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Chapter 30Chapter 30
ConservationConservation
Chapter 30 2
What Is Biodiversity?What Is Biodiversity?Biodiversity Biodiversity refers to the variety of living refers to the variety of living
organisms on the planet, including their organisms on the planet, including their genes, ecosystems, and community genes, ecosystems, and community interactionsinteractions
The goal of The goal of conservation biology conservation biology is to preserve is to preserve biodiversity bybiodiversity by• Preventing extinction of species caused by Preventing extinction of species caused by
human activityhuman activity• Maintaining large population numbers that Maintaining large population numbers that
sustain genetic diversitysustain genetic diversity• Preserving community interactions that sustain Preserving community interactions that sustain
ecosystemsecosystems
Chapter 30 3
Ecosystem ServicesEcosystem Services
Why preserve ecosystems?Why preserve ecosystems?• Worth preserving for own sakeWorth preserving for own sake• They support us by providing They support us by providing ecosystem ecosystem
servicesservices
Chapter 30 4
Chapter 30 5
Ecosystem ServicesEcosystem ServicesEcosystem servicesEcosystem services include processes through include processes through
which natural ecosystems sustain human lifewhich natural ecosystems sustain human life• Purify water and airPurify water and air• Replenish oxygenReplenish oxygen• Pollinate plants and disperse seedsPollinate plants and disperse seeds
Provide wildlife habitatProvide wildlife habitatDecompose wastesDecompose wastesControl erosion and floodingControl erosion and floodingControl pestsControl pestsProvide recreationProvide recreation
Chapter 30 6 Direct BenefitsDirect Benefits
Hunting and fishing for Hunting and fishing for foodfood
Harvesting wood for Harvesting wood for heat and cookingheat and cooking
Extracting medicines Extracting medicines from plantsfrom plants• Example: Tamiflu is Example: Tamiflu is
based on chemicals based on chemicals extracted from the extracted from the Chinese star aniseChinese star anise
Chapter 30 7 Indirect BenefitsIndirect Benefits
Indirect ecosystem services have even Indirect ecosystem services have even greater impact on human welfare and greater impact on human welfare and includeinclude• Soil formationSoil formation• Erosion and soil controlErosion and soil control• Climate regulationClimate regulation• Genetic resourcesGenetic resources• RecreationRecreation
Chapter 30 8
Indirect BenefitsIndirect Benefits
Soil formationSoil formation• Rich soils that sustain agriculture can take Rich soils that sustain agriculture can take
thousands of years to build upthousands of years to build up• Soil harbors nitrogen-fixing bacteria and Soil harbors nitrogen-fixing bacteria and
decomposers that break down wastes and decomposers that break down wastes and recycle nutrientsrecycle nutrients
Chapter 30 9
Indirect BenefitsIndirect Benefits
Plants prevent erosion and provide flood Plants prevent erosion and provide flood control bycontrol by• Blocking wind that blows away loose soilBlocking wind that blows away loose soil• Providing roots that stabilize soil and enhance Providing roots that stabilize soil and enhance
its capacity to hold waterits capacity to hold water
The consequences of destroying riverside The consequences of destroying riverside forest and coastal marshes have been seen forest and coastal marshes have been seen in recent floods in the U.S.in recent floods in the U.S.
Chapter 30 10
1993 – Missouri River
Chapter 30 11
2005 Hurricane Katrina – New Orleans
Chapter 30 12 Indirect BenefitsIndirect Benefits
Plants regulate climatePlants regulate climate• Provide shade, reducing temperatureProvide shade, reducing temperature• Provide windbreaksProvide windbreaks• Buffer against global warming by absorbing COBuffer against global warming by absorbing CO2 2
• Return water to the atmosphere through Return water to the atmosphere through transpiration, influencing water cyclestranspiration, influencing water cycles
Plants harbor genetic resources Plants harbor genetic resources • Genes identified in wild plants may be Genes identified in wild plants may be
transferred into crops to enhance productivity transferred into crops to enhance productivity and disease resistanceand disease resistance
Chapter 30 13 Indirect BenefitsIndirect Benefits
RecreationRecreation• 350 million people visit U.S. national parks and 350 million people visit U.S. national parks and
protected refuges annuallyprotected refuges annually• ““Ecotourism” is an expanding industryEcotourism” is an expanding industry
Chapter 30 14
Ecological EconomicsEcological Economics
Ecological economics Ecological economics evaluates the trade-evaluates the trade-offs that occur when natural ecosystems offs that occur when natural ecosystems are damaged during human profit-making are damaged during human profit-making activitiesactivities
One application is to weigh the pros and One application is to weigh the pros and cons of draining a wetland to irrigate cropscons of draining a wetland to irrigate crops
Possible loss of benefits?Possible loss of benefits?
Chapter 30 15 Ecological EconomicsEcological Economics
Also used to estimate costs of disasters that Also used to estimate costs of disasters that could have been prevented or reduced by could have been prevented or reduced by maintaining natural ecosystemsmaintaining natural ecosystems• $12 billion in damage from the 1993 Missouri $12 billion in damage from the 1993 Missouri
River flood River flood • $100 billion in damages associated with $100 billion in damages associated with
Hurricane Katrina in 2005 Hurricane Katrina in 2005
Chapter 30 16
Ecological EconomicsEcological Economics
Used in government planningUsed in government planningNew York City gets much of its water from New York City gets much of its water from
the Catskills Mountainsthe Catskills MountainsEconomic analysis revealed that protecting Economic analysis revealed that protecting
the mountain ecosystem, which purifies the the mountain ecosystem, which purifies the water naturally, costs less than building a water naturally, costs less than building a water purification plantwater purification plant
Chapter 30 17 ExtinctionExtinction
Extinction is a process that occurs slowly at Extinction is a process that occurs slowly at a a background extinction ratebackground extinction rate under natural under natural conditions conditions
The fossil record suggests that five previous The fossil record suggests that five previous mass extinctionsmass extinctions led to the eradication of led to the eradication of many life forms within short time periodsmany life forms within short time periods
Possible causes of mass extinctions includePossible causes of mass extinctions include• Meteor impactsMeteor impacts• Rapid climate changesRapid climate changes
Chapter 30 18
ExtinctionExtinction
Most biologists believe that human activities Most biologists believe that human activities are now causing a sixth mass extinctionare now causing a sixth mass extinction
The current extinction rate is 100 to 1000 The current extinction rate is 100 to 1000 times the background rate predicted in the times the background rate predicted in the absence of peopleabsence of people
Chapter 30 19 ExtinctionExtinction
Many species may have become extinct Many species may have become extinct before being discovered, as suggested by before being discovered, as suggested by two newly described speciestwo newly described species• The Australian snubnose dolphin and the The Australian snubnose dolphin and the
Aftrican kipunji monkey Aftrican kipunji monkey • Only about 1000 of each remainOnly about 1000 of each remain• Both are threatened by human activity and Both are threatened by human activity and
might have become extinct before discoverymight have become extinct before discovery
Chapter 30 20
Chapter 30 21 Threatened SpeciesThreatened Species
Increasing numbers of species are Increasing numbers of species are threatenedthreatened with with extinctionextinction
Depending on the likelihood of extinction in the Depending on the likelihood of extinction in the near future, threatened species are described as near future, threatened species are described as critically endangeredcritically endangered, , endangeredendangered,, or or vulnerablevulnerable
As of 2004 there are 15,589 threatened species As of 2004 there are 15,589 threatened species • 12% of all birds12% of all birds• 23% of all mammals23% of all mammals• 32% of all amphibians32% of all amphibians• 42% of all turtles and tortoises42% of all turtles and tortoises
Chapter 30 22
Mammals
Chapter 30 23 Threats to BiodiversityThreats to Biodiversity
Two processes are fueling the decline in Two processes are fueling the decline in Earth’s biodiversityEarth’s biodiversity• Increasing use of resources to support human Increasing use of resources to support human
lifestyleslifestyles• Human activities that destroy habitats and pollute Human activities that destroy habitats and pollute
the environmentthe environment
Comparison of humanity’s footprint with Comparison of humanity’s footprint with Earth’s biocapacity in 2002Earth’s biocapacity in 2002• Footprint: 5.4 acres (24 in U.S.)Footprint: 5.4 acres (24 in U.S.)• Biocapacity: 4.5Biocapacity: 4.5
Chapter 30 24 Earth’s “Ecological Capital”Earth’s “Ecological Capital”
Human depletion of the Earth’s ecological Human depletion of the Earth’s ecological capital can be illustrated by estimatingcapital can be illustrated by estimating• Ecological footprint: Ecological footprint: surface area required to surface area required to
produce our resources and absorb our wastesproduce our resources and absorb our wastes• Biocapacity: Biocapacity: actual and available sustainable actual and available sustainable
resources and waste-absorbing capacity of resources and waste-absorbing capacity of EarthEarth
Chapter 30 25 Earth’s “Ecological Capital”Earth’s “Ecological Capital”
Humans have exceeded the Earth’s Humans have exceeded the Earth’s biocapacity by 20%biocapacity by 20%
““Ecological deficit” degrades ecosystems, Ecological deficit” degrades ecosystems, drawing on “ecological capital”drawing on “ecological capital”
Deficit will grow as living standards of less-Deficit will grow as living standards of less-developed nations increasedeveloped nations increase
Chapter 30 26
Chapter 30 27 Human Threats to BiodiversityHuman Threats to Biodiversity
Humans threaten biodiversity in a number of Humans threaten biodiversity in a number of waysways• Habitat destructionHabitat destruction• OverexploitationOverexploitation• Harmful interaction with invasive speciesHarmful interaction with invasive species• PollutionPollution• Global warmingGlobal warming
Chapter 30 28 Habitat DestructionHabitat Destruction
Farming activities over past 11,000 years Farming activities over past 11,000 years have led to loss of ½ of total forest coverhave led to loss of ½ of total forest cover
½ of tropical rain forests cut down over past ½ of tropical rain forests cut down over past 50 years for50 years for• WoodWood• Conversion to agricultureConversion to agriculture
Chapter 30 29
Chapter 30 30 Habitat DestructionHabitat Destruction
Other activities that lead to habitat destructionOther activities that lead to habitat destruction• Damming riversDamming rivers• Draining wetlandsDraining wetlands• Building roads and housingBuilding roads and housing• IndustryIndustry
Some species need thousands of acres to find Some species need thousands of acres to find food and breedfood and breed
Habitat fragmentation Habitat fragmentation threatens wildlife by threatens wildlife by splitting up natural ecosystemssplitting up natural ecosystems
Chapter 30 31
Chapter 30 32 Habitat DestructionHabitat Destruction
Preserves created to protect endangered Preserves created to protect endangered species must support a species must support a minimum viable minimum viable population (MVP)population (MVP)• Smallest natural population that can persist in Smallest natural population that can persist in
spite of natural events (disease, fires, floods)spite of natural events (disease, fires, floods)
Chapter 30 33 OverexploitationOverexploitation
Overexploitation Overexploitation involves hunting or harvesting involves hunting or harvesting natural populations at rates that exceed natural populations at rates that exceed replenishmentreplenishment
Impacts 30% of threatened birds and Impacts 30% of threatened birds and mammalsmammals
Over fishing and overharvesting threatens Over fishing and overharvesting threatens many marine life formsmany marine life forms• Cod, sharks, red snapper, swordfish, tuna, Cod, sharks, red snapper, swordfish, tuna,
turtlesturtlesUnintentional trapping in fishing nets Unintentional trapping in fishing nets
threatensthreatens• Whales, porpoises, dolphinsWhales, porpoises, dolphins
Chapter 30 34
Chapter 30 35 Invasive SpeciesInvasive Species
When non-native species are introduced into an When non-native species are introduced into an area, they can becomes area, they can becomes invasiveinvasive
Invasive Invasive species can displace native species species can displace native species and disrupt community interactions throughand disrupt community interactions through• Competion for food and/or habitatCompetion for food and/or habitat• Direct predationDirect predation
Island and lake communities are particularly Island and lake communities are particularly vulnerable to invasive speciesvulnerable to invasive species• The mongoose, imported to Hawaii to control rats, The mongoose, imported to Hawaii to control rats,
now threatens birdsnow threatens birds• The Nile perch, introduced to Lake Victoria for The Nile perch, introduced to Lake Victoria for
fishing, now threatens 200 other speciesfishing, now threatens 200 other species
Chapter 30 36
Chapter 30 37
Chapter 30 38
PollutionPollution
Pollutants that threaten biodiversity include Pollutants that threaten biodiversity include synthetic chemicalssynthetic chemicals• Plasticizers, flame retardants, pesticidesPlasticizers, flame retardants, pesticides
Enter air, water, soilEnter air, water, soilAccumulate in animal tissues, disrupting Accumulate in animal tissues, disrupting
development or reproductiondevelopment or reproduction
Chapter 30 39 PollutionPollution
Accumulation of high levels of some natural Accumulation of high levels of some natural substances are also threatssubstances are also threats• Mercury, lead, and arsenic from mining and Mercury, lead, and arsenic from mining and
manufacturing are toxic manufacturing are toxic • Oxidized nitrogen and sulfur released by Oxidized nitrogen and sulfur released by
burning fossil fuels lead to acid rainburning fossil fuels lead to acid rain
Chapter 30 40 Global WarmingGlobal Warming
Burning of fossil fuels and deforestation has led Burning of fossil fuels and deforestation has led to increased atmospheric COto increased atmospheric CO22 levels levels
Increase is associated with rising global Increase is associated with rising global temperaturestemperatures
Global warming is associated with dramatic Global warming is associated with dramatic changeschanges• Many species are shifting ranges toward polesMany species are shifting ranges toward poles• Plants and animals initiate springtime activities Plants and animals initiate springtime activities
earlier each yearearlier each year• Glaciers, ice shelves, and ice caps are meltingGlaciers, ice shelves, and ice caps are melting• Extreme weather patternsExtreme weather patterns
Chapter 30 41 Global WarmingGlobal Warming
Leads to habitat destructionLeads to habitat destructionRapid pace of global warming taxes abilities Rapid pace of global warming taxes abilities
of species to adapt to changing conditions of species to adapt to changing conditions through natural selectionthrough natural selection
By 2050: estimated that 1 million species will By 2050: estimated that 1 million species will be threatened with extinction due to global be threatened with extinction due to global warmingwarming
Chapter 30 42
Conservation BiologyConservation Biology
The goals of conservation biology are toThe goals of conservation biology are to• Understand the impact of human activities on Understand the impact of human activities on
species, populations, communities, and species, populations, communities, and ecosystemsecosystems• Preserve and restore natural communitiesPreserve and restore natural communities• Reverse loss of biodiversity caused by Reverse loss of biodiversity caused by
humanshumans• Foster sustainable use of Earth’s resourcesFoster sustainable use of Earth’s resources
Chapter 30 43
Integrated Scientific ApproachIntegrated Scientific Approach
Conservation requires integrated efforts of Conservation requires integrated efforts of many many • Ecologists, geneticists, botanists, zoologistsEcologists, geneticists, botanists, zoologists• Wildlife managersWildlife managers• Environmental lawyersEnvironmental lawyers• Ecological economistsEcological economists• Social scientistsSocial scientists• EducatorsEducators• Individuals making choices and taking actionIndividuals making choices and taking action
Chapter 30 44
Conserving Wild EcosystemsConserving Wild Ecosystems
Each threatened species faces different Each threatened species faces different survival challenges, requiring unique survival challenges, requiring unique conservation effortsconservation efforts
One approach involves the creation of One approach involves the creation of core core reserves and corridorsreserves and corridors
Core reserves Core reserves are protected natural areas are protected natural areas that preserve all levels of biodiversitythat preserve all levels of biodiversity• Exclude all but low-impact human activitiesExclude all but low-impact human activities• Must provide a Must provide a minimal critical areaminimal critical area that can that can
sustain a minimum viable populationsustain a minimum viable population
Chapter 30 45 Conserving Wild EcosystemsConserving Wild Ecosystems
Wildlife corridors Wildlife corridors are are strips of protected strips of protected land that link core land that link core reservesreserves
Allow safe passage Allow safe passage of animals between of animals between habitats separated habitats separated by human by human activities, activities, increasing size of increasing size of reservesreserves
Chapter 30 46
Conserving Wild EcosystemsConserving Wild Ecosystems
Reserves and corridors Reserves and corridors ideally ideally should be should be surrounded by buffer zones that prohibit surrounded by buffer zones that prohibit clear-cutting, mining, freeways and clear-cutting, mining, freeways and housinghousing
However, a San Diego freeway underpass However, a San Diego freeway underpass currently serves as a corridor for cougarscurrently serves as a corridor for cougars
Chapter 30 47
Chapter 30 48
SustainabilitySustainability
Sustainable living and development promote Sustainable living and development promote long-term ecological and human well-beinglong-term ecological and human well-being
Sustainability requiresSustainability requires• Diverse communities and interactionsDiverse communities and interactions• Populations stabilized below the carrying Populations stabilized below the carrying
capacity of the environmentcapacity of the environment• Recycling and efficient use of raw materialsRecycling and efficient use of raw materials• Reliance on renewable sources of energyReliance on renewable sources of energy
Chapter 30 49 SustainabilitySustainability
Sustainable development Sustainable development fulfills present fulfills present needs without compromising the ability of needs without compromising the ability of future generations to meet their needsfuture generations to meet their needs
Current commercial fishing practices (e.g. Current commercial fishing practices (e.g. netting, trawling) endanger many speciesnetting, trawling) endanger many species
Sustainable fishing would requireSustainable fishing would require• Preservation of spawning groundsPreservation of spawning grounds• Limiting fish catchesLimiting fish catches• Developing technologies to avoid damagDeveloping technologies to avoid damag
Chapter 30 50 Biosphere ReservesBiosphere Reserves
One approach to meeting the needs of One approach to meeting the needs of humans in a sustainable manner has been humans in a sustainable manner has been the creation of a world network of the creation of a world network of biosphere biosphere reservesreserves
Part of a program run by the United NationsPart of a program run by the United NationsThe goals are toThe goals are to• Maintain biodiversityMaintain biodiversity• Evaluate techniques for sustaining Evaluate techniques for sustaining
development while preserving local cultural development while preserving local cultural valuesvalues
Chapter 30 51 Biosphere ReservesBiosphere Reserves
Each biosphere consists ofEach biosphere consists of• A central A central core reserve: core reserve: protected area allowing protected area allowing
research and sustainable usesresearch and sustainable uses• A surrounding A surrounding buffer zonebuffer zone: permits low impact : permits low impact
activity and developmentactivity and development• An outer An outer transition areatransition area: supports settlements, : supports settlements,
tourism, fishing, agriculturetourism, fishing, agriculture
Chapter 30 52
Chapter 30 53
Chapter 30 54 Sustainable AgricultureSustainable Agriculture
Major habitat loss has occurred due to the Major habitat loss has occurred due to the conversion of natural ecosystems to conversion of natural ecosystems to agricultural use agricultural use
Many current agricultural practices are Many current agricultural practices are unsustainable approachesunsustainable approaches• Failure to plant following harvest leads to soil Failure to plant following harvest leads to soil
erosionerosion• Herbicides and insecticides pollute, and kill Herbicides and insecticides pollute, and kill
natural predatorsnatural predators• Irrigation practices deplete underground water Irrigation practices deplete underground water
suppliessupplies
Chapter 30 55
Sustainable AgricultureSustainable Agriculture
Many farmers now realize that sustainable Many farmers now realize that sustainable practices save money and preserve landpractices save money and preserve land• No-till No-till cropping leaves remnants of harvested cropping leaves remnants of harvested
crops as mulchcrops as mulch• Organic farming excludes herbicides, Organic farming excludes herbicides,
pesticides and fertilizerspesticides and fertilizers• Natural predators used to control pestsNatural predators used to control pests• Planting diverse crops reduces pest and Planting diverse crops reduces pest and
disease infestationsdisease infestations
Chapter 30 56
Chapter 30 57 Human Population GrowthHuman Population Growth
Most of the world’s human population lives Most of the world’s human population lives in less-developed countries and lacks basic in less-developed countries and lacks basic amenitiesamenities
75-80 million people are added to the planet 75-80 million people are added to the planet every yearevery year
Growth rate is incompatible with a Growth rate is incompatible with a sustainable increase in quality of life for the sustainable increase in quality of life for the present 6.5 billion inhabitantspresent 6.5 billion inhabitants
Chapter 30 58
Lifestyle and TechnologiesLifestyle and Technologies
Changes that humans can make to develop Changes that humans can make to develop sustainable approachessustainable approaches• Make responsible reproductive choicesMake responsible reproductive choices• Reduce energy consumption and use of fossil Reduce energy consumption and use of fossil
fuelsfuels• Develop and use energy-saving technologiesDevelop and use energy-saving technologies• Rely on renewable energy sourcesRely on renewable energy sources• Make consumer choices that promote Make consumer choices that promote
sustainable practicessustainable practices
Chapter 30Chapter 30
The EndThe End
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