Pseudoleskea julacea is a moss in the Leskeaceae family. This breed (HAUSCH &amp; HARRIS) by HA Crum, Steere &amp; LE Anderson first described science in 1973. 

Pseudoleskea Moss (Pseudoleskea julacea)

View,Of,Lagoon,And,Wetland,Habitat,,Lagunas,De,Villafafila,Rese

Wetlands fringe the edges of land adjacent to the sea and, although they represent a small proportion of Earth’s terrestrial <a href="https://www.earth.com/news/shrinking-habitats-alien-species-threaten-native-trout/">habitats</a>, they provide important ecosystem services. They protect communities against the worst effects of hurricanes and typhoons and the plants sequester large amounts of carbon. But, as sea levels rise, the fate of wetlands hangs in the balance. Will they adapt or will they drown?



For decades, scientists have hoped that rising concentrations of carbon dioxide (CO2) would stimulate increased plant growth in general. In the case of coastal wetlands, this scenario would enable them to grow fast enough to outpace the rise in sea level. A new study, conducted by researchers from the <a href="https://serc.si.edu/">Smithsonian Environmental Research Center</a>&nbsp;(SERC), has now shed light on this question, and the findings do not look as hopeful.



The study took place at SERC’s&nbsp;<a href="https://serc.si.edu/gcrew">Global Change Research Wetland</a>, a research site run by biogeochemist Pat Megonigal on the western shore of Maryland. The research on wetland plant growth there represents the longest-running field experiment in the world on the impact of rising CO2&nbsp;levels on plants. Started in 1987, the design involves enclosing 15 small areas of wetland within open-top chambers, and then modifying the concentration of CO2 in the chambers and monitoring the growth responses of the plants as sea levels have slowly risen. A further 15 chambers serve as experimental controls that did not have any CO2 enrichment.



Over time, the scientists have raised the concentration of CO2 within the experimental chambers by an additional 340 parts per million, roughly doubling the atmospheric levels of 1987. In monitoring plant growth, they have focused particularly on the 10 chambers that contain “C3” plants that use a specific metabolic pathway to incorporate carbon from the atmosphere into sugars in their cells. These plants include roughly 85 percent of all plant species on Earth and they are known to respond vigorously to CO2&nbsp;enrichment.



The results, published today in the journal Science Advances, show that plant growth in the higher CO2 chambers flourished for about the first two decades of the study. Above ground, plants in the high-CO2&nbsp;chambers grew on average 25 percent more than plants in the untreated chambers. The effect was even more powerful underground, where higher levels of CO2&nbsp;triggered about 35 percent more root growth. Root growth is especially critical for wetland survival, as roots help wetlands trap soil and keep the foundations growing&nbsp;upward&nbsp;even as seas continue to rise.&nbsp;



“Even though elevated CO2&nbsp;contributes to sea-level rise, it also enhanced the marsh’s ability to accrete vertically during the early years of the experiment,” said Don Cahoon, a co-author and research ecologist, emeritus, with the&nbsp;<a href="https://www.usgs.gov/">U.S. Geological Survey</a>.



“In some ways, this is a race, a race between what CO2&nbsp;can do and what sea level can do," said study co-author Lewis Ziska, a plant physiologist at the&nbsp;<a href="https://www.publichealth.columbia.edu/">Columbia University Mailman School of Public Health</a>.



But after 2005, the growth effect declined and then stopped altogether. For the past 14 years of data in the study, there was no average difference in plant growth between the high-CO2&nbsp;and the normal chambers.&nbsp;



“The CO2&nbsp;effect has always been one of the silver linings of climate change,” said study co-author Adam Langley, an ecologist with&nbsp;<a href="https://www1.villanova.edu/university.html">Villanova University</a>. “Well, at least plants are going to grow more. But we see here that they didn’t. So the silver lining to me just got a little cloudier.”



The team investigated several possible explanations for the return to normal growth rate: precipitation, temperature, the saltiness of the water during growing season, and the presence of critical soil nutrients, like nitrogen. Only sea-level rise showed any link to plant growth. Once the sea level at the wetland rose by 15 centimeters from where it was in 1987, the benefits of higher CO2&nbsp;disappeared.



Sea water contains far less oxygen than air does and so, when wetlands flood, plants are deprived of oxygen. Plants need oxygen as well as CO2 for growth, and wetland plants are adapted to get most of their oxygen from the air rather than extracting it from water. As sea levels rise, the frequency of flooding increases and plants are unable to obtain the oxygen they need, so growth rates slow down.&nbsp;



“Plants are aerobic, oxygen-breathing organisms,” explained Megonigal. “And that includes their roots. And so they’re fundamentally faced with this problem of having their root system in an environment that doesn’t have any oxygen in it.”



Some wetlands may still be able to escape drowning. If wetlands cannot rise higher by building soil, migrating inland is another possibility. However, that can only happen if they have enough space to move into. For many communities, allowing room for wetlands to move inland would require a shift in how they use and value the land.



In the meantime, Earth’s climate accountants will need to rethink the planet’s carbon budget because it is possible that wetlands will not be around to absorb carbon from the atmosphere, as was originally thought. Now that scientists know extra CO2&nbsp;does not always stimulate wetland growth as much as they thought, the amount of carbon that can be sequestered in wetland plants in the coming decades is no longer certain.&nbsp;



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Wetlands are caught in a battle between CO2 and rising seas

Wetlands fringe the edges of land adjacent to the sea...

Alternative,Medicine.,Rosemary,,Mint,,Chamomile,,Thyme,In,A,Glass,Mortar.

Herbal supplements may not always be safe, according to a new study published by <a href="https://www.elsevier.com/">Elsevier</a>. The research highlights how serious side effects can result from the imprudent use of herbal supplements.



The report describes a case in which a patient was diagnosed with a dangerous cardiac arrhythmia after taking hemp oil containing <a href="https://www.earth.com/news/cbd-improves-eases-arthritis-symptoms-in-dogs/">CBD</a> and CBG along with berberine supplements.



“More and more people are taking herbal supplements for their potential benefits. Yet their ‘natural’ character can be misleading, since these preparations can have serious adverse side effects on their own or if combined with other supplements or medications,” said Dr. Elise Bakelants, an expert in the Department of Cardiology at the University Hospital of Geneva. “Their use should not be taken lightly, and dosing recommendations should always be respected.”



The study examined the case of a 56-year-old woman who experienced dizziness and fainting without warning. After physical exams came back as normal, doctors determined that the condition was caused by the herbal supplements she was taking to cope with stress.&nbsp;



Four months earlier, the patient had started taking six times the recommended dose of hemp oil, and had recently added berberine to the mix. She was then diagnosed with a life-threatening cardiac arrhythmia.



During her hospital stay, all supplements were stopped resulting in positive changes, which strongly validated a link between the supplements and the arrhythmia.



The popularity of herbal supplements has grown in recent years, especially those containing CBD (cannabidiol). This particular supplement is very accessible and available without any prescription.&nbsp;



CBD has been promoted for its anti-inflammatory, antipsychotic, and immunomodulatory properties. The products do not contain THC (tetrahydrocannabinol) - therefore, it is not subjected to scrutiny by drug regulatory agencies.&nbsp;



Berberine, found in many medicinal plants, is frequently used in traditional Chinese and ayurvedic medicine for various types of treatment.&nbsp;



The preparation of herbal supplements is largely unregulated. Exact composition can vary greatly from one distributor to another, and properties of these substances are not well known. There are limited data on their effectiveness and toxicity, making it&nbsp; difficult to predict potential side effects.



Dr. Bakelants cautioned patients and physicians to follow dosing recommendations and consider possible interactions with other medications, particularly in patients with underlying cardiac disease or those already taking QT-prolonging medication.



The study is published in the journal <a href="https://www.heartrhythmcasereports.com/">HeartRhythm Case Reports</a>.



---



By <a href="mailto:katherinebucko@gmail.com">Katherine Bucko</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Herbal supplements are not always safe

Herbal supplements may not always be safe, according to a...

Forest,Trail,Scene.,Woodland,Path

<a href="https://www.earth.com/news/we-still-have-much-to-learn-about-tree-growth/">Tree</a> planting is often an environmental solution to offset emissions that contribute to climate change. However, if the trees burn in a forest fire, all of the carbon they store could be thrown back into the atmosphere. When trees die, they also stop scrubbing carbon dioxide from the air due to drought or insect damage.



According to new research from the <a href="https://www.utah.edu/">University of Utah</a>, the likelihood of these threats is increasing worldwide. Relying on forests to absorb carbon emissions could be riskier than previously thought.



“U.S. forests could look dramatically different by the end of the century,” said study lead author William Anderegg. “More severe and frequent fires and disturbances have huge impacts on our landscapes. We are likely to lose forests from some areas in the Western U.S. due to these disturbances, but much of this depends on how quickly we tackle climate change.”



The researchers modeled the risk of tree death from fire, climate stress, such as heat or drought, and insect damage for forests throughout the United States, projecting how those risks could increase overtime.&nbsp;



The models found that by 2099, United States forest fire risks may increase between four and 14 times, depending on different carbon emissions scenarios. The risks of climate stress-related tree death and insect mortality could double over the same time.



“Climate change is going to supercharge these three big disturbances in the U.S.,” said Anderegg. “We’ve seen devastating fire seasons with increasing severity in the past several years. Generally, we expect the western U.S. to be hit hardest by all three of these. And they’re somewhat interconnected too. Really hot and dry years, driven by climate change, tend to drive lots of fires, climate-driven tree mortality and insect outbreaks.”



In each model, actions to tackle climate change mattered significantly. Reducing the severity of climate change dramatically reduced the likelihood of fire, drought and insect-driven forest die-off. This signals an opportunity - taking action to address climate change now can help maintain healthy forests, and the offsetting of emissions trees provide.&nbsp;



The study is published in the journal <a href="https://onlinelibrary.wiley.com/journal/14610248">Ecology Letters</a>. The research was supported by the National Science Foundation, U.S. Department of Agriculture, David and Lucille Packard Foundation and Microsoft’s AI for Earth.



Click <a href="https://carbonplan.org/research/forest-risks">here</a> to see the findings in an interactive map.



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By <a href="mailto:katherinebucko@gmail.com">Katherine Bucko</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Climate change will "supercharge" forest disturbances

Tree planting is often an environmental solution to offset emissions...

A new study led by the <a href="https://www.udel.edu/">University of Delaware</a> has found that increasing our daily intake of apiaceous vegetables, such as <a href="https://www.earth.com/news/colorful-foods-can-prevent-cognitive-decline/">celery</a>, carrots, and parsley, could mitigate the effects of air pollutants in our bodies. According to the experts, these vegetables protect the body from the accumulation of acrolein, an irritant of the lungs and skin with a strong unpleasant smell, which is abundantly found in cigarette smoke and automobile exhaust.



Through a series of laboratory tests, study senior author Jae Kyeom Kim (an assistant professor of Behavioral Health and Nutrition at the University of Delaware) and his team analyzed how apiaceous vegetables mitigated acrolein-induced toxicities and reduced the oxidative stress triggered by these harmful substances.



“Kim’s research discovered that apiaceous vegetables supported detoxification through an increase in antioxidant enzyme activity,” said study co-author Jillian Trabulsi, an associate professor of Nutrition at the University of Delaware. “The results suggest that apiaceous vegetables may provide protection against acrolein-induced damages and inflammation because, in the liver, the vegetables enhance conversion of acrolein into a water-soluble acid for bodily excretion.”



In a next step, the scientists investigated what is a reasonable dosage amount for human consumption in order to fully benefit from these vegetables. 



“When we calculated this, we determined the actual daily calorie amount of apiaceous vegetables for humans is roughly 1 and 1/3 cups per day,” Professor Kim said. “It doesn’t require a high intake to see a difference, and this is an achievable amount in daily life.”



In future studies, Professor Kim and his team plan to integrate human intervention trials to better understand the health benefits of apiaceous vegetables. For the moment, they stress the importance of implementing behavioral changes in diet as a solution for combating the buildup of toxic substances derived from air pollution.



“Research has identified that it is the totality of nutrients in fruits and vegetables that support beneficial health outcomes, rather than a single nutrient. Focusing on a healthy whole food diet is more impactful than relying on individual supplements,” Professor Trabulsi concluded.



The study is published in the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0955286322000109#!">Journal of Nutritional Biochemistry</a>.&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Eating vegetables can protect us against air pollutants

A new study led by the University of Delaware has...

Beautiful,Field,View,,As,A,Spiritual,Person,,Nature,For,Me

It's been long believed that the first farmers originated 11,000 years ago in the Fertile Crescent in the Near East. Still, researchers were not sure whether Europe's first farmers <a href="https://www.earth.com/news/unraveling-one-of-the-greatest-feats-of-human-migration/">migrated</a> from the Fertile Crescent or learned it through cultural dissemination.&nbsp;&nbsp;



While previous research implied that Europe's farmers came from hunter-gatherers in Anatolia, a new study led by the <a href="https://www.unibe.ch/index_eng.html">University of Bern</a> suggests that farming did not come from a single region.&nbsp;



Earlier studies indicated that the first agriculturalists were genetically different from other human groups. However, this study implies that there was a genetic mixing of hunter-gatherers from Europe and Anatolia approximately 14,000 years ago, which was 3,000 years before the first farmers.&nbsp;



"We now find that the first farmers of Anatolia and Europe emerged from a population admixed between hunter-gatherers from Europe and the Near East," said study co-author Nina Marchi.



The genetic mixing was followed by thousands of years of extreme genetic differentiation. Perhaps one of the most impressive aspects of this study is the interdisciplinary work that brings us these results.&nbsp;



The researchers used high-quality genetic material from prehistoric skeletons and analyzed demographic data to gather the necessary data. The team labeled this method "demogenomic modeling."&nbsp;



"It is necessary to have genome data of the best possible quality so that the latest statistical genomic methods can reconstruct the subtle demographic processes of the last 30 thousand years at high resolution," said study senior author Laurent Excoffier.



It took the researchers almost ten years to gather and study the skeletons. They also consulted with several anthropologists and archeologists.



"Simply comparing the similarity of different ancient genomes is not enough to understand how they evolved," said Marchi. "We had to reconstruct the actual histories of the populations studied as accurately as possible. This is only possible with complex population genetic statistics."



The discoveries made by the team only further their desire to learn more, as demonstrated by Excoffier, who wants to explore other time gaps and geographic areas. "Of course, spatial and temporal gaps remain, and this does not imply the end of studies on the evolution of humans in this area."



This study is published in <a href="https://www.cell.com/cell/fulltext/S0092-8674(22)00455-X?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS009286742200455X%3Fshowall%3Dtrue">Cell</a>.



---



By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Study sheds new light on the origins of the first farmers

It's been long believed that the first farmers originated 11,000...

Our school textbooks teach us that <a href="https://www.earth.com/news/scientists-grow-plants-in-lunar-soil-for-the-first-time/">plants</a> make their own food using water from the soil, carbon dioxide from the atmosphere, and energy from sunlight. This process, known as photosynthesis, would thus be limited by the availability of these three resources. But it seems that plant growth is not as simple as this. For trees, growth can also be limited by the rate at which new cells can form in the trunks and branches, a process that is affected by temperature.&nbsp;



Understanding the factors that limit the growth of the world’s forests will become more critical as the effects of global warming take hold. Will increased atmospheric carbon dioxide help trees to grow? Or will extremes in temperature and precipitation restrict this growth? Until now, the question of whether plant growth is limited by the rate of photosynthesis or by the environmental conditions that affect cell growth was not adequately answered, despite its fundamental nature.



A new study led by <a href="https://www.utah.edu/">University of Utah</a> researchers, along with an international team of collaborators, has now attempted to answer this question. They have measured and compared the rates of photosynthesis and woody growth in forest trees at sites in North America, Europe, Japan and Australia. Their results, published today in the journal <a href="https://dx.doi.org/10.1126/science.abm4875">Science</a>, suggest that we need to rethink the way we forecast forest growth in a changing climate, and that forests in the future may not be able to absorb as much carbon from the atmosphere as we hoped.



“A tree growing is like a horse and cart system moving forward down the road,” said Professor William Anderegg, who is the principal investigator of the study. “But we basically don’t know if photosynthesis is the horse most often, or if it’s cell expansion and division. This has been a longstanding and difficult question in the field. And it matters immensely for understanding how trees will respond to climate change.”



The scientists distinguish between a tree’s carbon source and its carbon sink. Carbon dioxide in the atmosphere is the carbon source – the tree uses this during photosynthesis to make food for its own use. Some of the carbon-based food is then used to grow new wood cells, and to enlarge existing ones. The tree’s wood is thus its carbon sink.&nbsp;



If the growth of trees is source-limited, then the amount of carbon dioxide available in the air is what would determine the rate of photosynthesis, and tree growth would be relatively easy to predict in a mathematical model. In this case, rising carbon dioxide levels in the atmosphere would be a good thing and forests would be expected to expand and proliferate.&nbsp;



However, if tree growth is sink-limited then they can only grow as fast as their cells can divide and mature. Many environmental factors can impact cell growth rate, including temperature, the supply of water and nutrients, and the rate of photosynthesis. In this case, modeling potential tree growth in future would have to take into account the impacts of these different factors.&nbsp;



In order to find out whether tree growth is limited by source or sink factors, the researchers compared the rates of photosynthesis and cell growth at forest sites on different continents. Measuring cell growth (sink) rates was done by sampling the growth rings of the trees.&nbsp;



“Extracting wood cores from tree stems and measuring the width of each ring on these cores essentially lets us reconstruct past tree growth,” said study lead author Antoine Cabon.&nbsp;



Measuring carbon sources was more difficult. Source data was measured with 78 eddy covariance towers, 30 feet tall or more, that record carbon dioxide concentrations and wind speeds in three dimensions at the top of forest canopies. “Based on these measurements and some other calculations, we can estimate the total forest photosynthesis of a forest stand," explained Cabon.



The researchers expected to find that the processes of photosynthesis and cell growth were coupled – that when photosynthesis increased (or decreased), a corresponding increase (or decrease) would be seen in cell growth. They did not find this. Trees did not necessarily add more growth when the photosynthetic rate increased.



“Strong coupling between photosynthesis and tree growth would be expected in the case where tree growth is source-limited,” said Cabon. “The fact that we mostly observe a decoupling is our principal argument to conclude that tree growth is not source-limited.”



Although the decoupling of these two processes was recorded in environments across the globe, there were instances where it was weaker. The researchers were interested in what conditions led to stronger or weaker decoupling. Fruit-bearing and flowering trees, for example, exhibited different source-sink relationships to those of conifers. Greater diversity in a forest increased coupling, whereas dense leaf canopies decreased it.



Finally, coupling between photosynthesis and growth increased in warm and wet environments, while in cold, dry conditions the processes were decoupled and tree growth was more limited by the rate of cell growth.&nbsp;



According to Cabon, this last finding suggests that the source vs. sink issue depends on the tree’s environment and climate. “This means that climate change may reshape the distribution of source and sink limitations of the world’s forests," he said.&nbsp;



The key finding from this study is that vegetation models, which use mathematical equations and plant characteristics to estimate future forest growth, may need to be updated. “Virtually all these models assume that tree growth is source-limited,” said Cabon.



For example, he explained, current vegetation models predict that forests will thrive with higher atmospheric carbon dioxide. “The fact that tree growth is often sink-limited means that for many forests this may not actually happen.”



That has additional implications: forests absorb and store about a quarter of our current carbon dioxide emissions. If the growth of forests slows down, their ability to take in carbon and mitigate the effects of climate change may be significantly reduced.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

We still have much to learn about tree growth

Our school textbooks teach us that plants make their own...

What are the impacts of reforestation or converting other lands to new <a href="https://www.earth.com/news/hotter-drier-deadlier-how-much-can-forests-tolerate/">forests</a>? We know that such a move can help sequester carbon, but what is the impact on the water cycle? A new study published in the journal <a href="https://www.nature.com/ngeo/">Nature Geoscience</a> attempts to answer this question.&nbsp;



Martin Herold from the <a href="https://www.gfz-potsdam.de/en/">GFZ German Research Centre for Geosciences</a> contributed to the study, which was led by Anne Hoek van Dijke from Wageningen University &amp; Research.&nbsp;



“Restoration and planting more trees is seen as a viable solution for enhancing carbon storage and the biodiverse functioning of ecosystems," said Herold. "With innovative data and analysis, our interdisciplinary analysis highlights that the hydrological effects are important for how and where such nature-based solutions are more suitable to achieve towards more climate-smart and sustainable future landscapes."



The scientists looked at a global model which focused on 900 million hectares of land where trees could grow given local climatic conditions. The change in evaporation given new tree cover was calculated across these locations. The researchers estimated the amount of water that would evaporate and that which would go to streams.&nbsp;



“These models include a vegetation parameter for forest and non-forest conditions that was calibrated to a range of different evaporation and streamflow measurements," said van Dijke. "Afterwards, we calculated where, and to what extent, the increased evaporation would return to the land surface as increased precipitation.”



The results show that increases in water evaporation vary depending on the local climate. In the tropics, water evaporation can increase by 250 liters of water per square meter of land. In other areas, the increase is a more modest 10 liters.&nbsp;



Around 70 percent of this water is rained back down on land, while 30 percent is precipitated over oceans. Worldwide, this means that reforestation could lead to a loss of water availability.&nbsp;



On the local scale, the impact is more complex. In some watersheds, reforestation leads to a decrease in stream flow. In others, such as the Amazon, the increase in rainflow is enough that the streamflow reduction is nearly zero.&nbsp;&nbsp;



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Reforestation may reduce water availability in some places

What are the impacts of reforestation or converting other lands...

Pseudoleskea Moss

Description

Taxonomic tree: