Download Wetlands mind map

Wetlands mind map
Early European settlers believed the wetland areas of Australia to be little more than ugly, smelly, mosquito-infested
wastelands. Even into the twentieth century, much was done to destroy these vital ecosystems. Many were drained and
modified to provide farmland or to allow the construction of canal housing estates. Only in recent decades has their value
been fully recognised.
Wetlands come in a variety of forms, each with a
unique role to play.
Food webs
Wetlands form the basis of many of nature’s food webs. Regular inundation of the land ensures a rich supply of nutrients,
which promotes a biological diversity rivalling that of rainforests and coral reefs. Here, plant life and microscopic
organisms flourish. Valuable breeding and feeding grounds are provided for a vast array of birds, fish, prawns and frogs.
Without wetlands, commercial fish and shellfish industries would fail and migratory birds that depend on them would face
an uncertain future.
A typical wetlands ecosystem
© John Wiley & Sons Australia, Ltd 2005
2005-01-wetland.pdf
(Page 1 of 3)
Filtration
Wetlands also play an important role as nature’s filtration system. Mangroves, for example, have special roots called
pneumatophores, which are exposed to enable the plants to breath when the region is flooded. They trap sediments and
any toxic substances they may contain, preventing them from entering our waterways. They thus help to control water
quality in much the same way as a filter on your tap.
Water storage
Wetlands have also been likened to giant sponges. They store water during times of flood, soaking it up. This water is
then released slowly throughout the ecosystem, enabling ground water stores to be replenished via slow infiltration.
Erosion is also reduced as wetlands slow the velocity of the water and hold it, thus reducing its momentum and erosive
force.
Climate regulation
In addition, wetlands play a significant role in regulating global climate. Carbon is stored within wetland plants and soil,
preventing its release into the atmosphere as the greenhouse gas carbon dioxide.
Algal blooms a sign of an ecosystem out
of balance
Clearing and draining of wetlands for residential development are
having a dramatic impact on the environment and, in particular, on
the health and quality of our waterways. Toxins found in pesticides,
industrial waste and other compounds (both natural and man-made),
which would normally be filtered out as they pass through wetlands,
will now flow freely into major waterways. This will lead to an
overgrowth of organisms and the growth of toxic algal blooms.
Algal blooms pose a serious health risk for swimmers and native
marine life. The algae sucks oxygen from the water, killing marine
plants and organisms and causing skin irritations and other ailments
in humans. The effects slowly filter up through the food chain, and
can threaten the economic viability of fishing and shellfish industries.
© John Wiley & Sons Australia, Ltd 2005
2005-01-wetland.pdf
(Page 2 of 3)
Use the information in this worksheet and in the source listed as a reference to
complete a mind map in your workbook, predicting what could happen if wetlands
disappeared (either by deliberate or accidental destruction). It has been started for
you.
Erosion would
increase
Ground water
stores would be
reduced
Velocity and
momentum of
flood waters
would increase
Water storage after
floods would be
diminished
If all the
wetlands
disappeared …
Reference:
SOSE Alive Geography 2, pp. 130–1, 134–5,138–9, 188–9
© John Wiley & Sons Australia, Ltd 2005
2005-01-wetland.pdf
(Page 3 of 3)