Transcript Human uses of ecosystems

1. LIST 3 WAYS THAT ECOSYSTEMS ARE
IMPORTANT FOR HUMANS.
1. Ecosystems supply food, fuel, natural resources and
water.
2. Ecosystems cycle nutrients and decompose wastes.
3. Ecosystems regulate climate.
2. DEFINE THE TERM SUSTAINABLE USE
Sustainable use means using an ecosystem’s
resources in a way that meets our current
needs without compromising the ability of
future generations to meet their needs.
3. A) WHAT IS GENETIC DIVERSITY
Genetic diversity differences among individuals
of the same species. This comes from the fact
that we each have differences in our DNA.
B) WHY IS GENETIC DIVERSITY IMPORTANT TO MEMBERS OF A
SPECIES? HOW DOES IT IMPROVE SURVIVAL OF A POPULATION?
Differences in individuals help keep a population healthy.
Because we are all different, we have different
strengths and weaknesses that allow individuals in a
species to be able to cope differently should there be
a change in our environment.
Lack of genetic diversity in a population can threaten the
survival of a species.
C) DEFINE EXTINCTION AND GIVE ONE REASON
THAT THE LOSS OF GENETIC DIVERSITY CAN
CAUSE EXTINCTION
Extinction is the death of every member of a species. As
a population approaches extinction, the numbers of
individuals drops. This reduces genetic diversity
(there are few individuals able to reproduce, so their
offspring are genetically similar). Because of this, the
strengths and weaknesses of individuals are similar.
Should there be a change in the environment, there
may not be enough differences between individuals
for the species to survive.
EXTINCTION AND LOSS OF GENETIC DIVERSITY
In the spring of 1987, an American biologist went to the cloud forest of Costa Rica to
study Golden toads and counted fifteen hundred of them in temporary breeding
pools. That spring was unusually warm and dry and most of the pools evaporated
before the tadpoles in them had time to mature. The following year, only one male
was seen at what previously had been the major breeding site. Seven males and
two females were seen at a second site a few miles away. The year after, on May
15, 1989, the last sighting of only one male occurred. No golden toad has been
seen since then.
By 2004 IUCN listed the species as extinct IUCN gives numerous possible reasons in
its description of the past threats to the species, including "[the golden toad's]
restricted range, global warming, and airborne pollution“, as well as an increase
in UV-B radiation, fungus or parasites, or lowered pH levels contributed to the
Golden Toad's extirpation.
GOLDEN TOAD
D) HOW ARE THE TERMS BIODIVERSITY AND
GENETIC DIVERSITY DIFFERENT?
Biodiversity refers to the variety of ecosystems on Earth,
based on the number of different species that live in a
certain area.
Genetic diversity refers to differences in the DNA of
individuals of the same species. We are all a little
different from each other because our DNA is different
from each other. The exception to this is identical
twins, who have almost identical DNA.
4 A) DESCRIBE AND GIVE EXAMPLE OF HABITAT
CHANGE
Habitat change is the process by which humans alter a
habitat enough that the native species (the species that
normally inhabit the area) can no longer live there.
Example of habitat change is clearing a forested area for
agriculture, forestry or urban development. The animals
and plants that normally inhabited the forest now have
to find a new location to live in. This leads to greater
competition for resources between these organisms and
those in the location to which they move.
WHAT ARE 2 CONSERVATION STRATEGIES USED
TO REDUCE THE PROBLEM OF HABITAT CHANGE
FOR AT-RISK SPECIES?
1. Protecting species in human-made habitats (for
example, moving species to zoos). This is known as exsitu conservation. Species are removed from their
natural habitats (either because their habitat is
threatened or no longer exists, or population numbers
are so small) and brought to zoos, botanical gardens
or reserves. This is generally a last resort to
protecting a species.
2. Protecting species in their native habitats (in-situ
conservation) – this type of conservation focus on
maintaining habitats, removing predators, cleaning
and restoring habitats that have been damaged or
isolating a habitat by creating reserves.
B) OVEREXPLOITATION
Overexploitation is using a resource faster than it can be
replaced. In extreme cases, it can lead to extinction of a
species.
Example: over fishing of Atlantic cod. These fish were an
abundant species in the North Atlantic for centuries.
Advances in fishing techniques since the 1960s and 70s have
caused fish stocks to be taken at too fast a rate. Young fish
that normally would be too small to be caught in nets were
taken, resulting in too small of a young population to
reproduce and maintain the overall fish population. By 1990,
the fish stocks were so low that the fishery for Atlantic cod
was closed.
C) POLLUTION
Pollution is any substance that is added to an
environment that produces a condition that is harmful
to organisms.
Pollution can affect land (e.g litter), water (e.g oil from oil
spills) and air (e.g. exhaust from cars and industry).
LIST WAYS THAT GOV’T AND INDUSTRY RESTORE
POLLUTED ECOSYSTEMS OR PREVENT FURTHER
POLLUTION
Remedial action plans
1. Identify the source of pollution
2. Develop a plan to follow to fix the problems created by
the pollution
3. Restore the habitat (cut off the source of pollution,
clean up, habitat rebuilding)
4. When the problem has been cleaned up, monitor
conditions to ensure actions taken are effective
D) INVASIVE SPECIES
An invasive species is a non-native species that causes harm to the
ecosystem, usually by out-competing native species for resources
and through rapid reproduction.
An example of an invasive species is the European Starling. 100
European starlings were introduced to Central Park in New York
City in 1899. Now there are more than 200 million of these birds
all over North America. They out-compete native
starling species for nesting spaces and food,
and destroy grain and fruit crops.
See P. 66 the round goby
GIVE 2 EXAMPLES OF HOW GOV’T TRY TO
PREVENT THE SPREAD OF INVASIVE SPECIES
1. Establishing laws that prevent the movement of
potentially contaminated materials from a location
known to be home to invasive species to uninhabited
areas (e.g. laws to prevent movement of wood that
may contain Asian Longhorned Beetles)
2. Laws against the importing of foreign food, animals or
plants into the country
E) CLIMATE CHANGE
Climate change is a deviation from the average climate
that has occurred in an area over at least 30 years. It
can cause temperatures to rise or fall, the amount of
rainfall to increase or decrease, and wind directions to
change. Climate change is currently being driven by
global warming (an increase in the Earth’s average
temperature caused partly by an increase in carbon
dioxide in the atmosphere).
Global warming is largely due to increased burning of fossil fuels
and loss of large amounts of forested areas. Global warming has
caused rapid climate change. In
Arctic areas warming has resulted in
loss of ice packs, which is reducing
habitat for native species like polar
bears and walruses. Their populations
are
declining as a result.
5. NAME AN INVASIVE SPECIES IN ONTARIO. HOW HAS
IT AFFECTED NATIVE SPECIES? WHAT CAN BE DONE TO
ELIMINATE NEGATIVE EFFECTS ON ECOSYSTEM?
Dog-strangling weed – this was brought in as a garden plant from
Eurasia (southern Russia). It invades sunny hillsides and ravines.
It grows in dense colonies and chokes out native small trees,
plants and shrubs. It also affects
affects
Monarch butterflies, who lay eggs
their
eggs on the vine, but the larva
are not
unable to obtain the nutrients they
they
need from the vine, and
therefore die.
6. 3 STRESSES ON FRESHWATER LAKES IN ONTARIO,
AND HOW STRESSES AFFECT THE ECOSYSTEM
1. Motor boats – oil contaminates water and reduces
oxygen in water (affects fish and water organisms)
2. Sewage – raw waste increases nitrogen in water
3. Docks – disturbs fish spawning grounds and aquatic
vegetation
4. Boat wakes – waves disturb aquatic and terrestrial
vegetation and nesting sites
5. Beaches – removal of aquatic and terrestrial
vegetation causes habitat loss
6. Clearing shoreline – loss of shade in water (needed
for fish)
7.A) HOW DOES URBAN SPRAWL AFFECT
NIAGARA ESCARPMENT
Urban sprawl is the unplanned, disorganized growth of
urban and suburban development into the
surrounding countryside.
It has affected the Niagara Escarpment by resulting in
loss of forests, causing habitat change and habitat
fragmentation (dividing a large habitat into smaller
sections. It prevents organisms from using a large
area for finding food and shelter. When a habitat is
divided by roads, it can cause damage when
organisms try to cross busy roadways).
B) WHAT IS DONE TO PROTECT ESCARPMENT?
The Niagara Escarpment plan was established, which is
a land-use plan that focuses on environmental
protection. It has guidelines on how land in the
escarpment area can be developed (a more planned
and managed system to counter the effects of urban
sprawl).
8A WHAT IS CLEAR CUTTING AND HOW DOES IT
AFFECT BOREAL ECOSYSTEMS
Clear cutting is a logging process where all the trees in
an area are cut down at one time, regardless of size.
Clear cutting causes habitat loss and fragmentation, it
alters water flow and can lead to soil degradation.
B) WHAT MEASURES HAVE THE ONTARIO GOV’T TAKEN
TO MINIMIZE EFFECTS OF CLEAR CUTTING?
1. Companies have to plant new trees in areas that have
been clear-cut.
2. Companies are not allowed to cut down more trees
than they can replant in one year.
3. Companies have started using sustainable logging
practices
WHAT IS SUSTAINABLE FOREST MANAGEMENT?
WHAT PRACTICES MUST BE FOLLOWED TO BE
CERTIFIED?
Sustainable forest management is a practice whereby
forestry proceeds with logging, but it allows for the
resources to be available to future generations and
has a more limited impact on the environment.
This practice leaves forested areas near water ways that
prevent erosion of soil and reduces changes to water
flow). A variety of tree species are planted to allow for
more biodiversity in the area.