New technology to provide a deeper look inside Earth’s forests
Satellites play a major role in helping scientists understand the natural world, climate, and the impacts of climate change. But within the next two years, NASA will launch several new satellites that will provide never-before-seen insight into vegetation and forests on Earth.
Although satellite imagery has been able to show the size and location of the world’s forests, maps made from satellite data haven’t been able to indicate the height of vegetation. But now, two of the new NASA instruments will use spaceborne lasers to successfully measure tree height and give a more accurate idea of life in these forests.
One instrument called the Global Ecosystem Dynamics Investigation (GEDI) will be mounted on the International Space Station. The other is a satellite called the Ice, Cloud and land Elevation Satellite-2 (ICESat-2), which will measure snow and ice. Information from both instruments will help researchers create a larger, three-dimensional map of the forests on Earth.
Once scientists know the height of trees, they can more accurately measure how much carbon is being absorbed by plants and will then be able to calculate how much carbon dioxide is in the atmosphere.
“Combining ICESat-2 with GEDI, we’re going to have a new view of the state of the biosphere on our planet,” said Tom Neumann, the deputy project scientist for the ICESat-2 project at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Both of the instruments use light detection, but the GEDI will also use near-infrared wavelength, which is necessary for measuring plants and trees. The GEDI lasers will be able to pierce through forest canopies and reflect off the ground.
Even if researchers can measure plant mass, tree height, and carbon absorption, there is still necessary data on plant health that is missing, such as the ways that plants are impacted by stress due to drought.
NASA Jet Propulsion Laboratory’s (JPL) ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission will be able to measure plant health by examining water and carbon cycles in the plant.
This data will also help researchers measure how much carbon dioxide is taken in by plants throughout the day.
“ECOSTRESS will enable a detailed investigation into plant water use throughout the day,” said Josh Fisher, the mission’s science lead at JPL. “Furthermore, we’ll be able to better understand how certain regions are being impacted by drought. This could have important implications for managing forests or agricultural systems.”
These upcoming missions will help researchers better understand Earth’s vast forests, measure carbon levels in the atmosphere, evaluate plant stress due to water availability, and monitor water and carbon cycles worldwide.
Study: Biodiversity on Earth connected to oxygen levels
More than 400 million years ago, Earth saw an unprecedented explosion of new life. In a new study, geologists have added to the growing mountain of evidence connecting this burst of biodiversity to rising oxygen levels on the planet.
A team of scientists led by Dr. Cole Edwards of Appalachian State University found that oxygen levels spiked at around the same time that life began diversifying during the Ordovician Period, between 445 and 485 million years ago.
“This oxygenation is supported by two approaches that are mostly independent from each other, using different sets of geochemical records and predicting the same amount of oxygenation occurred at roughly the same time as diversification,” Edwards said in a press release about the study.
The researchers made use of geochemical proxies, high-resolution data and chemical signatures preserved in rocks to identify when oxygen levels rapidly increased during the Middle and Late Ordovician Period. Their discovery of a nearly 80 percent oxygen increase during that period coincides with what’s become known as the Great Ordovician Biodiversification Event.
The explosion of life led to enormous changes in existing species and a spike in new marine life.
Previous studies have estimated that Earth’s oxygen levels spiked to nearly modern levels during the Cambrian Period from 485 to 541 million years ago. However, measuring prehistoric oxygen levels is difficult because there’s no way to directly measure ancient seabeds or atmospheric makeup. The new study shows oxygen levels may not have peaked until the Ordovician Period.
“This study suggests that atmospheric oxygen levels did not reach and maintain modern levels for millions of years after the Cambrian explosion, which is traditionally viewed as the time when the ocean-atmosphere was oxygenated,” Edwards said. “In this research, we show that the oxygenation of the atmosphere and shallow ocean took millions of years, and only when shallow seas became progressively oxygenated were the major pulses of diversification able to take place.”
However, it still remains unclear what effect higher oxygen levels may have had on animal life, the researchers said.
The study has been published in the journal Nature Geoscience.
Image credit: luisrsphoto, Shutterstock.com
Carbon emissions from plant respiration largely underestimated
Plant respiration contributes more to carbon emissions than previously thought, according to a new study from the Centre for Ecology & Hydrology. The scientists also found that global warming may weaken the ability of Earth’s surface to absorb emissions.
The researchers based their study on the comprehensive global trait database, which contains over 10,000 measurements of carbon dioxide plant respiration. The experts linked this data to computer models of global land carbon cycling.
“The study uses plant respiration data from over 100 remote sites around the world, from hot deserts in Australia, to the deciduous and boreal forests of North America and Europe, the arctic tundra in Alaska, and the tropical forests of South America, Asia, Africa and northern Australia,” said study co-author Owen Atkin.
The analysis revealed that plant respiration has been an underestimated source of carbon dioxide emissions. Carbon release by plant respiration worldwide was found to be as much as 30 percent higher than previously calculated.
The study also demonstrated that as global temperatures rise, respiration will increase significantly and vegetation will become less effective in absorbing carbon dioxide emissions triggered by fossil fuels.
“Plants both capture carbon dioxide and then release it by respiration,” explained lead author Chris Huntingford. “Changes to either of these processes in response to climate change have profound implications for how much ecosystems soak up carbon dioxide emissions from burning fossil fuels.”
Dr. Mary Heskel from the Ecosystems Center, Marine Biological Laboratory said, “We are now one-step closer to more accurately modelling carbon-exchange in ecosystems across the world. Indeed, the study provides the most informed picture to date of current and future carbon release from plants in terrestrial systems.”
The research is published in the journal Nature Communications.
How succulents are so efficient with water
New research on succulents could help boost crop production in drought-prone regions.
Succulents are an increasingly popular houseplant due to their incredible efficiency with water, which makes them especially easy to care for.
Succulents, cacti, and agaves are all considered drought-resistant because they use a special type of photosynthesis that conserves water called crassulacean acid metabolism (CAM).
Succulents and other CAM plants harvest carbon dioxide and stores it overnight. This stored CO2 is then used during photosynthesis the next day.
CAM photosynthesis is dependent on the plant’s internal circadian clock.
A new study conducted by plant scientists at the University of Liverpool examined this unique photosynthesis in succulents to see what genetic factors were at work during the CAM process.
For the study, the researchers focused on an enzyme called PPCK. PPCK is used to convert CO2 that is stored overnight into malic acid and then back to CO2 the next day. This process is integral to CAM photosynthesis.
The researchers were able to effectively switch off the PPCK gene in a succulent plant called Kalanchoë fedtschenkoi to see how this affected the CAM process.
Without PPCK, the succulent wasn’t able to perform the CAM process properly and only stored one-third of the CO2 that most other plants store.
The results also showed that switching off the PPCK gene interfered with the plant’s circadian clock.
The researchers were able to gain insight into the CAM process, but further research is necessary in order to fully understand the roles that CAM photosynthesis and the PPCK gene play in water conservation in CAM plants.
“Our work demonstrates that ongoing efforts to engineer CAM photosynthesis into other plants will need to include PPCK,” said Dr. James Hartwell, one of the authors of the study. “The unexpected complexity we revealed in the relationship between PPCK, CAM, and the circadian clock also highlights the need for continued research into CAM processes before we can fully understand and exploit their ways.”
The researchers hope by examining the CAM process further, it will help enhance global agriculture by producing crops that can thrive in hot, arid, regions.
Toxic algae is a growing threat in the United States
Algae is growing out of control across the United States, making people sick and even killing animals. Over the last ten years, toxic algae outbreaks have become a major environmental problem in every state, and the trend is likely to gain momentum as water temperatures rise.
In 2016, a state of emergency was declared in Florida and beaches were closed when algae blooms spread from Lake Okeechobee to surrounding streams. In Utah, over 100 people got sick after swimming in the lake, while 32 cows died from toxic algae on a ranch in Oregon.
According to scientists, monster blooms of algae are created by excessive agricultural fertilizer runoff into warm, calm waters. Chemicals and manure are washed into streams, lakes, and oceans.
Dead zones, areas starved of oxygen due to algae decay, are 30 times more prevalent since 1960. Every summer a dead zone appears in the Gulf of Mexico, and this year’s was the largest ever measured.
“It’s a big, pervasive threat that we as a society are not doing nearly enough to solve,” said University of Michigan environmental scientist Don Scavia. “If we increase the amount of toxic algae in our drinking water supply, it’s going to put people’s health at risk. Even if it’s not toxic, people don’t want to go near it. They don’t want to fish in it or swim in it. That means loss of jobs and tax revenue.”
Federal agencies have conducted billions of dollars worth of studies, but the findings of an analysis from the Associated Press (AP) suggest that the research has not helped matters much.
The AP found that the levels of algae-feeding nutrients are rising in many lakes and streams. The report also said that only a small minority of farms participate in federal programs that promote practices to reduce fertilizer runoff, and farmers are often turned away from funding because there is not enough money.
The U.S. Natural Resources Conservation Service reports spending $29 million on such voluntary programs since 2009, and says that 500,000 operations have participated.
The Environmental Protection Agency says indirect runoff is now the biggest source of water pollution in the United States, yet the Clean Water Act of 1972 prevents the government from regulating runoff as it does not release waste directly into waterways.
The government only asks farmers to volunteer to participate in safer practices regarding fertilizer runoff, such as planting cover crops and developing more efficient irrigation systems.
According to University of Florida wetland ecologist Mark Clark, farmers are free to use excessive fertilizer to produce higher yields with no consequences in place for allowing runoff.
Sparkling grass discovered in Australia tastes like potato chips
Researchers have identified a new species of grass that is covered in minute drops of liquid that make it sparkle. The grass, which is named Triodia scintillans, also tastes like potato chips, according to the scientists.
The species was found during a four-year research project conducted by PhD student Ben Anderson at the University of Western Australia. It is a type of spinifex, a tough grass that grows across nearly one-third Australian Outback.
Scientists became aware that the newly-discovered grass had unique properties during experimentation in Perth.
“We were doing late-night experiments, handling specimens of that species,” research scientist Matthew Barrett told ABC News. “Someone licked their hand at some point and tasted that flavor.”
“It looks pretty inconspicuous when you first get to it, but if you look at it very closely it has very, very minute sparkling droplets on the stems,” explained Barrett. “When you lick them, they taste like salt-and-vinegar chips.”
According to ABC, Barrett said the tiny droplets that give the spinifex its distinctive flavor is the liquid that makes the grass sparkle.
Because of its strength and special properties, spinifex has many commercial uses. Spinifex has already been used in the mining and condom industries, and scientists believe it has the potential to transform the plastic industry.
Dr. Barrett has been analyzing various types of spinifex in the the Australian Outback for 15 years. He explained that there are more than 30 species in the Pilbara region alone, and a total of 64 spinifex species across the outback. The sparkling grass is one of eight new species recently identified.
Image Credit: Thomas Schoch/Wikimedia Commons
This flower pretends to be a mushroom to attract insects
Aspidistra elatior is a popular houseplant nicknamed the “cast iron plant” for its resilience. Its unique pollination ecology was not understood until recently, when scientists discovered that this flowering plant is primarily pollinated by fungus gnats, which is likely due to the fact that it intentionally resembles a mushroom.
Prior to this analysis, experts thought that the flowers of A. elatior were pollinated in the most unusual way, by slugs and amphipods. Closer observation revealed this was not the case. Senior researcher Sueyoshi Masahiro of the Forest Zoology Group teamed up with Professor Suetsugu Kenji of Kobe University for the study.
Native to southern Japanese islands, A. elatior is characterized by purple, fleshy flowers which bloom directly above the soil, almost burrowing into the ground and often hidden by leaves. The researchers believe the oddly-shaped flowers of A. elatior are likely a strategy to mimic mushrooms in order to trick fungus gnats into pollinating them.
While many plants rely on pollinating insects that fly, some plants use animals for pollination. For example, there are species of bananas that are pollinated by bats.
Documentation that slugs pollinate A. elatior dates back 100 years, when slugs were observed visiting plants in Europe. Despite the fact that this theory is still widely accepted and reported in textbooks, the observation was not made in the plant’s natural habitat. In addition, slugs have been known to visit plants for reasons other than pollination such as eating leaves and flowers.
In 2009, it was claimed that fungus gnats were visiting A. elatior flowers. However, this observation was also made outside the plant’s native habitat and was only a single report that did not provide enough evidence. The research team took a new approach for their study.
“For two years we observed the animals that visited these flowers in their native habitat, continuously, day and night,” said the study authors. “We discovered that no slugs visited, and hardly any beach fleas. The candidate that emerged as an effective pollinator was the fungus gnat. Fungus gnats that visited the plants quickly dived into the center of the flowers, attached a large amount of pollen to their bodies, and flew away.”
The team also witnessed fungus gnats carrying pollen to A. elatior flowers from other flowers, and noted that the flowers they visited produced fruit. Therefore, the research team established that fungus gnats were the true pollinators of A. elatior.
“We believe that the similar appearance of A. elatior and mushroom fruit bodies may help attract fungus gnats,” said Professor Suetsugu. “In addition, A. elatior emits a strong musty odor. Therefore, the fungus gnats may be deceived by both visual and chemical mimicry.”
The findings of the study are published in the online edition of Ecology.
Image Credit: Kobe University
Trees grow faster in cities, study confirms
A study from the Technical University of Munich (TUM) is the first to confirm that trees in metropolitan areas have been growing faster worldwide. The research also points out that urban trees have been exposed to changing climate conditions for a long time, while trees in rural areas are only just beginning to be exposed to a changing climate.
“While the effects of climate change on tree growth in forests have been extensively studied, there is little information available so far for urban trees,” said co-author Hans Pretzsch.
The research team set out to investigate the growth of urban trees mainly due to the current trend toward global urbanization. According to the United Nations, the urban population worldwide is expected to increase by more than 60 percent by 2030. Trees already improve the environment in metropolitan areas, and the continuing upward trend in urbanization makes them even more significant in improving the health and well-being of city residents.
The team collected and analyzed tree samples from Berlin, Brisbane, Cape Town, Hanoi, Houston, Munich, Paris, Prince George, Santiago de Chile, and Sapporo for the study. The cities cover different climate zones, ranging from boreal to temperate, Mediterranean, and subtropical. Overall, the researchers examined nearly 1400 trees.
“We can show that urban trees of the same age are larger on average than rural trees because urban trees grow faster,” said Pretzsch.
Upon further analysis, the researchers established that the size difference between urban and rural trees decreases with age, yet it is still relevant.
“While the difference amounts to about a quarter at the age of 50, it is still just under 20 percent at a hundred years of age,” explained Pretzsch.
The researchers attribute the accelerated growth of urban trees to the heat island effect, which is the occurrence of higher temperatures in urban settings. Compared to the surrounding rural area, cities are hotter by as much as ten degrees Celsius. Higher temperatures affect the trees in two major ways – by stimulating photosynthetic activity and by extending their growing season.
The positive effect of faster-growing trees also comes with the negative aspect of more rapidly aging trees. According to Pretzsch, the sped-up life cycle means that cities will have to replace aging trees sooner.
The study, which is published in the journal Scientific Reports, is the first of its kind to examine the growth of urban trees worldwide for trends resulting from changing climate conditions.
Climate change altering plants and bird populations in Hawaii
Researchers at the U.S. Forest Service’s Pacific Southwest Research Station have been investigating the interactions between native birds and plants in Hawaii. Their study has revealed that seasonal changes in plants from year to year, which are heavily influenced by climate change, have an alarming impact on bird populations.
The scientists set out to examine the changes in bird abundance, breeding, and molting based on climate-induced alterations to vegetation. To do this, the team reviewed extensive data collected between 1976 and 1982 at a 40-acre monitoring site on Hawaii Island.
The experts established that “bottom-up processes” in the food chain strongly influence the survival rates of Hawaiian bird communities. The density of bird populations was frequently found to mirror the availability of their food sources.
“Our results suggest that changes in climate can cascade up the food chain and strongly affect wildlife at higher levels in the chain,” said lead author Jared Wolfe.
The researchers observed that three native bird species all timed their breeding season with the availability of specific flowers, which were abundant after periods of heavy rain. Similar correlations were found in other bird varieties, both native and non-native. The birds based breeding patterns on the accessibility of their flower or fruit food sources as well as the timing of molting, a physically demanding process by which the birds replace their feathers.
“The susceptibility of many Hawaiian birds to climatically-induced changes in their food web is alarming when considering that the archipelago has been subject to an increasingly drier climate during the last 30 years,” said Wolfe.
“These types of studies are rare because they depend on long-term data and labor-intensive field work,” said co-author C. John Ralph. “But findings from long-term studies, such as this one, are critically important because they provide insights into how changes in climate might affect organisms in seemingly indirect ways.”
The study is published in this month’s issue of Ecology.
Ayahuasca may be effective treatment for alcoholism, depression
Researchers have found that a psychedelic drug called Ayahuasca that is often used in the Amazon region gives people an improved sense of wellbeing, and may be an effective treatment for alcoholism and depression.
Ayahuasca is a potent brew used in healing ceremonies as a spiritual medicine that contains dimethyltryptamine (DMT), a psychedelic drug. DMT is classified as a Schedule 1 drug in the United States and is illegal in almost every country.
A growing collection of research suggests that psychedelic drugs such as magic mushrooms and LSD can help treat alcoholism and depression. Researchers from the University of Exeter and University College London analyzed Global Drug Survey data from more than 96,000 people worldwide to examine the potential therapeutic benefits of ayahuasca.
The study revealed that ayahuasca users reported significantly lower alcohol issues than people who took LSD or magic mushrooms. In addition, those who took ayahuasca reported higher overall well-being in the year leading up to the survey.
“These findings lend some support to the notion that ayahuasca could be an important and powerful tool in treating depression and alcohol use disorders,” said lead author Dr. Will Lawn. “Recent research has demonstrated ayahuasca’s potential as a psychiatric medicine, and our current study provides further evidence that it may be a safe and promising treatment.”
Dr. Lawn pointed out that ayahuasca users still reported high drinking levels, and that further research is needed “to fully examine ayahuasca’s ability to help treat mood and addiction disorders.” He added that, this study is still important because it is most likely “the largest survey of ayahuasca users completed to date.”
The acute effects of ayahuasca last around six hours, and are felt most intensely one hour after ingestion. Most people surveyed reported taking the drug with a healer or a shaman.
“If ayahuasca is to represent an important treatment, it is critical that its short and long-term effects are investigated, and safety established,” said senior author Celia Morgan.
Of the survey participants, 527 were ayahuasca users, 18,138 used LSD or magic mushrooms, and 78,236 did not take psychedelic drugs.
“In this work, long-term ayahuasca use has not been found to impact on cognitive ability, produce addiction or worsen mental health problems,” said Morgan. “In fact, some of these observational studies suggest that ayahuasca use is associated with less problematic alcohol and drug use, and better mental health and cognitive functioning.”
The study is published in the Nature journal Scientific Reports.
Let nature take its course: Regeneration restores biodiversity
Letting nature take its course might be the best way for restoring biodiversity in tropical forests, as a new study has found that nature bests human intervention at recovering native tree species.
Previous research has often asserted that human intervention was needed to recover habitat and tree loss in forests. Active intervention methods like planting trees and limiting deforestation through policy-change were thought to be pivotal ways to recover habitat loss.
However, new research conducted by Renato Crouzeilles, an expert in the fields of landscape ecology and restoration, shows that natural regeneration in tropical forests is more effective and impactful than active intervention.
The number of previous studies that focus on efficient forest restoration methods is limited, and the results often contradictory.
Crouzeilles wanted to investigate if an active intervention was, in fact, the best way to recover tropical forests.
For the study, a team of researchers conducted a meta-analysis of 133 different studies, examining the recovery of biodiversity and forest restoration in different sites that had either used active recovery methods or natural regeneration.
Surprisingly, natural regeneration was more effective at restoring biodiversity and increasing plant growth compared to those sites that had used active interventions.
The results, published by the American Association for the Advancement of Science, show that natural regeneration can be a powerful tool in recovering tropical rainforests. However, the researchers also note that some forests may need a combination of both active intervention and natural restoration to fully recover its biodiversity.
Image Credit: Robin L. Chazdon
Cover crops help moderate soil temperature
The quality of soil is an incredibly important factor in the sustained, healthy growth of our crops. Soil quality can make or break a farmer’s crop yield and the very value of the land it sits on. Characteristics such as the content of organic matter and the moisture of the soil play vital roles in helping plants grow. Now, researchers have found that soil temperature is also of the utmost importance.
Plants rely on certain consistent soil temperatures in order to grow. “Most plants are sensitive to extreme changes in soil temperature,” says Samuel Haruna, a researcher at Middle Tennessee State University. “You don’t want it to change too quickly because the plants can’t cope with it.”
The ability of soil to buffer against temperature change is dependent on a variety of factors. How much the soil is compacted is just one of those factors.
Compacted soil actually causes the soil particles to transfer temperatures much faster, thus increasing temperature change. This can be caused by farmers dragging heavy machinery over the soil – which must happen often, as you can imagine. However, research has shown that cover crops and perennial biofuel crops help relieve soil compaction and moderate temperature.
Haruna set out to determine if these cover crops and perennial biofuel crops could also help soils protect themselves against fluctuating temperatures. He and a team of researchers grew multiple types of these crops in the field and then tested the soil in the lab for its ability to regulate temperature.
“I was amazed at the results,” says Haruna. The team found that both cover crops and perennial biofuel crops help soils become better buffers against extreme temperatures by slowing down how quickly temperatures spread through the soil. The roots of these crops break up the soil, preventing soil molecules from clumping together and compacting. These roots also add organic matter to the soil, which is an additional benefit in temperature regulation.
Furthermore, perennial biofuel and cover crops help soil retain moisture, which keeps soils from heating up too quickly as water itself is a heat buffer.
“Water generally has a high ability to buffer against temperature changes,” explains Haruna. “So if soil has a high water content it has a greater ability to protect the soil.”
Major temperature fluctuations are in our future as climate change becomes more prominent around the world. Haruna believes that increasing the use of cover crops may help to lessen the effects of climate change on soil quality and ultimately crop production. He looks to continue this research with more field experiments in the future.