Chapter 38 Introduction Conservation Biology - Staff Web …staff.bbhcsd.org/gardnere/files/2012/09/Chapter-38-Not… · · 2012-09-19Chapter 38 Conservation Biology Introduction

© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko

PowerPoint Lectures for

Campbell Biology: Concepts & Connections, Seventh EditionReece, Taylor, Simon, and Dickey

Chapter 38Chapter 38 Conservation BiologyIntroduction

Over the past century, wild tiger populations havebeen reduced from about 100,000 to 3,200.

Tigers are threatened by

– declining habitat,

– poaching, and

– human populations encroaching into their habitat.

© 2012 Pearson Education, Inc.

Figure 38.0_1

Chapter 38: Big Ideas

The Loss of Biodiversity Conservation Biologyand Restoration Ecology

Figure 38.0_2

THE LOSS OFBIODIVERSITY


Biodiversity has three levels:

1. ecosystem diversity,

2. species diversity, and

3. genetic diversity.

38.1 Loss of biodiversity includes the loss ofecosystems, species, and genes


As natural ecosystems are lost, so are essentialservices, including

– productivity of natural environments for human foodsupplies and

– the purification of water used by cities.



Figure 38.1A

At present, scientists have described and formallynamed about 1.8 million species.

– It is difficult to estimate species loss.

– Species loss may be 1,000 times higher than at any timein the past 100,000 years.

– Extirpation is the loss of a single population of a species.

– Extinction is the irreversible loss of all populations of aspecies.



Figure 38.1B

0%Birds Amphibians Freshwater

fishes

Reptiles

(N 1,429)

(N 2,689)

(N 4,688)(N 9,933)(N 4,653)

20%

40%

60%

80%

100%

Lowest risk Nearthreatened

Threatened Extinct

Pe

rce

nta

ge

of

sp

ec

ies

as

se

ss

ed

Mammals

Because of the network of community interactionsamong populations of different species within anecosystem,

– the loss of one species

– can negatively affect the species richness of anecosystem.



Figure 38.1C

Genetic diversity of a species is reduced if

– local populations are lost and

– the total number of individuals declines.



Figure 38.1D

38.2 CONNECTION: Habitat loss, invasivespecies, overharvesting, pollution, andclimate change are major threats tobiodiversity

Human alteration of habitats poses the greatestthreat to biodiversity.

Habitation alteration is caused by

– agriculture,

– urban development,

– forestry,

– mining, and

– environmental pollution.


Figure 38.2A

Invasive species rank second behind habitatdestruction as a threat to biodiversity.

Invasive species

– compete with native species,

– prey on native species, and

– parasitize native species.



Figure 38.2B

Overexploitation is the third major threat tobiodiversity. Overharvesting has threatened

– rare trees,

– reduced populations of tigers, Galápagos tortoises,whales, and rhinoceroses, and

– depleted wild populations of game fish.



Figure 38.2C


Human activities produce diverse pollutants that mayaffect ecosystems far from their source.

– The water cycle transfers pollutants from terrestrial toaquatic ecosystems.

– The release of chemicals into the atmosphere promotedthe thinning of the ozone layer.

Biological magnification concentrates synthetictoxins that cannot be degraded by microorganisms.


Figure 38.2D

Figure 38.2E

Concentrationof PCBs

Herringgull eggs124 ppm

Lake trout4.83 ppm

Smelt1.04 ppm

Phytoplankton0.025 ppm

Zooplankton0.123 ppm

38.3 CONNECTION: Rapid warming is changingthe global climate

The scientific debate about global warming is over.

Increased global temperatures caused by risingconcentrations of greenhouse gases are changingclimate patterns with grave consequences.

– Global temperature has risen 0.8°C in the last 100 years.

– 0.6°C of that increase occurred in the last three decades.

– 2 to 4.5°C increases are likely by the end of the 21st century.

– Temperature increases are not distributed evenly.

– Precipitation patterns are changing too.


Figure 38.3A

4.1 4 2 1 0.5 0.2 0.2 0.5 1 2 4 4.1

Figure 38.3B

1938 1981 2005

38.4 CONNECTION: Human activities areresponsible for rising concentrations ofgreenhouse gases

Much of the rapid warming is the result of burningfossil fuels.

– Atmospheric CO2 did not exceed 300 ppm for 650,000years.

– The preindustrial concentration was below 300 ppm.

– Atmospheric CO2 is approximately 385 ppm today.

– High levels of methane and nitrous oxide also trap heat.


Figure 38.4A

400

350

300

250

0 500 1000 1500 2000

600

Year

800

1,000

1,200

1,400

1,600

1,800

2,000

CH

4(p

art

sp

er

billi

on

)

Carbon Dioxide (CO2)

Nitrous Oxide (N2O)

Methane (CH4)

CO

2(p

pm

),N

2O

(part

sp

er

billi

on

)

Figure 38.4B

Photosynthesis Atmosphere

Respiration

Combustion offossil fuels Ocean

38.5 Global climate change affects biomes,ecosystems, communities, and populations

Climate change in western North America hasspawned catastrophic wildfires.


Figure 38.5A


The greatest impact of global climate change isaffecting organisms that live at

– high latitudes and

– high elevations.


Figure 38.5B


Warming oceans threaten coral reef communities.

Earlier arrival of warm temperatures in the spring isdisturbing ecological communities.

– Birds and frogs have begun their breeding periods earlier.

– Migratory birds may experience mismatches, arrivingafter peak food availability has already passed.



Climate change has also

– increased the range of disease-carrying mosquitoes and

– enabled bark beetles to reproduce faster, promoting thedestruction of millions of acres of conifers in westernNorth America.


38.6 EVOLUTION CONNECTION: Climatechange is an agent of natural selection

Phenotypic plasticity

– has minimized the impact of global climate change onsome species, and

– cases of microevolutionary changes have been observed.

– The rapidity of the environmental changes makes itunlikely that evolutionary processes will save manyspecies from extinction.


In Europe, the great tit bird

– has shifted its breeding season earlier, in an example ofdirectional selection,

– favoring individuals that lay their eggs sooner, and

– better matching the earlier emergence of caterpillars.



Figure 38.6A

In the Yukon Territory of Canada,

– where the spring temperatures have increased byabout 2°C,

– red squirrels have begun breeding earlier in the spring.



Figure 38.6B

CONSERVATION BIOLOGYAND RESTORATION ECOLOGY


38.7 Protecting endangered populations is onegoal of conservation biology

Conservation biology is a goal-driven science thatseeks to

– understand and

– counter the rapid loss of biodiversity.

Some conservation biologists direct their efforts at

– protecting populations and

– increasing endangered populations.

– Threats posed by human activities are also assessed.



The black-footed ferret in the United States

– is one of three ferret species worldwide and the onlyferret found in North America,

– was reduced to just 18 individuals,

– has been bred in captivity, and

– was reintroduced into the wild.


Figure 38.7A


In Hawaii, the silversword plants once abundant onthe cinder cone of the volcano Mauna Kea

– were bred in greenhouses and

– reintroduced to reestablish wild populations.


Figure 38.7B

38.8 Sustaining ecosystems and landscapes is aconservation priority

Conservation efforts are increasingly aimed atsustaining

– ecosystems and

– landscapes, a regional assemblage of interactingecosystems.

Landscape ecology is the application of ecologicalprinciples to the study of the structure and dynamicsof a collection of ecosystems.


Figure 38.8A

38.8 Sustaining ecosystems and landscapes is aconservation priority

Edges between ecosystems have distinct sets offeatures and species.

The increased frequency and abruptness of edgescaused by human activities can increase speciesloss.

Movement corridors connecting isolated habitatsmay be helpful to fragmented populations.


Figure 38.8B

Figure 38.8C

38.9 Establishing protected areas slows the loss ofbiodiversity

To establish parks, wilderness areas, and otherlegally protected reserves, conservation biologistsare applying their understanding of

– population,

– ecosystem, and

– landscape dynamics.



Choosing locations for protection often focuses onbiodiversity hot spots, relatively small areas with

– a large number of endangered and threatened species,and

– an exceptional concentration of endemic species, thosethat are found nowhere else.


Figure 38.9A

Equator

Migratory species pose a special problem forconservationists.

– Monarch butterflies occupy many areas.

– Sea turtles travel great distances.



Figure 38.9B

Figure 38.9_UN

38.10 Zoned reserves are an attempt to reverseecosystem disruption

Zoned reserves are undisturbed wildlandssurrounded by buffer zones of compatible economicdevelopment.

Costa Rica has established many zoned reserves.

Ecotourism

– is travel to natural areas for tourism and recreation and

– has become an important source of revenue forconservation efforts.


Figure 38.10A

National Parks and Reserves

COSTA RICA

NICARAGUA

PANAMA

Figure 38.10B

38.11 CONNECTION: The Yellowstone to YukonConservation Initiative seeks to preservebiodiversity by connecting protected areas

The Yellowstone to Yukon Conservation Initiative

– created a string of parks and reserves in a 3,200-kmwildlife corridor,

– extends from Alaska south across Canada to northernWyoming,

– included the reintroduction of wolf populations,considered a keystone species in this region, and

– sparked angry protests from some ranchers.


Figure 38.11A

YUKONTERRITORY

Whitehorse

MA

CK

EN

ZIE

MO

UN

TA

INS

NORTHWEST TERRITORIES

ALBERTA

RO

CK

Y

MO

UNTA

INS

BRITISHCOLUMBIA

WASHINGTON

OREGON

MONTANA

Calgary

Bozeman

Spokane

Vancouver

CO

LUM

BIA

MO

UNTA

INS

PACIFICOCEAN

Jackson

IDAHO WYOMING

Figure 38.11B Figure 38.11C

38.12 CONNECTION: The study of how to restoredegraded habitats is a developing science

Restoration ecology uses ecological principles torestore degraded areas to their natural state, aprocess that may include

– detoxifying polluted ecosystems,

– replanting native vegetation, and

– returning waterways to their natural course.


38.12 CONNECTION: The study of how to restoredegraded habitats is a developing science

Large-scale restoration projects attempt to restoredamaged landscapes.

The Kissimmee River Restoration Project in Floridais

– restoring river flow and wetlands and

– improving wildlife habitat.


Figure 38.12A

Widenedcanal

Water controlstructure remaining

Water controlstructure removed

River channelrestored

Phase 1completed

Water controlstructure tobe removed inPhase 2

Miles

KissimmeeRiver

Floodplain

Canal backfilled

FLORIDA

0 10

Ksis

im

R

mee

iver

Figure 38.12B

Former canal

38.13 Sustainable development is an ultimate goal

Sustainable development

– seeks to improve the human condition while conservingbiodiversity,

– depends on increasing and applying ecologicalknowledge, and

– values our linkages to the biosphere.


38.13 Sustainable development is an ultimate goal

We are most likely to

– save what we appreciate and

– appreciate what we understand.

Now is the time to

– aggressively pursue more knowledge about life and

– work toward long-term sustainability.


Figure 38.13

You should now be able to

1. Describe the three components of biodiversity.

2. Describe the greatest current threats to biodiversity,providing examples of each.

3. Describe the process of biological magnification.

4. Describe the causes and consequences of globalwarming.

5. Explain why the efforts to save the black-footedferret and silversword plant from extinction are agood model for future conservation efforts.



6. Describe the goals of landscape ecology. Describethe significance of edges and movement corridorsin maintaining biodiversity.

7. Describe the significance of biodiversity hotspots.

8. Explain how zoned reserves are being used toprotect ecosystems.

9. Describe the goals of the Yukon to YellowstoneInitiative.



10. Describe the goals and methods of restorationecology.

11. Explain why sustainable development should bethe ultimate goal for the long-term maintenance ofhuman societies and the ecosystems that supportthem.


Figure 38.UN01

Ecosystemdiversity

Speciesdiversity

Geneticdiversity

Figure 38.UN02

Conservationbiology

seeks to conserve may involve

ecosystems andlandscapes

(c)

(a)

attemptto restore

naturereserves

may be

restorationprojects

which uses

to

detoxify orreplenish degraded

ecosystems

FLORIDA

ATLANTICOCEAN

(d)

sustainabledevelopment

which support

GULF OFMEXICO

may beprotected in

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Chapter 38 Introduction Conservation Biology - Staff Web …staff.bbhcsd.org/gardnere/files/2012/09/Chapter-38-Not… · · 2012-09-19Chapter 38 Conservation Biology Introduction