Measurements of the State of the Environment 1 Erosion 2 Salinity 3 Land Clearing 4 Over Irrigation 5 Pests 6 Introduced marine species <ul><li>7 Loss of river flow </li></ul><ul><li>8 Soil Acidity </li></ul><ul><li>9 Vegetation loss </li></ul><ul><li>10 Greenhouse gas emissions </li></ul><ul><li>Habitat modification </li></ul><ul><li>Biodiversity </li></ul>
Erosion Soil erosion is a natural process. Human interaction has in many cases speed up the process of erosion. What have we done to speed up the process? Clearing vegetation introduced species (rabbit, cow, buffalo ) Increased water sheeting
Examples: Beach Creek erosion Dust storm Land slips
Soil erosion removes the topsoil. The removal of the topsoil removes nutrients from the location, which are essential for plant growth and animal nutrition. The soil also clogs up the rivers and creeks, which affects the river wild life and causing lowland flooding. Possible solutions to erosion:
Solutions <ul><li>Eradicate feral animals </li></ul><ul><li>Plant more vegetation </li></ul><ul><li>Improve drainage </li></ul><ul><li>Monitor sensitive farming areas </li></ul><ul><li>Restrict people from access altogether </li></ul><ul><li>Restrict actives during sensitive times (winter) </li></ul>
Mostly caused by irrigation and tree clearing. Over irrigation causes water tables to rise, causing water logging and root rot. In dry areas salt is brought to the surface with the rising of the watertable which in turn kills off the plants that cannot tolerate the salty conditions. Solutions?
Solutions <ul><li>Plant Salt tolerant trees to soak up water </li></ul><ul><li>Pump away ground water </li></ul><ul><li>Restrict Land clearing </li></ul><ul><li>Change farming practices - Crop rotations </li></ul>
Introduced Marine Species Many marine species are accidentally introduced. They have arrived in the ballast water of ships. Ships enter ports often only carrying water in their hulls for stability in the water. They then discharge this water (only with many foreign species) into the harbors when loading up with other materials Solutions?
Introduced marine species Northern pacific sea star Asian green mussel New Zealand half crab Japanese Kelp
Solutions <ul><li>Treatment of ballast water before discharge </li></ul><ul><li>How can this be done? </li></ul>
Loss of River flow Hydroelectricity, irrigation and town water supplies have dramatically altered river flows. E.g. Snowy river (hydroelectricity) West Barwon dam (town water) Murray river (irrigation) Solutions?
Solutions <ul><li>Release more water to original water flow. </li></ul><ul><li>Remove dams/wiers </li></ul>
Soil acidity Is caused by too much fertilizer on crops, legume crops and wet land drainage Solutions?
Vegetation Loss Carbon sinks – air quality, trees absorb the carbon from, the atmosphere Affects habitats for birds animals and insects. Water quality and quantity, increases erosion From grazing, housing, logging, mining, crops
Greenhouse Gas Emissions (worksheet) Greenhouse effect: global warming caused by the release ‘greenhouse gases’ that act as a thermal blanket trapping heat. Gases include Carbon dioxide, methane, and CFC’s. All occur naturally but have risen dramatically since the industrial revolution.
<ul><li>Australia </li></ul><ul><li> Over the past 200 years Australia has: </li></ul><ul><li> Cleared the forested areas in half </li></ul><ul><li> Introduced hard-hooved animals </li></ul><ul><li> Over grazed most areas </li></ul><ul><li> Raised water tables by over irrigation and deforestation </li></ul><ul><li>Increased soil erosion </li></ul>
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