Conservation of Biodiversity

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Conservation of Biodiversity

• Chapter 40

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Conservation biology

• Biodiversity!!
• Emerged in response to a crisis
• At least 1020 of all species now living most
  likely will become extinct in the next 2050
  years
• Bioinformatics

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Conservation biology

• Supports following ethical principles
• Biodiversity is desirable for the biosphere and,
  therefore, for humans
• Extinctions, due to human actions, are
  undesirable
• Complex interactions in ecosystems support
  biodiversity and are desirable
• Biodiversity from evolutionary standpoint has
  value in and of itself, regardless of practical
  benefit

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Biodiversity

• Variety of life on Earth
• Between 10 and 50 million species may exist
• Extinction
• Of the described species, nearly 1,200 in the
  United States and 40,000 worldwide are in danger
  of extinction
• Endangered species
• Threatened species

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Understanding Biodiversity

• Genetic diversity
• variations among the members of a population
• Ecosystem diversity
• dependent on interactions of species at a locale
• Conserve species that play a critical role in an
  ecosystem
• Saving an entire ecosystem can save many species
• Landscape diversity
• interacting ecosystems within one landscape
• Fragmentation reduces can disrupt seasonal
  behaviors
• Distribution of Biodiversity
• Biodiversity not evenly distributed throughout
  the biosphere
• biodiversity hotspots
• contain unusually large concentrations of species

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Disrupted ecosystem in Flat-head Lake, Montana
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Direct Value of Biodiversity

• Wildlife Has Medicinal Value
• Most prescription drugs in the United States
  originally derived from living organisms

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Direct Value of Biodiversity

• Wildlife Has Agricultural Value
• Crops are derived from wild plants that have been
  modified
• Biological pest controls are often preferable to
  chemical pesticides

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Direct Value of Biodiversity

• Wildlife Has Consumptive Use Value
• freshwater and marine harvests depend on the
  catching of wild animals
• Provides a variety of other products that are
  sold in the marketplace worldwide

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Indirect Value of Biodiversity

• 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
• Intact ecosystems naturally retain soil and
  prevent erosion
• Ecotourism Is Enjoyed by Many
• In U.S., people spend 4 billion each year on
  ecotourism

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Wildlife Extinctions

• Habitat loss
• Introduction of alien species
• Pollution
• Overexploitation
• Disease

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1. Habitat loss

• 1,880 threatened and endangered species in U.S.
• 85 of cases
• Focus on tropical rain forests and coral reefs
• Loss of habitat also affects freshwater and
  marine biodiversity
• Coastal degradation mainly due to the large
  concentration of people living on or near the
  coast
• 60 of coral reefs have been or are on verge of
  destruction

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2. Alien Species

• Nonnative members brought into new ecosystems
  through
• Colonization
• Europeans brought various familiar species with
  them when they colonized new places
• Horticulture and agriculture
• Aliens have escaped from cultivated areas
• Accidental transport
• Global trade and travel
• Aliens on Islands
• Islands are particularly susceptible to
  environmental discord caused by the introduction
  of alien species

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2. Alien Species

• Everglades National Park, Florida
• Pythons
• Caiman
• Wooly rat
• Monitor lizards

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3. Pollution

• Environmental change that damages lives and
  health of organisms
• Acid deposition
• sulfur dioxide from power plants
• nitrogen oxides in automobile exhaust
• converted to acids when they combine with water
  vapor in the atmosphere
• Eutrophication
• Overenrichment
• algae blooms occur and upon death, the
  decomposers break down the algae
• in so doing, they use up oxygen

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3. Pollution

• Ozone depletion
• Ozone shield absorbs most of the wavelengths of
  harmful ultraviolet (UV) radiation so they do not
  strike the Earth
• Organic chemicals
• used in products ranging from pesticides to
  dishwashing detergents, cosmetics, plastics, etc
• Global warming
• A 1 meter rise in sea level could inundate 2550
  of U.S. coastal wetlands
• Bleaching coral reefs

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4. Overexploitation

• Number of individuals taken from a wild
  population so great that the population becomes
  severely reduced in number
• Positive feedback cycle
• Smaller population
• Greater incentive to capture few remaining
  organisms
• Poachers
• Overexploited 11 of 15 major oceanic fishing
  areas
• Fish are a renewable resource
• More efficient fishing fleets to decimate fishing
  stocks

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5. Diseases

• Due to encroachment of humans on habitat and
  other general interventions
• Pollution can weaken organisms
• more susceptible to disease
• May be due to alien species
• Chytrid fungus

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Conservation Techniques

• Habitat Preservation
• Habitat Restoration

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Habitat Preservation

• Keystone species
• influence the viability of a community
• Extinction of a keystone species can lead to
  other extinctions and a loss of biodiversity
• Metapopulation
• population subdivided into several small,
  isolated populations
• Habitat fragmentation by humans
• Landscape Preservation
• Landscape protection for one species is often
  beneficial for other wildlife that share the same
  space

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Habitat Restoration

• Restoration ecology
• Subdiscipline of conservation biology
• 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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Habitat Restoration

• The Everglades
• Located in southern Florida
• 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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Global Climate Change

• Emissions of greenhouse gases are accelerating
• From 20002005 global CO2 emissions increased
  four times faster than in the preceding 10-year
  span

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Climate Change

• In many plants and animals, life cycle events are
  triggered by
• Warming temperatures
• Day length
• As global temperatures warm, and day length
  remains steady, natural interactions may become
  out of sync
• Plants may bloom before pollinators have emerged
• Eggs may hatch before dependable food sources are
  available

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Human Impact on Biomes

• Sustainability
• goal of developing, managing, and conserving
  Earths resources
• meet the needs of people today without
  compromising the ability of future generations to
  meet their needs

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2001
1975
Figure 18.39
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The Greenhouse Effect and Global Warming

• Greenhouse gases
• Include CO2, water vapor, and methane
• Are transparent to solar radiation
• Absorb or reflect heat
• Contribute to increases in global temperatures

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Some heat energy escapes into space
Sunlight
Atmosphere
Radiant heat trapped by greenhouse gases
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400
350
Carbon dioxide (CO2) (ppm)
300
250
1500
1000
500
2000
0
Year
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Looking to Our Future

• Emissions of greenhouse gases are accelerating.
• From 20002005 global CO2 emissions increased
  four times faster than in the preceding 10-year
  span.
• In addition, eating locally grown fresh foods may
  lower the greenhouse gas emissions that result
  from food processing and transportation.

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Our future?

• carbon (ecological) footprint
• amount of greenhouse gas emitted as the result of
  the actions of a single individual
• reduce our carbon footprints by
• Reducing our use of energy
• Driving less
• Recycling