Transcript CHAPTER 5: Biological Diversity and Conservation

CHAPTER 5:
Biological
Diversity
and
Conservation
Penguins are flightless birds living in the southern
hemisphere. Contrary to popular belief, they are not
found in only cold climates, such as Antarctica. The
largest species average about 1.1 meters (3 ft 7 in) tall
and weigh 35 kilograms (75 lb) or more. The smallest
penguin species stands around 40 cm tall (16 in) and
weighs 1 kilogram (2.2 lb). Generally larger penguins
retain heat better and inhabit colder regions, while
smaller penguins are found in temperate or even
tropical climates.and will occasionally cross the equator
while feeding.
5.1 Vanishing Species
A. Biodiversity = the variety of
organisms (number of different
species) in a given area
1. Where is Biodiversity Found?
Terrestrial biodiversity tends to
increase as you move towards
the equator.
Ex: Tropical regions contain 2/3 of
all land species.
• Large islands tend to
have greater biodiversity
than small islands
Hence, la Hispaniola has more
biodiversity than Puerto Rico
which has more diversity than
Aruba.
B. Importance of Biodiversity
1. Importance to Nature
-Organisms are adapted to
living in communities. (habitat,
niche, food chain, food web,
symbiotic relationships,
predators necessary to
maintain carrying capacity)
-Biodiversity brings stability
2. Importance to People
-dependent on other organisms
for needs: O2, CO2 removed,
diverse diet, clothes, furniture,
buildings, pharmaceuticals.
C. Loss of Biodiversity
-extinction: disappearance of
a species
-threatened species: population of a
species begins declining rapidly
-endangered species: numbers
become so low that extinction is
Possible
-hunting: entire species can
become endangered or extinct from
excessive hunting for food or other
products
-Critical because of the
interactions of ecosystems.
Unbalance could cause a collapse.
D. Threats to Biodiversity
1. Habitat Alteration /
Fragmentation
– Natural habitats can be
destroyed from developing land
– The habitats can be broken up
into patches of natural habitat
surrounded by developed land
(fragmentation)
biotic issues:
predation/reestablishment
abiotic issues: edge effect
2. Habitat Degradation
Pollution:
-Air:
- The Ozone Layer (O3) is toxic at
ground level but necessary in the
Earth’s atmosphere.
• It shields the biosphere from UV
Radiation from the sun, which is
known to cause cancer, damage eyes,
and harm plant tissue and
phytoplankton.
• CFC’s (Chlorofluorocarbons) react
with this vital atmospheric layer and
allow UV Rays to break apart ozone
molecules
• Acid Precipitation: from greatest
source of pollution … the burning of
fossil fuels
-Water:
-fertilizer, animal waste get into
runoff
 Algal Bloom
-eroded soil – clogs gills
-Detergent , metals, industrial
chemicals
in runoff
-Drift nets abandoned
NOTE: THE EXCESS NUTRIENTS IN RUNOFF
CAN CAUSE EUTROPHICATION: Having
waters rich in mineral and
organic nutrients that promote a
proliferation of plant life,
especially algae, which reduces
the dissolved oxygen content
and often causes the extinction
of other organisms.
BIOMAGNIFICATION
Pollution
Pollution from oil, pesticides like DDT, and
other chemicals have caused a
major decrease in
Biodiversity.
The concentration of
these pollutants inside
animals increases as it
travels up a food chain:
Biological Magnification
3. Introduction of Exotics
-harmless foreign plants and animals
are introduced into an ecosystem
-These new organisms have little
competition and thrive in their new
environments, devastating other life in
the ecosystem.
5.2 Conservation of
Biodiversity
Conservation: studies methods
and implements plans to protect
biodiversity
1. Legal protection of species:
US Endangered Species Act
2. Preserving Habitats –
-establishing parks and protected
areas
-sustainable use
-habitat corridors
3. Reintroduction Programs
-Captivity