How plants sense electric fields

The cells of plants, animals and humans all use electrical signals to communicate with each other. Nerve cells use them to activated muscles. But leaves, too, send electrical signals to other parts of the plant, for example, when they were injured and are threatened by hungry insects.

"We have been asking ourselves for many years what molecular components plants use to exchange information among each other and how they sense the changes in electric voltage," says Professor Rainer Hedrich, Head of the Chair for Molecular Plant Physiology and Biophysics at the University of Würzburg.

Results published in Plant Biology

This question has been intriguing Hedrich since the mid 1980s when he was still a postdoc in the laboratory of Erwin Neher at the Max Planck Institute in Göttingen. "Back then, we used the patch clamp technique to make the first-time discovery of an ion channel in plants which is activated by calcium ions and an electric field." In 2005, other scientists then found the gene underlying this ion channel (name: TCP1). And now it has been Hedrich's team again that has identified that part of the channel which functions as a sensor for electric voltage and activates the channel.

After decades of clean up attempts, world's lakes still suffer from phosphorus pollution

Leading scientists warn: Phosphorus pollution is a major concern. We need to speed up recovery treatments of lakes - or accept poor freshwater quality. In a series of studies published in a special issue of the journal Water Research, leading scientists assess how to control phosphorus pollution in lakes.

- In 40 % of Europe's lakes the water quality does not meet the demands of EUs Water Framework Directive, mainly due to phosphorus pollution. That is a huge problem for biodiversity and society and we need to put an effort into developing effective approaches to restore these lakes, says Associate Professor Kasper Reitzel, Department of Biology, University of Southern Denmark.

Together with colleagues Sara Egemose and Henning S. Jensen, Reitzel is co-author of several contributions in a special issue of the journal Water Research. Kasper Reitzel is also co-editor. They are experts in lake restoration and are associated with the Villum Kann Rasmussen Centre of Excellence, Centre for Lake Restoration, (CLEAR).

Researchers assess heatwave risks associated with climate change

Combining climate and mortality data, researchers have estimated that 315 deaths in Greater London and 735 deaths in Central Paris can be strongly linked to the 2003 heatwave that set record-breaking temperatures across Europe. Taking their analysis a step further, they determine that 64 (± 3) deaths from the London dataset and 506 (± 51) deaths from the Paris dataset are attributable to anthropogenic climate change, which increased the risk of heat related mortality by 20% and 70%, respectively, in the two cities. The team, led by scientists from the University of Oxford and Public Health England, has reported its latest findings in the journal Environmental Research Letters.

NASA's airborne mission to explore the global atmosphere

Ice sheets, deserts, rivers, islands, coasts and oceans -- the features of Earth's surface are wildly different, spread across a vast geography. The same is true for Earth's thin film of atmosphere and the mix of gases it holds, although the details are invisible to human eyes. Pollutants emitted to the atmosphere -- soot, hydrocarbons, nitrogen oxides -- are dispersed over the whole globe, but remote regions are cleaner, by factors of 1000 or more, than areas near the continents. A new NASA airborne campaign aims to map the contours of the atmosphere as carefully as explorers once traced the land and oceans below.

The Atmospheric Tomography, or ATom, mission is the first to survey the atmosphere over the oceans. Scientists aboard NASA's DC-8 flying laboratory will journey from the North Pole south over the Pacific Ocean to New Zealand and then across to the tip of South America and north up the Atlantic Ocean to Greenland. ATom will discover how much pollution survives to the most remote corners of the earth and assess how the environment has changed as a result.

Insect populations in sharp decline

Every spring since 1989, entomologists have set up tents in the meadows and woodlands of the Orbroicher Bruch nature reserve and 87 other areas in the western German state of North Rhine-Westphalia. The tents act as insect traps and enable the scientists to calculate how many bugs live in an area over a full summer period. Recently, researchers presented the results of their work to parliamentarians from the German Bundestag, and the findings were alarming: The average biomass of insects caught between May and October has steadily decreased from 1.6 kilograms (3.5 pounds) per trap in 1989 to just 300 grams (10.6 ounces) in 2014. 

"The decline is dramatic and depressing and it affects all kinds of insects, including butterflies, wild bees, and hoverflies," says Martin Sorg, an entomologist from the Krefeld Entomological Association involved in running the monitoring project. 
 

Weathering of rocks by mosses may explain climate effects during the Late Ordovician

During the Ordovician period, the concentration of CO2 in the earth's atmosphere was about eight times higher than today. It has been hard to explain why the climate cooled and why the Ordovician glaciations took place. A new study, published in Nature Communications, shows that the weathering of rock caused by early non-vascular plants had the potential to cause such a global cooling effect.

"When we can better understand the carbon cycle in the past, we can better predict what happens with the climate in the future," says Philipp Porada of Stockholm University, one of the authors of the study.

'The Blob' overshadows El Nino

New research based on ocean models and near real-time data from autonomous gliders indicates that the "The Blob" and El Niño together strongly depressed productivity off the West Coast, with The Blob driving most of the impact.

The research published in the journal Geophysical Research Letters by scientists from NOAA Fisheries, Scripps Institution of Oceanography and University of California, Santa Cruz is among the first to assess the marine effects of the 2015-2016 El Niño off the West Coast of the United States.

"Last year there was a lot of speculation about the consequences of 'The Blob' and El Niño battling it out of the U.S. West Coast," said lead author Michael Jacox, of UC Santa Cruz and NOAA Fisheries' Southwest Fisheries Science Center. "We found that off California El Niño turned out to be much weaker than expected, The Blob continued to be a dominant force, and the two of them together had strongly negative impacts on marine productivity."

The Antarctic Ozone Hole May Be Closing

There’s good news from Antarctica, where researchers with tools like ozonesondes — pictured above — have been following the infamous ozone hole as it waxes and wanes over the seasons. The ozone hole has shrunk by 1.5 million square miles – around 4 million square kilometers — and this “healing” trend appears to be continuing.

A major ecological catastrophe has been averted, and we can cite human intervention as the reason. When the globe swept into action with 1987′s Montreal Protocol, which banned a number of substances known to contribute to ozone depletion, it apparently worked.

When scientists first began to observe a hole in the ozone layer over Antarctica, it was a cause for grave concern. Though ozone levels actually fluctuate throughout the year, they perform an important function by blocking the sun’s harmful UV radiation.

Bees' ability to forage decreases as air pollution increases

Air pollutants interact with and break down plant-emitted scent molecules, which insect pollinators use to locate needed food, according to a team of researchers led by Penn State. The pollution-modified plant odors can confuse bees and, as a result, bees' foraging time increases and pollination efficiency decreases. This happens because the chemical interactions decrease both the scent molecules' life spans and the distances they travel.

While foraging for food, insects detect floral scent molecules in the air. Wind currents can carry these molecules up to thousands of feet from their original source to where bees have their hives.

"Many insects have nests that are up to 3,000 feet away from their food source, which means that scents need to travel long distances before insects can detect them," said Jose D. Fuentes, professor of meteorology and atmospheric science, Penn State. "Each insect has a detection threshold for certain kinds of scents and they find food by moving from areas of low concentrations of scents to areas of high concentrations."

Carbon emissions from Indonesia forest fires hit new high

Forest fires in Indonesia last year released 11.3 million tonnes of carbon per day, researchers have found. This figure exceeds the daily rate of 8.9 million tonnes of carbon emissions from the whole of the European Union, the study says.

The 2015 fires were the worst since 1997, when a strong El Niño also fanned widespread fires, says the study, published in the journal Scientific Reports.

Fire is widely used in South-East Asia to clear vegetation and maintain land for the growing of crops, the paper explains. Last year, fires were exacerbated by extended drought associated with El Niño, releasing 857 million tonnes of carbon dioxide from September to October 2015, the authors say. This represents 97 per cent of the country’s annual carbon emissions.