Biodiversity and Conservation
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Biodiversity and Conservation
Levels of Biodiversity Humans are reducing Earth’s diversity of
life Biodiversity – sum total of all organisms
in an area Split into three specific levels:
Species diversity Genetic diversity Ecosystem diversity
Species Diversity Species Diversity = the number or
variety of species in the world or in a particular region Richness = the number of species Evenness or relative abundance = extent
to which numbers of individuals of different species are equal or skewed
Speciation generates new species and adds to species richness
Extinction reduces species richness
TaxonomyTaxonomists = scientists who classify species
Physical appearance and genetics determines a speciesGenera = related species are grouped togetherFamilies = groups of genera
Every species has a two-part scientific name: genus and species
Subspecies Subspecies =
populations of species that occur in different areas and differ slightly from each other Divergence stops
short of separating the species
Subspecies are denoted with a third part of the scientific name
Siberian tiger = Panthera tigris altaica
Bengal tiger = Panthera tigris tigris
Genetic Diversity Encompasses the differences in DNA among
individuals within species and populations The raw material for adaptation to local
conditions Populations with higher genetic diversity can
survive They can cope with environmental change
Populations with low genetic diversity are vulnerable To environmental change Disease Inbreeding depression = genetically similar
parents mate and produce inferior offspring
Diversity Ecosystem diversity = the number
and variety of ecosystems Also encompasses differing
communities and habitats Rapid vegetation change and varying
landscapes within an ecosystem promote higher levels of biodiversity
Diversity Species are not evenly distributed among
taxonomic groups Insects predominate over all other life-forms 40% of all insects are beetles
Groups accumulate species by Adaptive radiation Allopatric speciation (species isolation) Low rates of extinction
Review Evolution Microevolution, macroevolution, natural selection,
artificial selection, fitness, adaptation, niche, mutation, sympatric vs. allopatric speciation, bottleneck, founder effects.
Measuring Biodiversity Out of the estimated 3 - 100 million species
on Earth, only 1.7 - 2 million species have been successfully catalogued
Very difficult to identify species Many remote spots on Earth remain
unexplored Small organisms are easily overlooked Many species look identical until thoroughly
examined Entomologist Terry Erwin found 163 beetle
species specialized on one tree species Refer to lab and Simpson’s Index
Biodiversity is not evenly distributed
Living things are distributed unevenly across Earth
Latitudinal gradient = species richness increases towards the equator
Canada has 30 - 100 species of breeding birds, while Costa Rica has more than 600 species
Latitude Gradient and Biodiversity
Loss of Species Extinction = occurs
when the last member of a species dies and the species ceases to exist
Extirpation = the disappearance of a particular population from a given area, but not the entire species globally Can lead to extinction
Extinction is a natural process
Paleontologists estimate 99% of all species that ever lived are now extinct
Background rate of extinction = natural extinctions for a variety of reasons 1 extinction per 1 to 10
million species for mammals and marine species
1 species out of 1,000 mammal and marine species would go extinct every 1,000 to 10,000 years
Endangered and Threatened Species
Endangered and Extinct Species
Could become extinct soon. Population declining very
fast.Spectacled Bear
ThreatenedEndangered
Endangered and Extinct Species
Characteristics of Endangered Species• Extremely small range• Requiring large territories• Living on islands• Low reproductive success• Specialized breeding areas• Specialized feeding habits
Tiburon mariposa lilyCalifornia condor
Hawaii ‘O’ oBlue whaleGreen sea turtle
Giant panda
Endangered and Extinct Species- Most Impacted areas- Hawaii and other island habitats- Tropical rain forests http://www.pbs.org/wnet/nature/episodes/the-
dragon-chronicles/video-komodo-dragon-chases-rom/4520/
Past Mass Extinctions In the past 440
million years, mass extinctions have eliminated at least 50% of all species
After every mass extinction the biodiversity returned to or exceeded its original state
Current Mass Extinction is Human Caused
During this Quaternary period, we may lose more than half of all species Hundreds of human-induced species
extinctions, and multitudes of others, teeter on the brink of extinction
The current global extinction rate is 100 to 1,000 times greater than the background rate This rate will increase tenfold in future
decades due to human population growth and resource consumption
Loss of Biodiversity is more than extinction
Decreasing numbers are accompanied by smaller species’ geographic ranges
Genetic, ecosystem, and species diversity are being lost.
The Living Planet Index summarizes trends in populations Between 1970 and 2003,
the Index fell by 30%
Causes of Biodiversity Loss Reasons for biodiversity losses are
multifaceted, complex, and hard to determine Factors may interact synergistically
Four primary causes of population decline are: Habitat alteration Invasive species Pollution Overharvesting
Global climate change now is the fifth cause
Habitat Loss The greatest cause of
biodiversity loss Farming simplifies
communities Grazing modifies the
grassland structure and species composition
Clearing forests removes resources organisms need
Hydroelectric dams turn rivers into reservoirs upstream
Urbanization and suburban sprawl reduce natural communities
A few species (i.e., pigeons, rats) benefit from changing habitats
Invasive Species Introduction of non-native species to new
environments Accidental: zebra mussels Deliberate: food crops
Island species are especially vulnerable Invaders have no natural predators,
competitors, or parasites Cost billions of dollars in economic
damage
Pollution Harms organisms in many ways
Air pollution degrades forest ecosystems Water pollution adversely affects fish and
amphibians Agricultural runoff harms terrestrial and aquatic
species The effects of oil and chemical spills on wildlife
are dramatic and well known The damage to wildlife and ecosystems
caused by pollution can be severe But it tends to be less than the damage caused
by habitat alteration or invasive species
Overharvesting Vulnerable species are large, few in
number, long-lived, and have few young (K-selected species) The Siberian tiger is hunted without
rules and regulations The early 1990s saw increased
poaching because of powerful economic incentives
Many other species affected: Atlantic gray whale, sharks, gorillas
Today the oceans contain only 10% of the large animals they once did
Climate Change Emissions of
greenhouse gases warms temperatures Modifies global weather
patterns and increases the frequency of extreme weather events
Increases stress on populations and forces organisms to shift their geographic ranges
Most animals and plants will not be able to cope
Biodiversity is good for ecosystems (ecosystem services) Provides food, shelter, fuel Purifies air and water, and detoxifies wastes Stabilizes climate, moderates floods, droughts,
wind, temperature Generates and renews soil fertility and cycles
nutrients Pollinates plants and controls pests and disease Maintains genetic resources Provides cultural and aesthetic benefits Allows us to adapt to change
Biodiversity Loss in an Ecosystem Biodiversity increases the stability and resilience
of communities and ecosystems Decreased biodiversity reduces a natural
systems ability to function and provide services to our society
The loss of a species affects ecosystems differently If the species can be functionally replaced by
others, it may make little difference Extinction of a keystone species may cause
other species to decline or disappear “To keep every cog and wheel is the first
precaution of intelligent tinkering” (Aldo Leopold)
Biodiversity affects food security Genetic diversity within crops is
enormously valuable Turkey’s wheat crops received $50 billion
worth of disease resistance from wild wheat
Wild strains provide disease resistance and have the ability to grow back year after year without being replanted
Biodiversity and Medicines Each year
pharmaceutical products owing their origin to wild species generate up to $150 billion in sales The rosy periwinkle
produces compounds that treat Hodgkin's disease and leukemia
Some economic benefits of biodiversity People like to experience protected
natural areas, creating economic opportunities for residents, particularly in developing countries Costa Rica: rainforests (Excellent at
ecotourism) Australia: Great Barrier Reef Belize: reefs, caves, and rainforests
A powerful incentive to preserve natural areas and reduce impacts on the landscape and on native species
But, too many visitors to natural areas can degrade the outdoor experience and disturb wildlife
People Value and seek nature Biophilia = connections that humans
subconsciously seek with life Our affinity for parks and wildlife Keeping of pets High value of real estate with views of
natural lands Nature deficit disorder = alienation from the
natural environment May be behind the emotional and physical
problems of the young
Conservation Biology Conservation biology = devoted to
understanding the factors that influence the loss, protection, and restoration of biodiversity Arose as scientists became alarmed at the
degradation of natural systems An applied and goal-oriented science
Conservation Biology Conservation biologists integrate evolution and
extinction with ecology and environmental systems Design, test, and implement ways to mitigate human
impacts Conservation geneticists = study genetic
attributes of organisms to infer the status of their population
Minimum viable population = how small a population can become before it runs into problems
Metapopulations = a network of subpopulations Small populations are most vulnerable to extinction
and need special attention
Should we focus on endangered species? Endangered Species Act (1973) (ESA) =
forbids the government and private citizens from taking actions that destroy endangered species or their habitats-40 Year anniversary! To prevent extinction Stabilize declining populations Enable populations to recover
US has approximately 2050 endangered species.
http://www.fws.gov/endangered/ http://www.nmfs.noaa.gov/pr/laws/esa/
ESA Through federal action and by encouraging the establishment of
state programs, the 1973 Endangered Species Act provided for the conservation of ecosystems upon which threatened and endangered species of fish, wildlife, and plants depend. The Act: authorizes the determination and listing of species as endangered and
threatened; prohibits unauthorized taking, possession, sale, and transport of
endangered species; provides authority to acquire land for the conservation of listed species,
using land and water conservation funds; authorizes establishment of cooperative agreements and grants-in-aid to
States that establish and maintain active and adequate programs for endangered and threatened wildlife and plants;
authorizes the assessment of civil and criminal penalties for violating the Act or regulations; and
authorizes the payment of rewards to anyone furnishing information leading to arrest and conviction for any violation of the Act or any regulation issued thereunder.
Amendments to ESA Habitat Conservation Plans• 1982 amendment to ESA• Landowner allowed to set aside land
for endangered species, but develop other land with those species
Successes Peregrine falcons, brown pelicans, bald eagles,
and others have recovered and are no longer listed
Intensive management has stabilized other species The red-cockaded woodpecker 40% of declining populations are now stable
These successes occur despite underfunding of the U.S. Fish and Wildlife Service and the National Marine Fisheries Service In recent years, political forces have attempted to
weaken the ESA http://www.pbs.org/wnet/nature/episodes/americ
an-eagle/video-full-episode/4349/
Ways to preserve biodiversity Captive breeding – individuals are bred
and raised with the intent of reintroducing them into the wild Zoos and botanical gardens
Some reintroductions are controversial Ranchers opposed the reintroduction of
wolves to Yellowstone National Park Some habitat is so fragmented, a species
cannot survive Seed Banks
Cloning???? Cloning – a technique to create more
individuals and save species from extinction Most biologists agree that these efforts
are not adequate to recreate the lost biodiversity
Ample habitat and protection in the wild are needed to save species
Jurassic Park
Strategies Conservation biologists use particular species as
tools to conserve communities and ecosystems Protecting the habitat of these umbrella species
helps protect less-charismatic animals that would not have generated public interest
Flagship species – large and charismatic species used as spearheads for biodiversity conservation The World Wildlife Fund’s panda bear
Some organizations are moving beyond the single species approach to focus on whole landscapes
International Conservation UN Convention on International Trade in
Endangered Species of Wild Fauna and Flora (1973) (CITES) – protects endangered species by banning international transport of their body parts
Convention on Biological Diversity (1992) – Seeks to conserve biodiversity Use biodiversity in a sustainable manner Ensure the fair distribution of biodiversity’s
benefits By 2007, 188 nations had signed on Iraq, Somalia, the Vatican, and the U.S. did not
join
Hot spots Biodiversity hotspots – prioritizes
regions most important globally for biodiversity Support a great number of endemic
species = species found nowhere else in the world
The area must have at least 1.500 endemic plant species (0.5% of the world total)
It must have lost 70% of its habitat due to human impact
2.3% of the planet’s land surface contains 50% of the world’s plant species and 42% of all terrestrial vertebrate species
Community Based Conservation Protecting habitats makes good sense, but
this affects people living in and near these areas
Community-based conservation = conservation biologists actively engage local people in protecting land and wildlife Protecting land deprives people access to
resources But, it can guarantee that these resources will
not be used up or sold to foreign corporations and can instead be sustainably managed
Many projects have succeeded But, others have not, due mainly to funding
problems
Economic Incentives Debt-for-nature swap = a conservation
organization pays off a portion of a developing country’s international debt In exchange for a promise by the country to
set aside reserves Fund environmental education, and Better manage protected areas
Conservation concession = conservation organizations pay nations to conserve, and not sell, resources
Costa Rica and Debt Swap Under the U.S. Tropical Forest Conservation
Act, the United States agreed to forgive $26 million of Costa Rica’s debt in return for the Central American nation’s commitment to redirect that money toward conservation inside its borders. The U.S. government appropriated $12.6 million for the effort. Both Conservation International (CI) and The Nature Conservancy each gave $1.26 million to the debt purchase at a discounted rate.
Wildlife management Differs from conservation biology in that wildlife
managers focus more often on common organisms and manage those species primarily for human benefits
Management of Aquatic Organisms• Freshwater fisheries primarily managed by
state fishing regulations• Ocean fisheries commonly viewed as common
property-this has lead many species close to commercial extinction
Case Studies and FYI Sharks-32% of the world’s open-ocean species are
threatened. They are keystone species and can potential help cancer research.
E. O. Wilson-Champion of Biodiversity Vanishing Amphibians-an indicator Species.
Go to the media centers website and log onto discovery education-search Vanishing Frogs for a documentary
Polar Bears and Climate Change Elephants in Africa Black Rhinos and Poaching Kudzu, zebra mussels, termites, gypsy moths, Cane
toads http://www.youtube.com/watch?v=4mvV8OT-mmE (don’t know if you can get this at school)
Birds of Thailand
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