitats
Tactics
• Legally protect
endangered species
• Manage habitat
• Propagate
endangered species
in captivity
• Reintroduce species
into suitable habitats
Preserve sufficient areas
of habitats in different
biomes and aquatic
systems
Tactics
• Protect habitat areas
through private purchase or
government action
• Eliminate or reduce
populations of alien species
from protected areas
• Manage protected areas to
sustain native species
• Restore degraded
ecosystems
Protecting
Biodiversity
Conservation Biology
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Multidisciplinary science orig. in 1970’s
Emergency response to slow down the rate of human
degradation on earth’s biodiversity.
Identify “hot spots”- most endangered and species rich
ecosystems worldwide.
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Rapid Assessment Teams
Based on Leopold’s ethics – idea that something is right
when it tends to maintain the earth’s life-support system for us and
wrong when it does not.
Bioinformatics – applied area of science that involves managing,
analyzing and communicating biological information. (Uses
technology such as computer databases of DNA, high resol.
Images of all known species, etc)
Public Lands in the US
 35% of the land in the US is managed by the
federal govt. and available for public use (73% in
Alaska!)
Public Lands in the US
•
Multiple-use lands: National Forests; National
Resource Lands (managed by BLM) - used for logging,
mining, oil and gas extraction, livestock grazing; hunting, fishing,
recreation, farming; conservation watersheds, soil and wildlife
resources
•
Moderately-restricted use lands: National Wildlife
Refuges (managed by USFWS)- protect habitats and breeding
grounds for waterfowl and large game for hunters; some protect
endangered species; allow hunting, trapping fishing, oil & gas
development, mining, grazing, military activities, farming, logging
•
Restricted-use lands: National Park System
(managed by Natl. Parks service)- includes natl. recreation
areas, monuments, memorials, historical sites, trails, rivers,
shorelines; only camping, hiking, sport fishing and boating
National Wilderness Preservation System -most
restricted public lands; mostly open for hiking and sport fishing,
camping
Types of US Public Lands
Managing US Public Land: An
ongoing controversy
 Protecting biodiversity and ecological
function- argument over if this should be the primary
goal of public lands
 No subsidies or tax breaks for use of
resources from public lands- user-pays approach
 Public should get fair compensation for any
resources extracted from public lands
 Users held responsible for actions and any
envtl. damage caused
*Follows Leopold’s land-use
ethic
Managing and Sustaining Forests
TYPES OF FORESTS (based on age & structure)
 Old-growth (frontier or primary) forests- uncut
or not disturbed in several hundred years; lots of
biodiversity (36% of world’s forests)
 Second-growth forests- secondary succession
after being cleared from human activities or natural
disasters (60% of world’s forests)
 Tree farms/plantation- uniformly aged trees that
are harvested by clear-cutting when commercially
valuable; replanted and cycles again (4% of world’s
forests)
• May supply most of the industrial wood in the future
Natural Capital: An Old-Growth Forest
and an Old-Growth Tropical Forest
Managing and Sustaining Forests
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Ecological Importance:
Support food webs,
energy flow, and nutrient
cycling
Protect soils from erosion
Absorb / release water
Influence local and
regional climate
Numerous habitats and
niches
Air purification and store
atmospheric carbon
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Economic Importance:
Fuel wood
Lumber
Paper
Livestock grazing
Mineral extraction
Recreation
Employment
Estimated Annual Global Economic Values
of Ecological Services Provided by Forests
Forest Management
 Even-aged management- trees maintained
and grown to always stand around the same age
and size (industrial forestry); tree plantation with
a desirable species that can be harvested within
6-10 years
 Uneven-aged management- trees of
various ages/sizes; protects diversity; long-term
sustainable production of timber; allows multiple
use for timber, recreation, watershed and wildlife
protection
How trees are managed and harvested
Fig. 11-8 p. 201
Fig. 10-3b, p. 216
How are trees harvested?
Major tree harvesting methods:
 Selective cutting- remove intermediate-mature aged trees
singly or in small groups
High-grading - remove only largest and best trees of desirable
species; many tropical forests
 Shelterwood cutting – removes all mature trees in 2-3
cuttings over a period of time
 Seed-tree cutting- cut all trees but leave behind a few
evenly distributed seed producing trees to regenerate
 Clear-cutting- removes all trees in an area in a single cut
 Strip cutting- clear cutting in smaller strips of land; more
sustainable than clear-cutting
(a) Selective cutting
(b) Clear-cutting
Clear stream
Muddy
stream
(c) Strip cutting
Uncut
Cut 1 year ago
Dirt road
Cut 3–10 years ago
Uncut
Clear stream
 Shelterwood cutting
 Seed-Tree cutting picture
in textbook
Clear-Cut Logging in Washington
State, U.S.
Haiti – Dominican Republic Border
DR
Haiti
Haiti
DR
Roads Lead to Forest Degradation
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Increased erosion and runoff
Habitat fragmentation
Pathways for exotic species
Accessibility to humans
Deforestation is a Major Threat to Forest
Ecosystems
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Increased erosion
Decrease soil fertility
Sediment runoff into waterways
Accelerates flooding
Regional climate change from extensive clearing
Releases CO2 into atmosphere from burning and tree
decay
 Habitat fragmentation
 Loss of biodiversity
 Invasion by
• Nonnative pests
• Disease
• Wildlife species
Solution: Sustainable Forestry
Forest Resources and Management in
the US
Fire, Insects, and Climate Change Can Threaten
Forest Ecosystems
 Introduction of foreign diseases and insects
• Accidental
• Deliberate
 Global warming
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Rising temperatures
Trees more susceptible to diseases and pests
Drier forests: more fires
More greenhouse gases
Insect and Pathogen Threats to U.S. Forests
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Sudden oak death
White pine blister rust
Pine shoot beetle
Beech bark disease
Hemlock woolly
adelgid
See Fig. 11-14 p. 207
Fire, Insects, and Climate Change Can
Threaten Forest Ecosystems
 Surface fires
• Usually burn leaf litter and undergrowth
• May provide food in the form of vegetation that sprouts
after fire
 Crown fires
• Extremely hot: burns whole trees
• Kill wildlife
• Increase soil erosion
Surface and Crown fires
Solutions: How can we reduce damage
due to fires?
 Smokey the Bear educational campaign
 Prescribed fires – intentionally set to prevent underbrush
growth
 Allow fires on public lands to burn
 Protect structures in fire-prone areas
 Thin forests in fire-prone areas – introduction of goats
 Healthy Forests Initiative (2003- U.S.)
• Pros - timber companies can cut down trees for 10 yrs in
natl. forests in return for clearing fire-prone trees and
underbrush
• Cons- removes a lot of fire-resistant large trees; leaves
behind highly flammable smaller trees; loss of habitats
Logging in U.S. National Forests
Advantages:
 Provides local jobs
 Helps meet country’s
timber needs
 Cut areas grow back
 Keeps lumbar and paper
prices down
 Promotes economic
growth in nearby
communities
Disadvantages:
 Provides only 3% of
timber
 Increases environmental
damage
 Hinders recreation
income that can provide
more local jobs and
income than logging jobs.
We Can Reduce the Demand for
Harvested Trees
 Improve the
efficiency of wood
use
 Use recycled paper
products
 Make tree-free paper
• Use agricultural
residues – left overs
from wheat, rice, sugar
• Kenaf- a woody
annual plant that
grows quickly; insect
proof; nitrogen fixer
• Hemp
What Are the Major Threats to Forest
Ecosystems?
 Concept #1: Forest ecosystems provide ecological services
far greater in value than the value of raw materials obtained
from forests.
 Concept #2: Unsustainable cutting and burning of forests,
along with diseases and insects, are the chief threats to
forest ecosystems.
 Concept #3: 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.
CH. 10 notes continued…
Sections 6-10
Julia Butterfly Hill
 Known as an environmental heroine for bringing attention to clearcutting of ancient redwood trees in California.
 Lived in the canopy of a redwood tree, on a small platform for over 2
years as an act of protest and to protect the destruction of the trees.
 Julia lost her battle in saving the entire forest, however, did manage
to save the tree she lived in, “Luna”, and a 60-meter buffer zone
around it.
How Serious Is Tropical Deforestation and How Can It
Be Reduced?
 Concept: We can reduce tropical deforestation
by protecting large forest areas, teaching settlers
about sustainable agriculture and forestry, using
government subsidies that encourage
sustainable forest use, reducing poverty, and
slowing population growth.
Deforestation
Tropical forests- Especially in Central and
South Americas, Indonesia, and Africa; Brazil
contains 40% of the world’s remaining tropical
rain forest
Boreal Forests- Especially in Alaska, Canada,
Scandinavia, and Russia
 Role of deforestation in species’ extinctionmost endangered species, plant for medicinal
purposes.
Natural Capital Degradation: Extreme
Tropical Deforestation in Thailand
Satellite Images of Amazon Deforestation
between 1975 and 2001
Deforestation of Rondonia, Brazil from 1975-2001
Species Diversity
NATURAL CAPITAL
DEGRADATION
Major Causes of the Destruction and Degradation of Tropical Forests
Basic Causes
Secondary Causes
• Not valuing ecological services
• Crop and timber exports
• Government policies
• Poverty
• Population growth
Cattle
ranching
• Roads
• Fires
• Settler farming
• Cash crops
Tree
plantations
• Cattle ranching
• Logging
• Tree plantations
Logging
Cash crops
Settler
farming
Roads
Fires
Fig. 10-15, p. 225
Natural Capital Degradation: Large Areas
of Brazil’s Amazon Basin Are Burned
Natural Capital Degradation: Harmful
Environmental Effects of Deforestation
How to Protect Tropical Forests
 Teach settlers to practice small-scale sustainable
agriculture
 Harvest renewable resources from the forests
 Debt-for-nature swaps- protect forest reserves in return
for foreign aid or debt relief
 Conservation concessions/easements – money for
conservation efforts
 Gentler logging methods- cutting vines prior to cutting
large trees
Individuals Matter: Wangari Maathai and
Kenya’s Green Belt Movement
 Established backyard
small tree nursery
 Organized poor women
 Women paid for each
surviving seedling
planted
• Breaks cycle of poverty
• Reduces environmental
degradation
• People walk less
distance to get fuelwood
 Sparked projects in +30
African countries
How Should We Manage and Sustain
National Parks?
 Concept: Sustaining biodiversity will require
protecting much more of the earth’s remaining
undisturbed land area, starting with the most
endangered biodiversity hot spots.
National Parks
 >1,100 national parks in 120 countries
 Only 1% of parks in developing countries are
protected (lack of funding/education)
 Local people invade parks to survive
Problems Protecting National Parks
 Illegal logging
 Illegal mining
 Wildlife poaching
 Most parks too small to protect large animals
 Invasion of nonnative species
Stresses on U.S. Public Parks
 Biggest problem is popularity
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Noise
Congestion
Pollution
Damage or destruction to vegetation and wildlife
 Damage from nonnative species
 Threatened islands of biodiversity
 Repairs needed to trails and buildings
Natural Capital Degradation: Off-road
Vehicles
Fig. 8-18, p. 165
Solutions for Protection
 Requires action – bottom-up political pressure
 Nature Conservancy – world’s largest private
system of reserves
 Buffer zones around protected areas
 Locals to manage reserves and buffer zones
Designing and Connecting Nature
Reserves
 Large versus small reserves
 The buffer zone concept
• United Nations: 529 biosphere reserves in 105
countries
 Habitat corridors between isolated reserves
• Advantages
• Disadvantages
Example: Alligator Alley
Model Biosphere Reserve
Case Study: Costa Rica
 Superpower of biodiversity
 1963–1983: cleared much of the forest
 1986–2006: forests grew from 26% to 51%
• Goal: to reduce net carbon dioxide emissions to zero by
2021
• Now has conserved 25% of its land, 8 megareserves
• Government eliminated deforestation subsidies ($)
• Paid landowners to maintain and restore tree coverage
• Goal to make sustainable forestry profitable
 2/3 of the billion dollar tourism income comes from ecotourism! (*Interesting that Costa Rica was involved in shark finning
industry??!)
Costa Rica’s Megareserve Network
Fig. 8-21, p. 167
Case Study: Controversy over
Wilderness Protection in the U.S.
 Wilderness: legally set aside land to protect consisting of areas of
“undeveloped land affected primarily by the force of nature, where
man is a visitor and does not remain.”; Minimum size >4,000 km2
• Preserves natural capital
• Centers for evolution
 1964 Wilderness Act
• Legally defined wilderness and est. restrictions
• Protects 106 million acres of federal land
 Roadless Rule (2001)- 1/3 of national forests are off limits to roads,
logging, development of any kind; protects 400,000 sq. miles
 Pressure from oil, gas, mining, and logging
Protecting Global Biodiversity Hotspots
 17 megadiversity countries in tropics and
subtropics
 Two-thirds of biodiversity
 Developing countries economically poor and
biodiversity rich
 Protect biodiversity hotspots
34 Global Hotspots
Fig. 8-22, p. 169
Biodiversity Hotspots in the U.S.
Fig. 8-23, p. 169
Ecological Restoration - process of repairing damage
done to an ecosystem by humans
How we can help speed up the process:
 Restoration- return the ecosystem to it’s most natural state possible
 Rehabilitation- turn a degraded ecosystem back to a functional or
useful form, without trying to get it back to its natural state
(replanting trees that have been clear-cut to avoid erosion)
 Remediation- cleaning up chemical contaminants from a site
 Replacement- replacing a degraded ecosystem with a new one
(Tree farm to replace a degraded forest)
 Creating artificial ecosystems (man-made wetlands)
Science-based Principles for Restoration
 Identify cause of degradation
 Stop abuse by reducing factors
 Reintroduce species if necessary
 Protect area from further degradation
Case Study: Ecological Restoration of
Tropical Dry Forest in Costa Rica
 One of world’s largest ecological restoration
projects
 Restore a degraded tropical dry forest in
Guanacaste NP and reconnect it to adjacent rain
forests
 Involve 40,000 people in the surrounding area –
biocultural restoration
 Ecotourism
Will Restoration Encourage Further
Degradation?
 About 5% of the earth’s land is preserved from
the effects of human activities
 Preventing ecosystem damage is cheaper than
restoration
 Some worry environmental restoration suggests
any harm can be undone
 Scientists disagree
• Restoration badly needed
• Altered restored site better than no restoration
Protecting Ecosystem Services Is
Also an Urgent Priority
 U.N. Millennium Ecosystem Assessment: 2005
• Identify key ecosystem services
• Human activities degrade or overuse 62% of the
earth’s natural services
 Identify highly stressed life raft ecosystems
(well being of humans are affected as ecosystem fails)
ie. Sub-Saharan Africa
What Can You Do?