Chapter 40Conservation

BiologyLecture Outline

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40.1 Conservation biology

Conservation biology

Goal of conserving natural resources for this generation and all future generations

Support of biodiversity for all species

Helps reduce extinctions of species

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Biodiversity & Extinction

Biodiversity – variety of life on Earth Between 10 and 50 million species may exist

Of the described species, nearly 1,200 in the United States and 40,000 worldwide are in danger of extinction

Endangered species is in peril of immediate extinction throughout all or most of its range

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Genetic & Ecosystem Diversity

Genetic diversity

Variations among the members of a population

The more diverse a population, the more likely they survive

Ecosystem diversity

Conserve species that play a critical role in an ecosystem

Saving an entire ecosystem can save many species

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Landscape diversity

Landscape diversity Ecosystems can be so fragmented that they are connected by

patches or strips of land that allow organisms to move from one ecosystem to the other

Distribution of Biodiversity Biodiversity is not evenly distributed throughout the biosphere

Some regions of the world are called biodiversity hotspots because they contain unusually large concentrations of species

Exs: Madagascar, Great Barrier Reef in Australia, rainforests

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Medicinal & Agricultural Value

Medicinal Value Most prescription drugs in the United States were

originally derived from living organisms Valued at over $200 billion

Agricultural Value Crops such as wheat, corn, and rice are derived from

wild plants

Biological pest controls (natural predators and parasites) are often preferable to chemical pesticides Ladybugs, bats

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Figure 40.3 Direct value of diverse wildlife (Cont.)

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Consumptive Use Value

Consumptive Use Value Most freshwater and marine harvests depend on the

catching of wild animals, such as crustaceans, mammals, and fishes

Provides a variety of other products that are sold in the marketplace worldwide, including wild fruits and vegetables, skins, fibers, beeswax, and seaweed

Many trees in the natural environment are still felled for their wood

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Ecological Value

Biogeochemical Cycles Dispose of Waste Biodiversity contributes to workings of water, carbon,

phosphorus, and nitrogen cycles

Natural Areas Provide Fresh Water, Prevent Soil Erosion, and Regulate Climate Water-holding capacity of forests and wetlands reduces the

possibility of flooding Forests improve climate because they take up carbon dioxide

Ecotourism Is Enjoyed by Many In U.S., people spend $4 billion each year on ecotourism

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Figure 40.4 Tourists (inset) love to visit natural ecosystems, such as this forest, which has indirect value because of its water-holding

capacity and its ability to take up carbon dioxide

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Habitat Loss & Extinctions

Of 1,880 threatened and endangered species in U.S., habitat loss was involved in 85% of cases

Other significant causes of extinction are introduction of alien species, pollution, overexploitation, and disease

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Figure 40.5A Macaws, Ara macao, and other species are

endangered for the reasons graphed here

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Habitat loss

Alien species

Pollution

Overexploitation

Disease

0 20 40 60 80 100

% Species Affected

© Gunter Ziesler/Peter Arnold/Photolibrary

Non-native Species

Alien species – nonnative members brought into new ecosystems Introduced by

Colonization – Europeans brought various familiar species with them when they colonized new places

Dandelions Horticulture and agriculture – Aliens now taking over vast tracts

of land have escaped from cultivated areas Kudzu is a vine from Japan that the U.S. Department of

Agriculture thought would help prevent soil erosion Accidental transport – Global trade and travel accidentally bring

many new species from one country to another Zebra mussels

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Figure 40.6A Kudzu, a vine from Japan, has displaced many native plants in the southern United States

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40.7 Pollution contributes to extinctions

Exs. of Pollution

Acid deposition – (or “Acid Rain”):Both sulfur dioxide from power plants and nitrogen oxides in automobile exhaust are converted to acids when they combine with water vapor in the atmosphere

Eutrophication – Lakes are also under stress due to over-enrichment (excess nitrogen and phosphorus) Algae blooms occur and upon death, the decomposers break

down the algae, but in so doing, they use up oxygen

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Ozone & Organic Chemicals

Ozone depletion – Ozone (O3) “shield” absorbs most of the wavelengths of harmful ultraviolet (UV) radiation so they do not strike the Earth Severe ozone shield depletion can impair crop and tree growth

and also kill plankton that sustain oceanic life

Organic chemicals – Organic chemicals are used in pesticides, dishwashing detergents, cosmetics & plastics Mimic the effects of hormones and, in that way, most likely harm

wildlife

Solid waste disposal – plastic floating in the ocean creates a danger to wildlife

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http://www.youtube.com/watch?v=tnUjTHB1lvM http://www.youtube.com/watch?v=J-gqJAsXiKQ

http://thomasfortenberry.net/wp-content/uploads/2008/03/dead_bird.jpg

Figure 40.7 (Top) Normal coral reef. (Bottom) Bleaching of a coral reef. A temperature rise of only a few degrees causes coral reefs to “bleach” and become lifeless. As the

oceans warm and land recedes, coral reefs could move northward

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40.8 Overexploitation contributes to extinctions

Overexploitation occurs when the number of individuals taken from a wild population is so great that the population becomes severely reduced in number Overexploitation accounts for 17% of extinctions

U.N. Food and Agricultural Organization tells us that humans have now overexploited 11 of 15 major oceanic fishing areas

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40.9 Disease contributes to extinctions

Number of pathogens that cause diseases is on the rise, threatening human health as well as that of wildlife

Pollution can weaken organisms so that they are more susceptible to disease

Example: Almost half of sea otter deaths along the coast of California are now due to infectious diseases

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Figure 40.9The Harlequin toad is near extinction due to a fungal pathogen

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40.10 Habitat preservation: Keystone Species

Keystone species Species that influence the viability of a community,

although their numbers may not be excessively high

Extinction of a keystone species can lead to other extinctions and loss of biodiversity

Ex: Grizzly bears in northwestern US and Canada Berry seed distribution, control populations of other animals

Otters Keep populations of other species in check

Bats Essential pollinators 40-26

Figure 40.10A Landscape preservation will help grizzly bears, Ursus arctos horribilis, survive

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40.11 Restoration Ecology

Restoration ecology – seeks scientific ways to return ecosystems to former state

Three principles have so far emerged It is best to begin as soon as possible before remaining

fragments of the original habitat are lost Once the natural history is understood, it is best to use

biological techniques that mimic natural processes to bring about restoration

Goal is sustainable development, ability of an ecosystem to maintain itself while providing services to human beings

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The Everglades – southern Florida Vast sawgrass prairie, interrupted occasionally by a

hardwood tree island Beginning of 20th century, settlers began to drain land

to grow crops A restoration plan has been developed that will

sustain the Everglades ecosystem, while maintaining the services society requires

The Everglades is to receive a more natural flow of water from Lake Okeechobee

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Figure 40.11 A variety of

animals make their home in the Everglades

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Figure 40.12 These activities are characteristic of a sustainable society. Arrows point inward to signify that these activities increase the carrying capacity of the Earth

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

multi-use farming integrated pestmanagement

conservationof water

mass transit andenergy-efficienttransportation

recycling andcomposting

wetland, deltapreservation

and restoration

(farming): © Inga Spence/Visuals Unlimited; (wetland preservation):© Peter DeJong/AP Images; (recycling): © Jeffrey Greenberg/PhotResearchers, Inc.;(bus): Courtesy DaimlerChrysler; (drip irrigation): ©Inga Spence/Visuals Unlimited; (integrated pest management): Courtesy V.Jane Windsor, Division of Plant Industry, Florida Department of Agriculture &Consumer Services

40.13 Renewable Energy Sources

Traditional renewable energy sources Hydroelectric plants Geothermal energy Wind power Solar energy

In the future, biofuels may run power plants or your car

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Figure 40.13A Traditional sources of renewable energyCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Hydropower dams Wind power

Solar panels on roof-top Sun-tracking mirrors of a solarenergy plant

(dam): © David L. Pearson/Visuals Unlimited;(wind power): © S.K. Patrick/Visuals Unlimited; (solar panels, roof): © Argus Foto Archiv/Peter Arnold/Photolibrary; (solar energyplant): © Gerald and Buff Corsi/Visuals Unlimited

Connecting the Concepts:Chapter 40

Biodiversity includes genetic, ecosystem & landscape diversity

Organisms have medicinal, agricultural & ecological value Habitat loss & introduction of non-native species are

destructive Overexploitation, pollution & diseases contribute to

extinctions Importance of developing renewable energy sources Habitat preservation & restoration = sustainable

development

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