The United Nations states land degradation as:
"the reduction or loss of the biological or economic productivity and complexity of rain-fed cropland, irrigated cropland, or range, pasture, forest, or woodlands resulting from natural processes, land uses or other human activities and habitation pattern such as land contamination, soil erosion and the destruction of vegetation cover"
This map produced by the National Geographic shows Australia's position relative to the world as you can see on the lower left. The capital cities of each state is named and the Darling River is drawn on the map. The Murray Darling Basin is one of the most important rivers to Australia's agricultural industry and facing one of the most problems due to the over-usage of the water system.
Source: National Geographic
Australia
The Australian land is unique in comparison to countries in the Northern Hemisphere. The geological stability has led to the non-renewal of soil leading to more fragile and mineral-deficient soil as without volcanoes, soil slowly lose all their nutrients and minerals. However, Australia has a countless number of endemic animals located within the continent and this forms a dynamic and complex ecosystem and thus Australia is the only developed nation to have a 'megadiverse' status. The diverse flora and fauna is a result of hundreds of centuries of evolution for the animals to match the drier climate of Australia, which is the driest continent in the world (besides Antarctica). The high rainfall variability from one year to the next have also helped in the development of these endemic flora and fauna. Another factor that may have influenced this is that for 50,000 years, Aborigines have maintained the land of Australia in an environmentally sustainable way and European settlement on Australia has only just passed 200 years, years which has involved industrialization and non-environmental sustainable practices. Two thirds of Australia's land have been modified for human use, further showing that industrialization has changed the natural processes in Australia.
The Australian land is classified into 6 main groups (see figure 3): Equatorial, Tropical, Subtropical, Desert, Grasslands and Temperate. The Summer/Autumn/Winter/Spring pattern occurs in the Temperate, Grassland and Desert climatic zones while the Wet/Dry pattern occurs in the Equatorial, Tropical and Sub-tropical zones.
Equatorial climate (also know as Tropical rain forest climate) only occurs in the northernmost areas of Australia. It normally rains heavily while retaining a hot climate. The characteristics of each day is very similar due to the proximity to the equator. Tropical Climate is found underneath areas with equatorial climate. As figure 3 shows, tropical climate occurs on the northern tips of Australia. The tropical climate is Australia is classified as tropical savanna climate and the rainfall is between 60-120 mm each month. Sub-tropical Climate normally lies between latitudes of 25° and 40° of both the Northern and Southern Hemisphere and thus occurs on the upper right of Australia's landmass. The rainfall ranges from 1000mm-2000mm yearly and temperatures are quite high. The sub-tropical area contains one of the few soils in Australia that is naturally high is soil nutrients. Desert Climate covers most of Australia. The temperature is consistently over 40°C and due to the lack of rainfall there, the soil is very dry and prone to water and wind erosion. Most of Australia's deserts are located within the continent as the climate there is drier and harsher, allowing natural desertification. Grassland Climate boarders the areas that are covered by the desert (as figure 1 shows). This is most likely due to the sufficient rainfall (between 600-1200 mm) to support grass and smaller plants but not enough to support large rain forests. Temperate Climate occurs mostly around southern coastal areas such as Sydney and Melbourne, both very populous cities. The less harsh temperatures and higher rainfalls allows the climate to support nutrient rich soils and thus lots of vegetation. However due to the number of farms being based in this area, severe land degradation is a big problem. |
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Figure 1: A climate map produced by the Australia Government in 2005 showing the types of climates in Australia, differentiated with colours. The different climates is based on a modified Koeppen classification system. The key cities are listed on the map. This map is to scale, the key is on the bottom left.
Source: https://www.humanrights.gov.au/sites/default/files/content/
social_justice/nt_report/ntreport08/images/ch5_2big.jpg
While the drier climate and high rainfall variability have led to Australia having a 'megadiverse' status but from an economic standpoint, Australia's environment is not suited to many farming practices currently used. Only 6% of Australia's soil is arable without treatments such as irrigation. This low number is due to the fact that most of Australia's soil is either too high in salt stores, too shallow, prone to water logging or acidity. More land is made available by pumping water from surface and groundwater sources to make the land more arable for farming and the use of ploughing the soil has allowed more mineral rich soil to be expose d to the surface. However this practice has allowed more soil to be eroded away further acceleration the rate of land degradation and loss of top soil.
Drought is a major problem that farmers face very often compared to counterparts in the Northern Hemisphere, this leads to increased soil and wind erosion which increases the loss of top soil in Australia.
Drought is a major problem that farmers face very often compared to counterparts in the Northern Hemisphere, this leads to increased soil and wind erosion which increases the loss of top soil in Australia.
Australia's reliance on it's soils.
Agriculture in Australia is a industry that earned AU$8944 Million and made up 11.0% of Australia's Gross Domestic Product (GDP) in 2014. Figure 2 shows the increased of the total agricultural value in Australia while Figure 3 shows a decline in GDP trend over the years.While these statistics might be contradictory, the reason to this is due to the rise of secondary (manufacturing), tertiary (service), quaternary (knowledge-based) and quinary (human services) production in Australia. Although the sector have been contributing less to the overall GDP of Australia, the earnings have increased consistently. Due to the increased demand, the land usage has risen to record highs and in turn, this has led to increased levels of land degradation which is now a major problem that if not stopped will lead to increased flooding in over utilized lands and lead to loss of arable land in Australia which is a scarce resource in Australia, only 6% of the total soil in Australia is arable.
Figure 2: This line graph produced by the Australia Bureau of Statistics shows the increase of the total Agricultural value in Australia from 2001-2011. This increase is due to increased demand from overseas countries
Source: http://www.abs.gov.au/ausstats/[email protected]/Products/7503.0~2010-11~Main+Features~Summary?OpenDocument
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The agriculture industry of Australia relies on the productivity of the soil however increased land degradation has led to decline in the productivity of soils which costs farmers and the economy money. This has been caused by multiple factors such as erosion, fertility decline, overuse of pesticides and over saturation of salt in the soil. Factors such as erosion has been made worse by weather conditions such as the effects of global warming and other human activities that includes the pollution of the natural environment. This problem is now affecting farming in Australia as well as a general decline in health of the environment. If these problems are not treated, they will become more expensive as time goes on and the economic cost will increase per year.