Researchers investigate development of coastal peatland in Indonesia over thousands of years

Date: March 24, 2022

Source: University of Göttingen

Tropical peatlands are one of the most efficient carbon sinks. The flipside is that they can become massive emitters of carbon if they are damaged, for instance by land use change, degradation or fire. This can lead to faster climate warming. In research led by the University of Göttingen, researchers show how peatland in the coastal areas in Sumatra and Borneo in Indonesia developed over thousands of years and how climate and sea level influenced their dynamics throughout. The results were published in Global Change Biology.

To discover more about the environment over the past 17,000 years, researchers analysed two peat cores, each over eight meters long. They carried out analyses for traces of pollen, spores and charcoal, as well as conducting carbon dating and biogeochemical investigations. Their study found that there were much higher concentrations of charcoal between 9,000 to 4,000 years ago (the mid-Holocene), when sea level was even higher than it is now. This is a sign that there were much larger forest fires at that time. Later, around 3,000 years ago, irregular periodic variations in winds and sea surface temperatures (known as El Nino-Southern Oscillation or ENSO) would have caused prolonged drought, making the forests dry and thus susceptible to fires ignited by lightning. However, even at this time, the fires were fewer than in the earlier mid-Holocene, which presented a puzzle. A clue was that during the earlier period in the mid-Holocene period, researchers found a high proportion of mangrove pollen.

The pollen grains indicate the presence of mangrove forests which grow along the coast in salty water. Their presence is a good indicator of rising sea level and an increase of salt in the otherwise freshwater peatland ecosystem. Salt is harmful to freshwater (inland) vegetation, which is likely to have resulted in more dry and dead tree leaves and branches. Salt can also reduce forest canopy cover and air humidity, which is the one important factor that can prevent fire spreading in peatland ecosystems. Furthermore, mangrove woods are high-quality fuels that can burn for a long time and reach high temperatures. The increase in dry or dead trees and the availability of high-quality firewood alongside decreased canopy cover and humidity, could all contribute to the larger fires from that time. "We were surprised to find that rising sea levels could potentially exacerbate fires in coastal areas in Indonesia," says lead author Dr Anggi Hapsari, University of Göttingen. "Our findings underline how the interaction between rising sea levels and dry climate may contribute to massive forest fires even in relatively fire-proof ecosystems, such as pristine peatlands. This reveals the potential hidden impact of sea level rise exacerbating climate warming."

"However, in contrast to the past, the primary cause of peatland fires now is human activity," adds Hapsari. "If people's behaviour continues in terms of, for instance, extensive destruction of peat swamp forests, peatland drainage, and intentional burning, when met with current rapidly rising sea level and stronger future ENSO, this could lead to catastrophic and widespread forest fires and uncontrollable carbon release," she continues.

"Our unexpected finding adds an as yet unknown threat to the survival of these valuable ecosystems," explains coauthor Dr Tim Jennerjahn, Leibniz Centre for Tropical Marine Research in Bremen. He concludes, "It demonstrates how the reconstruction of past environmental change can help improve present-day management of coastal ecosystems. It is clear that fire risk assessment in tropical peatlands deserves more attention."


Journal Reference:
K. Anggi Hapsari, Tim Jennerjahn, Septriono Hari Nugroho, Eko Yulianto, Hermann Behling. Sea level rise and climate change acting as interactive stressors on development and dynamics of tropical peatlands in coastal Sumatra and South Borneo since the Last Glacial Maximum. Global Change Biology, 2022; DOI: 10.1111/gcb.16131

Rapid glacial advance reconstructed during the time of Norse occupation in Greenland

Date:March 25, 2022

Source:Geological Society of America

The Greenland Ice Sheet is the second largest ice body in the world, and it has the potential to contribute significantly to global sea-level rise in a warming global climate. Understanding the long-term record of the Greenland Ice Sheet, including both records of glacial advance and retreat, is critical in validating approaches that model future ice-sheet scenarios. However, this reconstruction can be extremely challenging. A new study published Thursday in the journal Geology reconstructed the advance of one of the largest tidewater glaciers in Greenland to provide a better understanding of long-term glacial dynamics.

"In the news, we're very used to hearing about glacial retreat, and that's because in a warming climate scenario -- which is what we're in at the moment -- we generally document ice masses retreating. However, we also want to understand how glaciers react if there is a climate cooling and subsequent advance. To do this, we need to reconstruct glacier geometry from the past," said Danni Pearce, co-lead author of the study.

An interdisciplinary team of researchers studied the advance of Kangiata Nunaata Sermia (KNS) -- the largest tidewater glacier in southwest Greenland -- during a period of cooling when the Norse had settlements in Greenland. Differing from glaciers that are strictly on land, tidewater glaciers extend and flow all the way to the ocean or a sea, where they can then calve and break up into icebergs.

Reconstructing the advance of glaciers can be exceptionally difficult, because the glacier typically destroys or reworks everything in its path as it advances forward. The research team undertook multiple field seasons in Greenland, traveling on foot to remote sites -- many of which hadn't been visited since the 1930s -- to try and uncover the record of KNS advance.

"When we went out into the field, we had absolutely no idea whether the evidence would be there or not, so I was incredibly nervous. Though we did a huge amount of planning beforehand, until you go out into the field you don't know what you're going to find," said James Lea, the other co-lead author of the study.

By traveling on foot, the research team was able to more closely examine and explore sites that otherwise may have been missed if traveling by helicopter. The team's planning paid off, and the sedimentary sequences they studied and sampled held the clues they were looking for to date and track the advance of the glacier.

The research team found that during the twelfth and thirteenth centuries CE, KNS advanced at least 15 km, at a rate of ~115 m/yr. This rate of advance is comparable to modern rates of glacial retreat observed over the past ~200 years, indicating that when climate is cooler glaciers can advance equally as fast as they are currently retreating. The glacier reached its maximum extent by 1761 CE during the Little Ice Age, culminating in a total advance of ~20 km. Since then, KNS has retreated ~23 km to its present position.

The period when the glacier was advancing coincided with when the Norse were present in Greenland. Prior to its maximum extent during the Little Ice Age, the researchers found that KNS advanced to a location within only 5 km of a Norse farmstead.

"Even though KNS was rapidly coming down the fjord, it did not seem to affect the Norse, which we found really unusual," said Pearce. "So the team started to think about the surrounding environment and the amount of iceberg production in the fjord during that time. At the moment, the fjord is completely filled with icebergs, making boat access challenging, and we know from historical record that it has been like this for the last 200 years while the glacier has been retreating. However, for KNS to advance at 115 m/yr, it needed to hang onto its ice and could not have been producing a lot of icebergs. So we actually think that the fjord would have looked very different with few icebergs, which allowed the Norse far more easy access to this site for farming, hunting, and fishing."

In the 1930s, archaeologists who visited the site hypothesized that conditions in the fjord must have been different from the present day in order for the Norse to have occupied the site, and this current research study provides data to support these long-held ideas.

"So we have this counterintuitive notion that climate cooling and glacier advance might have actually helped the Norse in this specific circumstance and allowed them to navigate more of the fjord more easily," said Lea.

The Norse left Greenland during the fifteenth century CE, and these results are consistent with the idea that a cooling climate was likely not the cause of their exodus; rather, a combination of economic factors likely led the Norse to abandon Greenland.

The results from this research reconstructing rapid glacial advance are also shown to be consistent with the ways ice sheet models work, which brings confidence to the projections from these models. Having accurate models and projections are crucial in understanding and preparing for future scenarios of continued retreat of the Greenland Ice Sheet and associated sea-level rise.

"Melt from Greenland not only impacts sea-level change but also the ecology around the ice sheets, fisheries, the biological productivity of the oceans -- how much algae is growing. And also because the types of glaciers we're looking at produce icebergs these can cause hazards to shipping and trade, especially if the Northwest Passage opens up as it is expected to," said James Lea.

Pearce added, "Our research shows that climate cooling can change iceberg calving behavior and drive glacier advance at rates just as rapid as current retreat. It also shows how resilient the Greenlandic Norse were to the changing environmental conditions. Such adaptation can give us hope for the changes we may face over the coming century.''

Journal Reference:
Danni M. Pearce, James M. Lea, Douglas W.F. Mair, Brice R. Rea, J. Edward Schofield, Nicholas A. Kamenos, Kathryn M. Schoenrock, Lukasz Stachnik, Bonnie Lewis, Iestyn Barr, Ruth Mottram. Greenland tidewater glacier advanced rapidly during era of Norse settlement. Geology, 2022; DOI: 10.1130/G49644.1

Nature-based carbon removal can help protect us from a warming planet

Date: March 29, 2022

Source: Simon Fraser University

A new study finds that temporary nature-based carbon removal can lower global peak warming levels but only if complemented by ambitious fossil fuel emission reductions.

Nature-based climate solutions aim to preserve and enhance carbon storage in terrestrial or aquatic ecosystems and could be a potential contributor to Canada's climate change mitigation strategy. "However, the risk is that carbon stored in ecosystems could be lost back to the atmosphere as a result of wildfires, insect outbreaks, deforestation or other human activities," says Kirsten Zickfeld, a distinguished professor of climate science in Simon Fraser University's Department of Geography who is on the research team.

The researchers used a global climate model to simulate temperature change through two scenarios ranging from weak to ambitious greenhouse gas emissions reductions. In the relatively weak emissions reduction scenario, carbon emissions continue through 2100. In the ambitious scenario carbon emissions reach net-zero by 2050.

In order to meet the Paris Agreement's climate goals, the world will need to reach net-zero CO2 emissions around or before mid-century, according to the United Nations' Intergovernmental Panel on Climate Change.

In both scenarios, it is assumed that carbon storage through nature-based climate solutions is temporary as forests are vulnerable to both natural and human disturbances. Therefore, nature-based climate solutions are anticipated to withdraw carbon from the atmosphere over the next 30 years then slowly release the carbon during the second half of the century.

The team found that in a scenario with carbon emissions decreasing rapidly to net-zero, temporary nature-based carbon storage can decrease the level of peak warming. However, in a scenario with continued carbon emissions temporary nature-based carbon storage would serve only to delay the temperature increase.

"Our study shows that nature-based carbon storage, even if temporary, can have tangible climate benefits, but only if implemented alongside a rapid transition to zero fossil-fuel emissions," says Zickfeld.

The findings are published in Communications Earth & Environment.

Zickfeld is also the lead author of the recent United Nations' Intergovernmental Panel on Climate Change (IPCC) Working Group I contribution to the Sixth Assessment Report released in summer 2021, and the IPCC's 2018 special report on the global warming of 1.5 degrees.

The researchers also note that investing in protecting and restoring nature offers social and environmental benefits for local and Indigenous communities beyond storing carbon to mitigate climate change. They add that biodiversity, water and air quality are inherently valuable and that efforts to enhance these can also help to build community resilience to climate change.

Related Multimedia:
YouTube video: Nature-based carbon removal can help protect us from a warming planet

Journal Reference:
H. Damon Matthews, Kirsten Zickfeld, Mitchell Dickau, Alexander J. MacIsaac, Sabine Mathesius, Claude-Michel Nzotungicimpaye, Amy Luers. Temporary nature-based carbon removal can lower peak warming in a well-below 2 °C scenario. Communications Earth & Environment, 2022; 3 (1) DOI: 10.1038/s43247-022-00391-z

Drought alters Mammoth Mountain’s carbon dioxide emissions

Date: March 29, 2022

Source: Stanford University

Summary:  A study suggests the weight of snow and ice atop the Sierra Nevada affects a California volcano's carbon dioxide emissions, one of the main signs of volcanic unrest.

Thirty years ago, on the flanks of a volcano in California's Sierra Nevada range, trees began to die en masse, suffocated at their roots by carbon dioxide seeping up from the mountain's depths after a swarm of small earthquakes.

The wave of tree deaths on Mammoth Mountain, which lies within one of the nation's largest active volcanic systems, prompted scientists to start monitoring the volcano's emissions more closely.

Now, researchers led by Stanford University geologist George Hilley have made a surprising discovery in the long-running record: The ebb and flow of carbon dioxide emissions from Mammoth Mountain are strongly linked to the weight of snow and ice atop the Sierra Nevada, and to the amount of water that percolates from ground level down into the volcano's plumbing.

"This really shows how the solid Earth is coupled to climate and the things that go on at the surface," said Hilley, professor of geological sciences in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "Droughts can change the way in which volcanoes breathe."

The research, published March 9 in Geophysical Research Letters, comes amid a dry winter that has left California snowpack well below average for this time of year, with less than a week remaining in the state's wet season and no major snowstorms in the forecast.

By the end of this century, state officials predict the Sierra Nevada snowpack will decline by 48 to 65 percent from the historical April 1 average. "Changes in Earth's hydrology due to climate change could actually impact something like the tempo at which gases are emitted from volcanic systems," Hilley said.

Horseshoe Lake

Hilley and coauthors analyzed measurements of carbon dioxide emissions taken every 30 minutes for six years from Horseshoe Lake, the best-studied tree kill area on Mammoth Mountain. The mountain rises along the southwest rim of Long Valley Caldera, a crater formed by a supervolcano eruption 760,000 years ago.

The results reveal a persistent 20 percent reduction in the amount of carbon dioxide seeping up from the ground during the spring of 2017. The downshift coincides with the region's emergence from intense drought and the pileup of the biggest Sierra Nevada snowpack in decades.

The study builds upon research by USGS volcanologist Jennifer Lewicki showing that carbon dioxide emissions in the Horseshoe Lake tree-kill area changed seasonally and across multiple years for reasons unrelated to a brewing eruption.

Seeking an explanation for these variations, Lewicki and Hilley -- with coauthor Curtis Baden of Stanford -- developed mathematical models to test out plausible mechanisms. Snowmelt and rainfall can wash away carbon dioxide that might otherwise seep from the ground, for example. But their calculations show Mammoth Mountain receives far too little precipitation to account for the low springtime CO2 levels observed in 2017.

The most likely explanation for the seasonal changes in Mammoth Mountain's carbon dioxide emissions has to do with an underground crack, or fault, which to a trained eye is evident in the vegetation patterns and topography of the landscape. Changes in the distribution of stress across the whole mountain range seem to open and close the fault like a valve, or like the tiny gaps between old floorboards that flex under shifting weight.

Using GPS data and snow depth measurements, the authors found compressive force on the fault between 2014 and 2020 generally peaked in winter as snowpack accumulated across the Sierra Nevada and eased during snow-free summer months. Carbon dioxide emission levels dipped during periods when the weight of snow and water in the mountains flexed Earth's crust, squeezing together the rocks on either side of the Mammoth Mountain fault.

One limitation of the study is that it does not provide a physics-based model of the fault's movement and how gas flows through it. "We're using stress changes as proxies for the opening and closing of a conduit," Hilley said. "An interesting study would run a three-dimensional model of gas transport through a conduit that you could actually open and close, and then run that model many times to see if its predictions quantitatively match the carbon dioxide measurements we're making."

Predicting future eruptions

The ability to distinguish between CO2 fluctuations driven by climate from those driven by an impending eruption will enable better hazard forecasts, which are based partly on signs that rising magma is triggering earthquakes, deforming the ground surface or ushering gases upward. "The alignment of all three of those is generally a clue that an eruption might be about to happen," Hilley said.

For decades, ground deformation and seismicity around some of the United States' active volcanoes have been monitored continuously using GPS and satellites, and scientists can view the data in close to real time. But they have a murkier view on volcanic gas. "In the past, at most volcanoes, scientists had to go into a volcanic area in advance of an eruption, or even between eruptions, and go collect this gas for later analysis. It's real Indiana Jones-type stuff," said Hilley.

The difficulty of collecting volcanic gases has resulted in limited records, sometimes with only a single snapshot of a volcano's degassing in any given year, which makes it challenging to detect changes that may warn of an eruption -- or to understand patterns linked to Earth's climate system.

The new study offers a glimpse of insights to come as scientists gain access to more volcanic emission data, thanks in part to the development of less expensive and more durable instruments.

"The hope is, in the next couple years, we can have a record of what the gas is doing in near real time," Hilley said. "When you look in detail, you can see there are seasonal fluctuations that probably have nothing to do with the actual volcanic state."


Journal Reference:
George E. Hilley, Jennifer L. Lewicki, Curtis W. Baden. Seasonal and Multiyear Changes in CO 2 Degassing at Mammoth Mountain Explained by Solid‐Earth‐Driven Fault Valving. Geophysical Research Letters, 2022; 49 (6) DOI: 10.1029/2021GL096595

Fuel from waste wood

Possibility to produce ethanol on a financially competitive and technically efficient basis

Date: March 29, 2022

Source: Technical University of Munich (TUM)

Summary: According to the latest assessment report from the Intergovernmental Panel on Climate Change, a considerable reduction in CO2 emissions is required to limit the consequences of climate change. Producing fuel from renewable sources such as waste wood and straw or renewable electricity would be one way to reduce carbon emissions from the area of transportation.


Ethanol is usually produced through the fermentation of sugars from starchy raw materials such as corn, or from lignocellulosic biomass, such as wood or straw. It is an established fuel that decarbonizes the transportation sector and can be a building block to reduce emissions of CO2 over the long term. In collaboration with the Lappeenranta-Lahti University of Technology (LUT) in Finland, researchers at the Straubing Campus for Biotechnology and Sustainability of the Technical University of Munich (TUM) have developed a new process for the production of ethanol.

In this context, offcut materials from the area of forestry are used together with hydrogen. The hydrogen is produced by separating water into hydrogen and oxygen with the use of electricity -- in other words, with the use of water electrolysis. In the future, this will allow the excess electricity to be used for the production of ethanol.

"The overall process mainly consists of technically mature sub-processes. However, the composition of the process steps and the final step -- the hydrogenation of acetic acid to produce ethanol -- are new," explains Daniel Klüh, a doctoral student at the Professorship of Renewable Energy Systems at the TUM Straubing Campus.

The costs of ethanol with the new production method are competitive

The researchers have also assessed the economic feasibility. "The prices we have calculated are based on assumptions for raw materials and energy. We are not using any current market prices. The calculation basis of our prices for the components in the chemical system is the year 2020," explains Klüh. The lowest cost for ethanol in the modeling was 0.65 euros per liter, with biomass costs of 20 euros per megawatt hour, electricity costs of 45 euros per megawatt hour, and a production volume of approximately 42 kilotons of ethanol per year.

"With the current lignocellulosic ethanol production options, the costs are therefore competitive. The price of ethanol is very sensitive to the costs of electricity, and fluctuates between 0.56 and 0.74 euros per liter," explains Assistant Professor Kristian Melin of LUT in Finland. One reason for the high profitability is that the ethanol yield is much higher compared to traditional fermentation based bioethanol process from straw or wood. This process produces 1350 to 1410 liters of ethanol, compared to only 200 to 300 liters of ethanol for the traditional process per dry ton of biomass.

Where production facilities could be located

Part of the study is focusing on the variable geographical positioning of production sites, which would enable a degree of independence from suppliers to be achieved. "Countries with a high potential for waste wood and green electricity, such as Finland or even Canada, can serve as producers of acetic acid, which, in the final process step, is hydrogenated to produce ethanol," explains Prof. Tuomas Koiranen of LUT.

"In the future, countries like Germany will hopefully have a green electricity mix and will be able to carry out the hydrogenation of acetic acid to ethanol at a domestic level. However, Germany does not have the waste wood potential for a large-scale biomass gasification which is required for the synthesis of acetic acid," adds Prof. Matthias Gaderer, Professor of Renewable Energy Systems at TUM.

The technology needs to mature further

With the use of green electricity to power the electrolysis, this process can produce a low CO2 fuel that has a greenhouse gas reduction potential of 75 percent in comparison with a fossil fuel such as gasoline. Ethanol is established as a fuel. It can be used in the form of both E-10 gasoline, with 10 percent ethanol in the fuel mixture for regular automobiles, as is already the case, or as ED95, which is 95 percent ethanol, as a diesel substitute for heavy goods transportation.

With their process simulation, the scientists have demonstrated the competitiveness of the process. "To commercialize this product, it is necessary to further improve the degree of technological maturity. The next steps could entail further catalyst developments, a reactor design and the construction and operation of a pilot system," says Prof. Gaderer.

Journal Reference:
Kristian Melin, Harri Nieminen, Daniel Klüh, Arto Laari, Tuomas Koiranen, Matthias Gaderer. Techno-Economic Evaluation of Novel Hybrid Biomass and Electricity-Based Ethanol Fuel Production. Frontiers in Energy Research, 2022; 10 DOI: 10.3389/fenrg.2022.796104

Chaos theory provides hints for controlling the weather

Date: March 28, 2022

Source: RIKEN

Under a project led by the RIKEN Center for Computational Science, researchers have used computer simulations to show that weather phenomena such as sudden downpours could potentially be modified by making small adjustments to certain variables in the weather system. They did this by taking advantage of a system known as a "butterfly attractor" in chaos theory, where a system can have one of two states -- like the wings of a butterfly -- and that it switches back and forth between the two states depending on small changes in certain conditions.

While weather predictions have reached levels of high accuracy thanks to methods such as supercomputer-based simulations and data assimilation, where observational data is incorporated into simulations, scientists have long hoped to be able to control the weather. Research in this area has intensified due to climate change, which has led to more extreme weather events such as torrential rain and storms.

There are methods at present for weather modification, but they have had limited success. Seeding the atmosphere to induce rain has been demonstrated, but it is only possible when the atmosphere is already in a state where it might rain. Geoengineering projects have been envisioned, but have not been carried out due to concerns about what unpredicted long-term effects they might have.

As a promising approach, researchers from the RIKEN team have looked to chaos theory to create realistic possibilities for mitigating weather events such as torrential rain. Specifically, they have focused on a phenomenon known as a butterfly attractor, proposed by mathematician and meteorologist Edward Lorentz, one of the founders of modern chaos theory. Essentially, this refers to a system that can adopt one of two orbits that look like the wings of a butterfly, but can change the orbits randomly based on small fluctuations in the system.

To perform the work, the RIKEN team ran one weather simulation, to serve as the control of "nature" itself, and then ran other simulations, using small variations in a number of variables describing the convection -- how heat moves through the system -- and discovered that small changes in several of the variables together could lead to the system being in a certain state once a certain amount of time elapsed.

According to Takemasa Miyoshi of the RIKEN Center for Computational Science, who led the team, "This opens the path to research into the controllability of weather and could lead to weather control technology. If realized, this research could help us prevent and mitigate extreme windstorms, such as torrential rains and typhoons, whose risks are increasing with climate change."

"We have built a new theory and methodology for studying the controllability of weather," he continues. "Based on the observing system simulation experiments used in previous predictability studies, we were able to design an experiment to investigate predictability based on the assumption that the true values (nature) cannot be changed, but rather that we can change the idea of what can be changed (the object to be controlled)."

Looking to the future, he says, "In this case we used an ideal low-dimensional model to develop a new theory, and in the future we plan to use actual weather models to study the possible controllability of weather."

The work, published in Nonlinear Processes of Geophysics, was done as part of the Moonshot R&D Millennia program, contributing to the new Moonshot goal #8.


Journal Reference:
Takemasa Miyoshi, Qiwen Sun. Control simulation experiment with Lorenz's butterfly attractor. Nonlinear Processes in Geophysics, 2022; 29 (1): 133 DOI: 10.5194/npg-29-133-2022

'An underutilized tool:' UV-LED lights can kill coronaviruses and HIV with the flip of a switch, study finds

Date: March 29, 2022

University of Toronto

The same light bulbs used in offices and public spaces can destroy coronaviruses and HIV, according to a new study from U of T Scarborough.

Researchers killed both viruses using UV-LED lights, which can alternate between white light and decontaminating ultraviolet (UV) light. With a cheap retrofit, they could also be used in many standard lighting fixtures, giving them a "unique appeal" for public spaces, says Christina Guzzo, senior author of the study.

"We're at a critical time where we need to use every single possible stop to get us out of this pandemic," says Guzzo, an assistant professor in the department of biological sciences. "Every mitigation strategy that can be easily implemented should be used."

UV lights kill viruses through radiation. Guzzo, alongside PhD students Arvin T. Persaud and Jonathan Burnie, first tested the lights on bacterial spores notorious for their resistance to this radiation (known as Bacillus pumilus spores).

"If you're able to kill these spores, then you can reasonably say you should be able to kill most other viruses that you would commonly encounter in the environment," says Guzzo, principal investigator at the Guzzo Lab.

Within 20 seconds of UV exposure, the spores' growth dropped by 99 per cent.

The researchers then created droplets containing coronaviruses or HIV, to mimic typical ways people encounter viruses in public, such as from coughing, sneezing and bleeding. The droplets were then exposed to UV light and placed in a culture to see if any of the virus remained active. With just 30 seconds of exposure, the virus' ability to infect dropped by 93 per cent.

Upon testing the viruses at different concentrations, they found samples with more viral particles were more resistant to the UV lights. But even with a viral load so high Guzzo calls it "the worst-case scenario," infectivity dropped 88 per cent.

Though it wasn't included in the study, Guzzo and her students also compared UV light to two heavy duty disinfectants used in lab research. They found the lights were similarly effective in their ability to deactivate viruses.

"I was really surprised that UV could perform on the same level of those commonly used lab chemicals, which we regard as the gold standard," she says. "That made me think, 'Oh, my gosh, this is a legitimate tool that's really underutilized.'"

Balance UV's pros and cons with clever use, researchers say

While the lights still left a small percentage of the virus viable, Guzzo references the "Swiss cheese model" of defence against COVID. Every strategy to fight the spread has its holes, but every layer is another chance to stop straggling virus particles.

Repeated exposure to UV light is key to catching those missed particles -- fortunately, it's as easy as flipping a switch. It's also simpler to change a light bulb than an air filtration system. Guzzo notes that UV-LEDs are cheap and could be easy to retrofit in existing light fixtures, and that the bulbs are long-lasting and simple to maintain.

"You could disinfect in a way that wouldn't be infringing on people's enjoyment of that everyday 'normal' life that they long for," Guzzo says.

The lights also benefit from automation. A standardized, germicidal dose of light can be delivered each time, while the process of wiping down spaces with disinfectants leaves room for human error. Chemicals and waste from these disinfectants also end up in watersheds and landfills as hands are washed and wipes thrown away.

But the lights aren't harmless, and there's a reason for wearing sunscreen and sunglasses -- UV radiation damages nucleic acid, and repeated, prolonged exposure is harmful. That's why Guzzo says the lights should be used when public spaces are empty, such as vacated buses that have finished their routes, or empty elevators travelling between floors. Escalator handrails could be continuously disinfected by putting UV lights in the underground part of the track, cleaning it with each rotation.

Safe Antivirus Technologies, Inc., a Toronto-based start-up company that partnered with Guzzo for the study, is developing unique UV-LED lighting modules. With motion sensors, the lights automatically switch to UV light when a room is empty, then turn back to regular light with movement.

Funded by the Natural Sciences and Engineering Research Council (NSERC) Alliance COVID-19 Grant and published in the Virology Journal, this study highlights UV-LEDs as a tool that could be used beyond the pandemic, ideally to help prevent another.

"Worldwide events like the COVID-19 pandemic, as terrible as they are, hopefully can still be learned from," Guzzo says. "One thing we learned is that this is an underutilized tool we should think more about implementing."

Journal Reference:
Arvin T. Persaud, Jonathan Burnie, Laxshaginee Thaya, Liann DSouza, Steven Martin, Christina Guzzo. A UV-LED module that is highly effective at inactivating human coronaviruses and HIV-1. Virology Journal, 2022; 19 (1) DOI: 10.1186/s12985-022-01754-w

New model predicts how geographic features influence evolutionary outcomes

Date: March 21, 2022

Source: Washington University in St. Louis

Biologists have developed a new method to measure the extent to which regional geographic features -- including barriers between regions, like mountains or water -- affect local rates of speciation, extinction and dispersal for species. As a test case, they successfully used their model to delineate the movement and diversification of neotropical anole lizards.

"Geographical features influence evolutionary outcomes in predictable ways," said Michael Landis, assistant professor of biology in Arts & Sciences at Washington University in St. Louis, first author of the study published in the Proceedings of the National Academy of Sciences (PNAS). "Our study lays the statistical groundwork to model how different geographical features might act as barriers to species movement or might accelerate extinction for other groups besides anoles.

"Such inferences can also help us predict which species are most likely to move, evolve or go extinct as climate change intensifies," he said.

Scientists have long recognized that geography plays a role in how species colonize new regions and whether widespread species eventually separate out into groups that become genetically distinct, losing the ability to reproduce with each other.

But even though geography plays a clear, describable role in the fate of many individual animal and plant species, no one has previously developed standardized models that allow geographical features to shape how evolutionary radiations unfold in space. To address this gap, Landis and his collaborators designed a new phylogenetic model of biogeography that they named FIG.

"FIG allows speciation, extinction and dispersal rates to depend on the local regional features that each species encounters in its range as it evolves," Landis said. "For example, the presence of a barrier interrupting a species range may cause that species to 'split' into two different species faster than if no barrier existed.

To demonstrate its capabilities, Landis and his collaborators used their approach to model the biogeography of Anolis lizards, a group of lizards known to have spread throughout the Caribbean islands and North and South America.

The qualitative part of what they learned was not surprising: that anoles tend to move over short distances rather than far distances, and that movements over water were less common than movements over land for equivalent distances.

"In other words, far places are far and water is wet -- which told us that our new model was in the right ballpark," Landis quipped. But with persistence, he soon proved that the model can quantify relationships between certain geographical features and evolutionary rates that were previously difficult to measure.

"For example, we were able to measure a maximum distance at which species ranges become too widespread to resist splitting in two," Landis said. "To our surprise and satisfaction, our estimated distances aligned nicely with where widespread anoles are found today: some continental anoles are widespread among adjacent regions, but water restricts the ranges of most insular anoles to just one region."

The scientists discovered that distance impedes the movement of Anolis lizards, both in terms of range expansion through dispersal and in terms of allowing widespread species with fragmented ranges to 'split' into two species.

Distances over water have a much greater effect on limiting movement than distances over land, Landis said. The model revealed that distances over water have three times the effect of equivalent distances over land.

Landis and his collaborators -- including Ignacio Quintero at the École Normale Supérieure in Paris, Michael Donoghue and Martha Muñoz at Yale University and Felipe Zapata at University of California, Los Angeles -- have made their new model freely available to others. They anticipate that other biologists will customize and apply FIG to test new hypotheses concerning how other groups of animal and plant species were shaped by the mountains and oceans that they encountered.

"Biogeographers recognize that greater distances and geographical barriers both limit movement," Landis said. "But it is harder to get biogeographers to agree on the extent to which distances or barriers should influence how species spread over millions of years.

"We biologists haven't had the right statistical tools to model how geographical features might influence speciation, extinction and dispersal rates among closely related evolutionary lineages, so we invented some," he said. "The key ideas that emerged in this study arose from a close collaboration among organismal and mathematical biologists who are fascinated by how species evolve in space."


Journal Reference:
Michael J. Landis, Ignacio Quintero, Martha M. Muñoz, Felipe Zapata, Michael J. Donoghue. Phylogenetic inference of where species spread or split across barriers. Proceedings of the National Academy of Sciences, 2022; 119 (13) DOI: 10.1073/pnas.2116948119

Unravelling the mystery of parrot longevity

Bigger brains have led some species of parrot to live surprisingly long lives, new research shows

Date: March 29, 2022 

Source: Max-Planck-Gesellschaft

Parrots are famous for their remarkable cognitive abilities and exceptionally long lifespans. Now, a study led by Max Planck researchers has shown that one of these traits has likely been caused by the other. By examining 217 parrot species, the researchers revealed that species such as the scarlet macaw and sulphur-crested cockatoo have extremely long average lifespans, of up to 30 years, which are usually seen only in large birds. Further, they demonstrated a possible cause for these long lifespans: large relative brain size. The study is the first to show a link between brain size and lifespan in parrots, suggesting that increased cognitive ability may have helped parrots to navigate threats in their environment and to enjoy longer lives.

Despite the fact that parrots are well known for their long lives and complex cognition, with lifespans and relative brain size on par with primates, it remains unknown whether the two traits have influenced each other.

"The problem has been sourcing good quality data," says Simeon Smeele, a doctoral student at the Max Planck Institute of Animal Behavior (MPI-AB) and lead author on the study, published in Proceedings of the Royal Society B. Understanding what has driven parrot longevity is only possible by comparing living parrots. "Comparative life-history studies require large sample sizes to provide certainty, because many processes are a play at once and this creates a lot of variation," says Smeele.

To generate an adequate sample size, scientists from the MPI-AB and the Max Planck Institute for Evolutionary Anthropology (MPI-EvA) teamed up with Species360, which draws on animal records from zoos and aquaria. Together, they compiled data from over 130,000 individual parrots sourced from over 1000 zoos. This database allowed the team to gain the first reliable estimates of average life span of 217 parrot species -- representing over half of all known species.

The analysis revealed an astonishing diversity in life expectancy, ranging from an average of two years for the fig parrot up to an average of 30 years for the scarlet macaw. Other long-lived species include the sulphur crested cockatoo from Australia, which lives on average 25 years.

"Living an average of 30 years is extremely rare in birds of this size," says Smeele who worked closely with Lucy Aplin from MPI-AB and Mary Brooke McElreath from MPI-EvA on the study. "Some individuals have a maximum lifespan of over 80 years, which is a respectable age even for humans. These values are really spectacular if you consider that a human male weights about 100 times more."

Next, the team employed a large-scale comparative analysis to determine whether or not parrots' renowned cognitive abilities had any influence on their longevity. They examined two hypotheses: First, that having relatively larger brains enable longer lifespans. In other words, smarter birds can better solve problems in the wild, thus enjoying longer lives. Second, that relatively larger brains take longer to grow, and therefore require longer lifespans. For each species, they collected data on relative brain size, as well as average body weight and developmental variables.

They then combined the data and ran models for each hypothesis, looking at which model best explained the data. Their results provide the first support that increased brain size has enabled longer lifespans in parrots. Because brain size relative to body size can be an indicator for intelligence, the findings suggest that the parrots with relatively large brains had cognitive capabilities that allowed them to solve problems in the wild that could otherwise kill them, and this intelligence enabled them to live longer lives.

"This supports the idea that in general larger brains make species more flexible and allow them to live longer," says Smeele. "For example, if they run out of their favourite food, they could learn to find something new and thus survive."

The scientists are surprised that factors such as diet, or the greater developmental time required to develop larger brains, did not lead to longer average lifespans. "We would have expected the developmental path to play a more important role because in primates it is this developmental cost that explains the link between brain size and longevity," says Smeele.

In the future, the team plan to explore if sociality and cultural learning in parrots might have also contributed to long lifespans. Says Smeele: "Large-brained birds might spend more time socially learning foraging techniques that have been around for multiple generations. This increased learning period could potentially also explain the longer life spans, as it takes more time but also makes the foraging repertoire more adaptive."

"One thing that makes us humans special is the vast body of socially learned skills. We are really excited to see if long-lived parrots also have a 'childhood' in which they have to learn everything from finding and opening nuts to avoid upsetting the dominant male. Ultimately, we would like to understand which evolutionary drivers create a species with a life-history very similar to our ancestors."


Related Multimedia:
Scarlet macaw

Journal Reference:
Simeon Q. Smeele, Dalia A. Conde, Annette Baudisch, Simon Bruslund, Andrew Iwaniuk, Johanna Staerk, Timothy F. Wright, Anna M. Young, Mary Brooke McElreath, Lucy Aplin. Coevolution of relative brain size and life expectancy in parrots. Proceedings of the Royal Society B: Biological Sciences, 2022; 289 (1971) DOI: 10.1098/rspb.2021.2397

How scientists found an African bat lost to science for 40 years

Now the first recording of the Hill’s horseshoe bat’s echolocation call may help find more

This critically endangered Hill’s horseshoe bat (Rhinolophus hilli), which was released after scientists measured its features, marks the first recorded observation of the species since 1981.
JON FLANDERS, BAT CONSERVATION INTERNATIONAL

By Anna Gibbs

Julius Nziza still remembers the moment vividly. Just before dawn on a chilly January morning in 2019, he and his team gently extracted a tiny brown bat from a net purposely strung to catch the nocturnal fliers. A moment later, the researchers’ whoops and hollers pierced the heavy mist blanketing Rwanda’s Nyungwe National Park. The team had just laid eyes on a Hill’s horseshoe bat (Rhinolophus hilli), which scientists hadn’t seen for nearly four decades.

Nziza, a wildlife veterinarian at Gorilla Doctors in Musanze, Rwanda, and a self-described “bat champion,” had been looking for the critically endangered R. hilli since 2013. For several years, Nziza and Paul Webala from Maasai Mara University in Narok, Kenya, with the help of Nyungwe park rangers, surveyed the forest for spots where the bats might frequent. They didn’t find R. hilli, but it helped them narrow where to keep looking.

In 2019, the team decided to concentrate on roughly four square kilometers in a high-elevation region of the forest where R. hilli had last been spotted in 1981. Accompanied by an international team of researchers, Nziza and Webala set out for a 10-day expedition in search of the elusive bat. It wasn’t rainy season yet, but the weather was already starting to turn. “It was very, very, very cold,” Nziza recalls.

Every night, from sunset until close to midnight, the researchers stretched nets across trails, where bats are most likely to fly, and kept watch. Then, after a few hours of rest, they woke early to check the traps again. It was cold enough that the bats could die if stuck too long.

At 4 a.m. on the fourth day, the researchers caught a bat with the distinctive horseshoe-shaped nose of all horseshoe bat species. But it looked slightly different from others they had captured. This one had darker fur and a pointed tip on its nose.

Everyone began shouting: “This is it!”

After a moment of celebration at 4 a.m., the research team began studying features of the specimen to see if what they caught was indeed R. hilli.

JON FLANDERS, BAT CONSERVATION INTERNATIONAL

The researchers felt “almost 99 percent sure” they had found the lost bat. “We had a couple beers in the evening,” Nziza says. “It was worth celebration.” To be 100 percent sure, though, the team needed to compare its specimen to past ones of R. hilli. Fortunately, there were two in museums in Europe.

That’s because this isn’t the first time that R. hilli was lost, then found, to science. Victor van Cakenberghe, a retired taxonomist at the University of Antwerp in Belgium, rediscovered R. hilli 17 years after it was first seen in 1964. He says he still remembers finding the bat tangled in a mist net strung across a river. He kept the specimen and brought it back to a Belgian museum.

Nearly 40 years later, Nziza and colleagues compared the measurements of their bat, which was released into the wild, to the preserved bat. At long last, it can be confidently said that R. hilli was rediscovered again, researchers report March 11 in a preprint submitted to Biodiversity Data Journal.

And, for the first time ever, the scientists recorded R. hilli’s echolocation call. Now, the rangers can use acoustic detectors to keep an eye — or rather, an ear — on the bat (SN: 10/23/20). In nine months, they’ve already captured R. hilli calls from eight different locations in the same small area.

Bat song

The last time scientists saw a Hill’s horseshoe bat was in 1981. An international team rediscovered the species in 2019 and, for the first time, recorded its echolocation call to help prevent it from being lost to science once again.

A Hill’s horseshoe bat echolocation call

BAT CONSERVATION INTERNATIONAL

Julius Nziza (far left) and Paul Webala (second from left) work with the research team to capture the first-ever audio recording of Hill’s horseshoe bat’s echolocation call.

WINIFRED FRICK, BAT CONSERVATION INTERNATIONAL

The team published its data to the open-access Global Biodiversity Information Facility in hopes of speeding up conservation efforts for the bat. Africa is home to over 20 percent of the world’s bats, but with a longstanding research focus on bats in Europe and the Americas, little is known about African bat species.

“It’s a whole new thing,” Nziza says. “That’s why everybody’s excited.”

sciencenews.org

CITATIONS

J. Flanders et al. Rediscovery of the critically endangered Hill's horseshoe bat (Rhinolophus hilli) and other new records of bat species in Rwanda. ARPHA Preprints. Posted March 11, 2022. doi: 10.3897/arphapreprints.e83547.


About Anna Gibbs
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Anna Gibbs is the spring 2022 science writing intern at Science News. She holds a B.A. in English from Harvard College.