Biodiversity and Conservation
Georgia Performance Standard:
Assess and explain human activities that influence
and modify the environment such as global warming,
population growth, pesticide use, and water & power
consumption.
Essential Questions:
EQ: What types of human activities can affect the biosphere?
EQ: What is the value of biodiversity?
EQ: What are the current threats to biodiversity?
EQ: What is the goal of conservation biology?
EQ: How could a worldwide increase in temperature affect organisms?
Chapter 5 Biodiversity and Conservation
Section 1: Biodiversity
Section 2: Threats to Biodiversity
Section 3: Conserving Biodiversity
Click on a lesson name to select.
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
What is biodiversity?
 Biodiversity is the variety of life in an area
that is determined by the number of different
species in that area.
 Biodiversity increases the stability of an
ecosystem and contributes to the health of
the biosphere.
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
 The variety of genes or inheritable
characteristics that are present in a population
comprises its genetic diversity.
 Genetic diversity increases the chances that
some species will survive during changing
environmental conditions or during the
outbreak of disease.
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
 The number of
different species
and the relative
abundance of each
species in a
biological
community is called
species diversity.
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
 The variety of ecosystems that are present
in the biosphere is called ecosystem
diversity.
 An ecosystem is made up of interacting
populations and the abiotic factors that
support them.
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
The Importance of Biodiversity
 Most of the world’s food crops
come from just a few species.
 Wild species serve as reservoirs
of desirable genetic
traits that might be
needed to improve
domestic crop
species.
Domestic corn plant
Teosinte plant
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
 Scientists continue
to find new extracts
from plants and
other organisms that
help in the treatment
of human diseases.
Madagascar periwinkle
Chapter 5
Biodiversity and Conservation
5.1 Biodiversity
 A healthy biosphere
provides many services
to humans and other
organisms that live
on Earth.
 Green plants provide
oxygen to the atmosphere and remove
carbon dioxide.
 Natural processes provide drinking water
that is safe for human use.
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Factors that Threaten Biodiversity
 The current high rate of extinction is due to the
activities of a single species—Homo sapiens.
 Humans are changing conditions on Earth
faster than new traits can evolve to cope with
the new conditions.
Threats to Biodiversity: Extinction &
Endangered Species
• Human activities are
altering trophic
structure, energy flow,
chemical cycling, and
natural disturbances.
• Humans and other
species depend on
these processes.
• Extinction occurs when a
species disappears from
all or part of its range.
• A species whose
population size is declining
in a way that places it in
danger of extinction is
called an endangered
species.
• As the population of an
endangered species
declines, the species loses
genetic diversity
Chapter 5
Biodiversity and Conservation
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Habitat Alteration and Fragmentation
• When land is developed,
natural habitats may be
destroyed. As habitats
disappear, the species that
live in those habitats
vanish.
• In addition, development
often splits ecosystems
into pieces, a process
called habitat
fragmentation.
• Habitat islands are
very different from
large, continuous
ecosystems.
• The smaller the
“island,” the fewer
species can live there.
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Fragmentation of Habitat
 The separation of an ecosystem into small pieces
of land is called habitat fragmentation.
 The smaller the parcel of land, the fewer species it
can support.
 Fragmentation reduces the opportunities for
individuals in one area to reproduce with individuals
from another area.
 Carving the large ecosystem into small parcels
increases the number of edges—creating edge
effects.
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Habitat Loss
 If a habitat is destroyed or disrupted, the native
species might have to relocate or they will die.
Destruction of Habitat
 The destruction of habitat, such as the clearing
of tropical rain forests, has a direct impact on
global biodiversity.
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Disruption of Habitat
 The declining
population of
one species
can affect an
entire
ecosystem.
Pollution
• In biological
magnification,
• Many forms of pollution
concentrations of a
can threaten
harmful substance
biodiversity, but one of
increase in organisms
the most serious
at higher trophic levels
problems occurs when
in a food chain or food
toxic compounds
web.
accumulate in the
tissues of organisms
• affects the entire food
web, although top-level
• EX: DDT
carnivores are at
highest risk.
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Pollution
 Pollution and atmospheric
changes threaten biodiversity
and global stability.
 Biological magnification is the
increasing concentration of
toxic substances in organisms
as trophic levels increase in a
food chain or food web.
Introduced Species
• Apparently harmless
plants and animals that
humans transport around
the world either
accidentally or
intentionally.
• Introduced into new
habitats, these organisms
often become invasive
species (exotic) that
reproduce rapidly.
• Invasive species
increase their
populations because
their new habitat lacks
the parasites and
predators that control
their population “back
home.”
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Overexploitation
 Overexploitation, or excessive use, of species that
have economic value is a factor increasing the
current rate of extinction.
 Bison
 Passenger pigeons
 Ocelot
 Rhinoceros
Rhinoceros
Ocelot
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Acid Precipitation (Acid Rain)
 Sulfur and nitrogen compounds react with
water and other substances in the air to form
sulfuric acid and nitric acid.
 Acid precipitation removes calcium, potassium,
and other nutrients from the soil, depriving
plants of these nutrients.
Assessing
Water Quality
The Formation of Acid Rain
Section 6-2
Chemical Transformation
Nitric acid
Sulfuric acid
Condensation
Emissions to Atmosphere
Nitrogen oxides
Sulfur dioxide
Dry Fallout
particulates, gases
Industry
Transportation Ore smelting
Power generation
Precipitation
Acid rain, fog,
snow, and mist
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Eutrophication
 Eutrophication occurs when substances rich
in nitrogen and phosphorus flow into
waterways, causing extensive algae growth.
 The algae use up the oxygen supply during
their rapid growth and after their deaths
during the decaying process.
 Other organisms in the water suffocate.
Chapter 5
Biodiversity and Conservation
5.2 Threats to Biodiversity
Introduced Species
 Nonnative species that are either intentionally or
unintentionally
transported to a
new habitat are
known as
introduced
species.
 Introduced species often reproduce in large numbers
because of a lack of predators, and become invasive
species in their new habitat.
Checkpoint!
• Natural resources are
materials that are
supplied by nature. A
renewable resource is
one that is replaceable.
• A nonrenewable
resource is one that
cannot be replenished
by natural processes.
Once a nonrenewable
resource is used up, it is
gone forever.
• Examine the list of natural
resources shown below.
Then, classify each natural
resource as either renewable
or nonrenewable.
a. Wood
b. Fossil fuels
c. Aluminum
d. Wool
e. Gold
• Describe the impact that the
loss of nonrenewable
resources would have on the
environment.
Human Activity:
EQ: What types of human activities can affect the biosphere?
• Humans take part in local
and global food webs and
chemical cycles within the
biosphere.
• Human activities can
change the flow of energy
in an ecosystem and
reduce the ability of
ecosystems to recycle
nutrients.
–
–
–
–
Hunting and gathering
Agriculture
Industry
Urban development.
Section 6-1
Human
Activities
that have changed the biosphere include
Hunting and
gathering
may have once caused
Industrial
growth
Agriculture
often relies on the methods of the
Extinctions of
large animals
Green
revolution
Food supply
Go to
Section:
Pesticide use
have resulted in
High standard
of living
which increased
Monoculture
use
Urban
development
Increased
pollution
Hunting, Gathering &
Agriculture
• Environmental
Benefit:
– Dependable supply of food
– Increase in nutrition (Green
Revolution)
– Domestication of animals
• Environmental Cost:
– Pesticides and fertilizers that
contaminate water and soil,
thus harming ecosystems
and changing biomes
forever.
– Overgrazing, erosion,
deplete water and energy
supply
Industrial Growth & Urban
Development
• The Industrial Revolution
– Large-scale agriculture
– Growth of cities
– Higher standard of living
• Depleted fossil fuels
• Pollute air, water, and
soil
• Farmland and natural
habitats are consumed
• Plant and animal
populations become
depleted
What is the goal of conservation
biology?
• Conservation biology is a goal-oriented
science that seeks to counter the
biodiversity crisis.
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
 Sustainable use means using resources at a
rate in which they can be replaced or recycled
while preserving the long-term environmental
health of the biosphere.
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
Protecting Biodiversity
 Currently, about seven percent of the world’s
land is set aside as some type of reserve.
 The United Nations supports a system of
Biosphere Reserves and World Heritage sites.
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
Natural Resources
 The consumption
rate of natural
resources is not
evenly distributed.
Land Resources
Sustainable Use:
• Plowing Soil erosion:
wearing away of
surface soil by water
and wind
• Farming, overgrazing,
and drought
Desertification
• contour plowing
• leaving the stems and
roots of the previous
year’s crop in place to
help hold the soil
• planting a field with
rye rather than
leaving it unprotected
from erosion
Forest Resources
– Temperate forests of the northeastern United
States can be considered renewable
– Old-growth forests in Alaska and the Pacific
Northwest are considered nonrenewable
• Takes a long time to grow back
• Contains a rich variety of species
• Deforestation erosion, grazing or plowing 
permanent changes to local soils and microclimates
that prevent the regrowth of trees
Forest Resources
• Sustainable Use:
– mature trees can be
harvested selectively to
promote the growth of
younger trees and preserve
the forest ecosystem
– Foresters plant, manage,
harvest, and replant tree
farms in places where
forests have already been
cut.
– Tree farms can now be
planted and harvested
efficiently, making them
fully renewable
resources.
– Tree geneticists are
also breeding new,
faster-growing tree
varieties that produce
high-quality wood.
Ocean Resources:
• Ocean Resources:
– Overfishing Fish populations declined
• Sustainable Use:
– limit the catch
– Aquaculture (farming of aquatic organisms)
• + produce animal protein.
• - can pollute water with fish wastes and
can damage local aquatic ecosystems
Air Resources:
• Air Resources:
– Burning of fossil fuels  pollute the air and cause smog
– Combustion processes release acidic gas  acid rain
kill plants and standing water ecosystems
– Sustainable Use:
• Automobile emission standards
• Clean Air Regulations on industries
Water Resources:
• Renewable Resource
– Total supply of fresh
water is limited
– Oil spills
– Sewage 
overgrowth of algae
and bacteria;
disease
• Sustainable Use:
– Wetlands purifying
water that passes
through them.
– Water treatment
plants
Sustainable Agriculture
Cover Crops
Legumes, grasses, and other
cover crops recycle soil
nutrients, reduce fertilizer
need, and prevent weed
growth.
Contour Plowing
Contour plowing reduces
soil erosion from land runoff.
On hilly areas, plowing is
done
across the hill rather than
straight up and down.
Controlled Grazing
By managing graze periods and herd
densities, farmers can improve
nutrient cycling, increase the
effectiveness of precipitation, and
increase the carrying capacity of
pastures.
Biological Pest Control
The use of predators and
parasites
to control destructive insects
minimizes pesticide use as well
as crop damage
Crop Rotation
Different crops
use and
replenish
different
nutrients.
By rotating
crops, the loss
of important
plant nutrients
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
 Resources that are replaced by natural
processes faster than they are consumed
are called renewable resources.
 Resources that are found on Earth in limited
amounts or those that are replaced by natural
processes over extremely long periods of time
are called nonrenewable resources.
Renewable and Nonrenewable
Resources
• Renewable resources
can regenerate and are
therefore replaceable.
– not necessarily unlimited
– Ex: trees, freshwater
(can be limited by
drought and overuse)
• Nonrenewable
resources cannot be
replenished by natural
processes.
–
–
–
–
fossil fuels
Coal
Oil
Natural gas
Chapter 5
Biodiversity and Conservation
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
Restoring Ecosystems
 The larger the
affected area, the
longer it takes for the
biological community
to recover.
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
Bioremediation
 The use of living
organisms, such as
prokaryotes, fungi, or
plants, to detoxify a polluted area is called
bioremediation.
Chapter 5
Biodiversity and Conservation
5.3 Conserving Biodiversity
Biological Augmentation
 Adding natural predators to a degraded
ecosystem is called biological augmentation.
Ladybugs help control aphid populations.
Photo courtesy of Nature’s Control
Checkpoint!!
1. List three ways in which other organisms have
proved to be a benefit to humans.
2. Compare biodiversity with other natural resources,
such as wood and fossil fuels. Do you think
biodiversity is a renewable or a nonrenewable
resource? Explain your answer.
3. What can be done to preserve the biodiversity of
organisms?