chapter 38 conservation biology - napa valley collegenapavalley.edu/people/briddell/documents/biol...

Copyright © 2009 Pearson Education, Inc.

PowerPoint Lectures for

Biology: Concepts & Connections, Sixth Edition

Campbell, Reece, Taylor, Simon, and Dickey

Chapter 38 Conservation Biology

Lecture by Brian R. Shmaefsky


Introduction: Saving the Tiger

Conservation biology is a goal-oriented science

– It seeks to counter the biodiversity crisis

– It can focus on a single species

– It can also protect many species at once by preserving habitats and ecosystems

Conservation biology touches all levels of ecology

– From a single tiger

– To the forest it roams


THE BIODIVERSITY CRISIS


38.1 Biodiversity is a vital resource that is being lost

Scientists estimate that the Earth has anywhere from 1.8 to 200 million species

– It is difficult to estimate species loss

– Species loss may be 1,000 times higher than in the past 100,000 years


Scientists are concerned about the ecological changes that underlie biodiversity loss

– Ecologists point out the “services” provided by the biodiversity of ecosystems

38.1 Biodiversity is a vital resource that is being lost


38.2 Biodiversity includes genetic, species, and ecosystem diversity

Biodiversity has three levels

– Genetic diversity

– Species diversity

– Ecosystem diversity


Endangered species

– One that is “in danger of extinction throughout all or a significant portion of its range”

– Protected by Endangered Species Act

Threatened species

– Those likely to become endangered in the foreseeable future



93% of coral reefs were damaged by human activities

40–50% of the reefs are home to one-third of marine fish species

These fish could be lost in the next 30 to 40 years


Video: Coral Reef

38_02BCoralReef_SV.mpg


38.3 Habitat destruction, invasive species, and overexploitation are major threats to biodiversity

Human alteration of habitats poses the greatest threat to biodiversity

Habitation alteration is caused by

– Agriculture

– Urban development

– Forestry

– Mining

– Environmental pollution


Invasive species rank behind habitat destruction as a threat to biodiversity

Invasive species

– Compete with native species

– Prey on native species

– Parasitize native species



Overexploitation is the third major threat to biodiversity

– Overharvesting has threatened

– Rare trees

– Fish

– Bison

Hunting of wild animals for bushmeat is depleting biodiversity worldwide



38.4 CONNECTION: Pollution of the environment compounds our impact on other species

The global water cycle can transport pollutants

– Pesticides used on land

– Sulfur and nitrogen oxides emitted into the atmosphere

Gradually thinning ozone layer

– Release of chlorofluorocarbons from aerosol cans and manufacturing

Nutrient pollution from fertilizer and wastes

– Linked to summer “dead zone” in the Gulf of Mexico


Pollutants in a food chain can lead to biological magnification

38.4 CONNECTION: Pollution of the environment compounds our impact on other species

Concentrationof PCBs

Herringgull eggs124 ppm

Lake trout4.83 ppm

Smelt1.04 ppm

Zooplankton0.123 ppm

Phytoplankton0.025 ppm


38.5 CONNECTION: Rapid warming is changing the global climate

The scientific debate about global warming is over

– 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

Global warming most evident in arctic

– Shrinking sea ice

– Thinning ice sheets

– Melting permafrost

–2 –1.6 –1.2 –.8 –.4 –.2 .2 .4 .8 1.61.2 2.1

200519811938


38.6 CONNECTION: Human activities are responsible for rising concentrations of greenhouse gases

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

Atmospheric CO2 is approximately 385 ppm today

High levels of methane and nitrous oxide also trap heat

15001000 2000

Year

1000

2000

1800

1600

1400

1200

800

600

5000

250

400

350

300

Carbon Dioxide (CO2)

Methane (CH4)

Nitrous Oxide (N2O)

CO

2(p

pm

), N

2O

(p

pb

)

CH

4(p

pb

)

Atmosphere

Ocean

Photosynthesis

Fossilfuel


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

Terrestrial biomes determined by temperature and rainfall

– Changing as a consequence of global warming

– Distributions of populations and species also changing

– Disappearance of many species being caused by changing climate

– Climate change affects seasonal events in some plants and animals


38.8 EVOLUTION CONNECTION: Global climate change is an agent of natural selection

Global climate change drives natural selection of some organisms

– Most of this selection is attributed to phenotypic plasticity

– Altering phenotype in response to environmental conditions

– Within the normal range of genetic expression

– Can involve genetic shifts that change a species

– Prevents extinction of some species


Red squirrels in Canada

– Natural selection to coordinate breeding time with food availability

38.8 EVOLUTION CONNECTION: Global climate change is an agent of natural selection


CONSERVATION BIOLOGY AND RESTORATION ECOLOGY


38.9 Protecting endangered populations is one goal of conservation biology

Habitat loss

– Population fragmentation

– A harmful effect of habitat loss

– Splitting and isolation of portions of populations

– Can lead to extinctions


Proactive conservation strategies attempt to stop declines in populations

– Recovery of the red-cockaded woodpecker

– From near-extinction to sustainable populations

– Results from providing its key habitat factors

38.9 Protecting endangered populations is one goal of conservation biology


38.10 Sustaining ecosystems and landscapes is a conservation priority

Conservation biology priority

– Past efforts

– Saving individual species

– Today

– Biodiversity of ecosystems

Landscape ecology

– Dynamics of a collection of ecosystems


Edges can fragment ecosystems

Fragmentation is corrected with movement corridors

38.10 Sustaining ecosystems and landscapes is a conservation priority


38.11 Protected areas are established to slow the loss of biodiversity

Conservation biology focuses on biodiversity hot spots

– Have a large number of endangered and threatened species

– Have a concentration of endemic species

Hot spot designation favors the most noticeable organisms

Equator


Migratory species pose a special problem for conservationists

– Monarch butterflies occupy many areas

– Sea turtles travel great distances

Reserves are set up to protect biodiversity

– 7% of world’s land is in various forms of reserves

38.11 Protected areas are established to slow the loss of biodiversity


38.12 Zoned reserves are an attempt to reverse ecosystem disruption

Zoned reserve

– Extensive region of land with one or more areas undisturbed by humans

– Contributes to sustainable development

– Long-term prosperity of human societies and the ecosystems

– Provide an economic base for people living there


Zoned reserves are used in Costa Rican conservation

38.12 Zoned reserves are an attempt to reverse ecosystem disruption

National parkland

Buffer zone

Pacific Ocean

Caribbean SeaNicaragua

CostaRica


38.13 CONNECTION: The Yellowstone to Yukon Conservation Initiative seeks to preserve biodiversity by connecting protected areas

Yellowstone to Yukon Conservation Initiative

– Created a string of parks and reserves

– 3,200-km wildlife corridor

– Alaska across Canada to northern Wyoming

– Included introduction of wolf populations

– Sparked angry protests from ranchers

NORTHWEST TERRITORIES

ALBERTA

YUKONTERRITORY

BRITISHCOLUMBIA

MONTANA

WASHINGTON

OREGON

IDAHOWYOMING

Jackson

Bozeman

Spokane

Calgary

Vancouver

PacificOcean

Whitehorse


38.14 CONNECTION: The study of how to restore degraded habitats is a developing science

Restoration ecology

– Uses ecological principles to restore environments

Restoring environments

– Bioremediation

– Using organisms to detoxify polluted ecosystems

– Replanting native vegetation

– Repairing waterways and wetlands

Widenedcanal

Water controlstructure remaining

LakeKissimmee

Kissimmee

River

Floodplain

Lake

Okeechobee

Atlantic

Ocean

Gulf of

Mexico

FLORIDA

Detail

Miles

0 10

Water control

structure removed

River channelrestored

Canal backfilled

Phase 1completed

Water control

structure to

be removed in

Phase 2

Formercanal


38.15 Sustainable development is an ultimate goal

Biosphere is made of complex interconnections

– Sensible decisions needed to conserve these networks

– Must work for a sustainable future

– Sustainable development depends on continued research and application

Habitat destruction Invasive species Overexploitation

Conservation

biology

may involveseeks to conserve

ecosystems and

landscapes

attemptto restore

may be

protected inwhich uses

nature

reserves

restoration

projects

may beneed to identify

and support detoxify or

replenish degraded

ecosystems

to

sustainable

development

which support

(e)minimum viable

population size

(d)

(c)

(b)(a)


You should now be able to

1. Explain why biodiversity must be protected

2. Describe the three components of biodiversity

3. Explain the major factors that threaten biodiversity

4. Explain the consequences of global climate change

5. Describe major strategies used in conservation biology

6. Explain the principles of sustainable conservation practices

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