Science by Email 11 May 2012

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	11 May 2012
News: Decade of drought comes to an end By Patrick Mahony Drought is one of Australia's most costly natural disasters. Australia is officially no longer in drought. Drought declarations in Bundarra and Eurobodalla in New South Wales expired last week, meaning Australia is drought-free for the first time in more than ten years. Recent heavy rains across many areas of the country eased dry conditions. Drought is not simply a lack of rain. If that were the case, many areas of inland Australia would be almost permanently in drought. In fact, there is no universal definition of a drought. One definition, according to the Bureau of Meteorology, is "a prolonged, abnormally dry period when there is not enough water for users' normal needs". This definition is useful as it takes into account different communities' water needs as well as local average rainfall. Drought is one of the most costly natural disasters to affect Australia. Drought leads to reductions in crop yield and herd size, which affect local and national economies. The stress and strain of drought has social impacts as well, such as rises in mental illness and the decline of rural communities. Drought also contributes to environmental issues such as erosion and bushfires. Australia is particularly prone to drought because of its geography. Many droughts in Australia are related to the El Niño Southern Oscillation, but there are a range of ocean and atmospheric phenomena that can have an impact. One of the possible impacts of climate change is an increase in the number and severity of droughts. Reducing carbon emissions, developing drought-resistant crops and climate research are some of the strategies used by organisations such as CSIRO and the Department of Agriculture, Fisheries and Forestry to lessen the impact of drought. More information Australia to be drought free Living with drought Climate dogs CSIRO link: Drought and farming Careers link Careers in agriculture
You will need these materials.   Cover one container with tape.   Line the containers with paper towel, sprinkle a layer of seeds over each and spray with water.   Put the container labelled 'cold' in the fridge each night. Place the others in a warm, sunny area. Try this: How does your garden grow? Part 2: Temperature   You will need Cress or mustard seeds (available from garden stores) Paper towels Plastic containers with lids Water in a spray bottle Black tape Marker What to do Line 4 plastic containers with paper towel. Cover one container with tape. Label one container 'cold'. Sprinkle a layer of seeds over the paper towel in each container. Spray water into the seed containers so the paper towel is well moistened. Place a lid on the taped container, the container labelled 'cold' and one of the other containers. Put the containers in a bright, well-lit place. Each night put the 'cold' container in the fridge. Each morning, take it out and put it with the others. Observe a few times a day, and spray with water in order to keep the paper moist. (You will probably have to water the lidless container more than the others to keep the paper moist.) Check on your sprouts every day. Observe any differences between the containers. When your sprouts are fully grown you can pick, rinse and eat them! What's happening? The air inside the containers absorbs heat from sunlight. Putting lids on the containers traps the air inside, raising the temperature. The black tape also absorbs heat, raising the temperature even further. Different types of plants grow better in different temperatures. Some have evolved to survive freezing polar conditions, while others grow in the scorching heat of the desert. In this activity, raising the temperature slightly can promote plant development, making them grow faster and bigger. The seeds in the 'cold' container grow much slower than the others, even though they receive a similar amount of sunlight. In some cases, raising the temperature too high can cause the plants to become stressed, so they don't develop as well as they would at room temperature. Applications Many crops grow best within a certain temperature range. With average global temperatures predicted to rise in the future, this has the potential to change crop yields or even damage crops. One way to deal with these predicted temperature increases is identify genes for heat tolerance and incorporate them into crops such as wheat and cotton to create new, heat-tolerant plant varieties. By Patrick Mahony CREST question: Is temperature the only variable that changes? Design and carry out an experiment to investigate variables other than temperature.   This is the second activity in the series 'How does your garden grow?' Try the first activity on water. More information DAFF: Adaptation project summaries CSIRO: Developing climate change resilient agribusinesses CSIRO: Adaptation science View the online version Quiz questions 1. How many seconds are there in 20 minutes? 2. Oncologists specialise in which branch of medicine? 3. An ozone molecule is made of three atoms of which element? 4. Ohm's law links voltage and current to which property of electrical conductors? 5. How many nuclear reactors are there in Australia? Did you know? Nimbadon are ancient relatives of modern wombats. They were the size of sheep, lived in trees and resembled koalas. Websites Watch it! What lurks at the bottom of the ocean? Find out in this video! Do it! How much do you know about Australian birds? Take this quiz to find out! Events National: Science and Engineering Challenge The University of Newcastle's Science and Engineering Challenge aims to inspire students to study science and engineering at a senior level. The challenge runs at a variety of locations across Australia. Schools compete as teams in a variety of challenges, such as building bridges, cracking codes and designing hovercraft. Successful schools may also earn the right to participate in Super Challenges! More information can be found at the University of Newcastle website. Crystals, Saturday 12 May at 9.00 am on Network Ten What do table salt and diamonds have in common? They're both crystals! From their internal structure to their unique beauty, crystals are sparkling with science. Join Dr Rob as he once again proves that the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 17 May: Animal homes Saturday 19 May: Solo sports Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. There are 1 200 seconds in 20 minutes. 2. Oncologists specialise in the diagnosis and treatment of cancer. 3. An ozone molecule is made of three oxygen atoms. 4. Ohm's law links voltage and current to the resistance of electrical conductors. 5. There is one nuclear reactor in Australia. The OPAL reactor is a research reactor located at Lucas Heights in New South Wales. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Jasmine Leong| Manage your subscription | FAQ

 

 

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