Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
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)