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Interrelationships
The Earth has
limited to resources to support populations of humans and
other organisms. Our ever increasing human numbers
is depleting many of our planet's resources and placing severe
stress on the natural processes that renew many of our
resources.
Ecosystem
Processes
Natural
ecosystems are involved in a wide variety of natural processes
influencing humans and other organisms. The
activities of humans in the environment are changing many of
these natural processes in a harmful
fashion. Some of these natural processes and
a brief description of a human influence on these processes is
indicated in the table which follows.
|
Human Influence on Some Ecosystem
Processes |
|
Ecosystem Process |
Human Influence |
|
Generation of Soils |
Agricultural practices have exposed soil to the
weather resulting in great loss of topsoil. |
|
Control of the Water Cycle |
The cutting of forests and other human activities
have allowed increased uncontrolled runoff leading to
increased erosion and flooding. |
|
Removal of Wastes |
Untreated sewage wastes and runoff from farms and
feedlots have led to increased water pollution. |
|
Energy Flow |
Some industries and nuclear plants have added thermal
pollution to the environment. The release of
some gases from the burning of fossil fuels may be
slowly increasing the Earth's temperature.
(Greenhouse Effect). |
|
Nutrient Recycling |
The use of packaging material which does not break
down, burning of refuse, and the placing of materials in
landfills prevents the return of some useful materials
to the environment. |
Some
Detrimental Human Activities
Humans are part of the Earth's ecosystem. Human
activities can either deliberately or inadvertently alter the
balance of an ecosystem. This destruction of
habitat, whether accidental or intentional, is threatening the
stability of the planet's ecosystems. If
these human influences are not addressed, the stability of
many ecosystems may be irreversibly affected. Some
of the ways that humans damage and destroy ecosystems are
indicated in the table below.
|
Some Ways Humans Adversely Influence
Ecosystems |
|
Human Influence |
Effect on Ecosystems |
|
Population growth |
Our increasing numbers are using excessive amounts of
the Earth's limited resources. |
|
Overconsumption |
Industrialized societies are using more resources per
person from our planet than people from poor nations. |
|
Advancing Technologies |
Often we introduce technology without knowing how it
will influence the environment |
|
Direct Harvesting |
This has resulted in a large loss of rainforest and
the many products associated with its biodiversity. |
|
Pollution |
Land, air, water, and nuclear pollution have had many
adverse influences on ecosystems. |
|
Atmospheric Changes |
These include the addition of Greenhouse gases mostly
due to the burning of fossil fuels and depletion of our
stratospheric ozone layer.
Other pollutants also have negative effects on living
things. |
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