Enviro2Go: Biodiversity

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Transcript Enviro2Go: Biodiversity

• “Biological Diversity” which means the
variety of life on Earth. This diversity
includes all the plants and animals which
are interconnected within ecological
systems. Biodiversity is one of the major
factors of a healthy and stable ecosystem
and it is vital for the world.
A population of sea urchins in a kelp forest ecosystem is being
overfished. A team of students believe that a decrease in the number
of sea urchins will affect the organisms in the kelp forest ecosystem.
The kelp forest food web below shows the relationships among the
organisms in the kelp forest ecosystem.
How stable is this ecosystem?
It’s not stable if it relies on one producer!
What would make this
more stable?
More biodiversity!
Biodiversity “hot spots” are places in the world
that have many different species living in one
place. Shade in the biodiversity “hot spots” of
the world below:
* In what biome are most of the “hot spots” found?
* What determines the type of biome that exists?
Biodiversity is threatened
by certain
1. Population growth:
increased need for
food and space.
This leads to
habitat loss.
Biodiversity is threatened
by certain biotic factors:
2. Deforestation, the
harvesting of trees for
This leads to
habitat loss
Biodiversity is threatened
by certain biotic factors:
3. Poaching- Illegal
hunting done by
humans that kills
animals for their
tusks, tortoise
shells, feathers, and
Biodiversity is threatened by certain biotic factors:
4. Invasive Species- species of plants and
animals occurring further than their normal
distribution within an ecosystem. Their
populations can grow out of control
because they have NO natural predators in
the ecosystems where they are introduced.
Often they can outcompete organisms in the
same niche. They can also introduce
pathogens and diseases that sicken and kill
other animals in the ecosystem.
– Invasive Species Example 1: The CANE
TOAD came from South America It was
introduced to Australia to eat cane grubs.
The cane toad did not eat grubs and
became a very big problem!
– Check out this video about cane toads!
Invasive Species Example 2
• Example 2: Zebra
Mussels came from
Asia transported in
ballast water. Their
populations grew so
out of control in some
U.S. waters they
clogged pipes of
wastewater facilities
creating a major
• Invasive Species Example 3: Snakeheads
from Canada and China introduced into the
Chesapeake Bay in 2002 compete with
native species for food (niches overlap!)
Biodiversity is threatened by
• Pollution- a harmful side-effect of
various activities .
– Eutrophication- when algae blooms deplete
oxygen levels in water.
– Bioaccumulation- when toxins become more
concentrated in successive trophic levels.
– Temperature- Increasing temperatures due to global
warming can impact the species that live in a delicate
range of temperatures like coral. This is known as
coral bleaching. Temperature can also increase the.
spread of disease.
Click here to see how coral reefs are threatened!
What are humans doing to
preserve biodiversity?
• Endangered Species A
list of organisms whose
populations are
threatened. If animals
become extinct
biodiversity is threatened.
The list promotes
awareness, preservation,
and legal consequences.
The list has over 1000
species! (Nearly half of
the species on the list are
there because of invasive
Endangered Species
• Often these animals like manatees,
elephants, and humpback whales have
few young only once a year or longer.
• Poaching in countries with few controls
• Habitat Loss caused by deforestation
and increasing human populations.
• So, man is making attempts to save as
many species as possible through public
awareness and special programs.
• Captive Breeding Programs: Mating
animals in parks, zoos and preserves to
increase threatened populations in the