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Biological Diversity - PowerPoint


  • pg 1
									This presentation is
drawn from an
International Union
for the Conservation
of Nature’s 1996
Species Survival
Commission Study,
and also from. . . .
The WR 2000-2001
report, produced by the
World Resources
Institute, the United
Nations Development
Programme (UNDP),
the UN Environment
Programme (UNEP),
and the World Bank,
with over 175 scientists
Biological Diversity
 The Variety of Species and the
Genetic Diversity within them: the
    Key to the Vitality of Life
of Species
Biodiversity Decline -
    An Overview
 Biodiversity Loss -- Greatest
Environmental Threat?
    Nearly 400 biologists in a recent poll
     think so.
      – Seven of 10 said they believed a
       "mass extinction" was already
     – An equal number fear that up to
       one-fifth of all living species
       could disappear within 30 years.
  25%  of all the world's wild
  mammals are threatened with
  –Habitat loss and degradation are
   primarily responsible.
African Elephants
 Closest cousins to humans (chimps,
  e.g., 98.5% of same dna)
 325 species, of these, 130 endangered,
  including all Orangutans,
  chimpanzees, and most gorillas.
    – with subspecies included, 608 distinct
   Gorillas and Chimpanzees
“critically endangered” (Nature, 2003)
   Due to hunting + now ebola.
   Popluations plumitted by ½ in Gabon
    and Republic of Congo between
    1983+2000; these 2 countries have
    80% of world’s gorillas and most of its
   rate of extermination is increasing.
   Princeton’s Walsh: “If we don’t do something radical,
    gorillas and chimpanzees will be effectively extinct from
    western equatorial Africa within the next ten years.”
Miss Waldron's red colobus ~ disappeared in 20th
   century, declared extinct September 2000
Golden Bamboo Leumr
Cross River Gorilla
   (Nigeria and Cameroon,
West Africa; about 150 remain in
  small, isolated populations)
Yellow-tailed woolly monkey
 1    in 8 plant species is
     threatened with extinction.
    In the United States it is 1 in 3.
     – 90% of plants on endangered list are native
       only to the U.S.
    Main causes:
     – habitat loss due to agriculture, logging,
       development and
     – exotic species invasions drive out native species
Semaphore Cactus
  Logging and conversion have shrunk the
   world’s forests by as much as half.
  9 percent of the world’s tree species are
   at risk of extinction

              World Resources 2000-2001: People and
               Ecosystems: The Fraying Web of Life, sept 2000
Extinct in the wild.
This species is
unique to Rodrigues
Island and once
included male and
female trees. The one
remaining female
tree was blown down
in a cyclone in 1984.
The male, pictured
here, died in 1994.
Cuttings of both
these trees have been
One remaining in the
wild. This palm is
the only known plant
of its species, which
is unique to the
island of Mauritius.
Although it produces
both male and
female flowers, no
viable fruit has been
produced, and efforts
to grow it in the
laboratory have
Tree - Old
Growth -
Plant diversity declining ~
fewer seed varieties cultivated
    In the USA:
      – 80% fewer seed varieties sold, compared to a
        century ago.
      – 29% of plant species (4,669) endangered
    Globally
      – 30,000 plant species endangered
    Genetic losses permanent
     – A pest-resistant gene found in a seed from Turkey
       was nearly extinct.
                 Worldwatch, 1999
    Jamaican
     about 100
 25%            already extinct
    Birds are probably suffering the greatest
     declines currently

                Vitousek, P. M., J. L. Mooney, and J. M. Melillo. July
                 25, 1997. Human Domination of Ecosystems. Science
                 277(5325): 494-9
Dusky Seaside Sparrow

                                                                          California Condor

- A huge vulture that declined from habitat loss and hunting until the few remaining birds were captured.
Now there are a few dozen of the birds in Arizona and California.
- Millions of dollars have been spent in an effort to bring them back from the brink of extinction. Some
captive bred birds were reintroduced to the wild.
- But in 2000 the reintroduction broke into disarray, as most of the reintroduced birds were re-captured
due to high mortality rates. (They kept eating animals with lead shot in their bodies, or consuming other
human-produced poisons, such as radiator fluid). Long-term survival of these birds is doubtful.
Spotted Owl &

                        Willow Fly-
                    SW United States
Endangered Marine Life
Green Sea Turtle
 Andronomous Fish declining,
 e.g., Pacific Salmon is extinct
from much of its original range
 Yet, Summer 2000:
 The Clinton administration refused to
  breach a series of dams in the upper
  Columbia River basin, even though
  government scientists concluded
  breaching was the best hope for wild
Atlantic Salmon also declining
                    The most critical
                     breeding-age fish
                     estimated at 2.5-5
                     million (originally)
                    800,000 (1975)
                    80,000 (1998)
                    Cross-breeding with less
                     hearty domesticated
                     salmon is suspected
Endangered Freshwater
Ecosystems & Organisms
         Dams, Channels and water
       diversions largely responsible
                                  Twenty   percent of the
   They have
                                   world’s freshwater
    fragmented nearly              species are extinct or
    60 percent of the              in peril
    world’s largest               At least 10,000
    rivers, seriously              freshwater fish
    degrading them.                species are threatened
               World Resources

               2000-2001           globally.
        Dam devastation
 In 1950: 5,270        Since Egypt's Aswan
  large dams             Dam completed in 1970,
 Today: there are       number of fish species
  36,500 large           harvested on the Nile has
  dams                   dropped by two thirds
                        Salmon are extinct in
                         much of the United
                         States due to dam
                         building, and are widely
                         imperiled elsewhere
  Channeling Death

 Channelized   waterways in
  1900 = almost 9,000
 Today = nearly 500,000
 Result: extinction of many
  species and dramatic declines
  in many others.
    Other insults threatening
     freshwater ecosystems
 Industrial discharges and agricultural and
  urban runoff
 Competition from nonnative species
  displace and drives native fish toward
 Overfishing,
    – e.g., is currently driving various sturgeon
      species toward extinction in the Caspian
      Sea and its tributaries.
   Is the Lake Winnebago Sturgeon next?
           Yet more insults
 Water   diversions
  – for agriculture and urban water supplies >> all
    native fish species in the lower Colorado River
    basin are either endangered or extinct
 Siltation
  – a major factor in the decline of endemic fishes
 Wetland      conversion
  – Half of the world’s wetlands destroyed in the
    last century.
              World Resources 2000-2001
Amphibian - Decline
  Frogs, toads, and salamanders
   going extinct and declining
  Primary cause: Destruction of
Declines are also occurring in
apparently undisturbed habitats
 (1)   Gastric brooding frogs (2 species), native
       to Australia, disappeared in the early
 (2)   The red-legged frog is no longer present in
       entire counties and valleys on the North
       American Pacific coast, where it was once
       abundant and common.
 (3)   The golden toad of Costa Rica was last
       seen in 1989.
       Golden Toads
Costa Rica (picture taken in 1989)
Amphibian - Deformities
 Since 1995, reports of malformed
   amphibians have increased. Suspects:
     funguses kill larvae and adult
  skin
  Non-nativepredators, such as
  voracious bullfrogs and trout, that kill
  native amphibian species.
Amphibian - Deformities
 EPA 2003: „Smoking Gun‟ study finds
   atrazine, a common pesticide, responsible
   for sexual abnormalities in frogs (producing
     company‟s scientists dispute the conclusions; and lead
     scientist resigned, complaining they tried to prevent the
     dissemination of the findings; a UF professor was
     implicated by the NY Times in the suppression effort.
 Atrazine is banned in 7 European, but not in
   North America.

    Other pollutants, including herbicides, insecticides and
     crop fertilizers remain suspects too.
Biodiversity Loss is also about
  declining genetic variety
 • Declining numbers fosters genetic
   “bottlenecks” which reduce genetic
 • Reduced genetic variety increases the
   vulnerability of species to disease by
   eliminating genetically resistant
The bottleneck
Main threats to Species
 Habitat destruction by logging and
  mining, for agricultural or human
  settlements and transportation
 Invasive Species introductions
   – Which eat or compete
     against/displace native species
   – Which reduce or eliminate food
     sources for native species
 Ecosystem Types

Not only species are at risk
 So are entire ecosystems
 North America‟s Ecosystems
Of North America‟s 116 large Ecoregions
 13 have biodiversity as great as in
  the Everglades
 32 are rated “globally outstanding”
 BUT  30 have shrunk 98% and are
 “critically endangered.”
            Source: "A Conservation Assessment of the Terrestrial Ecoregions of North
             America”, World Wildlife Fund
Endangered ecoregions
   Midwest‟s tallgrass prairies and oak savannas
    – have been almost entirely destroyed
   Southeastern pine forests (N. Florida)
    – Once supported one of the richest assemblages of forest-floor plants
      on earth, as well as now-endangered animals such as the red
      cockaded woodpecker and gopher tortoise.
    – Merely 2 percent of these forests remain
   Southern California Sage Scrub Ecosystems
    – These ecosystems, largely destroyed by intensive development,
      represent one of only five habitat groups on earth with
      “Mediterranean” climates.
    – Although these five habitat groups occupy only fragments of earth's
      surface, these unique habitats -- hot and dry in summer, cool and
      wet in winter -- they retain 20 percent of earth‟s plant species!
Endangered and Threatened
    Species in Florida
Atlantic Loggerhead          Hawksbill           Atlantic Green

        American Alligator               American Crocodile

        West Indian Manatee

Black Bear

                              Key Deer

Peregrine Falcon


Crested Caracara

                   Wood Stork                   Scrub Jay
       10 Million Years: period
      needed for recovery from
         extinction episodes
• Whether episode is massive or minor
• We may have already, or soon will
  have, destroyed enough species that
  recovery will require millions of years.
  • 10 million years is 20 times longer than
    we (Homo sapiens) have existed and
    longer than our species may persist.
          • From March 2000 study in Nature

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