How can forests be reforested in a climate-friendly way?

Europe's forests have already been severely affected by climate change. Thousands of hectares of trees have already died due to drought and bark beetles. Scientists from the University of Vienna and the Technical University of Munich TUM have now investigated which trees can be used for reforestation. Their findings: only a few tree species are fit for the future, such as English oak in the UK. However, mixed forests are important for the survival of forests, otherwise the forest ecosystem as a whole could be weakened. The results of the study were recently published in the renowned journal Nature Ecology and Evolution.

Although European forests are naturally home to a mix of trees, the number of tree species is lower than in climatically comparable areas of North America or East Asia. In the future, even fewer species will be available to the forestry industry, as scientists led by Johannes Wessely and Stefan Dullinger from the University of Vienna have shown in their new study. Depending on the region, between a third and a half of the tree species found there today will no longer be able to cope with future conditions. "This is an enormous decline," says lead author Johannes Wessely, "especially when you consider that only some of the species are of interest for forestry."

The scientists examined the 69 more common of the just over 100 European tree species with regard to the 21st century in Europe. On average, only nine of these 69 species per location are fit for the future in Europe, compared to four in the UK. "Trees that are planted now for reforestation must survive under both current and future conditions. This is difficult because they have to withstand the cold and frost of the next few years as well as a much warmer climate at the end of the 21st century. There is only a very small overlap," says Wessely. In the UK, these climate-fit species include, for example, the English oak. Which tree species will suit which region of Europe in the future varies greatly overall.

Forest ecosystem at risk due to restriction of species

However, even with the selected set of future-proof trees, a major problem remains: the average of nine species is not enough for a species-rich mixed forest. "Mixed forests consisting of many tree species are an important measure to make forests more robust against disturbances such as bark beetles. In some places in Europe, however, we could run out of tree species to establish such colorful mixed forests," explains last author Rupert Seidl from the Technical University of Munich TUM.

Not all trees offer important properties

Trees store carbon, provide a habitat or food source for animals or can be processed into timber -- these are all important properties of forests. But not all trees fulfill these functions equally; only an average of three of the nine climate-fit tree species can do this.

"Our work clearly shows how severely the vitality of forests is affected by climate change. We cannot rely solely on a new mix of tree species; rapid measures to mitigate climate change are essential for the sustainable protection of our forests," says Wessely.

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Climate change could become the main driver of biodiversity decline by mid-century

Global biodiversity has declined between 2% and 11% during the 20th century due to land-use change alone, according to a large multi-model study published in Science. Projections show climate change could become the main driver of biodiversity decline by the mid-21st century.

The analysis was led by the German Centre for Integrative Biodiversity Research (iDiv) and the Martin Luther University Halle-Wittenberg (MLU) and is the largest modelling study of its kind to date. The researchers compared thirteen models for assessing the impact of land-use change and climate change on four distinct biodiversity metrics, as well as on nine ecosystem services.

GLOBAL BIODIVERSITY MAY HAVE DECLINED BY 2% TO 11% DUE TO LAND-USE CHANGE ALONE

Land-use change is considered the largest driver of biodiversity change, according to the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). However, scientists are divided over how much biodiversity has changed in past decades. To better answer this question, the researchers modelled the impacts of land-use change on biodiversity over the 20th century. They found global biodiversity may have declined by 2% to 11% due to land-use change alone. This span covers a range of four biodiversity metrics1 calculated by seven different models.

"By including all world regions in our model, we were able to fill many blind spots and address criticism of other approaches working with fragmented and potentially biased data," says first author Prof Henrique Pereira, research group head at iDiv and MLU. "Every approach has its ups and downsides. We believe our modelling approach provides the most comprehensive estimate of biodiversity trends worldwide."

MIXED TRENDS FOR ECOSYSTEM SERVICES

Using another set of five models, the researchers also calculated the simultaneous impact of land-use change on so-called ecosystem services, i.e., the benefits nature provides to humans. In the past century, they found a massive increase in provisioning ecosystem services, like food and timber production. By contrast, regulating ecosystem services, like pollination, nitrogen retention, or carbon sequestration, moderately declined.

CLIMATE AND LAND-USE CHANGE COMBINED MIGHT LEAD TO BIODIVERSITY LOSS IN ALL WORLD REGIONS

The researchers also examined how biodiversity and ecosystem services might evolve in the future. For these projections, they added climate change as a growing driver of biodiversity change to their calculations.

Climate change stands to put additional strain on biodiversity and ecosystem services, according to the findings. While land-use change remains relevant, climate change could become the most important driver of biodiversity loss by mid-century. The researchers assessed three widely-used scenarios -- from a sustainable development to a high emissions scenario. For all scenarios, the impacts of land-use change and climate change combined result in biodiversity loss in all world regions.

While the overall downward trend is consistent, there are considerable variations across world regions, models, and scenarios.

PROJECTIONS ARE NOT PREDICTIONS

"The purpose of long-term scenarios is not to predict what will happen," says co-author Dr Inês Martins from the University of York. "Rather, it is to understand alternatives, and therefore avoid these trajectories, which might be least desirable, and select those that have positive outcomes. Trajectories depend on the policies we choose, and these decisions are made day by day." Martins co-led the model analyses and is an alumna of iDiv and MLU.

The authors also note that even the most sustainable scenario assessed does not deploy all the policies that could be put in place to protect biodiversity in the coming decades. For instance, bioenergy deployment, one key component of the sustainability scenario, can contribute to mitigating climate change, but can simultaneously reduce species habitats. In contrast, measures to increase the effectiveness and coverage of protected areas or large-scale rewilding were not explored in any of the scenarios

MODELS HELP IDENTIFY EFFECTIVE POLICIES

Assessing the impacts of concrete policies on biodiversity helps identify those policies most effective for safeguarding and promoting biodiversity and ecosystem services, according to the researchers. "There are modelling uncertainties, for sure," Pereira adds. "Still, our findings clearly show that current policies are insufficient to meet international biodiversity goals. We need renewed efforts to make progress against one of the world's largest problems, which is human-caused biodiversity change."

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High resolution techniques reveal clues in 3.5 billion-year-old biomass

To learn about the first organisms on our planet, researchers have to analyse the rocks of the early Earth. These can only be found in a few places on the surface of the Earth. The Pilbara Craton in Western Australia is one of these rare sites: there are rocks there that are around 3.5 billion years old containing traces of the microorganisms that lived at that time. A research team led by the University of Göttingen has now found new clues about the formation and composition of this ancient biomass, providing insights into the earliest ecosystems on Earth. The results were published in the journal Precambrian Research.

Using high-resolution techniques such as nuclear magnetic resonance spectroscopy (NMR) and near-edge X-ray Absorption Fine Structure (NEXAFS), the researchers analysed carbonaceous particles found rocks made of barium sulphate.

This enabled scientists to obtain important information about the structure of microscopically small particles and show that they are of biological origin.

It is likely that the particles were deposited as sediment in the body of water of a "caldera" -- a large cauldron-shaped hollow that forms after volcanic activity.

In addition, some of the particles must have been transported and changed by hydrothermal waters just beneath the surface of the volcano.

This indicates a turbulent history of sediment deposits. By analysing various carbon isotopes, the researchers concluded that different types of microorganisms were already living in the vicinity of the volcanic activity, similar to those found today at Icelandic geysers or at hot springs in Yellowstone National Park.

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Bottled water can contain hundreds of thousands of previously uncounted tiny plastic bits

In recent years, there has been rising concern that tiny particles known as microplastics are showing up basically everywhere on Earth, from polar ice to soil, drinking water and food. Formed when plastics break down into progressively smaller bits, these particles are being consumed by humans and other creatures, with unknown potential health and ecosystem effects. One big focus of research: bottled water, which has been shown to contain tens of thousands of identifiable fragments in each container.

Now, using newly refined technology, researchers have entered a whole new plastic world: the poorly known realm of nanoplastics, the spawn of microplastics that have broken down even further. For the first time, they counted and identified these minute particles in bottled water. They found that on average, a liter contained some 240,000 detectable plastic fragments -- 10 to 100 times greater than previous estimates, which were based mainly on larger sizes.

The study was just published in the journal Proceedings of the National Academy of Sciences.

Nanoplastics are so tiny that, unlike microplastics, they can pass through intestines and lungs directly into the bloodstream and travel from there to organs including the heart and brain. They can invade individual cells, and cross through the placenta to the bodies of unborn babies. Medical scientists are racing to study the possible effects on a wide variety of biological systems.

"Previously this was just a dark area, uncharted. Toxicity studies were just guessing what's in there," said study coauthor Beizhan Yan, an environmental chemist at Columbia University's Lamont-Doherty Earth Observatory. "This opens a window where we can look into a world that was not exposed to us before."

Worldwide plastic production is approaching 400 million metric tons a year. More than 30 million tons are dumped yearly in water or on land, and many products made with plastics including synthetic textiles shed particles while still in use. Unlike natural organic matter, most plastics do not break down into relatively benign substances; they simply divide and redivide into smaller and smaller particles of the same chemical composition. Beyond single molecules, there is no theoretical limit to how small they can get.

Microplastics are defined as fragments ranging from 5 millimeters (less than a quarter inch) down to 1 micrometer, which is 1 millionth of a meter, or 1/25,000th of an inch. (A human hair is about 70 micrometers across.) Nanoplastics, which are particles below 1 micrometer, are measured in billionths of a meter.

Plastics in bottled water became a public issue largely after a 2018 study detected an average of 325 particles per liter; later studies multiplied that number many times over. Scientists suspected there were even more than they had yet counted, but good estimates stopped at sizes below 1 micrometer -- the boundary of the nano world.

"People developed methods to see nano particles, but they didn't know what they were looking at," said the new study's lead author, Naixin Qian, a Columbia graduate student in chemistry. She noted that previous studies could provide bulk estimates of nano mass, but for the most part could not count individual particles, nor identify which were plastics or something else.

The new study uses a technique called stimulated Raman scattering microscopy, which was co-invented by study coauthor Wei Min, a Columbia biophysicist. This involves probing samples with two simultaneous lasers that are tuned to make specific molecules resonate. Targeting seven common plastics, the researchers created a data-driven algorithm to interpret the results. "It is one thing to detect, but another to know what you are detecting," said Min.

The researchers tested three popular brands of bottled water sold in the United States (they declined to name which ones), analyzing plastic particles down to just 100 nanometers in size. They spotted 110,000 to 370,000 particles in each liter, 90% of which were nanoplastics; the rest were microplastics. They also determined which of the seven specific plastics they were, and charted their shapes -- qualities that could be valuable in biomedical research.

One common one was polyethylene terephthalate or PET. This was not surprising, since that is what many water bottles are made of. (It is also used for bottled sodas, sports drinks and products such as ketchup and mayonnaise.) It probably gets into the water as bits slough off when the bottle is squeezed or gets exposed to heat. One recent study suggests that many particles enter the water when you repeatedly open or close the cap, and tiny bits abrade.

However, PET was outnumbered by polyamide, a type of nylon. Ironically, said Beizhan Yan, that probably comes from plastic filters used to supposedly purify the water before it is bottled. Other common plastics the researchers found: polystyrene, polyvinyl chloride and polymethyl methacrylate, all used in various industrial processes.

A somewhat disturbing thought: the seven plastic types the researchers searched for accounted for only about 10% of all the nanoparticles they found in samples; they have no idea what the rest are. If they are all nanoplastics, that means they could number in the tens of millions per liter. But they could be almost anything, "indicating the complicated particle composition inside the seemingly simple water sample," the authors write. "The common existence of natural organic matter certainly requires prudent distinguishment."

The researchers are now reaching beyond bottled water. "There is a huge world of nanoplastics to be studied," said Min. He noted that by mass, nanoplastics comprise far less than microplastics, but "it's not size that matters. It's the numbers, because the smaller things are, the more easily they can get inside us."

Among other things, the team plans to look at tap water, which also has been shown to contain microplastics, though far less than bottled water. Beizhan Yan is running a project to study microplastics and nanoplastics that end up in wastewater when people do laundry -- by his count so far, millions per 10-pound load, coming off synthetic materials that comprise many items. (He and colleagues are designing filters to reduce the pollution from commercial and residential washing machines.) The team will soon identify particles in snow that British collaborators trekking by foot across western Antarctica are currently collecting. They also are collaborating with environmental health experts to measure nanoplastics in various human tissues and examine their developmental and neurologic effects.

"It is not totally unexpected to find so much of this stuff," said Qian. "The idea is that the smaller things get, the more of them there are."

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Microbial awakening restructures high-latitude food webs as permafrost thaws

Alaska is on the front lines of climate change, experiencing some of the fastest rates of warming of any place in the world. And when temperatures rise in the state's interior -- a vast high-latitude region spanning 113 million acres -- permafrost there not only thaws, releasing significant amounts of its stored carbon back into the atmosphere where it further accelerates rising temperatures, but it decays. This decomposition has the potential to infuse above- and belowground food webs with carbon, which can affect energy flow between these critical ecological linkages and affect the species they support.

One of these species is the tundra vole, one of four Arctic or boreal forest animals that Philip Manlick, a research wildlife biologist with the USDA Forest Service Pacific Northwest Research Station in Juneau, Alaska, examined as part of his new study published today in the journal Nature Climate Change. Along with collaborators from the University of New Mexico and the University of Texas at Austin, Manlick used a novel technique to quantify the impacts of climate change on energy flow and carbon fluxes between plant-supported aboveground, or green, food webs and microbe-driven belowground, or brown, food webs using two species of vole, a shrew, and a spider as windows into the complex worlds.

"Understanding how energy moves through food webs helps us understand how ecosystems function and how animals might respond to stressors like climate change," Manlick said. "In Arctic and boreal ecosystems, it's well known that the climate is warming, permafrost is melting, and microbes are flourishing. But we know very little about the impacts of this process on terrestrial food webs and the animals they support."

A Novel Technique With Promise

The novel technique at the heart of the study involved measuring unique carbon isotope "fingerprints" in essential amino acids that only plants, bacteria, and fungi can produce. Animals can only acquire these molecules through their diets. This allowed these essential amino acids to serve as a biomarker that helped the researchers track how carbon was moving between green and brown food webs, which, ultimately, helped them detect changes.

"Scientists often argue about the importance of animals to ecosystem processes like carbon cycling, but when they eat resources from different food webs, they move carbon between storage pools," Manlick said. "In the future, we think this tool can be used to trace the fate of carbon through food webs to understand the functional roles of animals in ecosystem functions, like nutrient cycling."

The study analyzed bone collagen from museum specimens of tundra and red-backed voles and masked shrews from the Bonanza Creek Experimental Forest near Fairbanks, Alaska, in 1990 and 2021, a sample that represented animals exposed to long-term climate warming. To study the effects of short-term climate warming on animals, the researchers sampled Arctic wolf spiders near Toolik Lake, Alaska. Some of the spiders were gathered as controls and others were exposed to 2 °C warming in outdoor compartmentalized habitats called "mesocosms" in which the scientists could increase temperature on a micro scale to simulate climate warming.

At just over 12,000 acres, and encompassing interior forest and flood-plain habitats, Bonanza Creek Experimental Forest is an ideal site for studying the impacts of climate change on boreal forests and food webs because it provides a long-term record of change in interior Alaska. It was established by the USDA Forest Service 60 years ago and has been a National Science Foundation Long-term Ecological Research site since 1987. For Manlick, the site offers an opportunity to study how these boreal forest changes are affecting the animals living there and how the animals, themselves, affect forest processes through foraging and food web dynamics.

Significant Shift in Energy Source

Through their isotope analyses, Manlick and his colleagues detected significant changes in carbon assimilation in the mammals -- notably a shift from plant-based food webs to fungal-based food webs. In other words, fungi replaced plants as the main energy source -- with small mammals, like the shrews, assimilating up to 90 percent of their total carbon intake from fungal carbon, a more than 40-percent increase over historical specimens.

The same was true for the Arctic wolf spiders. They, too, shifted from plant-based to fungal-based food webs as the main source of their energy, assimilating more than 50 percent brown carbon under warming conditions, compared to 26 percent at control sites.

"Our study presents clear evidence that climate warming alters carbon flow and food web dynamics among aboveground consumers in Arctic tundra and boreal forest ecosystems -- across species, ecosystems, and long- and short-term warming scenarios," Manlick said. "And we show that these changes are the consequence of a change from predominantly green, plant-based food webs to brown, microbe-based food webs."

What's behind the shift?

The scientists suspect brown carbon is being transferred to aboveground consumers, like the mammals and spiders, in a series of predation events known as trophic pathways. Increased warming results in increased decomposition in both permafrost on the tundra and in boreal forests; fungi feed on this decomposing plant matter and are, in turn, consumed by arthropods, mites, and earthworms that transfer the fungal carbon upward in the food web where they, in turn, are consumed by the voles, shrews, and spiders.

"Climate warming significantly alters the flow of energy through food webs, such that animals who were historically supported by plant-based food webs are now supported by fungal-based food webs derived from belowground decomposition," Manlick said.

Animals Can Alter Carbon Cycling

Manlick and his colleagues' work underscores that animals serve as a crucial link between green and brown food webs; it also shows that climate warming alters this link across species in the Arctic and in boreal forests. The potential implications of these climate-induced shifts are greater than the small size of these species might imply.

"Shifts in these interactions can have indirect effects on nutrient cycling and ecosystem function," Manlick said.

For example, if voles are getting more of their energy from belowground sources, they may be consuming fewer plants, which could increase carbon storage in aboveground ecosystems.

"Much of the current work in high latitudes has focused on 'Arctic greening,' or the idea that climate warming is leading to more plant growth and greener ecosystems. We found the exact opposite pattern -- food webs are 'browning,'" he said.

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AI provides more accurate analysis of prehistoric and modern animals, painting picture of ancient world

A new Rice University study of the remains of prehistoric and modern African antelopes found that AI technology accurately identified animals more than 90% of the time compared to humans, who had much lower accuracy rates depending on the expert.

Composite images of teeth from five different antelope tribes analyzed and identified by artificial intelligence.

Photo courtesy of Manuel Domínguez-Rodrigo.

Identifying these animals and their habits helps paint a broader picture of ancient ecosystems, and with the assistance of this new technology, it can be done with more speed and accuracy than previously done by paleontologists, according to the study.

"African bovid tribe classification using transfer learning and computer vision" appeared in a recent edition of Annals of the New York Academy of Sciences.

The study outlines the groundbreaking AI technology used to analyze prehistoric livestock remains.

So why does it matter how these ancient animals lived and what they ate?

According to Manuel Domínguez-Rodrigo, visiting professor of anthropology at Rice, co-director of Madrid's Institute of Evolution in Africa and professor of prehistory at the University of Alcalá in Spain, the study sheds light on how the ecology of the time affected the evolution of mammal communities including humans, who over the past two million years have become highly dependent on other mammals.

"The evolution of ecosystems in Africa is of major relevance to understand what shaped our own evolution as humans," Domínguez-Rodrigo said.

"Our prehistoric ancestors were highly dependent on resources available in different habitats of African savanna ecosystems. Using fossil mammals -- highly specialized in their adaptations to different habitats -- to reconstruct these landscapes has been the most used method to interpret their ecology. Identifying those mammals by their teeth has not always been straightforward and was subjected to a high degree of expert knowledge and bias. Now we can do that with much more confidence. This will enable us to understand past environments but also understand better modern landscapes too when documenting the dead animals that they still contain."

And thanks to this technology, whose application to paleobiology is pioneered in Domínguez-Rodrigo's lab, he says archaeologists can now analyze information far more quickly and accurately than before.

"These AI methods are a revolution for the studies of paleobiology and human evolution in particular," he said.

"They provide an objective, replicable way of identifying animals, including the degree of confidence with which identifications are made."

Domínguez-Rodrigo said the success of AI in other fields, such as image-based medicine, was a proof of concept for its widespread application to other fields.

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Polar experiments reveal seasonal cycle in Antarctic sea ice algae

In the frigid waters surrounding Antarctica, an unusual seasonal cycle occurs. During winter, from March to October, the sun barely rises. As seawater freezes it rejects salts, creating pockets of extra-salty brine where microbes live in winter. In summer, the sea ice melts under constant daylight, producing warmer, fresher water at the surface.

This remote ecosystem is home to much of the Southern Ocean's photosynthetic life. A new University of Washington study provides the first measurements of how sea-ice algae and other single-celled life adjust to these seasonal rhythms, offering clues to what might happen as this environment shifts under climate change.

The study, published Sept. 15 in the International Society for Microbial Ecology's ISME Journal, contains some of the first measurements of how sea-ice microbes respond to changing conditions.

"We know very little about how sea-ice microbes respond to changes in salinity and temperature," said lead author Hannah Dawson, a UW postdoctoral researcher who did the work while pursuing her doctorate in oceanography at the UW. "And until now we knew almost nothing about the molecules they produce and use in chemical reactions to stay alive, which are important for supporting higher organisms in the ecosystem as well as for climate impacts, like carbon storage and cloud formation."

The polar oceans play an important role in global ocean currents and in supporting marine ecosystems. Microbes form the base of the food web, supporting larger life forms.

"Polar oceans make up a significant portion of the world's oceans, and these are very productive waters," said senior author Jodi Young, a UW assistant professor of oceanography. "These waters support big swarms of krill, the whales that come to feed on those krill, and either polar bears or penguins. And the start of that whole ecosystem are these single-celled microscopic algae. We just know so little about them."

The tiny organisms are also important for the climate, since they quietly perform photosynthesis and soak up carbon from the atmosphere. Polar algae are especially good at producing sulfur-containing molecules that give beaches their distinctive smell and, when lofted into the air in sea spray, promote formation of clouds that can reduce penetration of solar rays.

Antarctic sea ice, though long stable, is at an all-time record low this year.

In other oceans, satellite instruments can capture dramatic seasonal phytoplankton blooms from space -- but that isn't possible for microbes hidden under sea ice. And Antarctic waters are particularly challenging to visit, leaving researchers with almost no measurements in winter.

In late 2018, Dawson and co-author Susan Rundell traveled to Palmer Station, a U.S. research station on the West Antarctic Peninsula. They used a small boat to sample seawater and sea ice at the same nearby sites every three days.

Back on shore, the two graduate students performed 10-day experiments in tanks to see which microbes grew as temperature and salinity were adjusted to mimic sea-ice formation and melt. They also shipped samples back to Seattle for more complex measurements of the samples' genetics and metabolites, the small organic molecules produced by the cell.

Results revealed how single-celled algae deal with their fluctuating environments. As temperatures drop, the cells produce cryoprotectants, similar to antifreeze, to prevent their cellular fluid from crystallizing. Many of the most common cryoprotectant molecules were the same across different microbial lifeforms.

As salinity changes, to avoid either bursting in freshening waters or becoming desiccated like raisins in salty conditions, the cells change the concentration of salt-like organic molecules. Many such molecules serve a dual role as cryoprotectants, to balance conditions inside and outside the cell to maintain water balance.

The results show that under short-term temperature and salinity changes, community structure in each sample remained stable while adjusting the production of protective molecules. Different microbe species showed consistent responses to changing conditions. This should simplify modeling future responses to climate change, Young said.

Results also hint that the production of omega-3 fatty acids may decline in lower-salinity environments. This would be bad news for consumers of krill oil supplements, and for the marine ecosystem that relies on those algae-derived nutrients. Future research now underway by the UW group aims to confirm that result -- especially with the prospect of increasing freshwater input from melting sea ice and glaciers.

"We're interested in how these sea-ice algae contend with changes in temperature, salinity and light under normal conditions," Dawson said. "But then we also have climate change, which is completely remodeling the landscape in terms of when sea ice is forming, how much sea ice forms, how long it stays before it melts, as well as the quantity of freshwater input from glaciers. So we're both trying to capture what's happening now, and also asking how that can inform what might happen in the future."

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Multiple ecosystems in hot water after marine heatwave surges across the Pacific

Rising ocean temperatures are sweeping the seas, breaking records and creating problematic conditions for marine life. Unlike heatwaves on land, periods of abrupt ocean warming can surge for months or years. Around the world these 'marine heatwaves' have led to mass species mortality and displacement events, economic declines and habitat loss. New research reveals that even areas of the ocean protected from fishing are still vulnerable to these extreme events fueled by climate change.

A study published today in Global Change Biology, led by researchers at UC Santa Barbara, found that while California's network of marine protected areas (MPAs) provide many social and ecological benefits, they are not resilient to the effects of ocean warming. MPAs are locations in the ocean where human activities such as fishing are restricted to conserve and protect marine ecosystems, habitats, species and cultural resources. The study, part of a 10-year review of California's MPA network conducted at UCSB's National Center for Ecological Analysis & Synthesis (NCEAS), found that marine heatwaves impact ecological communities regardless of whether they are protected inside MPAs.

"MPAs in California and around the world have many benefits, such as increased fish abundance, biomass and diversity," said Joshua Smith, who led the study while he was a postdoctoral researcher at NCEAS . "But they were never designed to buffer the impacts of climate change or marine heatwaves."

Smith and co-authors from all over the world were part of an NCEAS working group formed to synthesize decades of long-term ecological monitoring data from California's diverse ocean habitats. The group, co-led by Jenn Caselle, a researcher with UCSB's Marine Science Institute, and Kerry Nickols, a professor from Cal State University Northridge who now works with the non-profit Ocean Visions, aimed to provide actionable scientific results to California's policy makers and natural resource managers, as part of a statewide Decadal Evaluation of the MPA network. Their analyses spanned the largest marine heatwave on record, which rolled through the Pacific Ocean toward California from 2014-2016. The monster marine heatwave was formed from an environmental double-whammy -- unusual ocean warming nicknamed "The Blob," followed by a major El Niño event that prolonged the sweltering sea temperatures. The marine heatwave blanketed the West Coast from Alaska to Baja and left a wake of altered food webs, collapsed fisheries, and shifted populations of marine life among various other consequences.

As MPA managers around the world face increasing climate shocks, the extent to which MPAs can buffer the worst of these events has become an important question. The working group scientists asked how the ecological communities in California's protected areas fared after such a severe and prolonged heatwave: Would the communities shift and if so, how? Would they 'bounce back' when the marine heatwave subsided? Could the marine protected areas protect sensitive populations or facilitate recovery?

To find answers to their questions, they synthesized over a decade of data collected from 13 no-take MPAs located in a variety of ecosystems along the Central Coast: rocky intertidal zones, kelp forests, shallow and deep rocky reefs. The team looked at fish, invertebrates and seaweed populations inside and outside these areas, using data from before, during and after the heatwave.

They also focused on two of these habitats, rocky intertidal and kelp forests, at 28 MPAs across the full statewide network to gauge whether these locations promoted one particular form of climate resilience -- maintaining both population and community structure.

"We used no-take MPAs as a type of comparison to see whether the protected ecological communities fared better to the marine heatwave than places where fishing occurred," said Smith, now an Ocean Conservation Research Fellow at Monterey Bay Aquarium.

The results are somewhat sobering, though not altogether unexpected.

"The MPAs did not facilitate resistance or recovery across habitats or across communities," Caselle said. "In the face of this unprecedented marine heatwave, communities did change dramatically in most habitats. But, with one exception, the changes occurred similarly both inside and outside the MPAs. The novelty of this study was that we saw similar results across many different habitats and taxonomic groups, from deepwater to shallow reefs and from fishes to algae."

The implication of these findings, according to Smith, is that every part of the ocean is under threat from climate change. "MPAs are effective in many of the ways they were designed, but our findings suggest that MPAs alone are not sufficient to buffer the effects of climate change."

The key question now is what will happen in the future? At the time of this study using data through 2020, the ecological communities have not returned to their former, pre-heatwave state. According to the paper, these ecological communities shifted toward a "pronounced decline in the relative proportion of cold-water species and an increase in warm water species." For example, increases in the abundance of the señorita fish (Oxyjulis californica), a subtropical species with warm water affinity and previously rare in central California, had an outsized influence on the shift of communities. Whether these species persist in their new locations remains to be seen.

"This study makes it clear why long-term monitoring of California's MPAs is so critical," said Caselle. "Some of these time series are longer than 25 years at this point and the data are critical to understanding and readying human communities for the changes occurring in our marine communities." Continued study will show if future shifts in marine communities occur at different rates or to different base states in MPAs compared to fished areas.

Despite the limited ability of MPAs to resist the grip of the marine heatwave, they do confer benefits, not the least of which is the ability to study the complex effects of climate change in areas not impacted by fishing. As areas of minimal human interference that are regularly monitored, they present opportunities to study the response of marine ecosystems to shifting conditions and potentially tailor management techniques accordingly. Moreover, as Smith stated, "the ecological communities in MPAs are still being protected, even if they are different as a result of the heatwave. Given that marine heatwaves are anticipated to increase in frequency and magnitude into the future, swift climate action and nature-based solutions are needed as additional pathways to enhance the health of our oceans."

Kerry Nickols adds, "With the devastating impacts of climate change already apparent, it is very important that we are upfront about climate solutions -- as long as we are burning fossil fuels and warming the globe marine ecosystems will be at risk, even if they are protected from fishing."

Read more at Science Daily

Conservation in Indonesia is at risk, a team of researchers who study the region argues

Indonesia, home to the largest tropical rainforest in Southeast Asia and over 17,500 islands, is a country packed with biodiversity and endangered species. However, scientists studying the region's species and ecosystems are getting banned from Indonesia and conservation plans are being blocked. In a letter publishing in the journal Current Biology on July 10, a team of conservation researchers with long-term experience in Indonesia discuss scientific suppression and other research challenges they have witnessed while working in the region. They offer suggestions for how to promote nature conservation, protect data transparency, and share research with the public in this and other regions of the world.

"If you look at a heat map of the Earth, and where endangered species are located, Indonesia and that general region are just off the charts," says tropical environmental scientist William F. Laurance of James Cook University, who has been doing research on the environmental impacts of development in Southeast Asia for over a decade.

Laurance and his co-authors say they felt drawn to raise awareness about the issues facing conservation in Indonesia because during their time working in the region, they witnessed many instances when governments and corporations impeded research -- including their own.

For example, they write in the letter, in 2022, five leading conservation researchers were banned from working in Indonesia on the premise that they had "negative intentions" to "discredit the government." The researchers reference papers about forest conservation and wildlife management in Sumatra, for which the teams had multiple colleagues from Indonesia decline co-authorship "out of concerns that it might adversely impact their funding, research permits, or opportunities for commercial contracts in Indonesia."

"The researchers said, 'Well, no, you can't tell that story, even though it's true, and you can't identify me or include all the relevant details.' And this just kept happening over and over again. It's a climate of fear," says Laurance.

To protect environmental research in Indonesia and the contributors who work on it, Laurance and his team suggest that organizations funding research in the region require data transparency for studies that they support. They also recommend the implementation and usage of online "safe houses" (whistleblower websites designed to protect anonymity and information leakage) and anonymized journals (publications in which contributors are not named). They say these interventions could help researchers get information out to the public without worrying about the consequences of being personally tied to their findings.

The authors do note that several organizations are advocating for change, especially in Indonesia. Some examples of these groups include the Indonesian Caucus for Academic Freedom and the Jakarta Legal Aid Foundation, which are organizing to support conservation and thwart efforts to silence researchers. They also note that "scientific suppression is by no means unique to Indonesia."

Read more at Science Daily

New research reveals the impact of different species and their traits on human wellbeing

New research has revealed for the first time that well-functioning ecosystems are crucial to human health and wellbeing, with human-biodiversity interactions delivering wellbeing gains equating to substantial healthcare cost-savings, when scaled-up across populations.

The University of Kent-led study, which is part of the European Research Council-funded project 'Relating Subjective Wellbeing to Biodiversity' (RELATE), set out to understand which components of nature and biodiversity played a particular role in human wellbeing.

The team, which was led by Kent's Professor Zoe Davies, analysed the effects of species' traits, based on people's feedback following a series of workshops, to identify those that generate different types of wellbeing e.g., physical, emotional, cognitive, social, spiritual, and 'global', the latter being akin to 'whole-person health'.

The team found that, in general, the vast majority of species and traits are beneficial to human wellbeing. They also discovered that each species may support multiple traits, potentially with different impacts. For example, the colours of brambles (black, pink, red) are linked to multiple positive physical, emotional and social wellbeing types, but their prickly texture generated negative emotional wellbeing. The numerous traits from across an ecological community can elicit a multitude of wellbeing responses, illustrating the true complexity of how people relate to biodiversity.

Professor Davies, a biodiversity conservationist at Kent's Durrell Institute of Conservation and Ecology (DICE), said: 'While we know that spending time in natural environments can improve our health and wellbeing, we still need to know more about which species, or traits of species (such as colours, sounds, smells, textures and behaviours), deliver these benefits -- and how people's relationships with biodiversity are both contextually and culturally specific. Understanding how people experience biodiversity is therefore key to successfully managing biodiversity to facilitate human wellbeing.'

Study co-author, Professor Martin Dallimer, from the School of Earth and Environment, University of Leeds, said: 'For the first time, through analysing people's own words and reflections, we are able to explicitly link that feeling of wellbeing with species and their traits. How people respond to biodiversity is hugely varied and if we want people's wellbeing to benefit from spending time in nature, then it is essential to make sure we are maintaining and restoring high quality biodiverse spaces for wildlife and for people. Our aim is that these findings really drive home how important biodiversity is in underpinning wellbeing benefits, particularly to healthcare and public sectors who include 'spending time in nature' as an element of mental health and wellbeing.'

Read more at Science Daily

Lost giants: New study reveals the abundance decline of African megafauna

Faysal Bibi (Museum für Naturkunde, Berlin) and Juan L. Cantalapiedra (University of Alcalá, Madrid) used measurements of thousands of fossil teeth to reconstruct the size and abundance of African large mammals (>15 kg) over the last 10 million years. Despite many uncertainties affecting preservation in the fossil record, the study revealed a highly similar relationship between an animal's size and its abundance between fossil and extant communities, indicating that fundamental ecological processes governing the structure of living communities are also preserved in the fossil record.

Above 45 kg, the researchers found evidence for decreasing abundance with increasing size, a pattern that aligns with the ecological 'rule of metabolic scaling', whereby larger species have lower population densities compared to smaller ones. A deviation from the predicted ecological pattern was that mammals between ~15 and 45 kg were far less numerous than expected, both in living and fossil communities. They interpreted this as a signature of savanna habitats (where monkeys and small forest-living antelopes are rare).

The big surprise came when the researchers examined how size-abundance distributions changed over time. They discovered that earlier communities, older than ~4 million years ago, had a considerably higher number of large-sized individuals and a greater proportion of total biomass in larger size categories, than did younger communities. The high abundance of large individuals in these fossil African communities -- with some individual elephants reaching sizes over 10 tons -- is unparalleled in ecosystems today. Since that time, there has been a gradual loss of large-sized individuals from the fossil record, reflecting the long-term decline of late Pliocene and Pleistocene large mammal diversity, and resulting in the impoverished and 'miniaturized' communities we know today.

The study confirms recent work arguing for the deep-time antiquity of African megafaunal losses and challenging the idea that the decline of African megafauna was primarily driven by human activities. While the spread of humans across the globe during the late Pleistocene and Holocene (the last ~100,000 years) coincided with major extinction of many large animals, the research supports the idea that megafaunal losses in Africa began much earlier, around 4 million years ago, and long before humans learned to engage in efficient hunting. Instead, the study highlights environmental factors, such as the long-term decrease in global temperatures and the expansion of tropical grasslands, as potential drivers of megafaunal extinctions.

The study also found that the loss of large individuals and the restructuring of biomass distributions in African large mammal communities could have been linked to decreases in primary productivity. Using an established relationship between the types of mammalian tooth shapes (morphological traits) and plant productivity (net primary productivity) today, the researchers calculated productivity for African communities in the past. They found an approximately two-thirds decrease in productivity since the Late Miocene (> 5 million years ago), a pattern observed globally, and that could have significantly diminished the carrying capacity of large mammal communities, leading to reduced diversity and accelerated extinction of large species.

The research opens new avenues for understanding the dynamics of ecosystems and the complex interactions between individuals, species, and their environment. By analyzing fossil abundance data and incorporating size-based approaches, scientists can gain valuable insights into the ecological dynamics underlying extinction.

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Fossils of a saber-toothed top predator reveal a scramble for dominance leading up to 'the Great Dying'

A tiger-sized saber-toothed creature called Inostrancevia has previously only been found in Russia. But scientists have discovered its fossils in South Africa, suggesting that it migrated 7,000 miles across the supercontinent Pangaea during the world's worst mass extinction 252 million years ago. Heading to South Africa allowed it to fill a gap in a faraway ecosystem that had lost its top predators.

Two hundred and fifty-two million years ago, Earth experienced a mass extinction so devastating that it's become known as "the Great Dying." Massive volcanic eruptions triggered catastrophic climate change, killing off nine out of every ten species and eventually setting the stage for the dinosaurs. But the Great Dying was a long goodbye -- the extinction event took place over the course of up to a million years at the end of the Permian period. During that time, the fossil record shows drama and upheaval as species fought to get a foothold in their changing environments. One animal that exemplifies this instability was a tiger-sized, saber-toothed creature called Inostrancevia: a new fossil discovery suggests that Inostrancevia migrated 7,000 miles across the supercontinent Pangaea, filling a gap in a faraway ecosystem that had lost its top predators, before going extinct itself.

"All the big top predators in the late Permian in South Africa went extinct well before the end-Permian mass extinction. We learned that this vacancy in the niche was occupied, for a brief period, by Inostrancevia," says Pia Viglietti, a research scientist at the Field Museum in Chicago and a co-author of the new study in Current Biology.

The prehistoric creature looked the part of "top predator." "Inostrancevia was a gorgonopsian, a group of proto-mammals that included the first saber-toothed predators on the planet," says Viglietti. It was about the size of a tiger and likely had skin like an elephant or a rhino; while vaguely reptilian in appearance, it was part of the group of animals that includes modern mammals.

Prior to this new paper, Inostrancevia had only ever been found in Russia. But while examining the fossil record of South Africa's Karoo Basin, Viglietti's colleague Christian Kammerer identified the fossils of two large predatory animals that were different from those normally found in the region. "The fossils themselves were quite unexpected," says Viglietti. It's not clear how they made it from what's now Russia, or how long it took them to cross Pangaea and arrive in what's now South Africa. But being far from home was just one element of what made the fossils special.

"When we reviewed the ranges and ages of the other top predators normally found in the area, the rubidgeine gorgonopsians, with these Inostrancevia fossils, we found something quite exciting," she says. "The local carnivores actually went extinct quite a bit before even the main extinction that we see in the Karoo -- by the time the extinction begins in other animals, they're gone."

The arrival of Inostrancevia from 7,000 miles away and its subsequent extinction indicates that these top predators were "canaries in the coal mine" for the larger extinction event to come.

"This shows that the South African Karoo Basin continues to produce critical data for understanding the most catastrophic mass extinction in Earth's history," says co-author Jennifer Botha, director of GENUS Centre of Excellence in Palaeosciences and professor at the Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg.

"We have shown that the shift in which groups of animals occupied apex predator roles occurred four times over less than two million years around the Permian-Triassic mass extinction, which is unprecedented in the history of life on land. This underlines how extreme this crisis was, with even fundamental roles in ecosystems in extreme flux," said Christian Kammerer, the study's first author and a research curator of paleontology at the North Carolina Museum of Natural Sciences and research associate at the Field Museum.

The vulnerability of these top predators matches what we see today. "Apex predators in modern environments tend to show high extinction risk, and tend to be among the first species that are locally extirpated due to human-mediated activities such as hunting or habitat destruction," says Kammerer. "Think about wolves in Europe or tigers in Asia, species which tend to be slow to reproduce and grow and require large geographic areas to roam and hunt prey, and which are now absent from most of their historic ranges. We should expect that ancient apex predators would have had similar vulnerabilities, and would be among the species that first go extinct during mass extinction events."

In addition to shedding new light on the extinction event that helped lead to the rise of the dinosaurs, Viglietti says that the study is important for what it can teach us about the ecological disasters the planet is currently experiencing.

Read more at Science Daily

Human ancestors preferred mosaic landscapes and high ecosystem diversity

A new study published in the journal Science by an international team finds that early human species adapted to mosaic landscapes and diverse food resources, which would have increased our ancestor's resilience to past shifts in climate.

Our genus Homo evolved over the past 3 million years -- a period of increasing warm/cold climate fluctuations. How early human species have adapted to the intensification of climate extremes, ice ages, and large-scale shifts in landscapes and vegetation remains elusive. Did our ancestors adjust to local environmental changes over time, or did they seek out more stable environments with diverse food resources? Was our human evolution influenced more by temporal changes in climate, or by the spatial character of the environment?

To test these fundamental hypotheses on human evolution and adaptation quantitively, the research team used a compilation of more than three thousand well-dated human fossil specimens and archeological sites, representing six different human species, in combination with realistic climate and vegetation model simulations, covering the past 3 million years. The scientists focused their analysis on biomes -- geographic regions which are characterized by similar climates, plants, and animal communities (e.g., savannah, rainforest, or tundra).

"For the archeological and anthropological sites and corresponding ages, we extracted the local biome types from our climate-driven vegetation model. This revealed which biomes were favored by the extinct hominin species H. ergaster, H. habilis, H. erectus, H. heidelbergensis, and H. neanderthalensis andbyour direct ancestors -- H. sapiens.," said Elke Zeller, Ph.D. student from the IBS Center for Climate Physics at Pusan National University, South Korea, and lead author of the study.

According to their analysis, the scientists found that earlier African groups preferred to live in open environments, such as grassland and dry shrubland. Migrating into Eurasia around 1.8 million years ago, hominins, such as H. erectus and later H. heidelbergensis and H. neanderthalensis developed higher tolerances to other biomes over time, including temperate and boreal forests. "To survive as forest-dwellers, these groups developed more advanced stone tools and likely also social skills," said Prof. Pasquale Raia, from the Università di Napoli Federico II, Italy, co-author of the study. Eventually, H. sapiens emerged around 200,000 years ago in Africa, quickly becoming the master of all trades. Mobile, flexible, and competitive, our direct ancestors, unlike any other species before, survived in harsh environments such as deserts and tundra.

When further looking into the preferred landscape characteristics, the scientists found a significant clustering of early human occupation sites in regions with increased biome diversity. "What that means is that our human ancestors had a liking for mosaic landscapes, with a great variety of plant and animal resources in close proximity," said Prof. Axel Timmermann, co-author of the study and Director of the IBS Center for Climate Physics in South Korea. The results indicate that ecosystem diversity played a key role in human evolution.

The authors demonstrated this preference for mosaic landscapes for the first time on continental scales and propose a new Diversity Selection Hypothesis: Homo species, and H. sapiens, in particular, were uniquely equipped to exploit heterogeneous biomes. "Our analysis shows the crucial importance of landscape and plant diversity as a selective element for humans and as a potential driver for socio-cultural developments" adds Elke Zeller. Elucidating how vegetation shifts have shaped human sustenance, the new Science study provides an unprecedented view into human prehistory and survival strategies.

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Ecosystem evolution in Africa

Ohio University's Nancy J. Stevens Ph.D., distinguished professor in the Department of Biomedical Sciences in the Heritage College of Osteopathic Medicine, is coauthor on a paper published in the journal Science and funded by the National Science Foundation that documents the evolution of grassland ecosystems on continental Africa.

Collaborating with an extensive team of geologists and paleoanthropologists from universities around the world, led by researchers from Baylor University and the University of Minnesota, the team synthesized data from nine Early Miocene fossil localities in the East African Rift of Kenya and Uganda to determine that the expansion of grassy biomes dominated by grasses with the C4 photosynthetic pathway in Eastern Africa occurred more than 10 million years earlier.

According to the paper, previous reconstructions of early Miocene ecosystems, 15-20 million years ago, have suggested that equatorial Africa was covered by a semi-continuous forest, with open habitats dominated by warm-season, or C4, grasses that were uncommon until 8-10 million years ago. C4 refers to the different pathways that plants use to capture carbon dioxide during photosynthesis. C4 plants produce a four-carbon molecule and are more adapted to warm or hot season condition under moist or dry environments.

As the researchers gathered expertise about geological features, isotopes and fossils found at the sites, the paradigm of a continuous forest blanketing equatorial Africa during the early Miocene shifted to a more complex mosaic of habitats that already included open environments with C4 grasses.

The result of this research pushes back the oldest evidence of C4 grass-dominated habitats in Africa -- and globally -- by more than 10 million years, with important implications for primate evolution and the origins of tropical C4 grasslands and savanna ecosystems across the African continent and around the world.

"We suspected that we would find C4 plants at some sites, but we didn't expect to find them at as many sites as we did, and in such high abundance," Daniel Peppe, lead author and associate professor at Baylor University, said.

A critical aspect of this work was that the team combined many different lines of evidence together: geology, fossil soils, isotopes and phytoliths (plant silica microfossils) to reach their conclusions.

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Humans need Earth-like ecosystem for deep-space living

Can humans endure long-term living in deep space? The answer is a lukewarm maybe, according to a new theory describing the complexity of maintaining gravity and oxygen, obtaining water, developing agriculture and handling waste far from Earth.

Dubbed the Pancosmorio theory -- a word coined to mean "all world limit" -- it was described in a paper published in Frontiers in Astronomy and Space Sciences.

"For humans to sustain themselves and all of their technology, infrastructure and society in space, they need a self-restoring, Earth-like, natural ecosystem to back them up," said co-author Morgan Irons, a doctoral student conducting research with Johannes Lehmann, professor in the School of Integrative Plant Science at Cornell University. Her work focuses on soil organic carbon persistence under Earth's gravity and varying gravity conditions. "Without these kinds of systems, the mission fails."

The first key is gravity, which Earth life needs to function properly, said co-author Lee Irons, Morgan Irons' father and executive director of the Norfolk Institute, a group that aims to solve problems of human resilience on Earth and in space.

"Gravity induces a gradient in the fluid pressure within the body of the living thing to which the autonomic functions of the life form are attuned," he said. "An example of gravity imbalance would be the negative affect on the eyesight of humans in Earth orbit, where they don't experience the weight necessary to induce the pressure gradient."

Morgan Irons said that it would be unwise to spend billions of dollars to set up a space settlement only to see it fail, because even with all other systems in place, you need gravity.

Humans and all Earth life have evolved within the context of 1G of gravity. "Our bodies, our natural ecosystems, all the energy movement and the way we utilize energy is all fundamentally based upon 1G of gravity being present," she said. "There is just no other place in space where there is 1G of gravity; that just doesn't exist anywhere else in our solar system. That's one of the first problems we must solve."

Oxygen is another key factor. Earth's ecosystem generates oxygen for humans and other life forms. If a technologically advanced primary and a back-up system failed to provide oxygen for the moon base, for example, it would mean instant doom for the astronauts. "A reserve exists everywhere in Earth's nature," Lee Irons said. "Think of the hundreds of thousands of species of plants that generate oxygen. That's the kind of system reserve we need to replicate to be truly sustainable."

Such an ecological system of an outpost would need an enormous amount energy from the sun. The more distant planets and moons from the sun in our own solar system get decreased amounts of energy.

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Increased droughts are disrupting carbon-capturing soil microbes, concerning ecologists

Soil stores more carbon than plants and the atmosphere combined, and soil microbes are largely responsible for putting it there. However, the increasing frequency and severity of drought, such as those that have been impacting California, could disrupt this delicate ecosystem. In a perspective publishing in the journal Trends in Microbiology on April 12, microbial ecologist Steven Allison warns that soil health and future greenhouse gas levels could be impacted if soil microbes adapt to drought faster than plants do. He argues that we need to better understand how microbes respond to drought so that we can manage the situation in both agricultural and natural settings.

"Soil microbes are beneficial, and we couldn't live without their cycling of carbon and nutrients, but climate change and drought can tweak that balance, and we have to be aware of how it's changing," says Allison of the University of California, Irvine.

Some soil microbes take carbon from decomposing plants and store it in the soil, while others release plant carbon back into the atmosphere. The carbon that ends up in the soil is beneficial in multiple ways. "The carbon in the soil has these reverberating effects out to the rest of the world in terms of the infrastructure in our natural and managed ecosystems," says Allison. "Carbon-rich soils hold more nutrients, so plants growing in those soils tend to be more productive, and the carbon changes the physical properties of the soil, which prevents erosion."

"In California now, we have this system where the droughts are more intense, and then the rainfall is more intense," he says. "So, if you're losing your soil carbon, when it rains really hard it could carry away your soil and cause erosion, landslides, mudslides, sediments, and all kinds of problems that we're actually seeing right now."

The carbon that is released back into the atmosphere is another story. "From a climate mitigation standpoint, what we want is for more carbon to be in plants and soils and less carbon to be in the atmosphere, so the more carbon we can absorb into plants through photosynthesis and the more we can transfer and keep in the soil, the better off we're going to be in terms of climate change," says Allison. "That's why it's really important to know how the balance of incoming versus outflowing carbon changes with drought, or warming, or any other climate factor."

Plants and microbes will both be impacted by the increasing frequency of drought, but Allison suspects that microbes will be able to bounce back faster. "Microbes are really adaptable -- they can change their physiology, they can change their abundances so that more drought-adapted microbes take over, and they can potentially evolve -- so we expect that they are going to resist or bounce back from drought," says Allison. "All those different processes can happen pretty quickly with microbes, and much more quickly than with plants."

If more carbon-releasing microbes survive than carbon-sequestering microbes, we could end up with carbon-depleted soils, which would have serious negative implications for plant productivity and future greenhouse gas levels.

We may be able to nudge the balance in the right direction, Allison says, but more research is needed first. "There's still a lot to be done. Right now, we have data that suggests that when we have drought, something changes that results in carbon loss, but we don't understand exactly how or why that's happening, whether drought's changing the abundance of beneficial plant associated microbes versus the carbon releasing microbes, or if it's causing the evolution of one of the microbe groups, or if it's more determined by changes to their immediate physiology," says Allison.

Some microbes could actually help plants cope with drought. If we knew which microbes were most beneficial to plants, and most likely to retain carbon in soil, we could try to tip the balance in their favor.

"There's a lot of potential for us to manage or engineer soil microbes," says Allison. "In agricultural systems, we can look into manipulating the soil or adding beneficial microbes back in. In more natural systems, management would probably be on the plant side: soil microbes are often closely intertwined with plants, so managing the plants can also benefit the microbial part of the ecosystem."

Read more at Science Daily

Legacy industrial contamination in the Arctic permafrost

Many of us picture the Arctic as largely untouched wilderness. But that has long-since ceased to be true for all of the continent. It is also home to oilfields and pipelines, mines and various other industrial activities. The corresponding facilities were built on a foundation once considered to be particularly stable and reliable: permafrost. This unique type of soil, which can be found in large expanses of the Northern Hemisphere, only thaws at the surface in summer. The remainder, extending up to hundreds of metres down, remains frozen year-round.

Accordingly, permafrost has not only been viewed as a solid platform for buildings and infrastructure. "Traditionally, it's also been considered a natural barrier that prevents the spread of pollutants," explains Moritz Langer from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). "Consequently, industrial waste from defunct or active facilities was often simply left on-site, instead of investing the considerable effort and expense needed to remove it." As a result of the industrial expansion during the cold war, over the decades this led to micro-dumps full of toxic sludge from oil and gas exploration, stockpiles of mining debris, abandoned military installations, and lakes in which pollutants were intentionally poured. "In many cases, the assumption was that the permafrost would reliably and permanently seal off these toxic substances, which meant there was no need for costly disposal efforts," says Guido Grosse, who heads the AWI's Permafrost Research Section. "Today, this industrial legacy still lies buried in the permafrost or on its surface. The substances involved range from toxic diesel fuel to heavy metals and even radioactive waste."

But as climate change progresses, this "sleeping giant" could soon become an acute threat: since the permafrost regions are warming between twice as fast and four times as fast as the rest of the world, the frozen soil is increasingly thawing. When this happens, it changes the hydrology of the region in question, and the permafrost no longer provides an effective barrier. As a result, contaminants that have accumulated in the Arctic over decades can be released, spreading across larger regions.

In addition, thawing permafrost becomes more and more unstable, which can lead to further contamination. When the ground collapses, it can damage pipelines, chemical stockpiles and depots. Just how real this risk already is can be seen in a major incident from May 2020 near the industrial city Norilsk in northern Siberia: a destabilized storage tank released 17,000 metric tons of diesel, which polluted the surrounding rivers, lakes and tundra. According to Langer: "Incidents like this could easily become more frequent in the future."

In order to more accurately assess such risks, he and an international team of experts from Germany, the Netherlands and Norway took a closer look at industrial activities in the High North. To do so, they first analysed freely available data from the portal OpenStreetMap and from the Atlas of Population, Society and Economy in the Arctic. According to these sources, the Arctic permafrost regions contain ca. 4,500 industrial sites that either store or use potentially hazardous substances.

"But this alone didn't tell us what types of facilities they were, or how badly they could potentially pollute the environment," says Langer. More detailed information on contaminated sites is currently only available for North America, where roughly 40 percent of the global permafrost lies. The data from Canada and Alaska showed that, using the location and type of facility, it should be possible to accurately estimate where hazardous substances were most likely to be found.

For Alaska, the Contaminated Sites Program also offers insights into the respective types of contaminants. For example, roughly half of the contaminations listed can be attributed to fuels like diesel, kerosene and petrol. Mercury, lead and arsenic are also in the top 20 documented environmental pollutants. And the problem isn't limited to the legacy of past decades: although the number of newly registered contaminated sites in the northernmost state of the USA declined from ca. 90 in 1992 to 38 in 2019, the number of affected sites continues to rise.

There are no comparable databases for Siberia's extensive permafrost regions. "As such, our only option there was to analyse reports on environmental problems that were published in the Russian media or other freely accessible sources between 2000 and 2020," says Langer. "But the somewhat sparse information available indicates that industrial facilities and contaminated sites are also closely linked in Russia's permafrost regions."

Using computer models, the team calculated the occurrence of contaminated sites for the Arctic as a whole. According to the results, the 4,500 industrial facilities in the permafrost regions have most likely produced between 13,000 and 20,000 contaminated sites. 3,500 to 5,200 of them are located in regions where the permafrost is still stable, but will start to thaw before the end of the century. "But without more extensive data, these findings should be considered a rather conservative estimate," Langer emphasises. "The true scale of the problem could be even greater."

Making matters worse, the interest in pursuing commercial activities in the Arctic continues to grow. As a result, more and more industrial facilities are being constructed, which could also release toxic substances into nearby ecosystems. Further, this is happening at a time when removing such environmental hazards is getting harder and harder -- after all, doing so often requires vehicles and heavy gear, which can hardly be used on vulnerable tundra soils that are increasingly affected by thaw.

Read more at Science Daily

Most of world's salt marshes likely to be underwater by 2100, study concludes

Cape Cod's salt marshes are as iconic as they are important. These beautiful, low-lying wetlands are some of the most biologically productive ecosystems on Earth. They play an outsized role in nitrogen cycling, act as carbon sinks, protect coastal development from storm surge, and provide critical habitats and nurseries for many fish, shellfish, and coastal birds.

And, according to new research from the Marine Biological Laboratory (MBL), more than 90 percent of the world's salt marshes are likely to be underwater by the end of the century.

The findings come from a 50-year study in Great Sippewissett Marsh in Falmouth, Massachusetts. Since 1971, scientists from the MBL Ecosystems Center have mapped vegetative cover in experimental plots in this marsh to examine whether increased nitrogen in the environment would impact species of marsh grass. Due to the study's length, they also were able to detect the effects of climate change on the ecosystem, especially those driven by accelerating sea level rise.

The researchers found that increased nitrogen favored higher levels of vegetation and accretion of the marsh surface, but that no matter what the concentration of nitrogen they applied to the marsh, these ecosystems won't be able to outpace submergence from global sea level rise.

"Places like Great Sippewissett Marsh will likely become shallow inlets by the turn of the century," says MBL Distinguished Scientist Ivan Valiela, lead author of the study. "Even under conservative sea level estimates…more than 90% of the salt marshes of the world will likely be submerged and disappear or be diminished by the end of the century."

"This is not a prediction from isolated scientists worried about little details. Major changes are going to be taking place on the surface of the Earth that will change the nature of coastal environments," says Valiela.

An Ecosystem Engineer

Salt marshes are gently sloping ecosystems and their plants have very narrow preferences for the elevations in which they can grow. Different species grow in the upper elevations (high marsh) versus the low elevation closer to the ocean (low marsh) and have different responses to changes in nitrogen supply. When change happens slowly enough, the grasses can migrate to their preferred elevation.

In the low marsh, cordgrass (Spartina alterniflora) prospered as scientists increased the nitrogen supply. Among high marsh species, the abundance of marsh hay (Spartina patens) in the experimental plots decreased with sea level rise. Saltgrass (Distichlis spicata) increased with nitrogen supply and also acted as what the researchers called an "ecosystem engineer" -- increasing the rate at which marsh elevation rose. Accretion of biomass left behind by the decomposing saltgrass compensated for the increased submergence resulting from rising sea level in these areas.

"Saltgrass disappeared after a few decades, but it left a legacy behind," says MBL Research Scientist Javier Lloret, adding that it was "extremely cool to see that interaction in the dataset."

Regardless of how much nitrogen was added to the environment, the research showed that at the current and future forecasted sea level rise, low marsh species will completely replace high marsh species. As sea levels continue to rise, even these species will be submerged.

"At some point, if sea level continues to increase at the rates that we anticipate, there will even be no more room for the low marsh plants. They're just going to be too submerged to survive." says Valiela.

The only alternative would be for salt marshes to migrate landward.

A Coastal Squeeze

Marshes around the world face what Lloret calls a "coastal squeeze," where sea level rise pushes from one direction and human development pushes from the other. A seawall that may protect a home from flooding will prevent the migration of a marsh naturally moving to higher ground.

"These barriers, whether they be geographic like a hill or a cliff, or people building along the edges of the ecosystem, constrain the potential for landward marsh migration," says MBL Research Assistant Kelsey Chenoweth. "On top of that, sea level rise is accelerating and marshes are having a hard time keeping up."

In a sea level rise scenario like the one we're facing, "the only solution for the plants will be to colonize new areas, to go uphill," says Lloret. "But that migration may just be impossible in some places."

"Sea level rise is the most important threat to salt marshes. We really need to figure out what's going to happen to these ecosystems and learn how to prevent some of the losses from happening or try to adapt to them, so marshes can continue to play these important roles for nature as well as humans," says Lloret.

Half a Century of Science

In 1971, the scientists at the MBL Ecosystems Center had no idea they would be using their data to study global sea level rise.

"This was an experiment that started looking at one ecological control (nitrogen), and then because of the longevity of the project, we were able to add new knowledge about this major accelerating agent of global change -- global sea level rise," says Valiela.

That's the benefit of long-term datasets like the one at Great Sippewissett Marsh.

"You're setting a baseline to the problems that haven't even happened yet," says Chenoweth.

When measuring ecological processes like climate change and eutrophication, the data can ebb and flow over the course of years as the ecosystem responds to external stimuli. The changes operate on a much longer time scale than changes on other biological systems.

"To study a tree, you look at changes through seasons and you should be able to see its whole cycle. For a leaf, you look at patterns between day and night. In single cells, you look at processes that take place at the timescale of minutes or seconds … but for an entire ecosystem, we're talking many years or decades," says Lloret. "You need to be thinking at the scale of decades or even centuries in order to be able to see substantial changes."

Read more at Science Daily

Sea ice will soon disappear from the Arctic during the summer months -- and it has happened before

The "Last Ice Area" north of Greenland and Canada is the last sanctuary of all-year sea ice in this time of rising temperatures caused by climate change. A new study now suggests that this may soon be over.

Researchers from Aarhus University, in collaboration with Stockholm University and the United States Geological Survey, analyzed samples from the previously inaccessible region north of Greenland.

The sediment samples were collected from the seabed in the Lincoln Sea, part of the "Last Ice Area." They showed that the sea ice in this region melted away during summer months around 10,000 years ago. The research team concluded that summer sea ice melted at a time when temperatures were at a level that we are rapidly approaching again today.

"Climate models have suggested that summer sea ice in this region will melt in the coming decades, but it's uncertain if it will happen in 20, 30, 40 years, or more. This project has demonstrated that we're very close to this scenario, and that temperatures only have to increase a little before the ice will melt," says Christof Pearce, Assistant Professor at the Department of Geoscience, Aarhus University.

The researchers have used data from the Early Holocene period to predict when the sea ice will melt today. During this time period, summer temperatures in the Arctic were higher than today. Although this was caused by natural climate variability opposed to the human-induced warming, it still is a natural laboratory for studying the fate of this region in the immediate future.

In Aarhus the marine samples have been analysed in collaboration with Associate Professor Marianne Glasius and academic technical staff Mads Mørk Jensen from the Department of Chemistry. Among other things, they studied molecules from certain algae that are only produced when there is sea ice. The researchers can thereby determine when summer sea ice was present in the area.

A wake-up call

When the sea ice in the Lincoln Sea begins to melt during the summer months, it can have major consequences for the climate. Where white ice reflects the rays of the sun, a dark sea will absorb more than ten times as much solar energy and thereby increase global warming. Moreover, it can affect ecosystems:

"The sea ice is a base for many ecosystems. The algae we examined are food for fish, fish are food for birds, etc. How will the marine ecosystems be affected globally if the sea ice disappears? We don't know the answer yet," says Henrieka Detlef, an assistant professor at the Department of Geoscience.

According to the researchers from Aarhus University, the study can be interpreted as good and bad news for the climate.

"The bad news is that we can see this happening very soon. The good news is that our data shows the trend is reversible and we can do something about it if we reduce greenhouse gas emissions and set ambitious political goals. If we can keep temperatures stable or perhaps even make them fall, the sea ice would return to the area," says Henrieka Detlef.

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Stressed out: Mapping the human footprint on coastal areas globally

A global mapping project led by University of Queensland researchers has revealed the major stressors placed upon global coastlines by human activity.

The team quantified and mapped the presence and extent of major land-based and marine stressors, finding that 97 per cent of coastal areas globally had at least one major stressor present.

Professor Salit Kark from UQ's School of Biological Sciences said the research team were surprised at the sheer extent and far-reaching impact revealed by the footprint map created.

"There is hardly anywhere on the planet, outside of the polar and arctic regions, that does not show some form of human pressure on their coastline," Professor Kark said.

"In essence, we have influenced the majority of coastal areas globally.

"We therefore should aim to map and understand our impacts, and also leave some untouched coastlines."

UQ PhD candidate Hannah Allan said the research outlined the spatial extent and magnitude of 10 major land-based stressors and 10 major marine stressors that occur across coastlines globally.

"The threats human activity pose to coastal ecosystems and biodiversity come from both the land and sea, sometimes arriving far from human activity," Ms Allan said.

"Therefore, coastal conservation must incorporate land-sea connections.

"Human population size, tourism, and roads were some of the biggest contributors to the terrestrial component of Australia's coastal human footprint.

"As for marine stressors, increasing sea surface temperatures, nutrient pollution, and shipping were found to be major drivers of human pressure on Australian coastlines."

Professor Noam Levin said a map of this kind, which assembles both terrestrial and marine stressors and presents the coastal human footprint globally, has rarely been attempted.

"This research offers valuable insights that could help decision-makers and managers identify where to mitigate particular impacts," Prof. Levin said.

"For example, the database underlying the human footprint can show specific areas with high oil and gas operations, such as in Western Australia.

"This can help develop preparedness procedures for the very realistic chance of environmental disasters that impact coastal areas, such as oil spills.

"An added benefit of our new global map is that it helps prioritise these decisions based on how widespread the potential pressures of our human footprint in certain areas of the world might be.

"Coastal areas, where 90 per cent of Australians live, were not immune to these stressors.

"For Australia, the highest human footprint was found in the coastal cities, in the order of Melbourne, Sydney, Perth, Adelaide, and Brisbane.

"We also mapped 160 areas on the planet with the most pristine coastal areas, including several in Australia.

"Of those, nearly 40 per cent were totally unprotected -- opening an opportunity to identify coastal areas for further conservation actions.

"A key finding was that light pollution is increasing, with more white LEDs being used, placing great strain on areas of high importance for biodiversity, disrupting the natural patterns of wildlife."

Moving forward, researchers are looking to fine-tune the mapping process, looking more specifically at Australia's coastlines.

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