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>.



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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...

Genes contain all the instructions living organisms need to survive, grow and reproduce. While identifying genes is becoming a rather simple scientific procedure, learning what are the functions of these genes is a more complicated matter. A team of researchers led by the <a href="https://www.ucr.edu/">University of California, Riverside</a> has now discovered the functions of hundreds of genes in algae, many of which are also present in <a href="https://www.earth.com/news/scientists-grow-plants-in-lunar-soil-for-the-first-time/">plants</a>, where they play similar roles.&nbsp;



The findings could help scientists genetically engineer algae for biofuel production and develop agricultural crops which can better withstand the effects of climate change.



“Plant and algae genetics are understudied. These organisms make the foods, fuels, materials, and medicines that modern society relies on, but we have a poor understanding of how they work, which makes engineering them a difficult task,” said study senior author Robert Jinkerson, an assistant professor of Chemical and Environmental Engineering at UC Riverside. “A common way to learn more about biology is to mutate genes and then see how that affects the organism. By breaking the biology we can see how it works.”



Professor Jinkerson and his colleagues used a variety of algal mutants and automated tools in order to perform experiments that generated millions of data points. By analyzing this vast dataset, the scientists learned the functional role of hundreds of poorly characterized genes and discovered new functions of previously known genes.&nbsp;



Several of the genes found in algae have counterparts in plants with similar roles, including photosynthesis, heat stress response, DNA damage response, or response to toxic chemicals and predators.



Better understanding how these genes function in algae could help engineer plants that are more resilient to heat or cold stress, have improved photosynthesis capacities, and grow well even in some contaminated soils. Such features which will be increasingly important as climate change advances and threatens the world’s food supply. Moreover, a deeper knowledge of algal genetics will also improve engineering strategies making them produce more biofuels.



“The data and knowledge generated in this study is already being leveraged to engineer algae to make more biofuels and to improve environmental stress tolerance in crops,” concluded Professor Jinkerson.



The study is published in the journal <a href="https://www.nature.com/articles/s41588-022-01052-9">Nature Genetics</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

Algae genetics could help engineer more resilient plants

Genes contain all the instructions living organisms need to survive,...

Scientists have made an incredible discovery. For the first time in history, researchers at the <a href="https://www.ufl.edu/">University of Florida</a> have grown plants in <a href="https://www.earth.com/news/lunar-soil-could-be-the-basis-of-moon-life-support-system/">soil</a> taken from the Moon. The experts have also learned how plants respond to lunar soil on biological and genetic levels.&nbsp;



After trying for 11 years, the researchers finally acquired just 12 grams of lunar soil. They filled tiny pots with a few Arabidopsis plant seeds, added nutrients, and exposed them to light. Much to their surprise, the seeds began to sprout. Through this experiment, the scientists have been able to gather further information.



The researchers noticed that plants grown in lunar soil were smaller and grew more slowly. There was also more variation in their sizes.&nbsp;



The experts used the Arabidopsis plant because its genetic code has been fully mapped. This means that the researchers could learn whether growing in lunar soil affected plants genetically.&nbsp;



“At the genetic level, the plants were pulling out the tools typically used to cope with stressors, such as salt and metals or oxidative stress, so we can infer that the plants perceive the lunar soil environment as stressful,” said study co-author Anna-Lisa Paul.



The experiment also revealed that plant growth may be affected by where the soil was gathered. It appears that plants grow better in less mature soil, which hasn’t been exposed to as much cosmic wind as mature soil.



The ability to grow a plant in Moon soil has significant implications for space travel and possible off-planet colonization.&nbsp;



“For future, longer space missions, we may use the Moon as a hub or launching pad. It makes sense that we would want to use the soil that’s already there to grow plants,” said study co-author Rob Ferl. “So, what happens when you grow plants in lunar soil, something that is totally outside of a plant’s evolutionary experience? What would plants do in a lunar greenhouse? Could we have lunar farmers?”



Furthermore, the research is vital for the Artemis Program, led by NASA, which aims to return humans to the Moon. Ferl believes the findings will help inform that mission.&nbsp;



This breakthrough is fantastic in its own right. We can be sure the scientific community will continue to build upon these findings.&nbsp;



The study is published in the journal <a href="https://www.nature.com/commsbio/">Communications Biology</a>.



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

Scientists grow plants in lunar soil for the first time

Scientists have made an incredible discovery. For the first time...

Taxonomic tree: