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Land Use: Landscapes, Forests, Land Use: Landscapes, Forests, Parks, and ReservesParks, and Reserves
Chapter 13 Botkin and KellerChapter 13 Botkin and Keller
Core Case Study: Core Case Study: Reintroducing Wolves to YellowstoneReintroducing Wolves to Yellowstone
Endangered SpeciesEndangered Species 1850-1900 two million 1850-1900 two million
wolves were destroyed.wolves were destroyed. Keystone SpeciesKeystone Species
Keeps prey away from open Keeps prey away from open areas near stream banks.areas near stream banks.
Vegetation reestablishes.Vegetation reestablishes. Species diversity expands.Species diversity expands.
Figure 10-1Figure 10-1
HUMAN IMPACTS ON TERRESTRIAL HUMAN IMPACTS ON TERRESTRIAL BIODIVERSITYBIODIVERSITY
We have depleted We have depleted and degraded and degraded some of the some of the earth’s earth’s biodiversity and biodiversity and these threats are these threats are expected to expected to increase.increase.
Figure 10-2Figure 10-2
Why Should We Care About Why Should We Care About Biodiversity?Biodiversity?
Use ValueUse Value: For the : For the usefulness in terms usefulness in terms of economic and of economic and ecological services.ecological services.
Nonuse ValueNonuse Value: : existence, aesthetics, existence, aesthetics, bequest for future bequest for future generations.generations.
Figure 10-3Figure 10-3
Fig. 10-4, p. 193
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
Forests
Natural Capital
Fuelwood
Lumber
Pulp to make paper
Mining
Livestock grazing
Recreation
Jobs
EconomicServices
EcologicalServices
Types of ForestsTypes of Forests
Old-growth forestOld-growth forest: uncut : uncut or regenerated forest that or regenerated forest that has not been seriously has not been seriously disturbed for several disturbed for several hundred years.hundred years. 22% of world’s forest.22% of world’s forest. Hosts many species with Hosts many species with
specialized niches.specialized niches. Mostly found in Russia, Mostly found in Russia,
Canada, Brazil, Indonesia, Canada, Brazil, Indonesia, Papua, New Guinea.Papua, New Guinea.
Figure 10-5Figure 10-5
Types of ForestsTypes of Forests
Second-growth forestSecond-growth forest: a stand of trees resulting : a stand of trees resulting from natural secondary succession.from natural secondary succession.
Tree plantationTree plantation: planted stands of a particular tree : planted stands of a particular tree species; highly managed tree are uniform is sizespecies; highly managed tree are uniform is size
Figure 10-6Figure 10-6
Fig. 10-6, p. 195
5
Clear cut
Weak treesremoved
Seedlingsplanted
Years of growth30
1525
10
Fig. 10-7, p. 196
• Decreased soil fertility from erosion
• Runoff of eroded soil into aquatic systems
• Premature extinction of species with specialized niches
• Loss of habitat for native species and migratory species such as birds and butterflies
• Regional climate change from extensive clearing
• Release of CO2 into atmosphere
• Acceleration of flooding
Harmful Environmental EffectsOf Deforestation
Deforestation and the Fuelwood Deforestation and the Fuelwood CrisisCrisis
Almost half the people in the developing Almost half the people in the developing world face a shortage of fuelwood and world face a shortage of fuelwood and charcoal.charcoal. In Haiti, 98% of country is deforested.In Haiti, 98% of country is deforested.
Solutions to deforestation problemSolutions to deforestation problem
1.1. Plant small tree plantations of fast growing Plant small tree plantations of fast growing trees for fuel. Also tree nuts can be used as trees for fuel. Also tree nuts can be used as protein source.protein source.
2.2. Provide cheap, efficient method for cooking Provide cheap, efficient method for cooking such as solar ovens or wind generated such as solar ovens or wind generated electricity.electricity.
3.3. Burn dried roots of gourds.Burn dried roots of gourds.
4.4. MIT scientist has found a way to make MIT scientist has found a way to make charcoal from spent sugarcane.charcoal from spent sugarcane.
Harvesting TreesHarvesting Trees
Building roads into previously inaccessible forests Building roads into previously inaccessible forests paves the way for fragmentation, destruction, and paves the way for fragmentation, destruction, and degradation.degradation.
Figure 10-8Figure 10-8
Harvesting TreesHarvesting Trees
Trees can be harvested Trees can be harvested individually from diverse individually from diverse forests (selective cutting), forests (selective cutting), an entire forest can be cut an entire forest can be cut down (clear cutting), or down (clear cutting), or portions of the forest is portions of the forest is harvested (e.g. strip harvested (e.g. strip cutting).cutting).
Figure 10-9Figure 10-9
Fig. 10-9a, p. 198
(a) Selective cutting
1. Selective cutting: mark & cut individual trees; usually smaller, poorly formed trees. Sometimes trees of specific species are removed like mahogany.
2. Shelterwood cutting: cut dead & less desirable trees; leave others to mature later.
3. Seed- tree cutting: removes all but a few seed trees (mature trees w/ good genetics) to regenerate forest.
Benefits of selective cutting methods
1. Reduces crowding
2. Removes diseased trees
3. Encourages growth of young trees
4. Maintains stand of trees of diff. species
5. Allows forest to be used in multiple ways
Fig. 10-9b, p. 198
(b) Clear-cutting
Disadvantages of clear cutting1. Changes chemical cycling like N22. Run off high3. EROSION!!4. Open to sunlight & rain ground temp. increases5. Exposed soil decays rapidly** Not always bad evaluate on case by case basis.
Fig. 10-9c, p. 198
Uncut(c) Strip cutting
Stream
Uncut
Cut 3–10years ago
Dirt road
Cut 1year ago
Strip Cutting advantages
1. Uncut strips protect trees from wind and direct sunlight
2. Trees provide seeds
3. Minimizes negative aesthetic effects of logging; leaves corridor for wildlife
4. More sustainable yield w/out widespread destruction
Harvesting TreesHarvesting Trees
Effects of clear-cutting in the state of Effects of clear-cutting in the state of Washington, U.S.Washington, U.S.
Figures 10-10 and 10-11Figures 10-10 and 10-11
Fig. 10-11, p. 198
Higher timber yields
Maximum profits in shortest time
Can reforest with fast-growing trees
Short time to establish new stand of trees
Needs less skill and planning
Good for tree species needing full or moderate sunlight
Disadvantages
Reduces biodiversity
Disrupts ecosystem processes
Destroys and fragments wildlife habitats
Leaves large openings
Increases water pollution, flooding, and erosion on steep slopes
Eliminates most recreational value
Trade-Offs
Clear-Cutting Forests
Advantages
SolutionsSolutions
We can use forests We can use forests more sustainably by more sustainably by emphasizing:emphasizing: Economic value of Economic value of
ecological services.ecological services. Harvesting trees no Harvesting trees no
faster than they are faster than they are replenished.replenished.
Protecting old-growth Protecting old-growth and vulnerable areas.and vulnerable areas.
Figure 10-12Figure 10-12
Fig. 10-12, p. 199
• Identify and protect forest areas high in biodiversity
• Grow more timber on long rotations
• Rely more on selective cutting and strip cutting
• Stop clear-cutting on steep slopes
• Cease logging of old-growth forests
• Prohibit 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 forests in estimating their economic value
• Plant tree plantations on deforested and degraded land
• Shift government subsidies from harvesting trees to planting trees
Sustainable Forestry
Solutions
FOREST RESOURCES AND FOREST RESOURCES AND MANAGEMENT IN THE U.S.MANAGEMENT IN THE U.S.
U.S. forests cover more area than in 1920.U.S. forests cover more area than in 1920. Since the 1960’s, an increasing area of old Since the 1960’s, an increasing area of old
growth and diverse second-growth forests growth and diverse second-growth forests have been clear-cut.have been clear-cut. Often replace with tree farms.Often replace with tree farms. Decreases biodiversity.Decreases biodiversity. Disrupts ecosystem processes.Disrupts ecosystem processes.
Types and Effects of Forest FiresTypes and Effects of Forest Fires
Depending on their intensity, fires can benefit or harm Depending on their intensity, fires can benefit or harm forests.forests.
Burn away flammable ground material; maintains habitat for small Burn away flammable ground material; maintains habitat for small mammals provides vegetation/sprouts after fire.mammals provides vegetation/sprouts after fire.
Release valuable mineral nutrients.Release valuable mineral nutrients. Certain plants (like chapparal plants) are regenerated by fire (seeds Certain plants (like chapparal plants) are regenerated by fire (seeds
only germinate after fire (giant sequoia, jack pine)only germinate after fire (giant sequoia, jack pine)Figure 10-13Figure 10-13
Solutions: Solutions: Controversy Over Fire ManagementControversy Over Fire Management
To reduce fire damage:To reduce fire damage: Set controlled surface Set controlled surface
fires.fires. Allow fires to burn on Allow fires to burn on
public lands if they don’t public lands if they don’t threaten life and threaten life and property. property.
Clear small areas Clear small areas around property subject around property subject to fire.to fire.
3 types of fires3 types of fires
Surface firesSurface fires Crown firesCrown fires Ground firesGround fires
Burn away Burn away surface littersurface litter
Most dangerous Most dangerous extremely hotextremely hot
Start as surface Start as surface go undergroundgo underground
Protect from Protect from more destructive more destructive fires laterfires later
Leap from Leap from ground to treetopground to treetop
Smolder for Smolder for days/weeksdays/weeks
releases, releases, nutrients, seeds, nutrients, seeds, controls insects controls insects & pathogens& pathogens
Usually occur Usually occur where buildup of where buildup of ground litterground litter
Common in peat Common in peat bogsbogs
Solutions: Solutions: Controversy Over Fire ManagementControversy Over Fire Management In 2003, U.S. Congress passed the In 2003, U.S. Congress passed the Healthy Healthy
Forest Restoration ActForest Restoration Act:: Allows timber companies to cut medium and Allows timber companies to cut medium and
large trees in 71% of the national forests.large trees in 71% of the national forests. In return, must clear away smaller, more fire-In return, must clear away smaller, more fire-
prone trees and underbrush.prone trees and underbrush. Some forest scientists believe this could increase Some forest scientists believe this could increase
severe fires by removing fire resistant trees and severe fires by removing fire resistant trees and leaving highly flammable slash.leaving highly flammable slash.
Should Logging be allowed in U.S. National Forests?Should Logging be allowed in U.S. National Forests?
Should U.S. national Should U.S. national forests be primarily forests be primarily used for:used for: Timber.Timber. Ecological services.Ecological services. Recreation.Recreation. Mix of these uses.Mix of these uses.
Figure 10-14Figure 10-14
Solutions: Solutions: Reducing Demand for Harvest TreesReducing Demand for Harvest Trees
Tree harvesting can Tree harvesting can be reduced by be reduced by wasting less wood wasting less wood and making paper and making paper and charcoal fuel and charcoal fuel from fibers that do from fibers that do not come from trees.not come from trees. Kenaf is a promising Kenaf is a promising
plant for paper plant for paper production.production.
Figure 10-15Figure 10-15
TROPICAL DEFORESTATIONTROPICAL DEFORESTATION
Large areas of ecologically and Large areas of ecologically and economically important tropical forests are economically important tropical forests are being cleared and degraded at a fast rate.being cleared and degraded at a fast rate.
Figure 10-16Figure 10-16
TROPICAL DEFORESTATIONTROPICAL DEFORESTATION
At least half of the At least half of the world’s terrestrial plant world’s terrestrial plant and animal species live and animal species live in tropical rain forests.in tropical rain forests.
Large areas of tropical Large areas of tropical forest are burned to forest are burned to make way for cattle make way for cattle ranches and crops.ranches and crops.
Figure 10-17Figure 10-17
Why Should We Care about the Loss of Why Should We Care about the Loss of Tropical Forests?Tropical Forests?
About 2,100 of the 3,000 plants identified by the National About 2,100 of the 3,000 plants identified by the National Cancer Institute as sources of cancer-fighting chemicals Cancer Institute as sources of cancer-fighting chemicals come from tropical forests.come from tropical forests.
Figure 10-18Figure 10-18
Causes of Tropical Deforestation and Causes of Tropical Deforestation and DegradationDegradation
Tropical Tropical deforestation deforestation results from a results from a number of number of interconnected interconnected primary and primary and secondary secondary causes.causes.
Figure 10-19Figure 10-19
Fig. 10-20, p. 207
Protect most diverse and endangered areas
Educate settlers about sustainable agriculture and forestry
Phase out subsidies that encourage unsustainable forest use
Add subsidies that encourage sustainable forest use
Protect forests with debt-for-nature swaps and conservation easements
Certify sustainably grown timber
Reduce illegal cutting
Reduce poverty
Slow population growth
Restoration
Reforestation
Rehabilitation of degraded areas
Concentrate farming and ranching on already-cleared areas
Solutions
Sustaining Tropical Forests
Prevention
MANAGING AND SUSTAINING MANAGING AND SUSTAINING GRASSLANDSGRASSLANDS
Almost half of the world’s livestock graze on Almost half of the world’s livestock graze on natural grasslands (rangelands) and natural grasslands (rangelands) and managed grasslands (pastures).managed grasslands (pastures).
We can sustain rangeland productivity by We can sustain rangeland productivity by controlling the number and distribution of controlling the number and distribution of livestock and by restoring degraded livestock and by restoring degraded rangeland.rangeland.
MANAGING AND SUSTAINING MANAGING AND SUSTAINING GRASSLANDSGRASSLANDS
Overgrazing Overgrazing occurs when too occurs when too many animals many animals graze for too long graze for too long and exceed and exceed carrying capacity carrying capacity of a grassland of a grassland area.area.
Figure 10-21Figure 10-21
MANAGING AND SUSTAINING MANAGING AND SUSTAINING GRASSLANDSGRASSLANDS
Example of restored area along the San Example of restored area along the San Pedro River in Arizona after 10 years of Pedro River in Arizona after 10 years of banning grazing and off-road vehicles.banning grazing and off-road vehicles.
Figure 10-22Figure 10-22
NATIONAL PARKSNATIONAL PARKS
Countries have established more than 1,100 Countries have established more than 1,100 national parks, but most are threatened by national parks, but most are threatened by human activities.human activities. Local people invade park for wood, cropland, Local people invade park for wood, cropland,
and other natural resources.and other natural resources. Loggers, miners, and wildlife poachers also Loggers, miners, and wildlife poachers also
deplete natural resources.deplete natural resources. Many are too small to sustain large-animal Many are too small to sustain large-animal
species.species. Many suffer from invasive species.Many suffer from invasive species.
Stresses on U.S. National ParksStresses on U.S. National Parks
Overused due to Overused due to popularity.popularity.
Inholdings (private Inholdings (private ownership) within ownership) within parks threaten parks threaten natural resources.natural resources.
Air pollution.Air pollution.
Figure 10-23Figure 10-23
Fig. 10-24, p. 211
• Integrate plans for managing parks and nearby federal lands
• Add new parkland near threatened parks
• Buy private land inside parks
• Locate visitor parking outside parks and use shuttle buses for entering and touring heavily used parks
• Increase funds for park maintenance and repairs
• Survey wildlife in parks
• Raise entry fees for visitors and use funds for park management and maintenance
• Limit the number of visitors to crowded park areas
• Increase the number and pay of park rangers
• Encourage volunteers to give visitor lectures and tours
• Seek private donations for park maintenance and repairs
Expanding National Parks
Suggestions for sustaining and
NATURE RESERVESNATURE RESERVES
Ecologists call for protecting more land to Ecologists call for protecting more land to help sustain biodiversity, but powerful help sustain biodiversity, but powerful economic and political interests oppose doing economic and political interests oppose doing this.this. Currently 12% of earth’s land area is protected.Currently 12% of earth’s land area is protected. Only 5% is strictly protected from harmful human Only 5% is strictly protected from harmful human
activities.activities. Conservation biologists call for full protection of Conservation biologists call for full protection of
at least 20% of earth’s land area representing at least 20% of earth’s land area representing multiple examples of all biomes.multiple examples of all biomes.
NATURE RESERVESNATURE RESERVES
A model biosphere A model biosphere reserve that reserve that contains a protected contains a protected inner core inner core surrounded by two surrounded by two buffer zones that buffer zones that people can use for people can use for multiple use.multiple use.
Figure 10-25Figure 10-25
NATURE RESERVESNATURE RESERVES
Geographic Information System (GIS) mapping can be used Geographic Information System (GIS) mapping can be used to understand and manage ecosystems.to understand and manage ecosystems. Identify areas to establish and connect nature reserves in Identify areas to establish and connect nature reserves in
large ecoregions to prevent fragmentation.large ecoregions to prevent fragmentation. Developers can use GIS to design housing developments Developers can use GIS to design housing developments
with the least environmental impact.with the least environmental impact.
We can prevent or slow down losses of biodiversity by We can prevent or slow down losses of biodiversity by concentrating efforts on protecting global hot spots where concentrating efforts on protecting global hot spots where significant biodiversity is under immediate threat.significant biodiversity is under immediate threat.
Conservation biologists are helping people in communities find ways to Conservation biologists are helping people in communities find ways to sustain local biodiversity while providing local economic income.sustain local biodiversity while providing local economic income.
34 hotspots identified by ecologists as important and 34 hotspots identified by ecologists as important and endangered centers of biodiversity.endangered centers of biodiversity.
Figure 10-26Figure 10-26
NATURE RESERVESNATURE RESERVES
WildernessWilderness is land legally set aside in a is land legally set aside in a large enough area to prevent or minimize large enough area to prevent or minimize harm from human activities.harm from human activities.
Only a small percentage of the land area of Only a small percentage of the land area of the United States has been protected as the United States has been protected as wilderness.wilderness.
ECOLOGICAL RESTORATIONECOLOGICAL RESTORATION
RestorationRestoration: trying to return to a condition as : trying to return to a condition as similar as possible to original state.similar as possible to original state.
RehabilitationRehabilitation: attempting to turn a : attempting to turn a degraded ecosystem back to being degraded ecosystem back to being functional.functional.
ReplacementReplacement: replacing a degraded : replacing a degraded ecosystem with another type of ecosystem.ecosystem with another type of ecosystem.
Re-creating artificial ecosystemsRe-creating artificial ecosystems: such as : such as artificial wetlands for flood reduction and artificial wetlands for flood reduction and sewage treatment.sewage treatment.
ECOLOGICAL RESTORATIONECOLOGICAL RESTORATION
Five basic science-based principles for Five basic science-based principles for ecological restoration:ecological restoration:
1.1. Identify cause.Identify cause.
2.2. Stop abuse by eliminating or sharply reducing Stop abuse by eliminating or sharply reducing factors.factors.
3.3. Reintroduce species if necessary.Reintroduce species if necessary.
4.4. Protect area form further degradation.Protect area form further degradation.
5.5. Use adaptive management to monitor efforts, Use adaptive management to monitor efforts, assess successes, and modify strategies.assess successes, and modify strategies.
Fig. 10-27, p. 219
• Adopt a forest.
• Plant trees and take care of them.
• Recycle paper and buy recycled paper products.
• Buy sustainable wood and wood products.
• Choose wood substitutes such as bamboo furniture and recycled plastic outdoor furniture, decking, and fencing.
• Restore a nearby degraded forest or grassland.
• Landscape your yard with a diversity of plants natural to the area.
• Live in town because suburban sprawl reduces biodiversity.
Sustaining Terrestrial Biodiversity
What Can You Do?