The findings have practical implications for conservation and climate policy.

“The takeaway for policymakers is that small-scale rural communities have the ability to manage community forests in sustainable ways, and they need to be supported to solve problems using their own customary practices,” said lead author Sean Downey, associate professor of anthropology at The Ohio State University. “It’s going to look different in Belize than it does in Africa or Indonesia.”

Swidden is one of humanity’s oldest farming systems, practiced in tropical and subtropical forests for around 10,000 years. In Belize, where much of Downey’s fieldwork has taken place, it involves several steps: Farmers clear a patch of forest and leave the fallen trees to dry out. Then the dried trees are burned, which releases the carbon stored in the wood back into the soil where it serves as fertilizer. When the rainy season begins, crops (often corn) are planted and harvested once or twice before the soil’s nutrients start to run low. Then the field is fallowed, essentially given time to rest while the forest regrows.

Downey has spent much of his career studying how small communities balance the demands of farming against the long-term health of the forests they depend on for their livelihood: “It’s a cyclical pattern of reciprocal exchanges of agricultural labor, social norms that help regulate land use, and fire and ecosystem services that regenerate the fertility of cleared forest patches.”He first became interested in Belize’s swidden agriculture in the early 2000s, and later discovered that satellite imagery revealed a stark contrast at the Guatemalan border: The forest had been cleared into pasture on the Guatemalan side, and there were intricate, patchwork mosaics of tropical forest on the Belizean side where Mayan communities were clustered.

A new study, published recently in the Proceedings of the National Academy of Sciences, found that the mosaics could originate from something as commonplace as neighbors deciding whether to help each other plant corn.

When a farmer asks neighbors to help clear and plant a new field, the scale of the request makes a difference. If it’s a reasonably sized plot, most will show up to help. But “if a farmer asks for too much — say, a 20-acre field instead of a two-acre field — fewer people show up to help,” Downey said. And if fewer people show up, the farmer can’t clear the larger plot of land. “Over time, this guides people to ask for the right amount of land, reducing overall land use,” he added.

This process, where shared expectations of right and wrong guide people’s behavior, is known as normative reasoning. It is connected to the work of Nobel Prize-winning economist Elinor Ostrom, who showed that small communities can protect shared local resources through social sanctions — in this case withholding cooperation — rather than formal rules or government enforcement.

Downey’s interdisciplinary research team – which included experts in anthropology, physics, applied mathematics and remote sensing – built a computer model and analyzed remote sensing images from real-world farming communities in Central and South America, sub-Saharan Africa, and South and Southeast Asia to study how people share labor, use land and select sites for swidden agriculture. They found that when farmers naturally coordinate their land clearing efforts, the result is a mosaic of swidden fields with fractal, self-repeating patterns. At the same time, cultural and social norms help reduce the total amount of land cleared.

Together, these things help communities balance their farming needs with long-term environmental sustainability. “Until now, there haven’t been many formal models that can show how small-scale swidden communities regulate land without top-down rules,” Downey said.

Importantly, the researchers also found that while clearing too much forest will turn it into grassland, the biodiversity of a forest increases when it experiences intermediate levels of disturbance.

“When you create swidden patches, you create new ecosystem niches during the fallow stage where different species thrive,” Downey explained, and “you end up with higher levels of biodiversity across the landscape than you do in a mature forest alone.”

In other words, the study found that swidden doesn't automatically lead to degradation. On the contrary, when used in moderation, it can enhance the ecosystem — a benefit, Downey said, that hasn't yet been incorporated into policy.

Co-authors include Shane A. Scaggs, Jensan Lebowitz, Rongjun Qin, Denis Tverskoi, Xinyi Wu and Zaarah Syed from the Ohio State University; and Stefan Thurner from the Complexity Science Hub, the Medical University of Vienna and the Santa Fe Institute. The work was supported by the National Science Foundation, including an NSF CAREER Award Downey received at Ohio State in 2017.

In a large-scale field experiment, researchers planted 640 tree saplings across 20 parks in Dayton, Ohio, and implemented varying irrigation methods. After monitoring sapling survival, growth and health in response to their irrigation methods and nearby temperatures, the team found that the effects of both water treatment and surrounding heat varied among tree species. 

An analysis of saplings at season’s end revealed an overall survival rate of about 48%, indicating that irrigation approaches impacted species’ health differently: Certain species, such as red maple, northern catalpa and honey locust, consistently thrived over others, particularly the white oak, black gum and sassafras saplings. 

Understanding the causes behind these environmental disparities could make urban forests both a lucrative and sustainable option for preventive climate action, said Erika Wright, first author of the study and a graduate student in entomology at The Ohio State University.

“People don’t necessarily think of how their yard connects to the surrounding environment, but we all contribute to the urban forest by planting in our own space,” said Wright. 

Urban forests — essentially functioning as citywide ecosystems because they include all the green spaces in a community — also provide valuable benefits to the health and well-being of local residents. Besides beautifying the environment and supporting biodiversity and wildlife, increased shade offers natural cooling that can reduce consumers’ summer electricity usage.  

Yet obstacles to expanding urban forests often include limited financial and labor resources to care for and maintain them, said Wright. To better consider these challenges, researchers sought to partner on a planting project with a legacy city, an urban area that once had a booming economy but whose shrinking population now lacks the means to manage long-term reforestation projects. 

“It’s going to keep getting hotter in the future,” said Wright. “So we need to know if we should be trying to create environments that are more resilient to those changes.”

The study was recently published in the journal Urban Forestry & Urban Greening. 

The study goal was to test the efficacy of different irrigation strategies on tree development, but with the saplings scattered throughout the city, researchers did not have access to public water sources and had to rely on water transported from nearby fire hydrants. 

Nonetheless, the team predicted that irrigation investments with higher input costs would lead to higher sapling survival, increased growth and improved health compared to less costly irrigation investments, outcomes expected to be partly related to lower water stress in regularly watered saplings.  

Actual sapling survival rates turned out to be slightly lower than the five-year post planting survival rates recorded in previous studies, but the researchers did find that the best watering tactic involved using gator bags – plastic bags that are typically applied for slow-release watering. 

While filling them once per month was not labor-intensive, researchers did note that the up-front and replacement cost of gator bags was high, illustrating the challenging nature of even securing the right supplies to successfully establish and expand urban forests, said Mary Gardiner, senior author of the study and a professor of entomology at Ohio State.

“When a city invests in reforestation of a park, you have to plant more trees than you want to last long term because there will be some percentage that dies off,” said Gardiner. “But even small differences in management can mean huge variations in survivorship.”

According to the study, of the 640 trees seeded, a large portion either went missing or were destroyed by outside factors, likely due to environmental or human interference. “Even after the trees were pretty well established, we saw losses, which was surprising,” said Wright.   

For legacy cities, such threats make gator bags a low- to mid-cost irrigation option as long as precautions like protective fencing are taken to ensure that the bags are not damaged. These investments, combined with having volunteers ensure sapling stock is of high quality before planting, could lead to impressive strides in future forest growth, said Gardiner. 

Overall, while the study’s results indicate that certain species performed better under heat and water stress, researchers don’t recommend limiting planting to only those few species, as urban forests with a mix of trees tend to be more resilient to pest and disease outbreaks.   

Instead, researchers recommend a tailored approach that takes elements like tree species, irrigation resources and surrounding infrastructure into consideration. It may also be worth exploring whether urban forest resilience could be bolstered by non-native tree species.

“Looking for cost-effective strategies for cities to be resilient in the face of a warming climate is an important tactic,” said Gardiner. “Conservation like this leads to a great payoff in the long term.”

Other co-authors include Ellen Danford and Samuel Ward from Ohio State and Christopher Riley with the Bartlett Tree Research Laboratories.

In a new study, researchers have developed a way to remove unpleasant aromas from plant-based proteins to make them smell more appealing. They did so by designing a two-step fermentation process to counter the odors that typically form during cultivation and extraction. 

The study’s results showed that their approach could remove between 95 to 99% of key smells, significantly outperforming one-stage fermentation across all proteins. 

Ultimately, the work paves the way for consumers to embrace a wider variety of safe and nutritious food choices, said Sheryl Barringer, senior author of the study and a professor in food science and technology at The Ohio State University. 

“Plant-based proteins are becoming more and more popular, either as people become vegetarians or just want to reduce their meat consumption,” she said. “Consumers want that option, but they don't want to give up on the taste.” 

Most plant-based proteins, especially those produced as alternatives to milk and dairy products, naturally emit odors that can negatively affect their reception by consumers. Since smell greatly influences flavor perception, these scents, often described as beany, grassy, earthy, sulfurous or cereal-like, can make it difficult for consumers to choose healthier food alternatives. 

“Lots of factors all contribute to food preference, but it’s really hard to say I’m going to force myself to eat a product because it’s good for me, even if it tastes bad,” said Barringer. 

Still, as global demand shifts toward more sustainable, health-conscious and allergen-friendly foods, scientists are having to get creative about raising interest in plant-based proteins. Aside from their compatibility with vegan and lactose-intolerant diets, alternative proteins would likely also be beneficial for the long-term health of the global food supply, as well as help reduce the environmental impact of our food systems. 

The study was recently published in the journal Foods. 

Depending on the product, successful fermentation can take anywhere from a few hours to a whole day.. Adding the second step doesn’t overcomplicate this process, meaning that future plant-based proteins created using this team’s anti-smell method won’t cost consumers more or take longer to make, said Manpreet Kaur, lead author of the study and a PhD student in food science and technology at Ohio State. 

“We are using the same things that are used in the normal fermentation process,” said Kaur. “The only thing changed is how we utilize the bacteria.”

In the first stage of the experiment, researchers added a type of beneficial bacteria, Lactobacillus plantarum, to their microbial cultures, allowing it to ferment and begin breaking down the compounds responsible for foul smells. In stage two, they used a traditional yogurt culture containing a variety of common bacteria known for developing and modulating desirable aromas to complete the fermentation process. 

The team then applied this method to solutions containing eight different plant proteins: 9% soy, pea, chickpea, mung bean, faba bean, rice, barley-rice and hemp. In each test, human sensory evaluation results revealed consistent and often near-complete reductions in smells. 

Kaur and colleagues also found that adding certain ingredients could affect the outcome of the process. For example, while the natural sugar allulose could enhance Lactobacillus plantarum activity, strawberry preserves aided the performance of the bacteria in the yogurt. In contrast, non-fermentable additives, such as pectin, xanthan gum and oil, were introduced with only minimal effects on odor reduction.  

Overall, this work not only advances the field’s understanding of how fermentation can be used to mitigate unsavory sensory challenges, but also offers a practical solution for the development of flavorful plant-based dairy snack alternatives, the researchers say.

“There’s a real focus on people wanting to be healthier and more environmentally conscious, and a push for plant-based products instead of meat and dairy products,” said Barringer. “So I expect this area of research will absolutely continue to grow in the next many years.”

Charlotte Gray from Ohio State was also a co-author. 

The study, published in the journal Insects, found that hemp leaf extract – which contains the active ingredient cannabidiol, or CBD – kills mosquito larvae from two different strains of the yellow fever mosquito within 48 hours, one that was resistant to typical insecticides and another that was not.

“Mosquitoes are one of the deadliest animals in the world, mainly because as adults they serve as vectors of disease,” said Erick Martinez Rodriguez, lead author of the study and a graduate student in entomology at The Ohio State University. “It’s very important to be able to control these pests at an early stage, when they are at the most vulnerable.”

Unlike adult mosquitoes that can fly across great distances and transmit disease by biting, mosquito larvae are aquatic organisms often found in standing water. Conventional synthetic insecticides are critical chemical tools for killing mosquito larvae populations, but their rampant overuse has led to both insecticide resistance and other detrimental effects on the environment. 

Inspired by previous Ohio State research that discovered that the bark properties of a plant native to Madagascar worked as a natural mosquito insecticide and repellent, Martinez Rodriguez sought to determine if hemp could act as a viable and safe alternative to current biopesticides.

The hemp plant is related to marijuana, but does not contain its levels of the ingredient that  makes people feel “high.” CBD from hemp is used in a variety of products from gummies and oils to treat anxiety, pain, insomnia and other conditions.

To test hemp’s toxic effects against mosquito larvae, the team took air-dried hemp leaves, pulverized them into a fine powder and soaked the material in methanol for a few weeks to reach the desired CBD concentrations. 

The methanol was later removed from the solution to make it easier to chemically analyze, resulting in an extract that was eventually given to the larvae with their food. 

Depending on the concentration of hemp extract used, the team discovered that the hemp leaf was potent enough to be equally toxic to both strains of mosquito larvae. What was surprising, though, said Martinez Rodriguez, was the small amount needed to be so deadly. 

“If you compare the amount of hemp extract needed to kill 50% of the population to other synthetic conventional insecticides, it is on the high side, but when you compare it side-by-side to other natural extracts we have tested in our lab, only a relatively low amount is required to produce high mortality values in larvae,” said Martinez Rodriguez. While CBD eventually led to 100% mortality for the larvae, different concentrations of the hemp extract caused different mortality rates in the hours leading up to that time. 

The mosquito larvae were considered dead if no movement was recorded after scientists gently touched their abdomen with a needle or pipette tip. Although it’s still unclear how the extract affects them biologically, the team’s findings showed that CBD was the primary active ingredient in the extract and that it can successfully bypass the larvae’s metabolic resistance to other insecticides, which aligns with past work that found CBD has notable growth-inhibiting properties against other insects. 

Since hemp is also a more sustainable crop than many other plant alternatives, insecticide products that use it could potentially be produced relatively cheaply, said Martinez Rodriguez. 

While this discovery bodes well for developing future natural-based mosquito control products, said Peter Piermarini, co-author of the study and a professor of entomology at Ohio State, further research would have to be done to investigate how safe hemp and CBD would be for non-target organisms, like honey bees or other pollinating insects that scientists don’t want to kill or disrupt by introducing potentially harmful additives to the environment. 

“CBD is a compound that appears to be safe for people and our companion animals to ingest,” said Piermarini. “It’ll be interesting to learn more about how CBD interacts with various proteins in mammals and insects to understand why it’s safe for people but not insects.”

This work was supported by the Infectious Diseases Institute and the College of Food, Agricultural, and Environmental Sciences at Ohio State. Other Ohio State co-authors include Larry Phelan, Luis Canas, Nuris Acosta and Harinantenaina L. Rakotondraibe. 

For one, no one can deliver takeout to the International Space Station. Likewise, because space food needs to be safe and nutritious, and last for at least five years, most of the fare onboard tends to be freeze-dried or packaged in disposable containers. 

Efforts to improve current food production systems so astronauts might have both nutritious and delicious menu choices was the focus of NASA’s Deep Space Food Challenge, the third and final phase of which was co-hosted by The Ohio State University. 

In 2019, NASA and the CSA (Canadian Space Agency) started the Deep Space Food Challenge, a multi-year international effort to develop sustainable food systems for long-duration habitation in space, including on the moon and Mars. Since Phase 1 of the challenge opened in 2021, more than 300 teams from 32 countries have developed innovative food system designs. On Aug. 16, NASA announced the final Phase 3 winners at Ohio State.

Presented at the Nationwide & Ohio Farm Bureau 4-H Center, the two-day event featured panel discussions with students, scientists and government representatives involved in developing sustainable food systems for long-duration human exploration, as the current system space agencies employ likely wouldn’t work well for extended planetary missions.  

“Food is the limiting factor for human spaceflight,” said Tor Blomqvist, a food researcher at the German Aerospace Center, during a dialogue on fostering collaborative relationships between government entities and commercial space companies. “Before we can have a continuous human presence on the lunar surface, we need to figure out a way to increase food production in space, especially if we want to reduce our dependencies on Earth as much as possible.”

Space food systems are required to carry out a variety of onboard processes. This includes being able to store food in areas with limited space and ensuring safe food preparation, as well as establishing a method to eliminate all the waste the process of cooking creates. Eating in microgravity can be difficult while adhering to the balanced diet astronauts must meet, but because food can play a critical role in the crew’s psychological well-being, like affecting their mood and morale, the future of space exploration is as intimately tied to the type of food we pack on the trip as it is to advances in cutting-edge rocketry.

“We’re going to need a roadmap for the food systems we’re trying to achieve and this is something that national space agencies can’t do themselves,” said Blomqvist. The solution, he said, is to inspire cooperation between the private and public sectors. 

Ohio State has already cemented its connection to the rising commercial space industry through the establishment of the George Washington Carver Science Park (GWCSP) in cooperation with Voyager Space Holdings.

Located at the north side of The Ohio State University Airport, the GWCSP will serve as an ecosystem to fortify commercial spaceflight research, technology, and economic development in low-Earth orbit. The park will also include terrestrial analogs of research and facilities aboard the upcoming commercial space station Starlab, said John Horack, Neil Armstrong Chair in aerospace policy at Ohio State and a key organizer of the event.

The ground-based research and development conducted there will help establish sustainable exploration beyond Earth by developing manufacturing technologies that inform space constructions, addressing novel ways to keep astronauts healthy and safe via closed-loop life support systems, and studying unique agricultural challenges. 

“Carver’s work was about creating new knowledge and research that would impact the largest number of people in the most profound way possible, so that their lives could be improved,” said Horack. “This anchor site will strive to do the same.”

The conclusion of the Deep Space Food Challenge, which is also geared toward helping Earth’s food scarcity issues, also featured demonstrations from The Ohio State University Simunauts, a group of current and former College of Food, Agricultural, and Environmental Sciences students who worked alongside NASA to operate the novel technologies being presented. Of the four teams who competed to win a prize purse of $1 million, Interstellar Lab received $750,000, while the two semi-finalists Nolux and SATED received an award of $250,000 each. 

“Congratulations to not only the winner of the Deep Space Food Challenge, but to all those companies whose products and technologies will help us not only to feed astronauts in deep space but use our research in space to feed people here on Earth,” said Horack. 

Researchers at The Ohio State University developed impacts-based thresholds for drought in Ohio, looking specifically at how corn yield and streamflow were affected by various drought indicators, such as notable changes in soil moisture, crops, and even livestock losses in the state.

The results suggest this impacts-based approach could give Ohio farmers earlier and more accurate notice when drought conditions are approaching, said Steven Quiring, co-author of the study and a professor of geography at Ohio State.

“We want to better understand what steps should be taken so that Ohio can better prepare for and also monitor the onset of drought conditions because a lot of the best ways to respond to drought is taking action early,” said Quiring. Moreover, with a more precise early warning system, agriculture producers might be able to save time and money by implementing water restrictions, or by switching to different or more drought-resistant crops.

The study was published in the Journal of Hydrometeorology. 

The Ohio State researchers compared how their method performed at predicting droughts with data from the U.S Drought Monitor (USDM). 

The problem with the USDM is that it uses fixed drought thresholds, or guidelines that use the same parameters to measure changes in all seasons and climate regions of the country. Unfortunately, this one-size-fits-all approach can cause monitoring plans to inaccurately gauge local weather conditions and how they impact those in certain communities, Quiring said.

By analyzing data from four drought indices commonly used in previous studies to monitor drought intensity across the United States, researchers were able to show that fixed thresholds tend to indicate milder drought conditions in Ohio than are indicated by the impacts-based thresholds identified in their study. 

It’s why Quiring and his team want to use the impacts-based method to revamp those thresholds to better reflect drought conditions in Ohio, a move that starts by updating The Ohio Emergency Management Agency’s state drought plan. 

To accomplish their goal, the researchers investigated how data from the four indices impacted streamflow, or how much water discharges over a designated point in a fixed period of time, and Ohio’s total corn yield, mainly because the crop covers an extensive area within the state, and nearly every county grows it. 

Identifying agricultural drought thresholds that are specific to Ohio is important, said Quiring. Because the impacts of drought can vary from region to region, using the same drought thresholds in California as in Ohio is absurd, he said. Additionally, the types of drought that occur can differ. Ohio, for example, in particular is prone to “flash droughts” — shortages caused by warm weather that can happen quickly over a few days or weeks. 

“These rapid-onset droughts can be particularly challenging for the agricultural community because they arrive quickly and conditions can rapidly go from normal to drier than normal,” said Quiring. “All of a sudden soil moisture is depleted, the crops are stressed and yield losses and impacts on the ecosystem occur.”  

The last time severe drought caused major losses in the United States was in 2012 when a record-breaking heat wave resulted in $34.2 billion in economic losses, 123 direct deaths and a 26% decrease in total corn crop yield across the country. 

As large areas of the country dried out, Ohio’s corn yield dropped from about 160 bushels per acre to 120 bushels per acre within a year. While such considerable losses have not happened since, according to the State Climate Office of Ohio, some areas of the state have experienced abnormally dry drought conditions this year.  

What’s more, the researchers’ impacts-based method of drought monitoring also takes into account how climate change can worsen flash drought events.

“One of the impacts that we found to be counterintuitive in Ohio is that with climate change, we do expect more rainfall overall, but we also expect to see more droughts because there are longer periods of time where no rain occurs,” said Quiring. 

The results of this study suggest that following guidelines that aren’t specific to a region’s issues can end up either systematically underestimating the impacts of severe drought conditions in some locations or overestimating them in others, Quiring said. 

While it’ll be some time before Quiring’s team can get their research incorporated into the next edition of the state drought plan, the study emphasizes that its methods could easily be applied to other regions beyond Ohio where long-term streamflow and crop yield data are readily available. Optimistically, it could help to improve drought monitoring worldwide and provide useful information to future agriculture producers and decision-makers, said Quiring. 

“This work is actually timely because it will provide a basis for decision-making in Ohio, rather than using research that’s been done in other parts of the country,” said Quiring. “Hopefully we can give better guidance to those who are making decisions on the ground.”

This study was supported by the National Integrated Drought Information System (NIDIS). Co-authors were Ning Zhang and Zhiying Li, who were both at Ohio State when the study was conducted. Zhang is now at the University of California, Davis and Li is at Indiana University.