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Isabel

Scientists present new data on the evolution of plants and the origin of species

By | News, Plant Science | No Comments

There are over 500,000 plant species in the world today. They all evolved from a common ancestor. How this leap in biodiversity happened is still unclear. An international team of researchers presents the results of a unique project on the evolution of plants. Using genetic data from 1,147 species the team created the most comprehensive evolutionary tree for green plants to date.

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Plant Health: prioritising the fight against 20 plant pests on the EU

By | News, Plant Health, Policy | No Comments

The EU has published a list of 20 regulated quarantine pests qualifying as priority pests, including Xylella fastidiosa, the Japanesebeetle, the Asian long-horned beetle, Citrus greening and Citrus Black Spot, whose economic, environmental and social impact on EU’s territory is the most severe. Member States will have to launch information campaigns to the public, do annual surveys, prepare contingency plans, simulation exercises, and action plans for the eradication of these pests.

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Communicating uncertainty about climate change

By | Climate change, News, Science communication | No Comments

The ways climate scientists explain their predictions about the impact of global warming can either promote or limit their persuasiveness.

The more specific climate scientists are about the uncertainties of global warming, the more the American public trusts their predictions, according to new research by Stanford scholars.

But scientists may want to tread carefully when talking about their predictions, the researchers say, because that trust falters when scientists acknowledge that other unknown factors could come into play.

In a study in Nature Climate Change, researchers examined how Americans respond to climate scientists’ predictions about sea level rise. They found that when climate scientists include best-case and worst-case case scenarios in their statements, the American public is more trusting and accepting of their statements. But those messages may backfire when scientists also acknowledge they do not know exactly how climate change will unfold.

“Scientists who acknowledge that their predictions of the future cannot be exactly precise and instead acknowledge a likely range of possible futures may bolster their credibility and increase acceptance of their findings by non-experts,” said Jon Krosnick, a Stanford professor of communication and of political science and a co-author on the paper. “But these gains may be nullified when scientists acknowledge that no matter how confidently they can make predictions about some specific change in the future, the full extent of the consequences of those predictions cannot be quantified.”

Effects of communicating uncertainty

Predicting the future always comes with uncertainty, and climate scientists routinely recognize limitations in their predictions, note the researchers.

“In the context of global warming specifically, scientific uncertainty has been of great interest, in part because of concerted efforts by so-called ‘merchants of doubt’ to minimize public concern about the issue by explicitly labeling the science as ‘uncertain,’” said Lauren Howe, who was a postdoctoral scholar at Stanford when she conducted the research with Krosnick and is first author on the paper.

“We thought that, especially in this critical context, it was important to understand whether expressing uncertainty would undermine persuasion, or whether the general public might instead recognize that the study of the future has to involve uncertainty and trust predictions where that uncertainty is openly acknowledged more than those where it is minimized,”

Howe said.

To better understand how the public reacts to scientists’ messages about the uncertainties of climate change, the researchers presented a nationally representative sample of 1,174 American adults with a scientific statement about anticipated sea level rise.

Respondents were randomly assigned to read either a prediction of the most likely amount of future sea level rise; a prediction plus a worst-case scenario; or a robust prediction with worst-case and best-case scenarios, for example: “Scientists believe that, during the next 100 years, global warming will cause the surface of the oceans around the world to rise about 4 feet. However, sea level could rise as little as 1 foot, or it could rise by as much as 7 feet.”

The researchers found that when predictions included a best-case and worst-case scenario, it increased the number of participants who reported high trust in scientists by 7.9 percentage points compared with participants who only read a most likely estimate of sea level rise.

Changes in environmental policies, human activities, new technologies and natural disasters make it difficult for climate scientists to quantify the long-term impact of a specific change – which scientists often acknowledge in their predictions, the researchers said. They wanted to know if providing such well-intended, additional context and acknowledging complete uncertainty would help or hurt public confidence in scientific findings.

To find out, the researchers asked half of their respondents to read a second statement acknowledging that the full extent of likely future damage of sea level rise cannot be measured because of other forces, such as storm surge: “Storm surge could make the impacts of sea level rise worse in unpredictable ways.”

The researchers found that this statement eliminated the persuasive power of the scientists’ messages. When scientists acknowledged that storm surge makes the impact of sea level rise unpredictable, it decreased the number of participants who reported high trust in scientists by 4.9 percentage points compared with the participants who only read a most likely estimate of sea level rise.

The findings held true regardless of education levels and political party affiliation.

Not all expressions of uncertainty are equal, Howe said: “Scientists may want to carefully weigh which forms of uncertainty they discuss with the public. For example, scientists could highlight uncertainty that has predictable bounds without overwhelming the public with the discussion of factors involving uncertainty that can’t be quantified.”

Read the paper: Nature Climate Change

Article source: Stanford University

Author: Melissa De Witte

Image credit: Jody Davis / Pixabay

Photosynthesis olympics: can the best wheat varieties be even better?

By | Agriculture, News, Plant Science | No Comments

Scientists have put elite wheat varieties through a sort of “Photosynthesis Olympics” to find which varieties have the best performing photosynthesis. This could ultimately help grain growers to get more yield for less inputs in the farm.

“In this study we surveyed diverse high-performing wheat varieties to see if their differences in photosynthetic performance were due to their genetic makeup or to the different environments where they were grown,” said lead researcher Dr Viridiana Silva-Perez from the ARC Centre of Excellence for Translational Photosynthesis (CoETP).

The scientists found that the best performing varieties were more than 30 percent better than the worst performing ones and up to 90 percent of the differences were due to their genes and not to the environment they grew in.

“We focused on traits related to photosynthesis and found that some traits behaved similarly in different environments. This is useful for breeders, because it is evidence of the huge potential that photosynthesis improvement could have on yield, a potential that hasn’t been exploited until now,” says Dr Silva-Perez.

During the study, published recently in the Journal of Experimental Botany, the scientists worked in Australia and Mexico, taking painstaking measurements in the field and inside glasshouses.

“The results that we obtained from our “Photosynthesis Olympics”, as we like to call them, are very exciting because we have demonstrated that there is scope to make plants more efficient, even for varieties working in the best conditions possible, such as with limited water and fertiliser restrictions. This means for example, that breeders have the potential to get more yield from a plant with the same amount of nitrogen applied,” says CoETP Director Professor Robert Furbank, one of the authors of this study.

Photosynthesis – the process by which plants convert sunlight, water and CO2 into organic matter – is a very complex process involving traits at different levels, from the molecular level, such as content of the main photosynthetic enzyme Rubisco, to the leaf, such as nitrogen content in the leaf and then to the whole canopy.

“This work is an important result for the CoETP, which aims to improve the process of photosynthesis to increase the production of major food crops such as wheat, rice and sorghum. There is a huge amount of collaboration, both institutional and interdisciplinary, that needs to take place to achieve this type of research. Without the invaluable cooperation between statisticians, plant breeders, molecular scientists and plant physiologists, we would have never achieved these results,” says co-author Tony Condon from CSIRO and the CoETP.

Read the paper: Journal of Experimental Botany

Article source: Arc Centre Of Excellence For Translational Photosynthesis

Author: Natalia Bateman

Image credit: Dr Viridiana Silva-Perez/COETP

Researchers Map the Evolutionary History of Oaks

By | Forestry, News | No Comments

Oaks have a complex evolutionary history that has long eluded scientists. New research, however, provides the most detailed account to date of the evolution of oaks, recovering the 56-million-year history that has made the oaks one of the most diverse, abundant and important woody plant groups to the ecology and economy of the northern hemisphere.

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