Monday, July 10, 2023

Study results show lead hunting ammunition hinders bald eagle recovery, resiliency


Peer-Reviewed Publication

MORRIS ANIMAL FOUNDATION

Bald eagle in flight 

IMAGE: A RECENTLY PUBLISHED PAPER FOUND THAT, DESPITE THE RESURGENCE OF BALD EAGLE POPULATIONS, EXPOSURE TO LEAD AMMUNITION FRAGMENTS IN WILD GAME GUT PILES AND CARCASS PARTS IS NOT ONLY SICKENING AND KILLING BALD EAGLES BUT ALSO IS MAKING THE BIRDS MORE SUSCEPTIBLE TO OTHER DANGERS. view more 

CREDIT: EEI_TONY




Denver/July 6, 2023 – A new published paper in the journal Wildlife Society Bulletin states that, despite the resurgence of bald eagle populations, exposure to lead ammunition fragments in wild game gut piles and carcass parts is not only sickening and killing bald eagles but also is making the birds more susceptible to other dangers.

“Bald eagles are an iconic American species,” said Krysten L. Schuler, the principal investigator of the Morris Animal Foundation-funded study and Assistant Research Professor at Cornell University. “Despite the apparent population rebound through major conservation efforts, our work showed that environmental lead sickens and kills bald eagles to such a degree that it makes the populations vulnerable to other threats such as avian influenza or wind energy development.”

Schuler highlighted the innovative methodology used for the study, developed by mathematician Brenda Hanley, who specializes in population demographics. Using data from seven Northeastern states, the research ultimately illustrated that lead poisoning has not stopped eagle recovery but affects their ability to withstand additional threats.

Schuler acknowledged the vital support from the Foundation, which enabled researchers to hire Hanley and develop the new modeling tool required to address these complex issues, particularly where data is limited.

Kevin Hynes, a wildlife biologist for the New York Division of Fish and Wildlife and a researcher involved in the study, noted that lead poisoning has long been recognized as a common cause of eagle deaths, accounting for more than 10% of eagle fatalities. However, thanks to the new modeling approach, researchers now know that lead is also hindering continued growth of eagle populations.

“This is an environmental problem with a currently available and low-tech solution: A simple switch to non-lead ammunition for hunting will eliminate lead ammunition fragments in gut piles and carcass parts, making them unavailable to eagles and other scavengers,” Hynes said.

About Morris Animal Foundation
Morris Animal Foundation’s mission is to bridge science and resources to advance the health of animals. Founded in 1948 and headquartered in Denver, it is one of the largest nonprofit animal health research organizations in the world, funding more than $149 million in nearly 3,000 critical studies across a broad range of species. Learn more at morrisanimalfoundation.org.

Media Contact: Annie Mehl

Deciphering the association between uterine microbiota and fertility in dairy cows


Researchers examine the association between uterine microbiota and fertility in dairy cows


Peer-Reviewed Publication

OKAYAMA UNIVERSITY

Does the microbial flora in the uterus determine fertility in cows? 

IMAGE: LOW FERTILITY CAN CAUSE SIGNIFICANT ECONOMIC LOSSES IN DAIRY FARMS. RESEARCHERS FROM JAPAN INVESTIGATE HOW MICROBIAL POPULATIONS IN THE UTERUS OF DAIRY COWS MAY BE LINKED TO THEIR FERTILITY FOLLOWING ARTIFICIAL INSEMINATION, AND PROPOSE MICROBIOME TESTING AS A POTENTIAL STRATEGY TO DIAGNOSE UNEXPLAINED INFERTILITY IN DAIRY COWS view more 

CREDIT: TAKUYA YAGISAWA AND JUMPEI UCHIYAMA, OKAYAMA UNIVERSITY, JAPAN




Reduced fertility prolongs the interval from calving to conception in dairy cows, resulting in significant economic losses to dairy farms. Up to 25% of cows are culled due to reproductive failure, and this accounts for a larger proportion than that caused by other major factors, including mastitis and lameness.

A variety of factors are considered to cause low fertility in cows, including farm management factors like estrus detection, nutritional control, and cowshed environment, as well as cow-specific factors like reproductive tract infections, endocrine disorders, and defective ova. However, there are cases of low fertility where the cause is undetermined, which results in economic losses. Identifying the factors associated with low fertility may help in the development of effective future strategies for improving reproductive performance in dairy farms.

Although the uterus has long been thought to be free of microbes, advancements in next-generation sequencing technology have revealed the existence of ‘uterine microbiota,’ unique to the uterine environment. Many studies on uterine microbiota have been conducted in humans, and fertility has been confirmed to vary according to the diversity of the uterine microbial population.

Could this knowledge be extended to reared animals?

To find out, Mr. Takuya Yagisawa, Section Chief at the Hokkaido Agriculture Mutual Aid Association, Japan, and Dr. Jumpei Uchiyama, Associate Professor at Okayama University, Japan, along with their teams of researchers, collaborated to investigate the association between low fertility and uterine microbiota in dairy cows.

Dairy farms set a voluntary waiting period (VWP) between calving and the first artificial insemination (AI; the procedure of injecting semen into the uterus) as a period for uterine involution in preparation for the next pregnancy. In cows, while the uterine microbiota has been studied in terms of postpartum uterine inflammation, little is understood about its association with fertility following the VWP. This is where the new study comes in.

Giving further insights into their work, Mr. Yagisawa states, “We used a metataxonomic approach to analyze the uterine microbiota using endometrial tissue biopsy samples from dairy cows.”

The team, which comprised Iyo Takemura-Uchiyama (Postdoctoral Fellow, Okayama University), Shun Ando (Assistant Section Chief, Hokkaido Agriculture Mutual Aid Association), Osamu Ichii (Associate Professor, Hokkaido University), Hironobu Murakami (Associate Professor, Azabu University), Osamu Matsushita (Professor, Okayama University), and Seiji Katagiri (Professor, Hokkaido University), used 16S rRNA gene amplicon sequencing to identify the various types of bacteria present in the sampled uterine tissues. Next, microbiota data obtained from 69 cows bred on four commercial dairy farms were analyzed. The researchers then compared the microbial diversity of the samples with respect to the farm, housing style, and feeding management practices. Further, they went on to correlate the uterine microbiota data with parity (the number of deliveries) and the frequency of AI to conception for each cow.

The findings of their study have been published in Microbiology Spectrum on April 26, 2023.

The findings revealed significant differences in farm management-related factors (i.e., housing style and feeding management) across the four farms. Notably, while these differences correlated with variations in uterine microbiota, no significant differences were observed with respect to AI frequency as related to conception and parity.

Next, to eliminate the effects of variations in farm management practices among farms, the researchers examined the correlation between fertility and uterine microbiota using data obtained from 31 cows from a single dairy farm. Cows that conceived within 3 AIs were considered to have normal fertility, and cows that needed more than 3 AIs were considered to have low fertility.

The data obtained in this study strongly suggests that uterine microbiota changes in relation to the fertility of cows. Microbial diversity correlates with AI frequency to conception, and the bacterial taxon Arcobacter was observed to increase its compositional rates. Furthermore, bacterial associations differed between normal- and low-fertility cows.

Overall, these findings suggest that farm-to-farm variations can have a major influence on the diversity of uterine microbiota in dairy cows. Moreover, the composition of uterine microbiota changes in relation to fertility in cows.

Dr. Uchiyama concludes with the applications of their work by saying, “We hope that further research will establish uterine microbiome testing as a new approach to diagnosing the causes of low fertility and contribute to improved reproductive management in animal husbandry.”
 

About Okayama University, Japan
As one of the leading universities in Japan, Okayama University aims to create and establish a new paradigm for the sustainable development of the world. Okayama University offers a wide range of academic fields, which become the basis of the integrated graduate schools. This not only allows us to conduct the most advanced and up-to-date research, but also provides an enriching educational experience.
Website: https://www.okayama-u.ac.jp/index_e.html


About Mr. Takuya Yagisawa and Dr. Jumpei Uchiyama

Mr. Takuya Yagisawa is a section chief at the Hokkaido Agriculture Mutual Aid Association, Japan. He is a clinical veterinarian specializing in cows. Along with his daily clinical practice, he is interested in studying the uterine microbiota of dairy cows and its associations with fertility; and the use of antibiotics in conditions like mastitis and uterine inflammation in cows. He has published peer reviewed articles in these subject areas.

Dr. Jumpei Uchiyama is an Associate Professor in the Department of Bacteriology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University. His research interests include Applied Microbiology, Veterinary Medicine, Genetics, Bacteriology, and Infectious Diseases. He has over 130 publications to his credit, all published in peer reviewed journals of repute.
 

Researchers discover drug-resistant, often deadly pathogen living in dogs’ ears, creating concern it may jump to humans


Peer-Reviewed Publication

MCMASTER UNIVERSITY

Jianping Xu 

IMAGE: JIANPING XU, A LEAD AUTHOR ON THE PAPER AND A PROFESSOR IN THE DEPARTMENT OF BIOLOGY AT MCMASTER UNIVERSITY. view more 

CREDIT: MCMASTER UNIVERSITY




Hamilton, ON, July 7, 2023 – Scientists at McMaster University and India’s University of Delhi have discovered and isolated the first live culture of the drug-resistant pathogen Candida auris from an animal, specifically from the ear canals of stray dogs.

The finding suggests pets could act as reservoirs for superbugs, potentially transmitting infections to humans.

First reported in Japan in 2009, C. auris, is a type of yeast which has since spread all over the world.

The emerging fungus can cause persistent and severe infections and widespread outbreaks in hospitals. Antifungal medications often do not work against it and more than one in three patients with serious, invasive infections will die, according to some estimates.

The World Health Organization has declared it one of the world’s four ‘critical priority’ fungal pathogens.

For a study published online in the Journal of Fungi, researchers tested skin and ear swab samples from 87 dogs housed in a shelter in Delhi. Of those, 52 were strays already under intensive care for severe lesions due to chronic skin diseases. The remaining 35 dogs were household pets treated for minor gastrointestinal and urinary infections. The subjects’ conditions were not related to the pathogen under study.

The swabs were analyzed for bacteria and fungi cultures using routine diagnostic protocols for skin and ear infections.  Researchers found evidence of C. auris within the ear canals of four of the animals with chronic skin infections.

“Dogs are common pets. Even though C. auris was only found in stray dogs in this study, there are many stray dogs in many parts of the world. These dogs could act as transmission vehicles for C. auris to reach other animals and humans,” says Jianping Xu, a lead author on the paper and a professor in the Department of Biology at McMaster University. He is also an investigator with the university’s Global Nexus School for Pandemic Prevention & Response.                        

While fungi are significant pathogens for animals, no live culture of C. auris had previously been isolated. 

A DNA analysis pointed to genomic similarities between some of the strains found in the dogs and those found in humans, providing further evidence that the spread of infection to other animals and humans is a risk.

 “We need to be vigilant in the surveillance of dogs, other domesticated pets and wild animals in regions where C. auris is endemic,” says Xu. “While C. auris spreads easily from human to human, the route of transmission among animals or from animals to humans is much less clear and further investigation is required.” 

When humans are infected with C. auris, inanimate objects in the environment are readily contaminated by the shedding of skin scales. Because the yeast was found within the ear canal of the dogs, versus exposed skin, shedding in the immediate environment was reduced, containing the spread of infection.

C. auris has also been discovered on the surface of stored apples, in tidal marshes, in environments with extremely high salinity and, recently, in wastewater, suggesting it can survive in harsh conditions. 

Ticks may be able to spread chronic wasting disease between Wisconsin deer

Peer-Reviewed Publication

UNIVERSITY OF WISCONSIN-MADISON

allogrooming camera capture 

IMAGE: A WILDLIFE CAMERA CAPTURES DEER PRACTICING ALLOGROOMING — GROOMING ONE ANOTHER TO GET PLACES THAT THEY CAN’T REACH ON THEIR OWN. DURING ALLOGROOMING, DEER MAY EAT TICKS THAT CONTAIN CWD-INFESTED BLOOD. SUBMITTED PHOTO view more 

CREDIT: UNIVERSITY OF WISCONSIN–MADISON



Madison ­— A new study from researchers at the University of Wisconsin–Madison finds that ticks can harbor transmissible amounts of the protein particle that causes Chronic Wasting Disease (CWD), implicating the parasites as possible agents in the disease’s spread between deer in Wisconsin. Her findings were published in the journal Nature.

 

            CWD is caused by a pathogenic agent called a prion, which can pass from deer-to-deer through contact with things like prion-contaminated soil and infected bodily fluids such as urine, saliva, blood and feces. Prions, which cause disease in animals and in humans, prompt certain proteins to fold abnormally, particularly in the brain, and prevent these proteins from carrying out their normal functions. Over time, the CWD prion can cause severe brain damage and eventually death in deer.

            A lot of CWD studies focus on the role soil plays in spreading the fatal neurological disease among deer. But Heather Inzalaco, a researcher in the Wisconsin Cooperative Wildlife Research Unit, housed in the UW–Madison Department of Forest and Wildlife Ecology, was curious about other potential environmental and behavioral means of transmission.

            “Deer live these secret lives; we don't see everything that they do,” Inzalaco says.

She started to consider what sort of things pester deer that could be connected to CWD: Ticks were the perfect parasitic potential culprit to investigate.

Ticks have a goal, of course, to feed on their host’s blood. Inzalaco began to wonder if ticks that acquire blood from CWD-infected deer could also host the prions and if so, could they contain enough prions to spread the disease.

            The question became even more intriguing when she discovered that the most common non-aggressive social behavior that deer engage in is allogrooming.

“Deer will groom one another to get places that they can't reach on their own through self-grooming,” Inzalaco says. “If they're grooming each other and they're doing that to remove ectoparasites [such as ticks], that might be problematic because they're probably eating the ectoparasites.”

            First, she needed to show that ticks can take up and harbor these prions when they feed on CWD-infected blood. She designed an experiment to do just that.

            “You'd think that it'd be easy to get ticks to take a blood meal, but they are surprisingly fussy in the lab,” Inzalaco says.

            She was able to determine that ticks can not only carry the prions in their blood meal, they can also carry enough of the agent to potentially infect another animal with CWD. After seeing that the phenomenon was possible in the lab, it was time to see what was happening in the wild.

            Inzalaco partnered with the Department of Natural Resources to study ticks collected from deer that hunters harvested and submitted for CWD testing. Of the 176 deer with ticks she studied, 15 of the deer were also positive for CWD. Inzalaco took the ticks from the infected deer and tested the blood they contained to quantify the amount of prion the ticks harbored.

            She determined that these engorged, wild ticks did carry transmissible levels of prions — just like those in the lab — making them potential mechanical vectors for the disease.

“They're just like a little CWD tic-tac that are possibly being eaten by the deer,” Inzalaco says.

The study did not test whether prion-carrying ticks did cause transmission to other deer.

Understanding more about how CWD can spread can help improve the management of the disease. While it isn’t practical to treat all wild deer with tick preventatives, Inzalaco believes better land stewardship could help manage tick populations.

For instance, having contiguous habitat of native plant communities and properly managing areas to continue a natural fire regime has been shown to limit tick populations, she says, while more fragmented, unbalanced ecosystems riddled with invasive plants may allow ticks to proliferate more readily.

Inzalaco says  it might be possible to use ticks as a way to screen for CWD in both wild and farmed deer. Current methods of diagnosis or screening involve invasive sample collection from animals or tissue sampling after their death. While testing the ticks from deer may not lead to the same level of accuracy as testing tissue samples, it could still be a useful tool to better understanding where the disease is affecting deer population in the state.

Inzalaco also believes her research can help improve the ecosystems that everyone relies on, especially the state’s hunters.

“We are all inextricably linked to ecosystem function and the biodiversity of those ecosystems,” she says. “That is really what drives my desire to learn and do good science on a daily basis. We need to make an effort to preserve our natural heritage so that we can continue living on this planet and not be overtaken by disease and have healthy animals and healthy functioning ecosystems.”

---Elise Mahon, etmahon@wisc.edu

Disclaimer: AAA

Uncovering secrets of plant regeneration


Japanese researchers identify how the fate of regenerating plant cells is negatively controlled by the WOX13 gene and how this can impact shoot regeneration efficiency

Peer-Reviewed Publication

NARA INSTITUTE OF SCIENCE AND TECHNOLOGY

IMAGE 

IMAGE: MUTUALLY REPRESSIVE WOX13 AND WUS PLAY KEY ROLES IN CELL FATE SPECIFICATION OF PLURIPOTENT CALLUS CELLS. SCHEMATIC ILLUSTRATION OF THE REGULATORY MECHANISMS (LEFT) AND SPATIAL EXPRESSION PATTERNS OF WOX13 AND WUS IN CALLUS CELL POPULATION (RIGHT). view more 

CREDIT: MOMOKO IKEUCHI




Ikoma, Japan – Plants have the unique ability to regenerate entirely from a somatic cell, i.e., an ordinary cell that does not typically participate in reproduction. This process involves the de novo (or new) formation of a shoot apical meristem (SAM) that gives rise to lateral organs, which are key for the plant’s reconstruction. At the cellular level, SAM formation is tightly regulated by either positive or negative regulators (genes/protein molecules) that may induce or restrict shoot regeneration, respectively. But which molecules are involved? Are there other regulatory layers that are yet to be uncovered?

To seek answers to the above questions, a research group led by Nara Institute of Science and Technology (NAIST), Japan studied the process in Arabidopsis, a plant commonly used in genetic research. Their research—which was published in Science Advances—identified and characterized a key negative regulator of shoot regeneration. They demonstrated how the WUSCHEL-RELATED HOMEOBOX 13 (WOX13) gene and its protein can promote the non-meristematic (non-dividing) function of callus cells by acting as a transcriptional (RNA-level) repressor, thereby impacting regeneration efficiency.

“The search for strategies to enhance shoot regeneration efficiency in plants has been a long one. But progress has been hindered because the related regulatory mechanisms have been unclear. Our study fills this gap by defining a new cell-fate specification pathway,” explains Momoko Ikeuchi, the principal investigator of this study.

Previous studies from her team had already established the role of WOX13 in tissue repair and organ adhesion after grafting. Hence, they first tested the potential role of this gene in the control of shoot regeneration in a wox13 Arabidopsis mutant (plant with dysfunctional WOX13) using a two-step tissue culture system. Phenotypic and imaging analysis revealed that shoot regeneration was accelerated (3 days faster) in plants lacking WOX13, and slower when WOX13 expression was induced. Moreover, in normal plants, WOX13 showed locally reduced expression levels in SAM. These findings suggest that WOX13 can negatively regulate shoot regeneration.

To validate their findings, the researchers compared the wox13 mutants and wild-type (normal) plants using RNA-sequencing at multiple time points. The absence of WOX13 did not considerably alter Arabidopsis gene expression under callus-inducing conditions. However, shoot-inducing conditions significantly enhanced the alterations induced by the wox13 mutation, leading to an upregulation of shoot meristem regulator genes. Interestingly, these genes were suppressed within 24 hours of WOX13 overexpression in mutant plants. Overall, they found that WOX13 inhibits a subset of shoot meristem regulators while directly activating cell wall modifier genes involved in cell expansion and cellular differentiation. Subsequent Quartz-Seq2-based single cell RNA sequencing (scRNA-seq) confirmed the key role of WOX13 in specifying the fate of pluripotent callus cells.

This study highlights that unlike other known negative regulators of shoot regeneration, which only prevent the shift from callus toward SAM, WOX13 inhibits SAM specification by promoting the acquisition of alternative fates. It achieves this inhibition through a mutually repressive regulatory circuit with the regulator WUS, promoting the non-meristematic cell fate by transcriptionally inhibiting WUS and other SAM regulators and inducing cell wall modifiers. In this way, WOX13 acts as a major regulator of regeneration efficiency. “Our findings show that knocking out WOX13 can promote the acquisition of shoot fate and enhance shoot regulation efficiency. This means that WOX13 knockout can serve as a tool in agriculture and horticulture and boost the tissue culture-mediated de novo shoot regeneration of crops,” concludes Ikeuchi.

###

Resource

Title: WUSCHEL-RELATED HOMEOBOX 13 suppresses de novo shoot regeneration via cell fate control of pluripotent callus

Authors: Nao Ogura, Yohei Sasagawa, Tasuku Ito, Toshiaki Tameshige, Satomi Kawai, Masaki Sano, Yuki Doll, Akira Iwase, Ayako Kawamura, Takamasa Suzuki, Itoshi Nikaido, Keiko Sugimoto, Momoko Ikeuchi

Journal: Science Advances

DOI: 10.1126/sciadv.adg6983

Information about the Plant Regeneration and Morphogenesis Laboratory can be found at the following website: https://bsw3.naist.jp/eng/courses/courses117.html

 

About Nara Institute of Science and Technology (NAIST)

Established in 1991, Nara Institute of Science and Technology (NAIST) is a national university located in Kansai Science City, Japan. In 2018, NAIST underwent an organizational transformation to promote and continue interdisciplinary research in the fields of biological sciences, materials science, and information science. Known as one of the most prestigious research institutions in Japan, NAIST lays a strong emphasis on integrated research and collaborative co-creation with diverse stakeholders. NAIST envisions conducting cutting-edge research in frontier areas and training students to become tomorrow's leaders in science and technology.

Top corn producing state to see future drop in yield, cover crop efficiency


Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES

Cover crops may be less effective in future climates 

IMAGE: IN A NEW STUDY, UNIVERSITY OF ILLINOIS RESEARCHERS FORECASTED THE EFFECTS OF ILLINOIS CLIMATE CHANGE, FINDING A DECLINE IN CORN YIELD, AN INCREASE IN NITRATE LOSSES, AND A DECREASE IN THE EFFICIENCY OF COVER CROPS TO REDUCE THOSE LOSSES. THE RESEARCHERS SAY ADDITIONAL BEST MANAGEMENT PRACTICES WILL BE NEEDED TO REDUCE NITRATE LOSSES IN THE FUTURE. view more 

CREDIT: LAUREN QUINN, UNIVERSITY OF ILLINOIS



URBANA, Ill. — Winter cover crops could cut nitrogen pollution in Illinois’ agricultural drainage water up to 30%, according to recent research from the University of Illinois Urbana-Champaign. But how will future climate change affect nitrogen loss, and will cover crops still be up to the job? A new study investigating near- and far-term climate change in Illinois suggests cover crops will still be beneficial, but not to the same degree. The report also forecasts corn and soybean yield across the state, finding corn will suffer much more than soybean, especially in southern regions. 

In their earlier study, the research team adapted a crop simulation model known as Decision Support System for Agrotechnology Transfer (DSSAT) to estimate how efficiently cereal rye could remove nitrate from tile drainage water if planted widely across Illinois. In their new study, the team used DSSAT again to forecast growth of cereal rye, as well as corn and soybean, in the near-term (2021-2040) and far-term (2041-2060) under two climate scenarios for Illinois: a best-case-scenario and a business-as-usual case. 

The team took a piecemeal approach, modeling each component of the system separately before combining them into a holistic prediction for the impact of cover crops under climate change. 

To start, they modeled climate impacts on cash crop yield and cover crop biomass. Corn yield decreased in most Illinois regions, future timeframes, and climate scenarios, with average yield coming in 11.5% below to 3.8% above present averages. Soybean yield, however, mostly increased across regions and scenarios, with yields forecasted up to 27.5% higher than present averages. Finally, the model predicted cover crop biomass would boom as a result of climate change, with increases between 25% and 103% beyond current figures.  

“Corn and soybean are two completely different kinds of crop, which is reflected in our results. The change in yield is due to multiple factors. Apart from the projected increase in temperature, the yield response is affected differently for each crop by changes in rainfall patterns and elevated CO2 levels in the future. We also found cover crops strongly benefit from warmer winter weather,” said study co-author Rabin Bhattarai, associate professor in the Department of Agricultural and Biological Engineering, a shared unit of the College of Agricultural, Consumer and Environmental Sciences (ACES) and The Grainger College of Engineering at Illinois. 

Looking at nitrogen loss under climate change, the team predicted 24% greater loss in the near-term future, rising to about 42% by 2060. 

“Warmer soil means microbes will be more active in converting nitrogen in organic matter to ammonium and then to nitrate in the soil. And if you have more nitrate in the soil, the potential for loss is higher,” Bhattarai said. “We already see high nutrient losses during warm, wet springs, even before crops are planted or fertilizer is applied. That nitrogen is escaping from the soil itself.” 

With these baselines established, the researchers began making connections. First, they looked at the impact of cover crops on cash crop yield. In their previous DSSAT study, the researchers found growing cereal rye before corn and soybean had a slightly positive effect on yield. According to Bhattarai, cover crops slowly scavenge soil nitrogen throughout the winter and return the nutrient to the crop, providing a growth boost, when terminated and incorporated into the soil. 

Under climate change, hungry swards of cover crops could deplete both soil water and nitrogen, even accounting for greater nitrogen availability predicted during warmer winters. Then, at termination, the sheer amount of cover crop biomass could overwhelm the mineralization apparatus of the soil, keeping some nitrogen locked up and unavailable for cash crops. However, although the yield benefit disappeared under future climate scenarios, the analysis did not reveal a yield penalty for growing cover crops.

“Whether you use cover crops or not, you're going to see a decline in corn yield in the future. The same applies to soybean. You may gain soybean yield whether or not cover crops are present,” Bhattarai said. “If you see any impact on the cash crop yield, it's not due to the cover crop, it's due to the changing climate.” 

Finally, the team looked at cover crop impact on nitrogen loss under climate change. Relative to current conditions in which cover crops reduce tile drainage nitrogen by about 30%, cover crops are likely to become less effective under future scenarios, with as low as 11% reduction under far-term worst-case-scenario predictions. 

“You don't get the same benefit that you get now. You will see better growth of cover crops with the warmer temperatures, but mineralization will overtake their ability to take up nitrogen; more supply than demand,” Bhattarai said. “Cover crops will help; they will still be effective at reducing loss. But the efficiency will drop.”

 He added that farmers will have to augment cover crops with additional best management practices to meet nutrient loss reduction goals in the face of a changing climate. 

The study, “Sustainability of cover cropping practice with changing climate in Illinois,” is published in the Journal of Environmental Management [DOI: 10.1016/j.jenvman.2023.117946]. Authors include Rishabh Gupta, Rabin Bhattarai, Hamze Dokoohaki, Shalamar Armstrong, Jonathan Coppess, and Prasanta Kalita. The research was supported by the Illinois Nutrient Research and Education Council (NREC) [project #017–3-360574–222]. Partial support was also provided by the USDA National Institute of Food and Agriculture.

Bezos Earth Fund grants $12 million to Smithsonian to support major forest carbon project


Science-based carbon storage biomass verification

Grant and Award Announcement

SMITHSONIAN TROPICAL RESEARCH INSTITUTE

Measuring 2.jpg 

IMAGE: THE GEO-TREES PROJECT WILL PROVIDE HIGHLY ACCURATE ESTIMATES OF THE CARBON STORED BY DIFFERENT FORESTS AROUND THE GLOBE BASED ON ON-THE-GROUND TREE MEASUREMENTS, WITH TERRESTRIAL AND AERIAL LASER SCANS (LIDAR). view more 

CREDIT: CREDIT: JORGE ALEMAN, STRI




By conserving and replanting forests, the world buys time until it brings other climate and sustainability solutions online. As a critical step toward this goal, the Smithsonian Tropical Research Institute (STRI) received a $12 million grant from the Bezos Earth Fund to support GEO-TREES. This international consortium is the first worldwide system to independently ensure the accuracy of satellite monitoring of forest biomass—a way to measure carbon stored in trees—in all forest types and conditions. The GEO-TREES alliance offers a freely accessible database that integrates on-the-ground measurements of individual trees with terrestrial and aerial laser scans (LiDAR) of forests—a highly accurate way to verify forest carbon estimates based on satellite images.

“The GEO-TREES project is as exciting as it is essential for our detailed understanding of the interplay between tropical forests and carbon capture,” said Smithsonian Secretary Lonnie Bunch. “Scientific research has been at the heart of the Smithsonian’s mission for more than 176 years, and the grant from the Bezos Earth Fund demonstrates the value of support and collaboration in the search for solutions to our planet’s shared challenges.”

“The Bezos Earth Fund is pleased to support and partner on this powerful project to use decades of long-term data to understand forest carbon,” said Cristián Samper, managing director and leader for nature solutions at the Bezos Earth Fund. “There are very few places like the Smithsonian Tropical Research Institute, where the tropical rainforest has been studied for 100 years. The longevity of tropical research at the Smithsonian, together with the expansion of a global network of forest study sites, will help address the climate crisis we face in a way not possible anywhere else.”

At the heart of the GEO-TREES system is the Smithsonian’s ForestGEO network, directed by STRI staff scientist, Stuart Davies, working closely with partners around the globe. With 40 years’ experience rooted in the tropics, ForestGEO is the most extensive, long-term, large-scale, forest-monitoring network in the world, representing researchers at 76 study sites in 29 countries. The ForestGEO project is distinguished by its emphasis on partnership, incorporating the need for data with local conservation and management goals.

Space agencies worldwide are putting satellites into orbit to image forests in real time, but for scientists to verify carbon-storage numbers from these images, they must calibrate the satellite measurements against high-quality ground-based measurements. To gather high-quality measurements, scientists are intensively studying forest biomass reference sites in mature and younger forests, leveraging several partner forest-plot networks.

Most of the grant will be spent in tropical countries—many of them middle- and low-income—not only for data collection, but to strengthen capacity for local stakeholders and early-career scientists. This effort will enable them to combine field data collection with cutting-edge technology to monitor and evaluate the carbon stored in their forests.

“Tropical forests are the most important, best-understood, carbon-capture devices in the world,” said Joshua Tewksbury, director of STRI, which will administer the funds via its ForestGEO program. “But to make large-scale carbon capture a reality, we need to engage all sectors of society. And we can only do that if we can clearly show where the carbon is—and how carbon stocks change in real time, at scales that landowners, countries and investors care about. The Smithsonian, with hundreds of partners around the world, has taken on the challenge of providing the definitive ground-based global forest database to make this work possible.”

Each tree species in the world is unique: a balsa tree’s soft wood stores much less carbon than an ebony or rosewood tree’s dense wood. The age of each forest and the species present—which vary wildly from place to place—affect how much carbon is stored. Trees absorb different amounts of carbon on sunny days compared with cloudy days, and carbon storage depends on available water and nutrients. Thus, quantifying the biomass of complex forests requires significant expertise.

“The Smithsonian recently launched Life on a Sustainable Planet, which harnesses all Smithsonian resources to focus on solutions for our changing planet,” said Ellen Stofan, Under Secretary for Science and Research at the Smithsonian Institution. “The GEO-TREES project is a major component of that effort, and this grant from the Bezos Earth Fund helps us take a significant step forward in strengthening connections between people and nature.”

STRI, headquartered in Panama City, Panama, is a unit of the Smithsonian. The institute furthers the understanding of tropical biodiversity and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems. Watch STRI’s video and visit the institute on its website and on FacebookTwitter and Instagram for updates.

Tropical forests pull carbon dioxide out of the atmosphere where it causes global warming and store it as wood. But the amount of carbon stored varies depending on tree species, age, climate conditions and other factors. Verifiable estimates of carbon stored in forests are necessary to calculate carbon credits.

CREDIT

Credit: Steve Paton, STRI