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    Some trees are coping with extreme heat surprisingly well

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    Ecologist Akhil Javad felt the thrill of fieldwork quickly fade when he was faced with the prospect of scaling trees over five times his height. But for some of the trees he was studying in India’s Western Ghat mountains, that was the only way to take their temperature.

    So, Javad got climbing. Sensors that he placed on leaves in the upper canopy are providing unprecedented insights into how tropical forests are weathering global warming. The findings suggest that the trees may be in better shape than scientists thought, he and colleagues report in the February Global Change Biology.

    Ecologist Akhil Javad (shown) and colleagues found that tropical trees’ ability to photosynthesize may be more resilient to rising global temperatures than previously thought.Akhil Javad

    In the summer, which lasts from March through June in the region, daily high temperatures in the mountains can cross 37° Celsius and are projected to rise by about 4 degrees Celsius in the next 60 years. That could be a problem for trees, since leaves can get much hotter than the surrounding air.

    As the temperature of a leaf rises, its ability to harness sunlight to make sugar and oxygen becomes less efficient. On average, when leaves surpass 46.7° C, their photosynthetic machinery shuts down, lab studies have shown. When that happens, trees don’t get the energy they need. Many trees in the tropics are already experiencing temperatures beyond that average limit. More

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      Some sea turtles are laying eggs earlier in response to climate change

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      Green sea turtles are adjusting their nesting habits in response to rising global temperatures. Individual females are laying their eggs earlier in the season to cope with warmer conditions, researchers report in the February Proceedings of the Royal Society B.

      Scientists have long known that the sex of most turtle species is determined by incubation temperature — higher temperatures give life to females, and lower ones produce males. As climate change drives up temperatures, more females and fewer males are being born, potentially weakening populations. Extreme heat can also be lethal for the eggs.

      Marine biologist Mollie Rickwood kneels next to a loggerhead turtle protected nest. The females dig themselves down in the sand using their flippers, then they dig a flask-shaped chamber where they lay eggs.Mollie Rickwood

      To understand how turtles are adapting, conservation ecologist Annette Broderick and colleagues analyzed three decades of nesting data from around 600 tagged green turtles (Chelonia mydas) on the beaches of Northern Cyprus. The data included the number of successful hatchlings in each nest and temperatures during incubation. The team found that individual females nested earlier as temperatures rose, laying eggs just over six days earlier, on average, for each 1-degree-Celsius increase.

      This is “the first time anyone looked at individual turtles and looked at how they’re changing,” rather than studying nesting behavior at a population level, says Broderick, of the University of Exeter in England. More

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      Warming is chasing cloud forests steadily uphill

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      Cloud forests are strange and ghostly places — akin to coral reefs hidden high on tropical mountains. Stunted trees loom in the mist, gnarled trunks and branches crusted in moss, lichens, orchids, ferns, bromeliads and even climbing cactus vines. Arboreal frogs and salamanders spawn in fog-fed bromeliad pools, and spider monkeys pause to sip drinks.

      But these enigmatic forests are being squeezed by warming and deforestation.

      Hundreds of tree and plant species that make up Mesoamerican cloud forests are being chased uphill by rising temperatures, at an average rate of 1.8 to 2.7 meters per year, researchers report in the March 7 Science. From 1979 to 2010, these forests retreated 84 meters uphill. At the same time, cattle grazing and deforestation higher on the mountains is pushing the forests downward 6.3 meters per year — squishing these ecosystems into ever narrower bands of territory. More

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      How a puffin patrol in Iceland is saving the iconic seabirds

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      A small, rocky island off Iceland is home to the world’s largest breeding colony of Atlantic puffins.

      When breeding season is in full swing, around 1.5 million adults pair up and nestle into burrows on the grassy seaside slopes above Heimaey island’s rocky cliffs.

      Once chicks hatch, puffin moms and dads devote about six weeks to caring for their babies, bringing meals of small fish and fending off predators such as seagulls. By late August or early September, the pufflings are mature enough to live on their own. Over four to five weeks, throngs of young birds head off to sea. Their instinct is to head for the open ocean, where they will spend most of their lives. They leave in the dark of night to hide from predators, guided by the moon.

      Puffin parents care for immature pufflings until they can fly on their own. The downy fluff around the neck of this puffling (right) indicates it’s not yet ready to fledge.Rachel Bennett/iStock/Getty Images Plus

      But sometimes fledglings lose their way. Heimaey’s only town got electricity about a century ago. Ever since, dazzled by night lights or swept along in stiff sea breezes, some young puffins have taken a wrong turn — toward town.

      Light pollution affects wildlife in perilous ways, disrupting crucial activities from pollination to mating. Some creatures, like these Atlantic puffins (Fratercula arctica), lose their orientation and can’t find their way to the ocean. Some could be attacked by predators; others might starve. Fortunately for these pufflings, the residents of Heimaey have taken a hands-on approach to addressing the problem. More

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      Fog collection could alleviate water stress in desert cities

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      Rural communities in arid regions have harvested tiny droplets of fog for years as a source of fresh drinking water. Now, researchers say that fog water can be a practical supplement to stave off water stress for larger desert cities.

      A yearlong assessment of the potential volume of harvested fog water near a city in northern Chile’s Atacama Desert found that it’s possible to collect as much as 5 liters per square meter each day, scientists report Feb. 20 in Frontiers in Environmental Science. More

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      Migrating whale sharks make pit stops at oil and gas rigs

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      Like rolling into a gas station during a road trip, whale sharks use oil and gas rigs as a pit stop during their migrations of thousands of kilometers across the oceans. The human-made structures attract marine life — including the sharks’ favorite snack: plankton. But experts worry that this lure could put the endangered behemoths at risk of ship strike or chemical pollution.

      Satellite tracking of whale sharks off the coast of western Australia shows how oil and gas platforms influence the movements of these gentle giants, marine ecologist Ben D’Antonio and colleagues report January 18 in Diversity and Distributions. “As they migrate across the ocean, they are stopping over and moving between features to presumably grab an easy meal before continuing with their migration,” says D’Antonio, of the Australian Institute of Marine Science (AIMS) and University of Western Australia in Perth. More

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      Historical writings reveal how people weathered the Little Ice Age

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      “Dear diary, it was freezing outside today…” If someone today wrote that in their journal, it might seem like an innocuous enough line, perhaps never to be carefully considered again. But what if, 500 years from now, scientists used that entry about the weather to answer climate mysteries?

      Researchers looking to the past have done just that, combing through diaries and other old documents to reconstruct the climate of 16th century Transylvania, part of modern-day Romania. What they found offers a glimpse at how a cooling period called the Little Ice Age may have affected people in the region, the team reports February 12 in Frontiers in Climate. More

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      Just a small rise in global temperatures could be deadly

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      Meghan Rosen is a staff writer who reports on the life sciences for Science News. She earned a Ph.D. in biochemistry and molecular biology with an emphasis in biotechnology from the University of California, Davis, and later graduated from the science communication program at UC Santa Cruz. More

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      Can geoengineering plans save glaciers and slow sea level rise?

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