Transcript Chapter 18

Conservation of Biodiversity
• Biodiversity of world is rapidly declining
• Decline of biodiversity – result of human activities
• Our history of conserving biodiversity:
• Protecting habitats as national parks, national monuments, national forests,
and wilderness areas
• 2006-2009 –215 million acres of marine habitats around the
northwestern Hawaiian Islands and other US Pacific islands
• Area of great biodiversity, but diversity has been declining
• Protected area solution?
• Marine reserves – newer idea
• But worldwide – Russia, UK, Australia, Canada, Belize
• Extinction- when there are no
longer any of the species in the
world
• Earth has had 5 major extinctions
in past 500 million years
• Currently experiencing 6th
major extinction
• Losing ~50,000 species per year
• Great species loss in a very short
time period
• First since humans have been on
planet
• Conserve genetic diversity important - increases species survival
Inbreeding depression – when individuals with similar
genotypes, generally relatives, breed with each other
• Examples:
• Cheetahs – natural process
• Panther (aka mountain lion, cougar) – human induced process
• Genetic diversity being lost due to artificial selection as well
• Categories:
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Extinct – no known species exist today
Endangered – serious risk of becoming extinct
Threatened – species with a high risk of extinction in the future
Near-threatened – species that are likely to become threatened in the
future
• Least concern – species are widespread and abundant
• Problems with evaluating status of plant and animal species:
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Extremely small (localized) range
Requiring a large territory
Living on an island
Having a low reproductive success
Small population size
Low reproductive rates
Requiring specialized breeding areas
Having specialized feeding habitats
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H- Habitat Loss
I- Invasive Species
P- Pollution
C- Climate Change
O- Overharvested
• The greatest cause of decline and
extinction for most species
• Most habitat loss is due to human
development – removing natural
habitats and replacing them with
homes, industries, agricultural fields,
shopping malls and roads
• Effects of habitat loss contributing to
species decline:
• Areas of concern:
• Alien species (exotic
species) – species that
live outside their
historical range
• Invasive species- when
alien species spread
rapidly across large
areas
• Ex- Kudzu Vine, Zebra
Mussel, Silver It’s even
happening in Clinton!
• Pond Mussel Invasion in
Clinton, NJ
• Threats to biodiversity can come from toxic contaminants such as
pesticides, heavy metals, acids, and oil spills
• Others:
• Concern is how climate change will affect temperature and
precipitation around the world, and how this will impact
biodiversity
• Will talk more about in Ch 19
• When individuals of a species are removed
at a rate faster than the population can
replace them
• Via hunting, fishing, poaching, commercial
harvest, efforts to control #s
• Ex- dodo, American bison, passenger pigeon
• One of the earliest laws in the U.S. to control the trade of
wildlife
• First passed in 1900
• Prohibited the transport of illegally harvested game animals,
primarily birds and mammals, across state lines
• Convention on International Trade in Endangered Species of
Wild Fauna and Flora
• Developed in 1973 – control the international trade of
threatened plants and animals
• Today…
• The IUCN keeps a list of threatened species, known as the Red
List
• Each country has its own way to monitor and regulate the
import and export of animals on the list
• Does not stop illegal trade though!
• 2 approaches to conserving
biodiversity:
• Single-species approach – focuses
efforts on one species at a time
• May include bringing individuals into
captivity and attempting to
reestablish in wild at a later date
• Ecosystem approach – recognizes
benefit of preserving particular regions
of the world
• Especially biodiversity hotspots
• Factors taken into consideration:
• 1972
• Prohibits the killing of all marine mammals in the U.S. and
prohibits the import or export of any marine mammal body
parts
• First passed in 1973, amended several times since
• Authorizes the U.S. Fish and Wildlife Service to determine which
species can be listed as threatened or endangered and
prohibits the harming of these species
• Controversy!
• 1992 – nations came together and made a treaty to protect
biodiversity
• The treaty had three objectives:
• Conserve biodiversity
• Sustainably use biodiversity
• Equitably share the benefits that emerge from the commercial use of
genetic resources such as pharmaceutical drugs
• 2002 – strategic plan to achieve a substantial reduction in
worldwide rate of biodiversity loss by 2010
• 2010 – convention determined goal not met:
• As previously noted: When designing and managing protected
areas we must consider how close to another area they should
be, how large the area is, and the amount of edge habitat the
area contains.
• Edge habitat - the area where two different communities come
together, typically forming an abrupt transition.
• Ex. A grassy field meeting a forest
• Must be taken into account when using an ecosystem approach
• Protected areas consisting
of zones that vary in the
amount of permissible
human impact
• Image:
• Central core
• Buffer zone
• Transition area
• 564 biosphere reserves
worldwide
• 47 in US – most well known
is Beg Bend National Park
in TX
• Involves: (overview)
• Protecting habitats
• Restoring damaged or destroyed habitats
• Zoos, aquaria, botanical gardens
• Seed banks
• Restoration ecology
• Study of the historical condition of a human-damaged ecosystem
• Goal is to return it to its former state
• Benefits
• Creates biological habitats
• Regeneration of soil damaged by agriculture or mining
• Disadvantages
• Expensive
• Take a long time to restore an area
Left: (1935) Early
stages of prairie
restoration
Right: (current day)
restored prairie
• Save organisms from
extinction
• Artificial insemination
• Embryo transfer
• Surrogate mothers (right)
• Goal is to reintroduce
organisms back to their
natural habitat
• Problems?
Bongo Calf and its surrogate
mother, a female eland
• Stored seeds are safe from
habitat destruction, climate
warming, etc.
• Can use seed banks to
reintroduce extinct plant
species
• Some seeds cannot be
stored