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First tops, then flops. That is one way of summing up the history of biofuels so far. A new study led by Empa gives an up-to-date picture of the ecobalance of various biofuels and their production processes. Only a few are overall more environmentally friendly than petrol.

In recent years, the demand for supposedly environmentally friendly biofuels has increased significantly worldwide; on the one hand, this has resulted in the increased cultivation of so-called energy plants and, on the other hand, innovative production methods for the second generation of biofuels have been developed. Parallel to this, ecobalance experts have refined and developed methods for environmental assessment. Since biofuels stem predominantly from agricultural products, the, in part, controversial discussion about their environmental sustainability revolves principally around whether the production of biofuels is defensible from an ecological viewpoint or whether there are possible negative effects, for example on the supply of foodstuff in times of drought, or whether eutrophication of arable land occurs.

In order to be able to give a well-informed response, Empa, on behalf of the Department of Energy (BFA) and in collaboration with the research institute Agroscope Reckenholz-Tänikon (ART), and the Paul Scherrer Institute (PSI), has updated the ecobalance of numerous biofuels, including their production chains. Compared with the first worldwide ecobalance study of its kind in 2007, also carried out by Empa, the team, led by Empa researcher Rainer Zah, included both innovative energy plants and manufacturing processes and also updated assessment methods.

Fewer greenhouse gases — and thus a different environmental impact

However, despite a more extensive data set and up-to-date methods, Empa comes to the same conclusion as the study in 2007: many biofuels based on agricultural products indeed do help to reduce the emission of greenhouse gases, but lead to other environmental pollution, such as too much acid in the soil and polluted (over-fertilised) lakes and rivers. "Most biofuels therefore just deflect the environmental impact: fewer greenhouse gases, thus more growth-related pollution for land used for agriculture," says Zah. This results in only a few biofuels having an overall better ecobalance than petrol, especially biogas from residues and waste materials, which — depending on the source material — impact on the environment up to half as much as petrol. And within the biofuel group, ethanol-based fuels tend to have a better ecobalance than those with an oil base; however, the results are very much dependent on the individual method of manufacture and the technology.

New findings on the effect of biofuels on greenhouse gases

However, the new methodology also allowed Zah and his colleagues to highlight the "weaknesses" of the earlier study. The researchers in 2007 underestimated the effects of changes to natural areas on the greenhouse gas balance, for example the deforestation of the rain forest. The current study now shows that biofuels from deforested areas usually emit more greenhouse gases than fossil fuels. This also applies to indirect land usage changes if existing agricultural land is used for the first time for biofuel production and, as a consequence, forested areas have to be cleared in order to maintain the existing foodstuff or animal feed production.

On the other hand, positive effects can be achieved if energy plant cultivation increases the carbon content of the soil, for example via the cultivation of oil palms on unused grazing land in Columbia or via jatropha plantations in India and eastern Africa, making deserted land arable again. "Despite this, you can't speak in general terms of Jatropha as being a 'wonder plant', as its ecobalance is very much dependent on the agricultural practices at the site in question and the land's previous use," says Zah. Each (new) biofuel must therefore be examined separately and in detail.

What should be heeded in terms of biofuel production?

Although the devil is in the detail, the new studies make it possible to make some general recommendations:

• Clearing woodland and bush areas in order to develop energy plants is to be avoided; this worsens the greenhouse gas balance considerably, which has a distinctly greater impact on the environment.
• If agricultural land is used for biofuel production, indirect change of land use should be avoided as far as possible, for example, by making it compulsory to provide evidence that any displaced production does not have indirect effects as a result of intensification.
• The use of land and forestry residues such as straw, garden and timber waste for energy purposes is advantageous, but only if these are not used in other ways or if their extraction from their natural cycle does not reduce the fertility of the soil and the bio-diversity.

NewsPsychology (Sep. 24, 2012) — Infectious bacteria received a taste of their own medicine from University of Missouri researchers who used viruses to infect and kill colonies of Pseudomonas aeruginosa, common disease-causing bacteria. The viruses, known as bacteriophages, could be used to efficiently sanitize water treatment facilities and may aid in the fight against deadly antibiotic-resistant bacteria.

“Our experiment was the first to use bacteriophages in conjunction with chlorine to destroy biofilms, which are layers of bacteria growing on a solid surface,” said Zhiqiang Hu, associate professor of civil and environmental engineering in MU’s College of Engineering. “The advantage to using viruses is that they can selectively kill harmful bacteria. Beneficial bacteria, such as those used to break down wastes in water treatment plants, are largely unaffected. Hence, viruses could be used to get rid of pathogenic bacteria in water filters that would otherwise have to be replaced. They could save taxpayers’ money by reducing the cost of cleaning water.”

Bacteria can be difficult to kill when they form a biofilm. The outer crust of bacteria in these biofilms can be killed by chlorine, but the inner bacteria are sheltered. Viruses solve this problem because they spread through an entire colony of bacteria. Hu noted that the bacteriophages are easier to create than the enzymes used to attack biofilms. The viruses also are better at targeting specific bacterial species.

Hu, along with MU’s recent graduate, Yanyan Zhang, found the greatest success in killing biofilms by using a combination of bacteriophages and chlorine. An initial treatment with viruses followed by chlorine knocked out 97 percent of biofilms within five days of exposure. When used alone, viruses removed 89 percent of biofilms, while chlorine removed only 40 percent.

“The methods we used to kill Pseudomonas aeruginosa could be used against other dangerous bacteria, even those that have developed resistance to antibiotics,” said Hu. “Our work opened the door to a new strategy for combating the dangers and costs of bacterial biofilms. The next step is to expand our experiment into a pilot study.”

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The above story is reprinted from materials provided by University of Missouri-Columbia.

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NewsPsychology (Sep. 24, 2012) — Life thrives on Planet Earth. In even the most inhospitable places — the freezing Antarctic permafrost, sun-baked saltpans in Tunisia or the corrosively acidic Rio Tinto in Spain — pockets of life can be found. Some of these locations have much in common with environments found on Mars, as discovered by orbiters and rovers exploring the surface. Researchers from the Centro de Astrobiología (CAB) in Madrid have made a series of field trips to the most Mars-like places on Earth.

They presented some of their findings at the European Planetary Science Congress in Madrid on September 24.

Dr Felipe Gómez, the project leader said, “The big questions are: what is life, how can we define it and what are the requirements for supporting life? To understand the results we receive back from missions like Curiosity, we need to have detailed knowledge of similar environments on Earth. Metabolic diversity on Earth is huge. In the field campaigns, we have studied ecosystems in situ and we have also brought samples back to the laboratory for further analysis. We have found a range of complex chemical processes that allow life to survive in unexpected places.”

Over the past 4 years, the team has carried out field trips to Chott el Jerid, a salt pan in Tunisia, the Atacama desert in Chile, Rio Tinto in Southern Spain and Deception Island in Antarctica.

Gómez and his colleagues visited Chott el Jerid salt pan 3 times between 2010 and 2012 and Atacama desert in 2010.

The team set up weather stations at a series of locations at each site. The weather stations measured surface and air temperatures, humidity, ultraviolet radiation levels, wind direction and velocity. The data collected from these field campaigns is comparable to the data now being collected by the Remote Meteorological Monitoring Station (REMS) carried by Curiosity, which was built by a team from CAB-INTA.

“We studied measurements in different locations over several daily cycles. As well as the large-scale changes to all the parameters through the day, we observed a small rise in the surface temperature after dusk. We found that this is caused by water condensing on the surface and hydrating salts, which releases heat in an exothermic reaction. This is very interesting from the perspective of the REMS instrument on Curiosity — it gives us a way to follow when liquid water might be present on the surface,” said Gómez.

Cloud cover in the sky could also be tracked through fluctuations in measurements of the solar radiation and luminosity (ultraviolet flux variations).

“The correlations we’ve found between these parameters and cloud cover means that we can use Mars orbiter measurements of cloud conditions to give us an indication of changes that are going on at the surface,” said Gómez.

The team used probes to study the electrical properties of the soil. By studying changes in resistivity with depth, they were able to identify different materials underground and the water-content. By setting up criss-crossing ‘transepts’ of resistivity probes, the teams were able to build up a 3-dimensional picture of the structure of the subsurface.

They also drilled samples to a depth of 3.6 metres in Chott El Jerid and to 6 metres in Atacama. The core samples showed subsurface ecosystems of completely different kinds of bacteria from those found on the surface. The populations of bacteria found at the surface decreased with depth, but there was an increase in archaea, and also single-celled halophilic organisms that are able to oxidize metabolites under aerobic and anaerobic conditions.

“In both Atacama and Chott El Jerid, we found ecosystems at a depth of a few metres that were completely isolated from the surface,” said Gómez.

The surface of Chott El Jerid salt pan is very pure sodium chloride with traces of other salts. The team found small accumulations of organic matter inside the salt crystals. When they analysed the samples, they found that these were populations of halophilic, salt-loving bacteria that were dormant.

Gómez said, “This was a really exciting find. These condensed accumulations of halophilic bacteria could have been dormant for possibly hundreds of years. Back in the laboratory, we were able to rehydrate the samples and restore the bacteria to life.”

The Mars Exploration Rover, Opportunity, discovered jarosite on the surface of Mars. Jarosite is only synthesised in the presence of water and contains very high concentrations of metals, such as iron. The team studied outcrops of jarosite at Rio Tinto, areas that have extraordinarily high levels of acidity. Unexpectedly, they found photosynthetic bacteria growing between the layers in salt crusts. When they analysed the bacteria back in the laboratory, they made a further discovery: that iron appears to protect the bacteria from ultraviolet radiation.

Gómez explains, “We took two samples of the bacteria, one with iron present and one without and exposed them to high levels of ultraviolet radiation. For the sample without iron, nearly all the bacteria were destroyed. For the sample with iron present the population survived. There was a small increase due to toxic super-oxides being created, but the protective effect of ferric compounds was significant.”

Their findings have implications for the development of life on Earth: early in its formation, Earth had no oxygen and its atmosphere would not have given the protection from ultraviolet radiation that it provides today.

“What the bacteria we found in Rio Tinto show is that the presence of ferric compounds can actually protect life. This could mean that life formed earlier on Earth than we thought. These effects are also relevant for the formation of life on the surface of Mars,” says Gómez.

The team also found that salt provides stable conditions that can allow life to survive in very hard environments.

“Within salts, the temperature and humidity are protected from fluctuations and the doses of ultraviolet radiation are very low,” explained Gómez. “In the laboratory, we placed populations of different bacteria between layers of salt a few millimetres thick and exposed them to Martian conditions. Nearly 100% of deinoccocus radiodurans , a hardy type of bacteria survived being irradiated. But fascinatingly, about 40% of acidithiobacillus ferrooxidans — a very fragile variety of bacteria also survived when protected by a salt crust.”

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The above story is reprinted from materials provided by Europlanet Media Centre, via AlphaGalileo.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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NewsPsychology (Sep. 24, 2012) — Refueling U.S. Navy vessels, at sea and underway, is a costly endeavor in terms of logistics, time, fiscal constraints and threats to national security and sailors at sea.

In Fiscal Year 2011, the U.S. Navy Military Sea Lift Command, the primary supplier of fuel and oil to the U.S. Navy fleet, delivered nearly 600 million gallons of fuel to Navy vessels underway, operating 15 fleet replenishment oilers around the globe.

From Seawater to CO₂

Scientists at the U.S. Naval Research Laboratory are developing a process to extract carbon dioxide (CO₂) and produce hydrogen gas (H₂) from seawater, subsequently catalytically converting the CO₂ and H₂ into jet fuel by a gas-to-liquids process.

“The potential payoff is the ability to produce JP-5 fuel stock at sea reducing the logistics tail on fuel delivery with no environmental burden and increasing the Navy’s energy security and independence,” says research chemist, Dr. Heather Willauer.

NRL has successfully developed and demonstrated technologies for the recovery of CO₂ and the production of H₂ from seawater using an electrochemical acidification cell, and the conversion of CO₂ and H₂ to hydrocarbons (organic compounds consisting of hydrogen and carbon) that can be used to produce jet fuel.

“The reduction and hydrogenation of CO₂ to form hydrocarbons is accomplished using a catalyst that is similar to those used for Fischer-Tropsch reduction and hydrogenation of carbon monoxide,” adds Willauer. “By modifying the surface composition of iron catalysts in fixed-bed reactors, NRL has successfully improved CO₂ conversion efficiencies up to 60 percent.”

A Renewable Resource

CO₂ is an abundant carbon (C) resource in the air and in seawater, with the concentration in the ocean about 140 times greater than that in air. Two to three percent of the CO₂ in seawater is dissolved CO₂ gas in the form of carbonic acid, one percent is carbonate, and the remaining 96 to 97 percent is bound in bicarbonate. If processes are developed to take advantage of the higher weight per volume concentration of CO₂ in seawater, coupled with more efficient catalysts for the heterogeneous catalysis of CO₂ and H₂, a viable sea-based synthetic fuel process can be envisioned. “With such a process, the Navy could avoid the uncertainties inherent in procuring fuel from foreign sources and/or maintaining long supply lines,” Willauer said.

NRL has made significant advances developing carbon capture technologies in the laboratory. In the summer of 2009 a standard commercially available chlorine dioxide cell and an electro-deionization cell were modified to function as electrochemical acidification cells. Using the novel cells both dissolved and bound CO₂ were recovered from seawater by re-equilibrating carbonate and bicarbonate to CO₂ gas at a seawater pH below 6. In addition to CO₂, the cells produced H₂ at the cathode as a by-product.

These completed studies assessed the effects of the acidification cell configuration, seawater composition, flow rate, and current on seawater pH levels. The data were used to determine the feasibility of this approach for efficiently extracting large quantities of CO₂ from seawater. From these feasibility studies NRL successfully scaled-up and integrated the carbon capture technology into an independent skid to process larger volumes of seawater and evaluate the overall system design and efficiencies.

The major component of the carbon capture skid is a three-chambered electrochemical acidification cell. This cell uses small quantities of electricity to exchange hydrogen ions produced at the anode with sodium ions in the seawater stream. As a result, the seawater is acidified. At the cathode, water is reduced to H₂ gas and sodium hydroxide (NaOH) is formed. This basic solution may be re-combined with the acidified seawater to return the seawater to its original pH with no additional chemicals. Current and continuing research using this carbon capture skid demonstrates the continuous efficient production of H₂ and the recovery of up to 92 percent of CO₂ from seawater.

Located at NRL’s Center for Corrosion Science & Engineering facility, Key West, Fla., (NRLKW) the carbon capture skid has been tested using seawater from the Gulf of Mexico to simulate conditions that will be encountered in an actual open ocean process for capturing CO₂ from seawater and producing H₂ gas. Currently NRL is working on process optimization and scale-up. Once these are completed, initial studies predict that jet fuel from seawater would cost in the range of $3 to $6 per gallon to produce.

How it Works: CO₂ + H₂ = Jet Fuel

NRL has developed a two-step process in the laboratory to convert the CO₂ and H₂ gathered from the seawater to liquid hydrocarbons. In the first step, an iron-based catalyst has been developed that can achieve CO₂ conversion levels up to 60 percent and decrease unwanted methane production from 97 percent to 25 percent in favor of longer-chain unsaturated hydrocarbons (olefins).

In the second step these olefins can be oligomerized (a chemical process that converts monomers, molecules of low molecular weight, to a compound of higher molecular weight by a finite degree of polymerization) into a liquid containing hydrocarbon molecules in the carbon C₉-C₁₆ range, suitable for conversion to jet fuel by a nickel-supported catalyst reaction.

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The above story is reprinted from materials provided by Naval Research Laboratory.

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NewsPsychology (Sep. 24, 2012) — A low-cost new material that could lead to innovative technologies to tackle global warming has been discovered by scientists at The University of Nottingham.

The porous material, named NOTT-300, has the potential to reduce fossil fuel emissions through the cheaper and more efficient capture of polluting gases such as carbon dioxide (CO₂) and sulphur dioxide (SO₂). The research, published in the scientific journal Nature Chemistry, demonstrates how the exciting properties of NOTT-300 could provide a greener alternative to existing solutions to adsorb CO₂ which are expensive and use large amounts of energy.

The new material represents a major step towards addressing the challenges of developing a low carbon economy, which seeks to produce energy using low carbon sources and methods.

Potential applications

Professor Martin Schröder, Dean of the Faculty of Science at The University of Nottingham, led the research. He said: “Our novel material has potential for applications in carbon capture technologies to reduce CO₂ emissions and therefore contribute to the reduction of greenhouse gases in the atmosphere.

“It offers the opportunity for the development of an ‘easy on/easy off’ capture system that carries fewer economic and environmental penalties than existing technologies. It could also find application in gas separation processes where the removal of CO₂ or acidic gases such as SO₂ is required.”

Carbon footprint reduction

The researchers understand the significance of their findings due to the importance of tackling greenhouse gases.

Professor Schröder said: “It is widely accepted that it is imperative that the CO₂ footprint of human activity is reduced in order to limit the negative effects of global climate change.

“There are powerful drivers to develop efficient strategies to remove CO₂ using alternative materials that simultaneously have high adsorption capacity, high selectivity for CO₂ and high rates of regeneration at an economically viable cost.”

And NOTT-300 delivers on each of these criteria. Because of this, the new discovery could signal a marked improvement in terms of environmental and chemical sustainability.

The material is economically viable to produce because it is synthesized from relatively simple and cheap organic materials with water as the only solvent.

High uptake of CO₂ and SO₂

Professor Schröder said: “The material shows high uptake of CO₂ and SO₂. In the case of SO₂, this is the highest reported for the class of materials to date. It is also selective for these gases, with other gases – such as hydrogen, methane, nitrogen, oxygen – showing no or very little adsorption into the pores.”

In addition to high uptake capacity and selectivity, it is also very easy to release the adsorbed gas molecules through simple reduction of pressure. The material has high chemical stability to all common organic solvents and is stable in water and up to temperatures of 400°C.

Professor Martin Schröder and Dr Sihai Yang led a team of researchers from the University’s School of Chemistry in conjunction with colleagues from Peking University, The University of Oxford, ISIS and Diamond Light Source. The team used the ISIS facility and the Diamond Synchrotron beam to gain important structural information about how the gases bind to the host material and to understand the properties of the NOTT-300 that make it selectively adsorb CO₂ and SO₂.

The research was funded by the ERC Advanced Grant COORDSPACE and ChemEnSus, an Engineering and Physical Sciences Research Council (EPSRC) Programme Grant. 

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The above story is reprinted from materials provided by University of Nottingham.

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NewsPsychology (Sep. 24, 2012) — A Florida State University chemist’s work could lead to big improvements in our ability to detect and eliminate specific toxic substances in our environment.

Featured on the cover of the Journal of the American Chemical Society (JACS), Sourav Saha’s specialized work to strip electrons from the toxic chemical known as fluoride is producing a variety of unique results.

“I started out with the very basic premise of trying to find new ways to detect toxic fluoride in solutions,” said Saha, an assistant professor of chemistry at Florida State. “As I got further into that work I was able to create a compound that could actually strip the electrons right off the molecule, producing a variety of tangible benefits such as toxin detection and removal.”

Saha’s initial fluoride-detection work led to a $100,000 grant from the Petroleum Research Foundation to further explore the possibilities of his research. Using that money, he was able to bring in additional expertise and build his “fluoride-robbing” compound that is the central feature of the work featured on the JACS cover.

“This work is very exciting and novel because the results are surprising,” said Timothy Logan, chairman of the Department of Chemistry and Biochemistry at Florida State. “Molecules always have affinity for electrons, with some molecules having a greater affinity than others. Flouride has the highest electron affinity of all, so the ability to strip off electrons from fluoride, especially in the presence of other molecules with lower electron affinity, is truly unique.”

Although Saha is excited about the possibilities of his new compound in toxin cleanup, he sees a huge variety of potential applications for his research.

“I think toxin removal is one of the most obvious and relatable benefits my work could lead to, but in reality, there are many additional implications this work could have on daily life,” Saha said. “For instance, we could develop this research to create all new types of plastics that could exhibit unique qualities, or improve the effectiveness of devices, such as batteries, that are used to store and transfer energy.”

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The above story is reprinted from materials provided by Florida State University. The original article was written by Tom Butler.

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NewsPsychology (Sep. 26, 2012) — A warming climate and rising seas will enable salt marshes to more rapidly capture and remove carbon dioxide from the atmosphere, possibly playing a role in slowing the rate of climate change, according to a new study led by a University of Virginia environmental scientist and published in the Sept. 27 issue of the journal Nature.

Carbon dioxide is the predominant so-called “greenhouse gas” that acts as sort of an atmospheric blanket, trapping Earth’s heat. Over time, an abundance of carbon dioxide can change the global climate, according to generally accepted scientific theory. A warmer climate melts polar ice, causing sea levels to rise.

A large portion of the carbon dioxide in the atmosphere is produced by human activities, primarily the burning of fossil fuels to energize a rapidly growing world human population. “We predict that marshes will absorb some of that carbon dioxide, and if other coastal ecosystems — such as seagrasses and mangroves — respond similarly, there might be a little less warming,” said the study’s lead author, Matt Kirwan, a research assistant professor of environmental sciences in the College of Arts & Sciences.

Salt marshes, made up primarily of grasses, are important coastal ecosystems, helping to protect shorelines from storms and providing habitat for a diverse range of wildlife, from birds to mammals, shell- and fin-fishes and mollusks. They also build up coastal elevations by trapping sediment during floods, and produce new soil from roots and decaying organic matter.

“One of the cool things about salt marshes is that they are perhaps the best example of an ecosystem that actually depends on carbon accumulation to survive climate change: The accumulation of roots in the soil builds their elevation, keeping the plants above the water,” Kirwan said.

Salt marshes store enormous quantities of carbon, essential to plant productivity, by, in essence, breathing in the atmospheric carbon and then using it to grow, flourish and increase the height of the soil. Even as the grasses die, the carbon remains trapped in the sediment. The researchers’ model predicts that under faster sea-level rise rates, salt marshes could bury up to four times as much carbon as they do now.

“Our work indicates that the value of these ecosystems in capturing atmospheric carbon might become much more important in the future, as the climate warms,” Kirwan said. But the study also shows that marshes can survive only moderate rates of sea level rise. If seas rise too quickly, the marshes could not increase their elevations at a rate rapid enough to stay above the rising water. And if marshes were to be overcome by fast-rising seas, they no longer could provide the carbon storage capacity that otherwise would help slow climate warming and the resulting rising water.

“At fast levels of sea level rise, no realistic amount of carbon accumulation will help them survive,” Kirwan noted.

Kirwan and his co-author, Simon Mudd, a geosciences researcher at the University of Edinburgh in Scotland, used computer models to predict salt marsh growth rates under different climate change and sea-level scenarios.

The United States Geological Survey’s Global Change Research Program supported the research.

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The above story is reprinted from materials provided by University of Virginia, via Newswise.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Matthew L. Kirwan, Simon M. Mudd. Response of salt-marsh carbon accumulation to climate change. Nature, 2012; 489 (7417): 550 DOI: 10.1038/nature11440

NewsPsychology (Sep. 26, 2012) — An international team of scientists, including geochemists from the University of California, Riverside, has uncovered new evidence linking extreme climate change, oxygen rise, and early animal evolution.

A dramatic rise in atmospheric oxygen levels has long been speculated as the trigger for early animal evolution. While the direct cause-and-effect relationships between animal and environmental evolution remain topics of intense debate, all this research has been hampered by the lack of direct evidence for an oxygen increase coincident with the appearance of the earliest animals — until now.

In the Sept. 27 issue of the journal Nature, the research team, led by scientists at the University of Nevada, Las Vegas, offers the first evidence of a direct link between trends in early animal diversity and shifts in Earth system processes.

The fossil record shows a marked increase in animal and algae fossils roughly 635 million years ago. An analysis of organic-rich rocks from South China points to a sudden spike in oceanic oxygen levels at this time — in the wake of severe glaciation. The new evidence pre-dates previous estimates of a life-sustaining oxygenation event by more than 50 million years.

“This work provides the first real evidence for a long speculated change in oxygen levels in the aftermath of the most severe climatic event in Earth’s history — one of the so-called ‘Snowball Earth’ glaciations,” said Timothy Lyons, a professor of biogeochemistry at UC Riverside.

The research team analyzed concentrations of trace metals and sulfur isotopes, which are tracers of early oxygen levels, in mudstone collected from the Doushantuo Formation in South China. The team found spikes in concentrations of the trace metals, denoting higher oxygen levels in seawater on a global scale.

“We found levels of molybdenum and vanadium in the Doushantuo Formation mudstones that necessitate that the global ocean was well ventilated. This well-oxygenated ocean was the environmental backdrop for early animal diversification,” said Noah Planavsky, a former UCR graduate student in Lyons’s lab now at CalTech.

The high element concentrations found in the South China rocks are comparable to modern ocean sediments and point to a substantial oxygen increase in the ocean-atmosphere system around 635 million years ago. According to the researchers, the oxygen rise is likely due to increased organic carbon burial, a result of more nutrient availability following the extreme cold climate of the ‘Snowball Earth’ glaciation when ice shrouded much of Earth’s surface.

Lyons and Planavsky argued in research published earlier in the journal Nature that a nutrient surplus associated with the extensive glaciations may have initiated intense carbon burial and oxygenation. Burial of organic carbon — from photosynthetic organisms — in ocean sediments would result in the release of vast amounts of oxygen into the ocean-atmosphere system.

“We are delighted that the new metal data from the South China shale seem to be confirming these hypothesized events,” Lyons said.

The joint research was supported by grants from the National Science Foundation, the NASA Exobiology Program, and the National Natural Science Foundation of China. Besides Lyons and Planavsky, the research team includes Swapan K. Sahoo (first author of the research paper) and Ganqing Jiang (principal investigator of the study) of the University of Nevada, Las Vegas; Brian Kendall and Ariel D. Anbar of Arizona State University; Xinqiang Wang and Xiaoying Shi of the China University of Geosciences (Beijing); and UCR alumnus Clint Scott of United States Geological Survey.

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Story Source:

The above story is reprinted from materials provided by University of California – Riverside. The original article was written by Iqbal Pittalwala.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Swapan K. Sahoo, Noah J. Planavsky, Brian Kendall, Xinqiang Wang, Xiaoying Shi, Clint Scott, Ariel D. Anbar, Timothy W. Lyons, Ganqing Jiang. Ocean oxygenation in the wake of the Marinoan glaciation. Nature, 2012; 489 (7417): 546 DOI: 10.1038/nature11445

NewsPsychology (Oct. 1, 2012) — Cheating. Conflict. Competition. It may sound like a soap opera but this is the complex life of the despised ragweed plant.

And in the highly competitive fight for nutrients, researchers have found ragweed will behave altruistically with its siblings, investing precious resources for the benefit of the group.

A growing body of work suggests plants recognize and respond to the presence and identity of their neighbours and the findings, published online in the journal PLOS ONE, provide further evidence of the importance of family in preserving cooperation within and between species.

Specifically, researchers examined the mutually beneficial relationship between common ragweed, or Ambrosia artemisiifolia L., and mycorrhizal fungi.

In this relationship, the plant provides carbohydrates to the fungi which allow it to grow and colonize the soil. In return, the plant receives water, much-needed nutrients and protection from dangerous pathogens.

“The stability of this relationship can be compromised by cheaters,” says Amanda File, a graduate student in the Department of Biology at McMaster University and lead author of the study.

“That happens because a single fungal network may interact with many plants, which creates opportunities for individuals to reap the rewards and the nutrients, without actually donating carbohydrates,” she says.

In this study, researchers conducted two separate experiments to determine how social environment affects the plants’ investment in the network. That is, whether the presence of family or strangers affects their behaviour.

When the ragweed was planted with its kin, the fungal network was larger — implying greater costs to the plants — but also creating greater benefits for them.

Moreover, increased fungal colonization of the roots was associated with a reduced number of root lesions caused by pathogens.

“If plant kin recognition is a real thing, we predict that social environment will affect many kinds of plant interactions,” says Susan Dudley, an associate professor in the Department of Biology. “We have seen kin recognition for traits involved in plant competition and here we see that cooperation between species is certainly enhanced by altruism towards relatives.”

The findings could have future implications for farming, she adds.

“Mycorrhizal fungi are now available commercially as soil additives for garden plants. And while conventional agricultural practices generally disrupt mycorrhizal fungi, there is potential for it to play an important role in sustainable farming by promoting growth naturally.”

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Story Source:

The above story is reprinted from materials provided by McMaster University, via Newswise.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Amanda L. File, John Klironomos, Hafiz Maherali, Susan A. Dudley. Plant Kin Recognition Enhances Abundance of Symbiotic Microbial Partner. PLoS ONE, 2012; 7 (9): e45648 DOI: 10.1371/journal.pone.0045648

NewsPsychology (Sep. 26, 2012) — The water quality of lakes and coastal systems will be altered if hurricanes intensify in a warming world, according to a Yale study in Geophysical Research Letters.

Bryan Yoon, the study’s co-author and a doctoral student at the Yale School of Forestry & Environmental Studies, found that last summer during Hurricane Irene — the worst storm in the New York area in 200 years — record amounts of dissolved organic matter darkened Catskill waters and affected the Ashokan Reservoir that supplies New York City with drinking water.

“This is the biggest rain event ever sampled for the region,” said Yoon, who conducted the study with Pete Raymond, professor of ecosystem ecology at Yale.

As a primary source of drinking water for New York City, the Catskill Mountains is designated as forest preserve, and roughly 62 percent of the watershed studied is protected by New York State. Over a two-day period in late August 2011, Irene dropped over 11 inches of rain — 17 percent of the average annual rainfall — on Esopus Creek that feeds the Ashokan.

Yoon found that the volume of water discharged by the creek increased 330-fold, and the creek exported an unprecedented amount of dissolved organic matter to the Ashokan, equivalent to 43 percent of its average annual export. Yoon likened the increase in dissolved organic matter to a person being fed 40 percent of his annual food in a few days.

Although not discussed as often as other water quality topics such as turbidity, dissolved organic matter plays a critical role in the aquatic environment and for the provision of clean drinking water. In moderate quantities, dissolved organic matter also provides food and nutrients for microbial communities.

In excessive amounts, however, dissolved organic matter could lead to numerous environmental problems, Yoon’s study found. Dissolved organic matter binds with metal pollutants and transports them; interferes with ultraviolet processes that reduce pathogens in water; affects aquatic metabolism; and leads to the formation of carcinogenic disinfection byproducts, such as trihalomethanes during chlorination.

“All of those problems become more serious as larger quantities of dissolved organic matter are transported to lakes and coastal systems,” he said. “Hurricane Irene was a prime example that there is no limit to the amount of dissolved organic matter that can be exported by extreme rain events. Surprisingly, concentrations of dissolved organic matter didn’t get diluted.”

Raymond said that frequent hurricanes will flush more organic matter out of the ground and into lakes, reservoirs and coastal waters, potentially altering their biogeochemical cycles.

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The above story is reprinted from materials provided by Yale University.

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