Team:Imperial College London/Project/Background

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   title[1] = "Sub-saharan Africa";
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   title[2] = "North American Plains";
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   text[0] = "Mouse over the map to read about the impact of desertification in different areas.";
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   text[0] = "Hover over the map to read about the impact of desertification in different areas.";
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   text[1] = "Africa is the region most affected by desertification. Two thirds of the continent is covered by dryland which is used extensively for agricultural production. Over-cultivation has led to large scale degradation, exacerbated by frequent drought, leading to extreme food scarcity for some 650 million people who are dependent on the affected land. If the degradation trend continues, it is estimated that two thirds of Africa’s arable may be lost by 2025 (FAO 2009). In an effort to combat desertification, 11 countries along the southern border of the Sahara are involved in the Great Green Wall project. With the help of international aid, the objective is to cover 8,000 km of dryland with vegetation as a protective barrier from erosive forces. However the operation is extremely time consuming and will take a long time before it is established.";
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   text[1] = "Africa is the region most affected by desertification. Two thirds of the continent is covered by drylands which are used extensively for agricultural production. Over-cultivation has led to large scale degradation, exacerbated by frequent drought, leading to extreme food scarcity for over 650 million people who are dependent on the affected land. If the degradation trend continues, it is estimated that two thirds of Africa’s arable land may be lost by 2025. In an effort to combat desertification, 11 countries along the southern border of the Sahara are involved in the Great Green Wall project. With the help of international aid, the objective is to cover 8,000 km<sup>2</sup> of dryland with vegetation as a protective barrier.";
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   text[2] = "Historically, North America has experienced one of the most extreme effects of desertification during the 1930’s. The famous dust bowls of the Great Plains were brought on by over-cultivation of land and severe drought, causing degraded soil to be swept up by strong winds. Today about three quarters of North America’s drylands are affected by desertification. Counter-measures include synthetic materials to protect dryland, trenches to collect water, and windbreak structures. The use of beneficial soil microbes to improve growth of cacti has also been explored in an effort to re-vegetate deserts.";
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   text[2] = "North America experienced one of the most extreme effects of desertification during the 1930s. The famous dust bowls of the Great Plains were brought on by over-cultivation of land and severe drought, causing degraded soil to be swept up by strong winds. Today, about three quarters of North America’s drylands are affected by desertification. Counter-measures include synthetic materials to protect dryland, trenches to collect water, and windbreak structures.";
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   text[3] = "China is one of the largest dryland areas in the world, nearly a quarter of which is at risk of desertification. The problem has been fed by large-scale industrialisation with the over-use of land and water resources, as well as prolonged drought. Since 1978 the Great Green Wall project has been underway in the Kubuqi desert to protect cities from wind erosion carrying dust. The trees (Xinjiang poplars and willow species) are planted as saplings protected with wooden frames so they can take root before being blown away. These plants form fibrous roots that help hold down the sand. Although this project has slowed the desertification process in China, it remains an imminent problem.";
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   text[3] = "China is one of the largest dryland areas in the world, nearly a quarter of which is at risk of desertification. The problem has been fed by large-scale industrialisation with the overuse of land and water resources, as well as prolonged drought. Since 1978 the Great Green Wall project has been underway in the Kubuqi desert to protect cities from dust storms. The trees (Xinjiang poplars and willow species) are planted as saplings protected with wooden frames so they can take root before being blown away. These plants form fibrous roots that help hold down the sand. Although this project has slowed the desertification process in China, desertification remains a pressing problem.";
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   text[4] = "30% of landmass in India is comprised of drylands and desertification is leading to crop losses of up to 41% in eastern Himalayan areas, which are recognised as biodiversity hotspots. Communities living in the Himalayas are heavily dependent on the forest as a resource for fuel wood and for their livestock. Increasing deforestation is leading to soil erosion and interference with water courses which is likely to have a major affect on inhabitants of the Ganges Plain who rely on the forest to slow flash floods. Small scale charities such as the Berkely Reafforestation Trust are working with local organisations to re-establish indigenous tree populations. So far they have funded the locally initiated reforestation of about 1600 hectares of degraded land and provided training programs to promote sustainability.";
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   text[4] = "In India, 30% of the landmass is comprised of drylands. Desertification is leading to crop losses of up to 41% in eastern Himalayan areas, which are recognised as biodiversity hotspots. Communities living in the Himalayas are heavily dependent on the forest as a resource for fuel wood and for their livestock. Increasing deforestation is leading to soil erosion and interference with water courses which is likely to have a major affect on inhabitants of the Ganges Plain who rely on the forest to slow flash floods. Small scale charities such as the Berkely Reafforestation Trust are working with local organisations to re-establish indigenous tree populations. So far they have funded the locally initiated reforestation of about 1600 hectares of degraded land and provided training programs to promote sustainability.";
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   text[5] = "In Australia, desertification and soil degradation are wide-spread problems in rangelands, particularly in the dry inner parts of the continent. They result from overgrazing of the land but also climate conditions and invasive animal species such as rabbits. Economic factors play a big role as pastoralism is mostly export and profit oriented. Land degradation has been was triggered by the arrival of European pastoralism and has been an ongoing problem for the last century.                                                                                                                                                                                                                         Source: Pickup, G. (1998) Desertification and climate change - the Australian perspective. Climate Research 11, pp.51-63.";
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   text[5] = "In Australia, desertification and soil degradation are widespread problems in rangelands, particularly in the dry inner parts of the continent. They result from overgrazing of the land but also climate conditions and invasive animal species such as rabbits. Economic factors play a big role as pastoralism is mostly export- and profit-oriented. Land degradation was triggered by the arrival of European pastoralism and has been an ongoing problem for the last century.<sup>[2]</sup>";
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<h1>Desertification</h1>
<h1>Desertification</h1>
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<p><b>Desertification is the degradation of drylands which include arid, semi-arid and sub-humid areas. Drylands make up roughly 40 percent of the Earth’s land and are home to some two billion people, most of which live in developing countries. Dryland soil sustains a fragile ecosystem adapted to infrequent precipitation and dramatic temperature changes. Over-exploitation of dryland for cultivation and feedstock purposes renders the soil unproductive, forcing migration of communities in search of fertile land, leaving the unproductive land bare and vulnerable to erosive forces. A lack of food supply in many developing countries forces constant cultivation of land for short-term gain as well as deforestation to provide arable land.</b></p>
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<p><b>Soil erosion and desertification are world-wide problems. They lead to loss of arable land, economic hardship and environmental degradation. Our project focuses on tackling these serious problems by engineering bacteria to enhance plant root growth. We are planning to implement our bacteria into a seed coat to aid re-vegetation of land at risk of erosion. Trees and plants help hold down the soil and prevent soil erosion which leads to desertification </p>
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<h1>Engineering bacteria to help fight soil erosion</h1>
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<p>In arid areas of the world soil erosion is a massive problem. It is caused by wind and rain sweeping away the fertile top soil and can eventually result in <i>desertification</i>.</p>
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<p>Climate change and unsustainable farming practices are accelerating the rate of desertification to over 31,000 hectares/day. That’s 62, 000 football pitches in a day or half the size of the UK every year.</p>
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<p>In ordinary circumstances the roots of well-established plants help to hold down the top soil, protecting it from erosion. In areas that suffer desertification however plants do not get the chance to establish large enough root networks to anchor the soil and themselves before erosion occurs.</p>
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<p>Desertification is the degradation of drylands which include arid, semi-arid and sub-humid areas. Drylands make up roughly 40 percent of the Earth’s land and are home to some two billion people, most of which live in developing countries. Dryland soil sustains a fragile ecosystem adapted to infrequent precipitation and dramatic temperature changes. Over-exploitation of dryland for cultivation and feedstock purposes renders the soil unproductive, forcing migration of communities in search of fertile land, leaving the unproductive land bare and vulnerable to erosive forces. A lack of food supply in many developing countries forces constant cultivation of land for short-term gain as well as deforestation to provide arable land.</p>
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<p>This year, Imperial College’s iGEM team have joined the international effort to fight desertification.</p>
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<h1>Case studies</h1>
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<p>We hope to engineer bacteria to accelerate plant root development. The bacteria will be designed to secrete the hormone auxin. Seeds will be coated with the bacteria and then planted in the soil. Once the seeds germinate the bacteria will move towards the roots and be taken in by the plant. Inside the roots the bacteria will release auxin – promoting growth and protecting the soil from erosion.</p>
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<h1>Case Studies</h1>
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<h2>Downstream Effects</h2>
<h2>Downstream Effects</h2>
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<p>Soil affects the climate and biodiversity and leads to often irreversible desertification (see figure above). Roots increase the stability of soil and prevent erosion (Gyssels & Poesen, 2003). In addition, trees provide cover and protect nearby fauna and flora. In areas prone to soil erosion, this is especially important as rainfall tends to be rare but when it does occur, it is often very intense and easily leads to topsoil being washed away.  
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<p>Soil erosion affects the climate and biodiversity and often leads to irreversible desertification (Figure 1). Roots increase the stability of soil and prevent erosion<sup>[7]</sup>. In addition, trees provide cover and protect nearby fauna and flora. In areas prone to soil erosion, this is especially important as rainfall tends to be rare but when it does occur, it is often very intense and easily leads to topsoil being washed away.</p>
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Roots are also important carbon sinks. Increasing root biomass is therefore very likely to improve the carbon budget of the plants we are seeding (Dr Alexandru Milcu, oral communication).</p>
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<p>Roots are also important carbon sinks. Increasing root biomass is therefore very likely to improve the carbon budget of the plants we are seeding (<a href="https://2011.igem.org/Team:Imperial_College_London/Human_Ecology">Dr Alexandru Milcu, oral communication</a>).</p>
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<p><i>Figure 1: The interplay between desertification, climate change, and biodiversity loss. Image taken from the Millenium Ecosystems Assessment - Desertification synthesis<sup>[1]</sup>.</i></p>
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<p><i>UN, Ecosystems and human well-being - Desertification synthesis.</i></p>
 
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<h2>References and Bibliography:</h2>
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<p>[1] Millenium ecosystem assessment (2005) <i>Ecosystems and human well-being: Desertification synthesis</i>. World Resources Institute, Washington, DC. (Online) Available from: http://www.maweb.org/documents/document.355.aspx.pdf</p>
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<p>[2] Pickup G (1998) Desertification and climate change - the Australian perspective. <i>Climate Research</i> <b>11:</b> 51-63.</p>
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<p>[3] UNCCD (2011) Desertification: a visual synthesis. (Online) Available from: http://www.unccd.int/knowledge/docs/Desertification-EN.pdf (Accessed on 12 August, 2011).</p>
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<p>[4] Science Daily (2007). Severity of desertification on world stage. (Online) Available from: http://www.sciencedaily.com/releases/2007/06/070619180431.htm. </p>
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<p>[5] The Encyclopedia of the Earth (2010). Desertification. (Online) Available from: http://www.eoearth.org/article/Desertification?topic=49461</p>
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<p>[6] Food and agriculture organisation of the United Nations. Desertification. (Online) Available from: http://www.fao.org/desertification/default.asp?lang=en </p>
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<p>[7] Gyssels G and Poesen J (2003) The importance of plant root characteristics in controlling concentrated flow erosion rates. <i>Earth Surface Processes and Landforms</i> <b>28:</b> 371-384.
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Latest revision as of 09:47, 25 October 2011




Desertification

Soil erosion and desertification are world-wide problems. They lead to loss of arable land, economic hardship and environmental degradation. Our project focuses on tackling these serious problems by engineering bacteria to enhance plant root growth. We are planning to implement our bacteria into a seed coat to aid re-vegetation of land at risk of erosion. Trees and plants help hold down the soil and prevent soil erosion which leads to desertification







Desertification is the degradation of drylands which include arid, semi-arid and sub-humid areas. Drylands make up roughly 40 percent of the Earth’s land and are home to some two billion people, most of which live in developing countries. Dryland soil sustains a fragile ecosystem adapted to infrequent precipitation and dramatic temperature changes. Over-exploitation of dryland for cultivation and feedstock purposes renders the soil unproductive, forcing migration of communities in search of fertile land, leaving the unproductive land bare and vulnerable to erosive forces. A lack of food supply in many developing countries forces constant cultivation of land for short-term gain as well as deforestation to provide arable land.


Case studies


Desertification
Mouse over the map to read about the impact of desertification in different areas.


Downstream Effects

Soil erosion affects the climate and biodiversity and often leads to irreversible desertification (Figure 1). Roots increase the stability of soil and prevent erosion[7]. In addition, trees provide cover and protect nearby fauna and flora. In areas prone to soil erosion, this is especially important as rainfall tends to be rare but when it does occur, it is often very intense and easily leads to topsoil being washed away.

Roots are also important carbon sinks. Increasing root biomass is therefore very likely to improve the carbon budget of the plants we are seeding (Dr Alexandru Milcu, oral communication).


Figure 1: The interplay between desertification, climate change, and biodiversity loss. Image taken from the Millenium Ecosystems Assessment - Desertification synthesis[1].



References and Bibliography:

[1] Millenium ecosystem assessment (2005) Ecosystems and human well-being: Desertification synthesis. World Resources Institute, Washington, DC. (Online) Available from: http://www.maweb.org/documents/document.355.aspx.pdf

[2] Pickup G (1998) Desertification and climate change - the Australian perspective. Climate Research 11: 51-63.

[3] UNCCD (2011) Desertification: a visual synthesis. (Online) Available from: http://www.unccd.int/knowledge/docs/Desertification-EN.pdf (Accessed on 12 August, 2011).

[4] Science Daily (2007). Severity of desertification on world stage. (Online) Available from: http://www.sciencedaily.com/releases/2007/06/070619180431.htm.

[5] The Encyclopedia of the Earth (2010). Desertification. (Online) Available from: http://www.eoearth.org/article/Desertification?topic=49461

[6] Food and agriculture organisation of the United Nations. Desertification. (Online) Available from: http://www.fao.org/desertification/default.asp?lang=en

[7] Gyssels G and Poesen J (2003) The importance of plant root characteristics in controlling concentrated flow erosion rates. Earth Surface Processes and Landforms 28: 371-384.

M1: Phyto-Route