Science Briefs: Christmas trees at risk due to climate change

Researchers who mimicked drought conditions in global warming scenarios have predicted a widespread death of needleleaf evergreen trees in south-western United States by 2100.
Researchers who mimicked drought conditions in global warming scenarios have predicted a widespread death of needleleaf evergreen trees in south-western United States by 2100.PHOTO: REUTERS

Christmas trees at risk due to climate change

There could one day be a December without the iconic Christmas tree in sight, and this could happen in fewer than 90 years. Researchers have predicted a widespread death of needleleaf evergreen trees (NET) in south-western United States by 2100.

The grim conclusion was reached after field results and a range of validated regional predictions and global simulation models were considered.

The paper on the findings was published in Nature Climate Change. "No matter how we investigated the problem, we got the same result," said team member Sara Rauscher from the University of Delaware.

South-western US is a semi-arid region that includes Arizona and parts of New Mexico and California. It is home to 11 national forests spanning more than 8 million ha in Arizona and New Mexico alone.

Over the five-year study, researchers restricted nearly 50 per cent of the rainfall from three plots to mimic drought conditions. Over the study period, 80 per cent of the mature pinon pines in the test plots died, with other trees experiencing drought stress.

The researchers used computational models to predict how the trees would respond to drought in the future under predicted global warming scenarios.

Averaging all the models together, the study results suggest that 72 per cent of the region's NET forests will die by 2050, with nearly 100 per cent mortality by 2100.

Scientists locate the Christmas spirit in brain

The Christmas spirit has been located in the human brain, reveals a study published in medical journal The BMJ's Christmas issue.

It is commonly described as feelings of joy and nostalgia mixed with associations to merry feelings, gifts, delightful smells and good food.

The authors of the study estimate that "millions of people are prone to displaying Christmas spirit deficiencies", and refer to this as the "bah, humbug" syndrome.

The researchers from Rigshospitalet, a hospital affiliated with Denmark's Copenhagen University, attempted to locate the "Christmas spirit" in the brain using functional magnetic resonance imaging scans, measuring changes in blood oxygenation and flow that occur in response to neural activity.

Participants were scanned while viewing 84 images before filling out a questionnaire about their Christmas traditions, feelings associated with Christmas and ethnicity.

Based on these results, 10 participants were allocated to the group which celebrated Christmas, and 10 to the group which did not celebrate Christmas. The Christmas group responded to Christmas images with a higher brain activation than the non-Christmas group in the left primary motor and premotor cortex, right inferior and superior parietal lobule, and bilateral primary somatosensory cortex. These cerebral areas have been associated with spirituality, bodily senses and recognition of facial emotion.

But the researchers explained: "Although merry and intriguing, these findings should be interpreted with caution.

"Something as magical and complex as the Christmas spirit cannot be fully explained by, or limited to, the mapped brain activity alone."

Robots could be Santa's new helper

Fleets of small autonomous robots could soon become a familiar presence on public pathways, with ground-based drones that aim to improve local delivery of goods and groceries.

Skype's former co-founders have launched a new company, Starship Technologies, which is preparing to test their self-driving delivery robots in London. The robots are small, safe and free from carbon dioxide emissions, according to the developers. They can carry the equivalent of two bags of shopping and complete local deliveries in five to 30 minutes from a designated place.

They are not designed for long-distance orders, but for completing the final mile of a delivery, said Mr Ahti Heinla, chief executive at Starship Technologies.

When a package is out for delivery with a robot, the customer can track it in real time on a smartphone.

When it arrives at the delivery address, the customer uses his smartphone to unlock the secure compartment to get the goods.

The robots are also overseen by human operators who can step in to ensure safety at all times.

"People don't like other machines flying over their backyard where their children are playing... but not so much for the robots that are land-based and safe and look cute," said Mr Heinla of earthbound drones, compared with airborne ones.

Starship Technologies will launch real-life trials of the robots in London and a few US cities next year.


Compiled by Samantha Boh

A version of this article appeared in the print edition of The Straits Times on December 25, 2015, with the headline 'ScienceBriefs'. Subscribe