Case Study: Remember Wolves In Yellowstone

Endangered SpeciesEndangered Species– 1850-1900 two million 1850-1900 two million

wolves were destroyedwolves were destroyed

Keystone SpeciesKeystone Species– Keeps herbivore population Keeps herbivore population

in check (elk, moose)in check (elk, moose)– Vegetation reestablishesVegetation reestablishes– Species diversity expands Species diversity expands

(beavers & ducks return)(beavers & ducks return)

Figure 10-1Figure 10-1

Types of “Protected” Lands in Types of “Protected” Lands in U.S.U.S.

Multiple-use landsMultiple-use lands National ForestNational Forest (U.S.F.S.) (U.S.F.S.)

sustainable yieldsustainable yield multiple usemultiple use used for logging, mining, grazing, used for logging, mining, grazing,

farming, oil, recreation, hunting and farming, oil, recreation, hunting and conservationconservation

National Resource landsNational Resource lands (BLM) (BLM) mostly out west and Alaskamostly out west and Alaska multiple usemultiple use used for mineral and oil extraction/ used for mineral and oil extraction/

grazinggrazing

Types of “Protected” Lands

Moderately Restricted-Use Moderately Restricted-Use LandsLands National Wildlife RefugesNational Wildlife Refuges

(USFWS)(USFWS)522 refuges522 refuges24% designated as wilderness24% designated as wildernessprotect habitatsprotect habitatsoil, farming, hunting, mineral oil, farming, hunting, mineral extraction are allowed as long as extraction are allowed as long as Dept. of Interior says OKDept. of Interior says OK

Types of Protected Types of Protected LandsLands Restricted-Use landsRestricted-Use lands

National Park SystemNational Park System (NPS) (NPS) 55 National Parks and 324 recreation 55 National Parks and 324 recreation

areas, battlefields, memorials, etc. areas, battlefields, memorials, etc. Preserve and interpret the country’s Preserve and interpret the country’s

historic and cultural heritage and historic and cultural heritage and protect wilderness areasprotect wilderness areas

Parks can be used for camping, Parks can be used for camping, hiking, fishing and boatinghiking, fishing and boating

Rec areas: also mining and oilRec areas: also mining and oil 49% of National Park system is 49% of National Park system is

wildernesswilderness

Locations of Parks, Preserves, Forests and Locations of Parks, Preserves, Forests and RefugesRefuges

Types of Types of ForestsForests

Old-growth forestOld-growth forest: : uncut uncut or regenerated forest that has or regenerated forest that has not been seriously disturbed not been seriously disturbed for several hundred yearsfor several hundred years– 22% of world’s forest22% of world’s forest– Hosts many species with Hosts many species with

specialized nichesspecialized niches

Figure 10-5Figure 10-5

Due to human activities over 50% of the earth’s original

forests have been removed.

Types of ForestsTypes of Forests

Second-growth forestSecond-growth forest:: a stand of trees a stand of trees resulting from natural secondary successionresulting from natural secondary succession

Tree plantationTree plantation:: planted stands of a planted stands of a particular tree speciesparticular tree species

Figure 10-6Figure 10-6

Impact of DeforestationImpact of Deforestation

Figure 10-7Figure 10-7

Case Study: Deforestation Case Study: Deforestation and the Fuelwood Crisisand the Fuelwood Crisis

• Almost half the people in the Almost half the people in the developing world face a shortage of developing world face a shortage of fuelwood and charcoalfuelwood and charcoal– In Haiti, 98% of country is deforestedIn Haiti, 98% of country is deforested– MIT scientist has found a way to make MIT scientist has found a way to make

charcoal from spent sugarcanecharcoal from spent sugarcane

Harvesting TreesHarvesting Trees

Figure 10-8Figure 10-8

Increased erosion and runoffHabitat fragmentationPathways for exotic speciesAccessibility to humans

Harvesting TreesHarvesting Trees

• Trees can be harvested Trees can be harvested individually from individually from diverse forests diverse forests ((selective cuttingselective cutting) )

• an entire forest can be an entire forest can be cut down (cut down (clear cuttingclear cutting))

• portions of the forest is portions of the forest is harvested (harvested (strip cuttingstrip cutting))

Figure 10-9Figure 10-9

Harvesting Harvesting TreesTrees

Effects of clear-cutting in the Effects of clear-cutting in the state of Washington, U.S.state of Washington, U.S.

Figures 10-10 and 10-11Figures 10-10 and 10-11

Types and Effects of Types and Effects of Forest FiresForest Fires

• Depending on their intensity, fires can Depending on their intensity, fires can benefit or harm forestsbenefit or harm forests– Burn away flammable ground materialBurn away flammable ground material– Release valuable mineral nutrientsRelease valuable mineral nutrients

Figure 10-13Figure 10-13

FireFireSurface fires Crown fires

Surface fireSurface fire Crown fireCrown fire

Solutions: Solutions: Controversy Over Fire Controversy Over Fire

ManagementManagement• To reduce fire damage:To reduce fire damage:

– Set controlled surface firesSet controlled surface fires– Allow fires to burn on public lands if they Allow fires to burn on public lands if they

don’t threaten life and propertydon’t threaten life and property– Clear small areas around property subject Clear small areas around property subject

to fireto fire

Controversy over Logging Controversy over Logging in U.S. National Forestsin U.S. National Forests

• There has been an There has been an ongoing debate ongoing debate over whether U.S. over whether U.S. national forests national forests should be primarily should be primarily for:for:– TimberTimber– Ecological servicesEcological services– RecreationRecreation– Mix of these usesMix of these uses

Figure 10-14Figure 10-14

Solutions: Solutions: Reducing Demand for Reducing Demand for

Harvest TreesHarvest Trees• Tree harvesting Tree harvesting

reduced by wasting reduced by wasting less wood, making less wood, making paper and charcoal paper and charcoal fuel from fibers that fuel from fibers that don’t come from don’t come from treestrees– Kenaf is promising Kenaf is promising

plant for paper plant for paper productionproduction

Figure 10-15Figure 10-15

American Forests in a American Forests in a Globalized EconomyGlobalized Economy

• Timber from tree plantations in temperate Timber from tree plantations in temperate and tropical countries is decreasing the and tropical countries is decreasing the need for timber production in the U.S.need for timber production in the U.S.– This could help preserve the biodiversity in This could help preserve the biodiversity in

the U.S. by decreasing pressure to clear-cut the U.S. by decreasing pressure to clear-cut old-growth and second-growth forestsold-growth and second-growth forests

– This may lead to private land owners to sell This may lead to private land owners to sell less profitable land to developersless profitable land to developers

– Forest management policy will play a key roleForest management policy will play a key role

CASE STUDY: TROPICAL CASE STUDY: TROPICAL DEFORESTATIONDEFORESTATION

• 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 ratebeing cleared and degraded at a fast rate

Figure 10-16Figure 10-16

CASE STUDY: TROPICAL CASE STUDY: TROPICAL DEFORESTATIONDEFORESTATION

• At least half of the At least half of the world’s terrestrial world’s terrestrial plant and animal plant and animal species live in tropical species live in tropical rain forestsrain 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 cropsranches and crops

Figure 10-17Figure 10-17

Why Should We Care about Why Should We Care about the Loss of Tropical the Loss of Tropical

Forests?Forests?

• About 2,100 of the 3,000 plants About 2,100 of the 3,000 plants identified by the National Cancer identified by the National Cancer Institute as sources of cancer-fighting Institute as sources of cancer-fighting chemicals come from tropical forests.chemicals come from tropical forests.Figure 10-18Figure 10-18

MANAGING AND MANAGING AND SUSTAINING SUSTAINING GRASSLANDSGRASSLANDS

• Almost half of the world’s livestock Almost half of the world’s livestock graze on natural grasslands graze on natural grasslands ((rangelandsrangelands) and managed grasslands ) and managed grasslands ((pasturespastures))

• We can sustain rangeland productivity We can sustain rangeland productivity by controlling the number and by controlling the number and distribution of livestock and by distribution of livestock and by restoring degraded rangelandrestoring degraded rangeland

MANAGING AND MANAGING AND SUSTAINING SUSTAINING GRASSLANDSGRASSLANDS

• Overgrazing Overgrazing (left) occurs (left) occurs when too many when too many animals graze animals graze for too long and for too long and exceed carrying exceed carrying capacity of a capacity of a grassland area.grassland area.

Figure 10-21Figure 10-21

MANAGING AND MANAGING AND SUSTAINING 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

Case Study: Grazing and Case Study: Grazing and Urban Development in the Urban Development in the

American WestAmerican West• Ranchers, ecologists, and Ranchers, ecologists, and

environmentalists joining together to environmentalists joining together to preserve grasslands on cattle ranchespreserve grasslands on cattle ranches– Paying ranchers Paying ranchers conservation easementsconservation easements

(barring future owners from development)(barring future owners from development)– Pressuring government to Pressuring government to zonezone land to land to

prevent development of ecologically prevent development of ecologically sensitive areassensitive areas

NATIONAL PARKSNATIONAL PARKS

• Countries established more than 1,100 Countries established more than 1,100 national parks, but most threatened by national parks, but most threatened by human activitieshuman activities– Local Local people invadepeople invade park for wood, park for wood,

cropland, & other natural resourcescropland, & other natural resources– Loggers, miners, & wildlife poachers also Loggers, miners, & wildlife poachers also

deplete natural resourcesdeplete natural resources– Many are Many are too smalltoo small to sustain large-animal to sustain large-animal

speciesspecies– Many suffer from Many suffer from invasive speciesinvasive species

Case Study: Stresses on Case Study: Stresses on U.S. National ParksU.S. National Parks

• Overused due to Overused due to popularitypopularity

• Inholdings (private Inholdings (private ownership) within ownership) within parks threaten parks threaten natural resourcesnatural resources

• Air pollutionAir pollution

Figure 10-23Figure 10-23

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 economic and political interests oppose doing this.doing this.– Currently 12% of earth’s land is protectedCurrently 12% of earth’s land is protected– Only 5% strictly protected from harmful Only 5% strictly protected from harmful

human activitieshuman activities– Conservation biologists call for full protection Conservation biologists call for full protection

of at least 20% of earth’s land area of at least 20% of earth’s land area representing multiple examples of all biomesrepresenting multiple examples of all biomes

NATURE RESERVESNATURE RESERVES• Large and medium-sized reserves with Large and medium-sized reserves with

buffer zones help protect biodiversity buffer zones help protect biodiversity and can be connected by corridors.and can be connected by corridors.

• Costa Rica has Costa Rica has consolidated its consolidated its parks and reserves parks and reserves into 8 megareserves into 8 megareserves designed to sustain designed to sustain 80% if its 80% if its biodiversity.biodiversity.

Figure 10-10BFigure 10-10B

NATURE RESERVESNATURE RESERVES• A model A model

biosphere biosphere reserve that reserve that contains a contains a protected inner protected inner core surrounded core surrounded by two buffer by two buffer zones that people zones that people can use for can use for multiple use.multiple use.

Figure 10-25Figure 10-25

• 34 hotspots identified by ecologists as important 34 hotspots identified by ecologists as important and endangered centers of biodiversity.and endangered centers of biodiversity.

Figure 10-26Figure 10-26

NATURE RESERVESNATURE RESERVES

• Wilderness is land legally set aside Wilderness is land legally set aside in a large enough area to prevent or in a large enough area to prevent or minimize harm from human minimize harm from human activities.activities.

• Only a small percentage of the land Only a small percentage of the land area of the United States has been area of the United States has been protected as wilderness.protected as wilderness.