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2006 International Year of Deserts and Desertification
2006 was the International Year of Deserts and Desertification. This was also the World Environment Day (June 5) theme the year. Australia is the driest inhabited continent in the world, so this year's theme is very relevant. At the top of this page are some fast facts. Following is some brief information on the 2006 International Year and World Environment Day, and then more detailed facts and information on drylands, deserts and desertification. The last section has facts and information particular to Australia. For more information have a look at the websites for:
There are also other references down the bottom of this page.
· Approximately 44% of the world cultivated systems are found in drylands
· The Mediterranean Basin contains 11,700 plant species that do not grow anywhere else
· Dry and sub-humid lands provide genetic sources for one third of the plant-derived drugs available in the US
· Desertification threatens the livelihood of more than 1 billion people worldwide
The United Nations (UN) each year declares an international theme. On top of this, World Environment Day, commemorated each year on June 5th, is one of the major ways the UN stimulates worldwide awareness of the environment and encourages political attention and action. The theme for 2006 is Deserts and Desertification, underlining the UN General Assembly's concern for the exacerbation of desertification. It gives the message that desertification affecting drylands is a global problem we ignore at our peril, and also that drylands are home to unique natural habitats - the deserts - that deserve protection.
Before jumping into deserts and desertification, what are drylands? As the name suggests, these are areas in the world that are dry, characterised by low rainfall and high evaporation. This includes areas inhabited by people, in fact drylands are home to around one third of the world's population. Inhabited drylands all over the earth are facing a certain type of land degradation called desertification. The term drylands also includes areas where very few people live: the deserts. Deserts Deserts are unique habitats with incredibly diverse fauna and flora. These harsh, dry environments support a wide diversity of life that has specially adapted over time. The deserts of the world are unique in terms of their origin, evolutionary history and climatic patterns. (c) Such places have been described as having a fragile beauty, because the species evolved to live there are so specialised they are often vulnerable to any disturbance. Deserts have also been home to some of the world's oldest civilisations. (b) It is not just the biological diversity and the unique ecosystems, but also the cultural heritage that deserts hold which makes them so special. The section below on Deserts and desertification in Australia has examples of the diverse flora and fauna as well as desert people and culture found in Australia. Desertification Many people think that desertification means the moving forward or expanding of existing deserts. However, it actually refers to the formation, expansion or intensification of degraded patches of soil and vegetation cover. Desertification is the land degradation that occurs in arid, semi-arid and dry sub-humid areas and results from a variety of factors, including climatic variations and human activities. (c) In other words, desertification is land degradation that causes a place to become more 'desert-like', in the sense that conditions become as harsh as in a desert for survival. For many species this spells disaster in affected areas. This degradation currently endangers over 2,300 species. (i) Animals and plants that live in deserts have become highly specialised over long periods of time to survive harsh conditions. However, the process of desertification occurs far too quickly for most drylands species to adapt in time, resulting in reduction or loss of biological productivity. Land degradation in drylands also includes reduction or loss of the economic productivity of drylands. (c) This means that humans are included in those finding it increasingly difficult to undertake basic survival activities in areas affected by desertification. In a little over one decade, the number of people living in the drylands of the world has increased roughly fourfold from around 500 million in 1993 to more than 2 billion today. (d, a) The Food and Agricultural Organisation of the UN (FAO) defined drylands as those areas with fewer than 120 growing days per year, (d) which shows how difficult it already is to farm on drylands. Because there has been a phenomenal increase in population in these areas, and with desertification currently found on 10 to 20% of drylands, the issue is huge. (c) Land degradation in drylands affects one third of the world's surface and more than one billion people. It is estimated that the total land area affected by desertification is between 6 and 12 million square kilometres (by comparison the countries of Brazil, Canada and China are between 8 and 10 million square kilometres). (c) Drylands contain 43% of the world's cultivated lands. (c) Yet land degradation continues to cause millions of hectares of agricultural land each year to become abandoned, while global population and demand for food grows at a rapid pace. Desertification has potentially devastating consequences in terms of social and economic costs. (b) Food insecurity, famine and poverty are high on this list, with ensuing social, economic and political tensions with the possibility of creating conflicts, causing more impoverishment, and further increasing land degradation. (c) The reduced biological productivity does not merely raise a moral argument either, as many people in these areas depend heavily on the environmental services provided by biodiversity. The vulnerability of humans and other species in drylands is interconnected.
Australia is the driest inhabited continent in the world, with more than 70% of its area classified as arid or semi-arid. (e) Drylands in Australia are prominent, and face many of the same problems as drylands elsewhere in the world. According to the United Nations, most of the world's endangered dryland regions lie near the five main desert areas. This includes the Sonoran Desert in northwest Mexico and southwest USA, the Atacama desert in South America between the Andes and the Pacific Ocean, the large desert area running eastward from the Atlantic Ocean to China (which includes the Sahara desert in north Africa and the Arabian Desert, through to the deserts of China and Mongolia), the Kalahari Desert in southern Africa, and last but not least "most of Australia". (g) Deserts - Australia Australia's total desert area equates to 18% of the total mainland area. Australia has 10 deserts, including the Great Victorian, Tanami, Simpson, and Sturt Stony Deserts. (f) There are many amazing species that have adapted to live in Australian deserts. Here are a couple of plants and animals (from the South Australia Museum website (h) ) and their adaptations peculiar to living in harsh, dry environments. The spinifex hopping-mouse (Notomys alexis) does not need to drink. It lives on the water provided by the roots, seeds and insects that it eats. It can't sweat, because it has no sweat glands, and its kidneys waste very little water by producing highly concentrated urine. The spinifex hopping-mouse is active at night when it is cooler, and lives together in burrows, which increases the humidity in the burrow and reduces water loss. The spiny fan flower (Eremophila spinescens) is a long lived woody shrub that can survive for long periods without rain. It can drop its leaves in times of drought to conserve water. Its spines help protect it from herbivorous animals. A layer of star shaped hairs form a protective insulating microclimate and reduce water loss. Like many desert plants it avoids high water loss during the hottest part of the day by closing the pores (stomata) on its leaves and stems. The spiny fan flower has deep roots to search out moisture underground and help maintain water levels. The water-holding frog (Cyclorana platycephalus) lives like most other frogs when there is water after a rainstorm. But when the water begins to dry up, the frog digs down into the soft earth. It can stay alive buried for years. The outside layer of its skin comes off and the frog is protected by a waterproof bag of dead skin that stops it losing too much water. The frog stores water in its bladder, and slows down its body's workings, and breathes slowly. When it rains again, the frog eats its skin bag and digs to the surface and feeds. After laying eggs in the pools left after the rains, the eggs hatch quickly so the tadpoles change into frogs before the water dries up. The paper daisy (Leucochrysum fitzgibbonii) is an annual plant with a small, shallow root system and a covering of hairs which help conserve water in the leaves and stems. It grows rapidly, flowers and sets seed quickly after rain and dies when the earth dries. The seeds are dispersed by wind and can remain dormant for many years until the next substantial rain. Dormancy until water comes is a survival feature of both the water-holding frog and seeds of the paper daisy. Australia is highly urbanised, with a concentration of the population on the coastal fringe. Just 180,000 people reside in the centrally located arid zone of the continent of just 0.9% of the total population across 3.5 million square kilometres. Overall the desert region of the continent covers 5.3 million square km (69% of Australia) and is occupied by 573,000 people (3% of the total population). (e) The small percentage of Australia's population that lives in dryland areas is one difference between Australia drylands and those in other countries. The people who live in Australian dryland areas, however, still face many of the dryland problems faced elsewhere in the world. The rest of the population are also connected to and dependent upon the agriculture, biodiversity, and cultural heritage that Australian drylands hold.
In Australia, the transformation of habitats for human use has played a large role in bringing about desertification. Two commonly cited causes are overgrazing and deforestation. (more soon)
a) 'About World Encironment Day 2006', UNEP, http://www.unep.org/wed/2006/english/About_WED_2006/index.asp, accessed 12/5/06. b) 'Background - Desertification', International Year of Deserts and Desertification website, http://www.iydd.org/, accessed 11/5/06. c) 'Facts About Deserts and Desertification', UNEP, http://www.unep.org/wed/2006/english/Information_Material/FactSheet.asp, accessed 11/5/06. d) 'Key aspects of strategies for the sustainable development of drylands', FAO, http://www.fao.org/documents/show_cdr.asp?url_file=/docrep/T0752E/T0752E00.htm, accessed 12/5/06. e) 'Facts about desert Australia', Desert Knowledge Australia, http://www.desertknowledge.com.au/dka/documents/Facts%20about%20Desert%20Australia.pdf, accessed 12/5/06. f) 'Deserts', Geoscience Australia, http://www.ga.gov.au/education/facts/landforms/deserts.htm, accessed 12/5/06. g) 'The United Nations Convention to Combat Desertification: A New Response to an Age-Old Problem', UNDPI, http://www.un.org/ecosocdev/geninfo/sustdev/desert.htm, accessed 11/5/06. h) "Life and adaptations to water: Desert', South Australia Museum, http://www.samuseum.sa.gov.au/water/riteframe.htm, accessed 12/5/06. i) 'International Day for Biological Diversity', Convention on Biological Diversity, UNEP, http://www.biodiv.org/programmes/outreach/awareness/biodiv-day-2006.shtml, accessed 12/5/06.
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