Agathis labillardierei

View,Of,The,Skyscrapers,Of,Manhattan,Through,The,Trees,On

According to a new study led by the <a href="https://www.isglobal.org/en">Barcelona Institute for Global Health</a> (ISGlobal), over four percent of deaths in cities during the summer months are caused by the formation of “<a href="https://www.earth.com/news/trees-are-the-best-option-to-reduce-the-urban-heat-island-effect/">urban heat islands</a>,” where cities experience higher temperatures than surrounding areas due to less vegetation, larger population density, and the presence of impermeable surfaces for buildings and roads, including asphalt. By analyzing data from 93 European cities (with a total of 57 million inhabitants), the experts determined that one third of these deaths could be prevented by reaching a tree cover of 30 percent.



Exposure to extreme heat has been associated with cardiorespiratory diseases, a higher number of hospital admissions, and premature deaths. While these problems are mainly caused by heatwaves, they also occur with moderately high temperatures in the summer. Due to the formation of urban heat islands, cities are especially vulnerable to higher temperatures, facing spikes in morbidity and mortality during summer worldwide.&nbsp;



“Predictions based on current emissions reveal that heat-related illness and death will become a bigger burden to our health services over the next decades,” warned study lead author Tamara Iungman, a biologist at ISGlobal.&nbsp;



The scientists found that, from June to August 2015, cities were on average 1.5C warmer than the surrounding countryside, a phenomenon leading to 6,700 premature deaths in the 93 cities that were examined (4.3 percent of total mortality during the summer months and 1.8 percent of year-round mortality). Cities with the highest excess heat-mortality rates were in Eastern and Southern Europe. However, projections revealed that one third of these deaths (2,644) could have been prevented by increasing tree cover by 30 percent.



These findings highlight the major benefit of planting more trees in cities, together with other interventions such as green roofs.&nbsp;



“Our results also show the need to preserve and maintain the trees that we already have because they are a valuable resource and it takes a long time to grow new trees. It is not only about increasing trees in the city, it is also about how they are distributed,” added study senior author Mark Nieuwenhuijsen, the director of the&nbsp;<a href="https://www.isglobal.org/urban-planning">Urban Planning, Environment and Health</a>&nbsp;Initiative at ISGlobal.&nbsp;



“Vulnerability to heat changes from city to city depending on several factors. Understanding the benefits of policies such as increasing tree cover can help inform action to reduce risks and prevent avoidable deaths, especially with climate change,” concluded co-author&nbsp;Antonio Gasparrini, a professor of Biostatistics and Epidemiology at the London School of Hygiene &amp; Tropical Medicine (LSHTM).



The study is published in the journal <a href="https://doi.org/10.1016/S0140-6736(22)02585-5">The Lancet</a>.&nbsp;



—-



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



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Increased tree cover could prevent heat-related deaths in cities

According to a new study led by the Barcelona Institute...

A new study led by the <a href="https://www.ncsu.edu/">North Carolina State University</a> has found that, under severe global warming scenarios, the inventory of trees used for timber in the continental United States may decline by up to 23 percent by the end of the century. The largest losses are expected to occur in two of the leading timber regions in the country, both located in the South. While these findings show relatively modest impacts on forest product prices, they suggest larger impacts in terms of carbon storage in U.S. <a href="https://www.earth.com/news/diverse-forests-are-more-resilient-and-productive/">forests</a>.



“We already see some inventory decline at baseline in our analysis, but relative to that, you could lose, additionally, as much as 23 percent of the U.S. forest inventory,” said study lead author Justin Baker, an associate professor of Forestry and Environmental Resources at NC State. “That’s a pretty dramatic change in standing forests.”



The scientists used computer modeling to estimate how 94 tree species will grow under six climate change scenarios, while also considering the impact of two different economic scenarios on demand growth for forestry products.



“Many past studies show a pretty optimistic picture for forests under climate change because they see a big boost in forest growth from additional carbon dioxide in the atmosphere,” Baker explained. “The effect that carbon dioxide has on photosynthesis in some of those models tends to outweigh the losses you see from precipitation and temperature induced changes in forest productivity and tree mortality. We have a model that is specific to individual tree species, and that allows us to better understand how climate factors influence growth rates and mortality.”



The analysis revealed that in several regions trees would grow more slowly and die faster in higher temperatures, particularly in Southeast and South-Central U.S. These regions may see tree inventories shrink by as much as 40 percent by 2095 compared to a baseline scenario. However, the researchers projected gains in tree supplies in the Rocky Mountains and Pacific Southwest regions, which will be driven by higher death rates of certain trees, leading to larger harvests initially, and followed by the growth of more heat-tolerant species (such as juniper trees). Overall, the total projected losses of U.S. tree inventory will likely range between three and 23 percent, with the value of lost carbon spiking up to $5.5 billion per year.



“We saw that the markets could be more resilient than the forests themselves. Your market effects may seem modest in terms of the effect it has on the consumers and producers, but those impacts are small compared to the carbon sequestration value that forests provide on an annual basis,” Baker warned.



“We don’t know a lot about how disturbance-related mortality or loss in tree productivity is going to bear out across the landscape as temperatures get warmer. We did our best to address a couple pieces of the puzzle with temperature and precipitation changes, and interactions between climate and market demand, but a lot more work needs to be done to get a good handle on climate change and forestry,” he concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.forpol.2022.102898">Forest Policy and Economics</a>. &nbsp;



—-



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



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Forest inventory will be greatly reduced by climate change

A new study led by the North Carolina State University...

At a time when global warming is making many regions of our planet hotter and drier, <a href="https://www.earth.com/news/study-reveals-that-deserts-breathe/">deserts</a> are relatively new biomes that have grown substantially over the past 30 million years, with vast arid areas like those covering much of North America emerging only during the past five to seven million years. Thus, a better understanding of how several species of plants have invaded these harsh environments and were able to survive could help predict how ecosystems will fare in a drier, hotter future.



According to a new study led by the <a href="https://www.berkeley.edu/">University of California, Berkeley</a>, plants that invaded deserts millions of years ago, such as rock daisies, had already developed adaptations to deal with heat and water stress before. These plants adapted while living on exposed rock outcroppings within older, moist areas or even tropical forests, which made it easier for them to invade expanding deserts.



“If you think about aridity only as a stimulus to plant evolution, then in many cases people could say these plants are survivors, they are adaptable, and they will be fine. They will take advantage of these new conditions, and they will thrive,” said study lead author Isaac Lichter-Marck, plant taxonomist, biogeographer, and evolutionary ecologist at UC Berkeley.



However, the history of rock daisies shows that, when deserts emerged, “plants that had the necessary preadaptations to take advantage of new conditions were the ones that thrived. Adding more aridification to the system doesn’t necessarily mean more rapid adaptive evolution will occur. There’s a limited source of lineages that can take advantage of new levels of aridity, and that is important for understanding the effect of climate change on biodiversity.”



By collecting and analyzing hundreds of rock daisy specimens from the deserts of Arizona, California, Texas, and Mexico, and comparing them to fossilized daisies, the scientists managed to develop a timeline of the evolution of these plants’ characteristics as they eventually invaded expanded deserts. The investigation revealed that most rock daisies – particularly the genus&nbsp;Laphamia, which was the first to move into deserts — had already adapted to the multiple stresses of heat, sun, aridity, and wind by growing on cliffs before invading deserts.



“This is a clear empirical demonstration of what was originally Axelrod’s hypothesis - of a desert plant group originating in dry microclimates prior to the widespread emergence of desert habitats. What this means is that the strategies for drought tolerance that are so characteristic of desert vegetation might not actually represent responses to the dry conditions found in deserts. Instead, they could be traits that evolved earlier in association with much older and more stable dry microclimates, such as rock outcrops in tropical settings,” Lichter-Marck concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1073/pnas.2214729120">Proceedings of the National Academy of Sciences</a>.



Image Credit: Isaac Lichter-Marck



—-



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



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Can plants adapt to rapid warming and drought?

At a time when global warming is making many regions...

The UK’s 14 Overseas Territories – many of them small, remote islands like St. Helena – are home to a variety of plant and animal species found nowhere else in the world. This makes them highly vulnerable to biological invasions that could lead to the extinction of their endemic species and irrevocably change their unique ecosystems.



Now, a team of researchers from the <a href="https://www.ceh.ac.uk/">UK Center for Ecology &amp; Hydrology</a> (UKCEH) and <a href="https://www.durham.ac.uk/homepage/">Durham University</a>, together with communities on the Overseas Territories, has assessed thousands of potential <a href="https://www.earth.com/news/managing-invasive-species-can-improve-climate-resilience/">invasive species</a> in order to estimate which are most likely to arrive and pose threats to the Territories within the next decade. Their findings could guide authorities, conservation ecologists, and the wider public to prevent these species from becoming established and causing ecological and economic damage.



“These Territories are exceptionally biodiverse. St Helena, for example, has over 400 invertebrates found nowhere else in world – it is simply unique. We hope that this study draws attention to these Overseas Territories and the inspiring people on them who are working so hard to protect their incredible wildlife and habitats,” said study senior author Helen Roy, an ecologist at UKCEH.



The analysis revealed that Gibraltar and St. Helena are threatened by biological invasion from the greatest number of species. While St. Helena is most at risk from invasion of plant species, the Falkland Islands and Tristan da Cunha are endangered by the most marine species. One of the species that could pose a threat to many of the Overseas Territories is the green mussel (Perna viridis), which can travel around the world on boats and ships, and form dense colonies in places where it establishes, outcompeting native species by reducing levels of phytoplankton. Other invasive species that pose a significant threat to many Territories include the little fire ant (Wasmannia auropunctata), the brown rat (Rattus norvegicus), and the mesquite tree (Prosopis juliflora).



“Preventing the introduction of invasive non-native species is key, because management of species that have established and spread is often extremely expensive and, in some cases, there are no options available. We hope that this list will help inform action, including supporting biosecurity activities, to safeguard the wildlife in these precious places,” Roy concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1111/conl.12928">Conservation Letters</a>.



—-



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



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

UK territories threatened by a variety of invasive species

The UK’s 14 Overseas Territories – many of them small,...

Plants let their <a href="https://www.earth.com/news/invisible-colors-in-sunflowers-dont-only-attract-bees/">flowers</a> fade quickly for protection from detrimental microbes, according to a study led by experts at <a href="https://www.kyoto-u.ac.jp/en">Kyoto University</a>. Using field experiments and plant microbiome analyses, the researchers discovered that microbes growing on flowers can have a negative impact on fruit yields. As a defense mechanism, plants are quick to shed their flowers before the microbes increase in abundance.



"The results suggest that old flowers harbor microbial communities different from those at anthesis, and that the microbes abundant on old flowers negatively affect plant reproduction," wrote the study authors.&nbsp;



"Although it has received little attention, antagonistic microbes that rapidly proliferate on the flowers may have affected the evolution of various flower characteristics such as flower volatiles and life span."



Previously, researchers have investigated the tradeoff between energy that plants spend on producing and maintaining their flowers. Since flowers serve as a reproductive structure, it seems that plants would benefit from keeping them longer.&nbsp;



In an earlier study, the Kyoto team had looked at the mystery of why plants invest their energy to produce fragile flowers that wither quickly, rather than investing a bit more energy to produce flowers that are more durable.



“Interestingly, flower lifespan is negatively correlated with temperature; the hotter the environment where they bloom, the shorter the period a plant retains them. The phenomenon has been known for a long time,” said study co-author Shoko Sakai.



“Then, at some point, I came up with the hypothesis that antagonistic microbes, such as bacteria and fungi growing on flowers after the flower bud opens, must be the driver that shortens the lifespan of a flower. I doubted that it was a coincidence that microbes grow faster in higher temperatures.”



The team conducted field experiments to determine what microbial communities appear on flowers that live longer. The experts transferred microbes from old flowers of wild ginger to other wild ginger plants with new flowers that had just opened.



The experimental plants ultimately produced fewer fruits, despite the fact that there were no visible signs of infection or disease. When the researchers analyzed the microbiomes of the plants, they found several groups of bacteria that were increasing with time.&nbsp;



“So far, flower characteristics have mostly been studied in the context of their interactions with pollinators," said Sakai. "Recent studies have raised the question whether we have overlooked the roles of microbes in the studies of floral characteristics. For example, flower volatiles - which are often regarded as a primary pollinator attractant - can also function to suppress antagonistic microbes."



"The impacts of microbes on plant reproductive ecology may be more deeply embedded in the evolution of angiosperms than we have considered."



The study is published in the journal <a href="https://mbmg.pensoft.net/">Metabarcoding and Metagenomics</a>.



---



By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Plants shed their flowers quickly for protection

Plants let their flowers fade quickly for protection from detrimental...

Party,Table,Setting,With,Various,Veggie,Snacks,,Top,Down,View

In order to produce <a href="https://www.earth.com/news/food-production-affects-earths-natural-processes/">food</a> for humanity, we have appropriated roughly 50 percent of all habitable land and 70 percent of the available fresh water. We harvest aquatic food from nearly every river, lake and ocean, pollute watersheds and coastal seas with excess nutrients and generate around 30 percent of all anthropogenic greenhouse gases. Like it or not, feeding humans puts enormous environmental pressure on our planet.&nbsp;



In past studies, researchers have attempted to calculate the environmental impact of producing various different types of foods. By considering such factors as greenhouse gasses emitted during production, or the extent of water pollution, they have made some headway in quantifying the environmental consequences of food production per pound or kilogram. However, with industrialized farming and complex supply chains, it is difficult to assess the true environmental pressures of our global food system.&nbsp;



“Everyone eats food, and more and more people are paying attention to the planetary consequences of what they eat,” said <a href="https://www.ucsb.edu/">UC Santa Barbara</a> marine ecologist&nbsp;<a href="https://bren.ucsb.edu/people/ben-halpern">Ben Halpern</a>. However, as the world’s population increases decisions will need to be made about how to reduce the environmental footprint of food production in order to keep it sustainable, and this will necessitate a more comprehensive understanding of the various types of impacts. This proves to be a gargantuan task as there are so many different types of foods, produced in various ways and leading to a range of environmental pressures depending on the location of production.&nbsp;



“The individual choice of eight billion people adds up,” said Halpern, “and we need to know the overall impact of&nbsp;total&nbsp;food production – not just per pound – especially when setting food policy.”



In a new study, Halpern and colleagues at UC Santa Barbara’s&nbsp;<a href="https://www.nceas.ucsb.edu/">National Center for Ecological Analysis &amp; Synthesis (NCEAS)</a>&nbsp;have analyzed the greenhouse gas emissions, freshwater use, habitat disturbance and nutrient pollution (e.g., fertilizer runoff) generated by the production of 99 percent of all foods on Earth, including both aquatic and terrestrial foods. In addition, they combine these four pressures to map the estimated cumulative pressure, or ‘footprint,’ of food production globally, as well as in individual countries. Their research is published in the journal Nature Sustainability.



For Halpern, executive director at NCEAS and a professor at UCSB’s Bren School of Environmental Science &amp; Management, understanding the impacts of food production along with the local context of these impacts has been a longstanding interest. By taking detailed data about greenhouse gas emissions, freshwater use, habitat disturbance and nutrient pollution generated by 99 percent of total reported production of aquatic and terrestrial foods in 2017, and mapping those impacts at high resolution, the researchers were able to create a more nuanced geospatial picture of the pressures – the inputs, processes and outputs – of global food production.



It turns out that the impacts of food production vary between countries, depending on the farming methods used and on environmental conditions prevalent at each locality. This leads to the unexpected situation that five countries contribute almost half of all environmental pressures arising from food production; these are India, China, the United States, Brazil and Pakistan.



In addition, the large proportion of the environmental footprint arising from terrestrial food production is generated from agricultural activities that take place over only 10 percent of the Earth’s surface. This means that, when looking at the cumulative pressure per unit of food production (efficiency), there are enormous variations between countries and it is not correct to assume, as has been the case previously, that the environmental footprint of production for any one food is the same in all locations.&nbsp;



For example, thanks to technology that reduces greenhouse gases and increases yields, the United States – the world’s number one producer of soy – is more than twice as efficient as India (the fifth largest producer) at producing the crop, making American soy the more environmentally friendly choice.



“The environmental efficiency of producing a particular food type varies spatially, such that rankings of foods by efficiency differ sharply among countries, and this matters for guiding which foods we eat and from where,” said&nbsp;<a href="https://www.eemb.ucsb.edu/people/faculty/froehlich">Halley Froehlich</a>, assistant professor in environmental studies at UCSB and a co-author of the study.



The research also uncovers connections between land and sea that get missed when looking only at one or the other, and that result in significant environmental impacts. In some countries, raising pigs and chicken gives rise to an ocean footprint because they are fed meal made from marine fish such as herrings, anchovies and sardines. The converse is true for mariculture farms that make use of crop-based feeds and thus extend the environmental pressure caused by fish farms onto the land.



Assessing cumulative pressures can bring to light results that could not have been predicted by examining individual pressures alone. For instance, while raising cattle uses by far the most land for grazing, farming pigs produces a lot of pollution and uses more water. When comparing the two types of food production, the cumulative environmental pressures end up being slightly greater when raising pigs than when raising cattle. Measured by cumulative pressures, the five foods with the most severe environmental impacts are pigs, cows, rice, wheat and oil crops.



It is crucial to consider the cumulative effects on the environment of producing food to feed a growing global population. If we wish to reduce environmental degradation while still ensuring food security, we may need to rethink the way in which we produce food in general, say the researchers. In some cases, farming might need to improve efficiency; in other cases, consumers might need to change their food choices. Understanding the different environmental costs of food production in different countries will help to steer consumption towards lower-impact foods and ultimately to restructuring the food system such that we will be able to feed humanity in a sustainable manner.&nbsp;



“We need this comprehensive information to make more accurate decisions about what we eat,” said Halpern, who modified his own food choices based on the results of this study.



“I became a pescatarian years ago because of wanting to reduce the environmental footprint of what I eat,” he said. “But then I thought, I’m a scientist, I should really use science to inform my decisions about what I eat. That’s actually why I started this research project. And now that we have the results, I see that from an environmental perspective, chicken is actually better than some seafood. And so I’ve shifted my diet to start including chicken again, while eliminating some high-pressure seafoods like bottom-trawl caught cod and haddock. I am actually eating my words.”



---



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



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Our dietary choices have enormous environmental impacts

In order to produce food for humanity, we have appropriated...

Plants in the mint family are rich in chemical molecules that give distinctive scents and flavors to their leaves. The mint family (Lamiaceae) is the sixth largest family of flowering plants and includes many familiar species, apart from mint itself, such as basil, rosemary, peppermint, lavender, sage and coleus. The aromatic and flavorful compounds produced by these plants function to attract <a href="https://www.earth.com/news/gardeners-can-make-small-changes-to-benefit-pollinators/">pollinators</a> and to deter herbivores, and they have been essential in driving the diversification of this large group of plants.



Researchers from <a href="https://msu.edu/">Michigan State University</a> have been studying the great variety of metabolites found in mint plants for many years, and have recently focused on a group of molecules called terpenoids. These compounds are essential in protecting the plants from predators and pathogens, and are also common ingredients in green and sustainable agrochemicals, antioxidants, cosmetics and fragrances.&nbsp;



“People easily recognize members of the mint family for their specialized metabolites,” said Dr. James K. Billman, Jr. and Professor&nbsp;<a href="https://biomolecular.natsci.msu.edu/faculty/alphabetical-directory/bjoern-hamberger/">Björn Hamberger</a>. “Metabolites are an efficient way for plants to defend themselves because they can’t run away.”



Professor Hamberger worked previously with Robin Buell, a former MSU genomics researcher, who sequenced the genomes from several different species in the mint family. This collaboration with Buell’s team led graduate students Abigail Bryson and Emily Lanier to discover how several genomes of the mint family have evolved over the past 60 million to 70 million years and how their chemistries have emerged.&nbsp;



“Over millions of years, plants have adapted and evolved for their particular niches where they thrive, and that means that these chemistries are diverse and have clearly adjusted to their environment,” said Professor Hamberger. “So, we try to identify and discover pathways to these specialized metabolites that plants make.”



According to the researchers, this family of plants have diversified the natural characteristics of their metabolites throughout their evolution, leading to the great variety of different chemical compounds found in today’s members of the group. In order to understand the mechanisms by which such diversity has evolved, the researchers took an interdisciplinary approach and analyzed the genetic and chemical pathways involved in terpenoid biosynthesis in different species in the mint family.



Bryson identified the genomic framework of terpenoid biosynthesis, and Lanier analyzed the chemical pathways. Together, Lanier and Bryson discovered something highly unusual in the beautyberry (Callicarpa americana) genome from the mint family. It has a large biosynthetic gene cluster (BGC), which is a group of genes, located close together in the genome, that are involved in the same metabolic pathways. Additionally, Bryson and Lanier found variants of this BGC in six other species in the mint family.



“We are learning that the physical location of genes within the genome is important,” Bryson said. “It can drive evolution of specialized metabolic pathways in the plant, leading to a vast diversity of interesting natural plant compounds.”&nbsp;



The BGC cluster of the beautyberry plant contains genes that encode two distinct terpenoid pathways. The team found these terpenoids accumulate in various parts of the plant, such as the leaves and roots, and may play distinct roles in helping the plant to adapt to its environment.&nbsp;



“It’s the same base molecule, but each species is making its own version and modifying it in different ways to fit their survival needs,” Lanier said.&nbsp;



Professor Hamberger describes it like a recipe that everyone has a copy of and changes to suit their requirements and preferences.&nbsp;



The researchers hope that a better understanding of the ways in which these compounds have been modified by different plant species will lead to potential future applications that could include new medicines and pesticides. We already use some of the compounds as flavor additives, fragrances, and anti-herbivory agents.



Previous research has led to unique medical uses for mint plants. For example, Indian Coleus can be used as a natural treatment for glaucoma and Texas sage is a natural antimicrobial that is effective against tuberculosis. The new molecular adaptations that have been found in the current study open the door for future applications of natural plant products from the mint family.



“Our team has been excited about the opportunities within the mint family,” said Professor Hamberger. “Those mint enzymes, as in the American beautyberry plant, give us the ability to make plant-natural products in the lab, including – hopefully in the future – natural good-smelling mosquito repellants.”



---



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



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Plants in the mint family may help produce new medicines

Plants in the mint family are rich in chemical molecules...

Agathis labillardierei

Taxonomic tree: