Atmospheric carbon dioxide levels rise, so does the pressure on the plant kingdom. The hope among policymakers, scientists and concerned citizens is that plants will absorb some of the extra CO2 and mitigate the impacts of climate change. For a few decades now, researchers have hypothesized about one major roadblock: nitrogen.
Scientist Adam Langley sprays plants in a test chamber with nitrogen. The additional nutrients changed the composition of the plants inside the chamber, spurring the growth of grasses that respond weakly to elevated levels of CO2. (Credit: SERC)
Plants build their tissue primarily with the CO2 they take up from the atmosphere. The more they get, the faster they tend to grow -- a phenomenon known as the "CO2 fertilization effect." However, plants that photosynthesize greater amounts of CO2 will also need higher doses of other key building blocks, especially nitrogen. The general consensus has been that if plants get more nitrogen, there will be a larger CO2 fertilization effect. Not necessarily so, says a new paper published in the July 1 issue of Nature.
The sedge, Schoenoplectus americanus, initially reacted as expected. However, after the first year something unanticipated happened. Two grass species that had been relatively rare in the plots, Spartina patens and Distichlis spicata, began to respond vigorously to the excess nitrogen. Eventually the grasses became much more abundant. Unlike sedges, grasses respond weakly to extra CO2 and do not grow faster. Thus, the nitrogen ultimately changed the composition of the ecosystem as well as its capacity to store carbon.
Megonigal and Langley placed 20 open-top chambers over random plots of plants. The chambers were 6 feet in diameter and had 5-foot-tall transparent plastic walls.
The large, plastic pods allowed the scientists to manipulate CO2 concentrations in the air and nitrogen levels in the soil. Half of the plots grew with normal, background CO2 levels; the other half were raised in an environment with CO2 concentrations roughly double that amount. Similarly, half of the chambers were fertilized with nitrogen and the other half were untreated.
This study was supported by the U.S. Geological Survey and U.S. Department of Energy. The Smithsonian scientists recently received funding from the National Science Foundation that will sustain the research for another 10 years.
Source: www.sciencedaily.com
Friday, July 30, 2010
Saturday, July 17, 2010
Camouflage by Joe Haldeman(2nd book review)
This is the second book that I am reading and its title is camouflage.
This a very interesting science fiction book about two aliens of Earth. One is the changeling and the other is the chameleon. The changeling survived by taking shapes of differnt organisms like the great whita shark and other animals, while the chameleon survived by destoying anything that threatens it. Both knew llittle about each other but the chameleon decides that he must kill the changeling. The book then continues about the adventure of the changeling and also about the chameleon and also about a biologist Russell Sutton. Russell found an artifact and is studyign it and both the aliens are also drawn to it. The chameleon and changeling later fought together and later the chameleon died and the changeling went back to its planet. This novel is very interesting in the adventures of the changeling which is the main part of this book. The story is clearly easy to understand and the ending is also satisfying. A very interecting and enjoyable book. Read it some day :)
Author: Joe haldeman
Haldeman's most famous novel is The Forever War (1975), inspired by his Vietnam experiences, which won both the Hugo and Nebula Awards. He later turned it into a series. Haldeman also wrote two of the earliest original novels based on the 1960s Star Trek TV series universe, Planet of Judgment (August 1977) and World Without End (February 1979). In October 2008 it was announced that Ridley Scott will direct a feature film based on The Forever War for Fox
Haldeman has written at least one produced Hollywood movie script. The film, a low-budget science fiction film called Robot Jox, was released in 1990. He was not entirely happy with the product, saying "to me it’s as if I’d had a child who started out well and then sustained brain damage".
He is a lifetime member of the Science Fiction and Fantasy Writers of America (SFWA), and past-president.
Haldeman is the brother of Jack C. Haldeman II (1941-2002), also a science-fiction author whose work included an original Star Trek novel (Perry's Planet, February 1980).
This a very interesting science fiction book about two aliens of Earth. One is the changeling and the other is the chameleon. The changeling survived by taking shapes of differnt organisms like the great whita shark and other animals, while the chameleon survived by destoying anything that threatens it. Both knew llittle about each other but the chameleon decides that he must kill the changeling. The book then continues about the adventure of the changeling and also about the chameleon and also about a biologist Russell Sutton. Russell found an artifact and is studyign it and both the aliens are also drawn to it. The chameleon and changeling later fought together and later the chameleon died and the changeling went back to its planet. This novel is very interesting in the adventures of the changeling which is the main part of this book. The story is clearly easy to understand and the ending is also satisfying. A very interecting and enjoyable book. Read it some day :)
Author: Joe haldeman
Haldeman's most famous novel is The Forever War (1975), inspired by his Vietnam experiences, which won both the Hugo and Nebula Awards. He later turned it into a series. Haldeman also wrote two of the earliest original novels based on the 1960s Star Trek TV series universe, Planet of Judgment (August 1977) and World Without End (February 1979). In October 2008 it was announced that Ridley Scott will direct a feature film based on The Forever War for Fox
Haldeman has written at least one produced Hollywood movie script. The film, a low-budget science fiction film called Robot Jox, was released in 1990. He was not entirely happy with the product, saying "to me it’s as if I’d had a child who started out well and then sustained brain damage".
He is a lifetime member of the Science Fiction and Fantasy Writers of America (SFWA), and past-president.
Haldeman is the brother of Jack C. Haldeman II (1941-2002), also a science-fiction author whose work included an original Star Trek novel (Perry's Planet, February 1980).
Thursday, July 15, 2010
Warmer Ecosystems
Research by scientists at Queen Mary, University of London has found that a predicted rise in global temperature of 4°C by 2100 could lead to a 13% reduction in ecosystems' ability to absorb carbon dioxide (CO2) from the atmosphere.
Research by scientists at Queen Mary, University of London has found that a predicted rise in global temperature of 4°C by 2100 could lead to a 13% reduction in ecosystems' ability to absorb carbon dioxide (CO2) from the atmosphere. (Credit: Image courtesy of Queen Mary, University of London)
"Photosynthesis by plants absorbs CO2 while respiration by animals returns CO2 to the atmosphere. Respiration has a higher 'activation energy' than photosynthesis meaning that it increases more rapidly with increasing temperature. So if climate change raises environmental temperatures, the balance between respiration and photosynthesis in the ecosystem will change, favouring more respiration and less CO2 absorption."
The work is complemented by another paper published this month by Dr Guy Woodward and other Queen Mary colleagues in the journal Global Change Biology. This research compared animals living in 15 similar Icelandic streams, a rare long-term 'natural experiment' in which geothermal activity heats some streams up to 45°C. The unique situation meant researchers could study how temperature affects Arctic ecosystems, where climate change is predicted to cause a rise of around 7.5°C within the next century.
"We saw longer food-chains, with predators becoming bigger and more abundant as temperatures increased from 5°C to 25°C. We also have more recent (as yet unpublished) data collected from the Icelandic streams by colleagues at the Macaulay Institute that show similar patterns to those seen in the experimental ponds: namely the warmer streams emitted far more CO2 than the cooler streams and acted as sources of carbon, rather than sinks."
Source: www.sciencedaily.com
Research by scientists at Queen Mary, University of London has found that a predicted rise in global temperature of 4°C by 2100 could lead to a 13% reduction in ecosystems' ability to absorb carbon dioxide (CO2) from the atmosphere. (Credit: Image courtesy of Queen Mary, University of London)
"Photosynthesis by plants absorbs CO2 while respiration by animals returns CO2 to the atmosphere. Respiration has a higher 'activation energy' than photosynthesis meaning that it increases more rapidly with increasing temperature. So if climate change raises environmental temperatures, the balance between respiration and photosynthesis in the ecosystem will change, favouring more respiration and less CO2 absorption."
The work is complemented by another paper published this month by Dr Guy Woodward and other Queen Mary colleagues in the journal Global Change Biology. This research compared animals living in 15 similar Icelandic streams, a rare long-term 'natural experiment' in which geothermal activity heats some streams up to 45°C. The unique situation meant researchers could study how temperature affects Arctic ecosystems, where climate change is predicted to cause a rise of around 7.5°C within the next century.
"We saw longer food-chains, with predators becoming bigger and more abundant as temperatures increased from 5°C to 25°C. We also have more recent (as yet unpublished) data collected from the Icelandic streams by colleagues at the Macaulay Institute that show similar patterns to those seen in the experimental ponds: namely the warmer streams emitted far more CO2 than the cooler streams and acted as sources of carbon, rather than sinks."
Source: www.sciencedaily.com
Saturday, July 3, 2010
Book Review (20 000 leagues under the sea by Jules Verne)
This is one of the most fascinating book I have ever read. Introducing you to the underwater world which is deeper and more interesting than you could ever expect. The details of the underwater world is so detailed that it captures your attention and can imagine the pictures very clearly in your head. In other words, Jules Verne is very good and clear when conveying what he writes to those who read them.
The story starts when there were several reports on several ships being attack by a so called "large creature" when sailing in the ocean. People suspected that it was a creature while some said it was a monster, but whatever it was, they knew that it could move a great distance in a very short amount of time. As the professor of the museum in Paris, the author had came to New York to identify the problem and later was invited on board the Abraham Lincoln to hunt down the creature. The author had a servant called Conseil and also followed him on the journey.
On Board the ship, the author met Ned Land, a skilled harpooner who was a Canadian. Ned Land refuses to believe that the creature they were chasing for really exists no matter how hard the author tried to convince him. After a long time, they finally met with a creature which may be the one they were looking for. It was full of light and circled the Abraham Lincoln before leaving and so the Abraham Lincoln gave chase and finally, the creatures light went out and Ned Land harpooned it. It was something hard. Then, there was a terrible crash and conseil, the author and ned land were also thrown aboard. They got up on the back of that creature and suddenly realised it was no creature, it was a submarine and at that time, the Abraham Lincoln was nowhere to be found.
Then, one of the plates on the submarine rose and they were brought into the submarine by eight strong men. They were then left in a room where there was nobody in it and waited for a very long time. Finally, the captain of the ship came in and they explained their voyage in different languages to the captain. The crew and the captain were speaking in an unknown and weird language among themselves. Finally, the captain and the three of them sealed a deal that they were free to roam around the ship but will have to stay in their rooms when necessary. They all had their rooms and later the Captain who was Captain Nemo introduced the author around the submarine which was called the Nautilus. Captain Nemo explained how the submarine works and every other thing to the author and so their voyage continues for months after months with Conseil the author and also Ned Land. As months after months passed, Ned Land was tired of the submarine and decided to escape but almost all the ways he could think of failed. Along the journey they went through secret tunnels, met a giant squid, went to the great ice barrier which almost killed everyone in board and also went to all of the oceans and also the South Pole.
When the Submarine was caught in a whirlpool, the three of them managed to somewhat escape and when the author woke up, he found himself in a village in the nearby Lofoten Islands. What happened to the submarine after that, the author was unsure but he wished it all the best.
This is certainly a very good book and the ending is up to you to decide. It is indeed the most interesting books I have ever read.
Author: Jules Gabriel Verne 8 February 1828 – 24 March 1905.
Verne wrote about space, air, and underwater travel before navigable aircraft and practical submarines were invented, and before any means of space travel had been devised. Consequently he is often referred to as the "Father of science fiction", along with H. G. Wells, Hugo Gernsback and Edgar Allan Poe.Some of his works have been made into films.
The story starts when there were several reports on several ships being attack by a so called "large creature" when sailing in the ocean. People suspected that it was a creature while some said it was a monster, but whatever it was, they knew that it could move a great distance in a very short amount of time. As the professor of the museum in Paris, the author had came to New York to identify the problem and later was invited on board the Abraham Lincoln to hunt down the creature. The author had a servant called Conseil and also followed him on the journey.
On Board the ship, the author met Ned Land, a skilled harpooner who was a Canadian. Ned Land refuses to believe that the creature they were chasing for really exists no matter how hard the author tried to convince him. After a long time, they finally met with a creature which may be the one they were looking for. It was full of light and circled the Abraham Lincoln before leaving and so the Abraham Lincoln gave chase and finally, the creatures light went out and Ned Land harpooned it. It was something hard. Then, there was a terrible crash and conseil, the author and ned land were also thrown aboard. They got up on the back of that creature and suddenly realised it was no creature, it was a submarine and at that time, the Abraham Lincoln was nowhere to be found.
Then, one of the plates on the submarine rose and they were brought into the submarine by eight strong men. They were then left in a room where there was nobody in it and waited for a very long time. Finally, the captain of the ship came in and they explained their voyage in different languages to the captain. The crew and the captain were speaking in an unknown and weird language among themselves. Finally, the captain and the three of them sealed a deal that they were free to roam around the ship but will have to stay in their rooms when necessary. They all had their rooms and later the Captain who was Captain Nemo introduced the author around the submarine which was called the Nautilus. Captain Nemo explained how the submarine works and every other thing to the author and so their voyage continues for months after months with Conseil the author and also Ned Land. As months after months passed, Ned Land was tired of the submarine and decided to escape but almost all the ways he could think of failed. Along the journey they went through secret tunnels, met a giant squid, went to the great ice barrier which almost killed everyone in board and also went to all of the oceans and also the South Pole.
When the Submarine was caught in a whirlpool, the three of them managed to somewhat escape and when the author woke up, he found himself in a village in the nearby Lofoten Islands. What happened to the submarine after that, the author was unsure but he wished it all the best.
This is certainly a very good book and the ending is up to you to decide. It is indeed the most interesting books I have ever read.
Author: Jules Gabriel Verne 8 February 1828 – 24 March 1905.
Verne wrote about space, air, and underwater travel before navigable aircraft and practical submarines were invented, and before any means of space travel had been devised. Consequently he is often referred to as the "Father of science fiction", along with H. G. Wells, Hugo Gernsback and Edgar Allan Poe.Some of his works have been made into films.
Friday, July 2, 2010
Ozone holes
A new NASA study of Earth's polar ozone layer reinforces scientists' understanding of how human-produced chlorine chemicals involved in the destruction of ozone interact with each other.
A team of scientists led by Michelle Santee of NASA's Jet Propulsion Laboratory, Pasadena, Calif., examined how nighttime temperatures affect chlorine monoxide, a key chemical involved in ozone destruction. Combining NASA satellite measurements with a state-of-the-art chemical model, they found this relationship to be more consistent with recent laboratory work than with some older laboratory and field observational data. This verification is important, because scientists have not been able to conduct appropriate laboratory experiments relevant to understanding how polar chlorine monoxide behaves at night at the lowest temperatures of the stratosphere, Earth's second lowest atmospheric layer.
At night, chlorine monoxide molecules combine to form chlorine peroxide, and the balance between these two chemicals is highly temperature-sensitive. Studying this balance quantitatively is challenging. Previous studies in the laboratory and using aircraft and satellites had found significantly different degrees of balance. The Microwave Limb Sounder's very large number of measurements has quantified this balance far better than before.
Chlorine and bromine from human-produced compounds cause the nearly total destruction of ozone in Earth's stratosphere in a layer about 20 kilometers (12 miles) above Antarctica.
Since its launch in 2004, the Microwave Limb Sounder has monitored most of the polar regions of both hemispheres daily, compiling tens of thousands of measurements of nighttime chlorine monoxide levels, along with various other chemicals, including ozone. These data are allowing scientists to test their understanding of chlorine-related chemistry on an unprecedented scale.
Source: http://www.sciencedaily.com/
A team of scientists led by Michelle Santee of NASA's Jet Propulsion Laboratory, Pasadena, Calif., examined how nighttime temperatures affect chlorine monoxide, a key chemical involved in ozone destruction. Combining NASA satellite measurements with a state-of-the-art chemical model, they found this relationship to be more consistent with recent laboratory work than with some older laboratory and field observational data. This verification is important, because scientists have not been able to conduct appropriate laboratory experiments relevant to understanding how polar chlorine monoxide behaves at night at the lowest temperatures of the stratosphere, Earth's second lowest atmospheric layer.
At night, chlorine monoxide molecules combine to form chlorine peroxide, and the balance between these two chemicals is highly temperature-sensitive. Studying this balance quantitatively is challenging. Previous studies in the laboratory and using aircraft and satellites had found significantly different degrees of balance. The Microwave Limb Sounder's very large number of measurements has quantified this balance far better than before.
Chlorine and bromine from human-produced compounds cause the nearly total destruction of ozone in Earth's stratosphere in a layer about 20 kilometers (12 miles) above Antarctica.
Since its launch in 2004, the Microwave Limb Sounder has monitored most of the polar regions of both hemispheres daily, compiling tens of thousands of measurements of nighttime chlorine monoxide levels, along with various other chemicals, including ozone. These data are allowing scientists to test their understanding of chlorine-related chemistry on an unprecedented scale.
Source: http://www.sciencedaily.com/
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