Transcript Global Biodiversity

Global Biodiversity
What is Biodiversity?
We’ll get to that, but
first. . . .
Let’s take a step back
in time.
Whatever Happened to
HIM??
. . . or Them ???
Almost all dinosaurs became extinct.
But why?
Does anyone really know?—It was 65 million years ago!!!!!
Could it have been “natural”
extinction?
Natural extinction happens when a
species fails to adapt to the
environment (or changes in the
environment) as efficiently as other
species and eventually dies off.
May have played a role, but scientists think there
was a more dramatic contributing cause . . .
Thought to Be Global Climate Change of Unknown Cause
(External or Internal; Sudden or Gradual)
Mass Extinction
• When more than 50% (half) of all known,
living species become extinct in a short
period of time (less than 2 million years)
Is this just irrelevant
ancient history?
NO! ! ! ! ! ! ! !
Why it’s relevant:
• The mass extinction involving the
dinosaurs was only one in a series of
known mass extinctions. There have been
others. Some scientists think we are on
the verge of yet another in our lifetimes.
Tiger
Elephant
Manatee
Bald Eagle
Northern Wild Monkshood
Dwarf Lake Iris
Hungerford’s Crawling Water Beetle
Karner Blue Butterfly
What do these species have
in common with dinosaurs?
They, too could
become EXTINCT!
Species
• Group of organisms capable of
interbreeding (reproducing) with each
other but not with other groups.
Species at Risk—
2 types
• “Endangered Species”: Species that are at
risk of becoming extinct in the near future
throughout much or all of their habitat range.
• “Threatened Species”: Species that are at
risk but not yet in as much danger as
endangered species. They are likely to become
endangered in the near future.
Notes About Endangered
and Threatened Species
• NOT JUST ANIMAL SPECIES! Includes
plant and insect species as well.
• Worldwide, there are at least 1832
endangered or threatened species. And
that’s just the official list!
• Over 1,000 are found in the United States.
• About half the counties in the U.S. contain
endangered or threatened species.
What’s the connection
between endangered
species and “biodiversity?”
Biodiversity is…
• Variety among all levels of life on
Earth. The two main levels for
thinking about biodiversity are the
species level and the ecosystems
level.
• We’ll discuss the current threats to
biodiversity by first looking at species,
then we’ll discuss ecosystems. The
same threats affect both levels of
biodiversity.
What threatens biodiversity today?
(Among other
things) WE DO!!
Human civilization and economic
activity put pressure on aspects of
biodiversity. The present rate of
extinction is believed to be much
higher than can be explained totally
by natural causes. We must be
careful to balance our needs with
those of other species.
Three major human-related threats
to biodiversity
• Trade (and illegal poaching)
• Development/ Loss of
Habitat
• Pollution
Threat One: Trade
• What is trade? Trade is traffic in goods,
such as by gift, barter (swapping), or sale.
• People all over the world engage in trade,
on the local, national, or global level.
• Sometimes when species are taken from
the wild or from other settings to be traded,
we refer to this as harvesting the species.
How do harvesting and trade affect
species?
• Some species are hunted for their meat,
their fur, or other parts of their body (such as
elephants for their ivory). Some are sought
as pets. Some of this trade is legal, but
some is illegal (poaching).
• If too many species are hunted or harvested
too quickly, the species population may
shrink. Not enough young are born to
become adults and make up for those being
harvested.
• Other animals can be indirectly harmed in
the process of other animals being hunted
or harvested (such as dolphins caught in
tuna nets).
What is Poaching?
The illegal practice of trespassing on private
or protected property (such as national parks
or wildlife preserves) to hunt, fish, or steal
game.
Also includes illegally removing game, fish,
plants, or parts of animals to trade illegally.
Illegal hunting is a major problem for certain
wildlife populations around the world. In
some areas poaching is devastating wildlife
and its ecosystems.
Elephant poaching is a problem in many
countries. They are hunted mainly for their
ivory tusks.
In some countries, such as India, tigers are
poached for their skins, bones, and claws.
These poachers were caught by Indian
authorities.
Why poach?
• As species become more and more
endangered, each remaining specimen
becomes more and more valuable. Some
people are willing to pay a lot of money to
get rare goods associated with these
species. This creates an incentive for
people to hunt, or “take” the species, even
though they are protected by law. The
poachers want to make money from this,
which usually is more than they could make
at other jobs.
Regulating Poaching
• Many individual countries have enacted specific
laws outlawing poaching of various species and
their products.
• Some international laws have also been put in
place to outlaw trade in endangered species.
• But the behavior is difficult to control. Sale of
poached goods provides income for the
poachers, who do not want to stop.
Some plants are illegally traded
too!
• Agarwood, the fragrant wood produced by a
species of the Asian Aquilaria tree family,
may be over-exploited to commercial
extinction due to over harvesting and illegal
trade.
• Ocean plants are also sometimes illegally
traded, which harms other species in their
ecosystems
Threat Two: Development
“Development” refers
to processes that
transform a place to
make it suitable for
commercial or
residential purposes.
Development can threaten
biodiversity by:
Destroying animal’s habitats
Destroying some animals’ food sources
(such as plants)
Bringing pollution to previously
clean areas
Case Study in Development:
The Everglades
Where and what are the
Everglades?
The Everglades is home to a
variety of plant and animal
species, such as. . .
Mangrove trees
Blue
Herons
Florida Panthers
Florida Alligators
How are the species of the
Everglades threatened by
development?
• 900 people move to Florida each day
• 39 million people vacation in Florida
annually
• 12 million people spend the winter in
Florida
And all those people need…
Places to live,….