Photoelectrocatalysis for high-value-added chemicals production

Peer-Reviewed Publication

DALIAN INSTITUTE OF CHEMICAL PHYSICS, CHINESE ACADEMY SCIENCES

 

IMAGE: SOLAR-TO-CHEMICAL ENERGY CONVERSION USING PHOTOELECTROCHEMICAL (PEC) TECHNOLOGY IS A PROMISING ROUTE TO ACHIEVE CARBON NEUTRALIZATION. THE RESEARCHERS GIVE A DETAILED SUMMARY AND DISCUSSION OF THE PEC REACTION SYSTEM, INCLUDING COMMON PEC WATER SPLITTING SYSTEMS AND HIGH-VALUE-ADDED CHEMICALS PRODUCTION SYSTEMS SUCH AS HYDROGEN PEROXIDE PRODUCTION, ORGANIC WASTEWATER TREATMENT, SELECTIVE CONVERSION OF ORGANIC RAW MATERIALS AND CARBON DIOXIDE REDUCTION. view more 

CREDIT: CHINESE JOURNAL OF CATALYSIS

The development and application of solar energy has attained extensive attention along with the aggravating global energy crisis due to its large resource reserves, wide distribution and environment friendly. Photoelectrocatalysis (PEC) has been regarded as a promising approach to transform solar energy and stored in the form of chemical energy. In recent years, water splitting has become the main application direction of PEC technology because of the security and simplicity of this reaction, and the hydrogen produced by the cathodic reaction. However, the anodic oxygen evolution reaction (OER) in PEC water splitting is a four-electron process with sluggish kinetics, leading to a poor efficiency of the system. Additionally, the O2 generated by OER has inferior economic value, which is not beneficial to reduce the overall cost of water splitting. Therefore, the design of efficient photoelectrode combined with the research for suitable OER alternative reaction are the critical issues to extending PEC technology to practical application.

Actually, there are various reactions that can be performed in the PEC system except for water splitting, such as H2O oxidative H2O2 synthesis reaction, organic oxidation reaction and CO2 reduction reaction (CO2RR). These reactions are all means to add value to chemicals to achieve high-value-added chemical production. For example, O2 obtained through OER is a common and budget chemical that is similar to its raw material of H2O, which can be replaced by photoelectrooxidation of H2O to high-value-added H2O2. Furthermore, as a low-cost biomass organic chemical, glycerol can be converted into more valuable chemicals such as 1,3-dihydroxyacetone and glyceraldehyde through an oxidation process. Moreover, this type of reaction requires a lower reaction potential in comparison OER, which means that the system can input less energy to get more products. As for photocathode, there are also many studies focus on the CO2RR, which play a dual purpose of converting solar energy into high-value-added chemicals (such as carbon monoxide, formate, methanol, and ethanol) and reducing anthropogenic CO2 levels.

To realize the above processes, the primary problem that must be solved is the matching of semiconductor materials and alternative reactions, such as the energy band position of the semiconductor must be appropriate to drive the reaction smoothly. In addition to screening materials, the selectivity of photoelectrodes for high-value-added products needs to be regulated. Therefore, it is a huge challenge to design a system with satisfactory performance photoelectrode that meets these requirements. Although some design methods of water splitting systems have been reviewed, there is no comprehensive discussion on the production of various high-value-added products in PEC systems.

Recently, a research team led by Prof. Mingfei Shao from Beijing University of Chemical Technology, China reported an Account that discusses the use of PEC technology to produce various high-value-added products and environmental treatment applications, where several PEC systems are discussed, including PEC water splitting, PEC organic oxidation coupled with hydrogen evolution, and PEC carbon dioxide reduction reaction. Based on the opinion of regulating the photoelectrode to match the production reaction of high-value-added chemicals and ensuring selectivity is the core of this field, the development of future PEC systems is also prospected. The results were published in Chinese Journal of Catalysis (https://doi.org/10.1016/S1872-2067(21)63923-2).

###

About the Journal

Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top six journals in Applied Chemistry with a current SCI impact factor of 8.271. The Editors-in-Chief are Profs. Can Li and Tao Zhang.

At Elsevier http://www.journals.elsevier.com/chinese-journal-of-catalysis

Manuscript submission https://mc03.manuscriptcentral.com/cjcatal

Researchers find limited economic cost to robust carbon emission goals

Peer-Reviewed Publication

OXFORD UNIVERSITY PRESS USA

A new paper in Oxford Open Climate Change, published by Oxford University Press, indicates that, while various models to measure the economic impact of reducing carbon emissions show low current economic benefits, after 2050, most scenarios show higher benefits than costs. These benefits are the largest in developing countries.

Climate stabilization pathways reviewed by the United Nations’ Intergovernmental Panel on Climate Change show the challenges and opportunities of reducing carbon emissions to meet the goal of the Paris Climate Agreement. The different scenarios provide information about the transition, including its economic repercussions due to industrial disruption and the implementation of new technology. However, these calculations often do not account for the economic benefits of lowering global temperature. Nevertheless, economic motives for acting to reduce emissions and adapt to climate change play an important role in the national and international negotiations surrounding emission reductions.

Researchers here explored many scenarios to combine the costs of carbon reduction with the growing literature by using 25 different economic damage functions of climate change,  predicting the economic impacts of carbon reduction. The researchers found that, comparing the net benefits plans to reduce carbon emissions by 1.5° or 2° Celsius above pre-industrial levels, the two climate targets yield similar economic results. The extra economic costs of tightening the policy by half a degree, are compensated by the additional benefits of reduced temperature. At a conservative estimate, the median net benefits are, respectively 6.0% and 5.4% of GDP for 1.5°C reduction and 2°C reduction. The benefits of a lower temperature target are larger than the costs.

While researchers find that immediate economic benefits of carbon emissions reductions are limited, most scenarios have net economic benefits after 2050, and the vast majority (more than 75%) by 2080. These benefits are most dramatic for developing countries. Overall, the paper’s authors find that, despite considerable uncertainty, the current benefits and costs of attaining temperature goals of 1.5-2° C are of comparable magnitude and not statistically different from each other. There is a limited net economic cost to the more robust 1.5° C reduction goal.

“Rapid climate action will inexorably generate economic benefits from avoided impacts in the second half of the century,” said the paper’s lead author, Laurent Drouet. “Those benefits will be much higher than the transition costs for the next decades.”

The paper, “Net economic benefits of well-below 2°C scenarios and associated uncertainties,” is available (at midnight on April 13th) at: https://doi.org/10.1093/oxfclm/kgac003.

Direct correspondence to: 
Laurent Drouet
European Institute on Economics and the Environment 
Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici
Via Bergognone, 34
20144 Milan, ITALY
laurent.drouet@eiee.org

To request a copy of the study, please contact:
Daniel Luzer 
daniel.luzer@oup.com

---

JOURNAL

Oxford Open Climate Change

DOI

10.1093/oxfclm/kgac003 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Net economic benefits of well-below 2°C scenarios and associated uncertainties

ARTICLE PUBLICATION DATE

13-Apr-2022

Singapore scientists demonstrate that some tropical plants have potential to remove toxic heavy metals from the soil

Peer-Reviewed Publication

NANYANG TECHNOLOGICAL UNIVERSITY

 

IMAGE: (L-R) PHD STUDENT MS WANG YAMIN FROM NTU’S SCHOOL OF MATERIALS SCIENCE AND ENGINEERING (MSE), PROF LAM YENG MING, CHAIR OF NTU’S MSE, AND ASSOC PROF TAN SWEE NGIN FROM THE ACADEMIC GROUP OF NATURAL SCIENCES AND SCIENCE EDUCATION AT NTU’S NATIONAL INSTITUTE OF EDUCATION PRESENTING PLANTS FOUND TO HAVE THE ABILITY TO REMOVE TOXIC HEAVY METALS AND METALLOIDS FROM CONTAMINATED SOIL. view more 

CREDIT: NTU SINGAPORE

A team of researchers from Nanyang Technological University, Singapore (NTU Singapore) and Singapore’s National Parks Board (NParks), has demonstrated that some plant species could help to remove toxic heavy metals and metalloids from contaminated soil.  

 

Phytoremediation is the use of plants to extract and store contaminants from soil. As a first step to determine if candidate plants had phytoremediation abilities, the team examined samples of them for levels of heavy metals and metalloids. A high concentration detected suggested an ability to absorb the pollutants.

 

The study by the Singapore research team discovered that there are existing tropical plants which could potentially play a role in the remediation of contaminated lands. The plants examined in the study are widely available and include species that are native or naturalised to Singapore. They could thus, be introduced and removed from plots of land with minimal impact to ecosystems and could lead to the development of a sustainable and environmentally friendly way of managing contaminants in soil (see video).

 

The findings were published in the scientific peer-reviewed journal Environmental Pollution in February.

 

Professor Lam Yeng Ming, Chair of NTU’s School of Materials Science and Engineering, who co-led the study, said: “In a small nation like Singapore, land may be repurposed to support new development plans, so it is important that we have a green and sustainable way to remediate land that is contaminated. We set out to uncover how to better make use of tropical plants to do phytoremediation and through advanced characterisation techniques, we showed how some of these tropical plant species can be an environmentally friendly and literally a “green” way to remove contaminants in soil. Phytoremediation also has benefits of cost effectiveness, simplicity of management, aesthetic advantages, and long-term applicability and sustainability. The strategy prevents erosion and metal leaching by stabilising or accumulating heavy metals, so that helps reduce the risk of contaminant spread.”

 

The team conducted a field survey and collected soil and plant samples between March 2019 and January 2020. A total of 46 plant species were studied as potential candidates for phytoremediation.

 

Among them, 12 plant species, which include the commonly seen Cow Grass (Axonopus compressus), hyperaccumulators like the Brake Fern (Pteris vittata) and the Indian Pennywort (Centella asiatica), were effective for the accumulation of several types of heavy metals and metalloids.

 

The elements investigated in the study were heavy metals and metalloids that are potentially toxic to humans and animals, such as cadmium, arsenic, lead, and chromium. They occur naturally in soils, but rarely at toxic levels. However, they can accumulate and reach higher levels over a long period of time, as heavy metal particles from air pollution (e.g. vehicle emissions, construction activities) tend to accumulate and remain in the top layers of soil.

 

Other factors that could result in high levels of heavy metals in soil include the use of synthetic products such as pesticides, paints, batteries, industrial waste, and land application of industrial or domestic sludge.

 

To assess whether the levels of heavy metal were dangerous, the team used the Dutch Standard, which provides values for the acceptable threshold of environmental pollutants in soils. This mode of assessment has also been adopted by Singapore’s government agencies.

CAPTION

The scientists found that Centella asiatica, commonly known as Indian pennywort, could effectively absorb cadmium, a toxic metal, from affected soils.

CREDIT

NTU Singapore

Associate Professor Tan Swee Ngin, from the Academic Group of Natural Sciences and Science Education at NTU’s National Institute of Education, who was the study’s co-author, said: “Our results revealed there were regions where levels of heavy metals and metalloids were relatively high and could affect the environment and the health of flora and fauna in Singapore. This would call for preventive actions, such as our method of using plants to remove these toxic materials, to be employed to minimise heavy metal contamination.”

 

The NParks researchers involved in the study are from its Centre for Urban Greenery and Ecology. They include Dr Subhadip Ghosh, Senior Researcher and Mr Mohamed Lokman Mohd Yusof, Senior Research Executive.

 

The development of this plant-based solution to improve soil quality is part of the University’s efforts to mitigate our impact on the environment, that is aligned with the NTU 2025 strategic plan, which aims to develop sustainable solutions to address some of humanity’s pressing grand challenges.

 

Team’s findings expand potential of environmentally friendly methods

 

Phytoremediation could serve as a more environmentally friendly alternative to existing industrial options to remove the heavy metals from polluted soil, which include methods such as soil washing and acid leaching. These methods can be costly and may utilise harsh chemicals to remove pollutants from soil.

 

Heavy machinery to conduct excavation and transportation of soil is also usually required in such processes and these procedures may negatively affect the environment by affecting soil health and fertility. These methods also run a high risk of exposing humans or animals to the heavy metals.

 

However, phytoremediation is a slow and long-term commitment and requires prudent management in the removal and disposal of the contaminated plant samples. Using different types of efficient plants to carry out phytoremediation in polluted soils, and with enough growth cycles through repeated planting, can ultimately lead to reductions in the level of heavy metals and metalloids in the soil.

 

The joint research team is currently testing the plants on plots of land in Singapore that have high concentrations of heavy metals to better determine the effectiveness of the plants in an urban setting.

 

They are also testing the usage of other inorganic particles that are incorporated into plants and that can both help in the plant growth and improve the uptake of these contaminants by the plants. This will reduce the time taken for the absorption of the heavy metals and hence speed up the remediation time.

 

###

---

JOURNAL

Environmental Pollution

DOI

10.1016/j.envpol.2021.118681 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Assessment of heavy metal and metalloid levels and screening potential of tropical plant species for phytoremediation in Singapore

A 4 V-class metal-free organic lithium-ion battery gets closer to reality

Peer-Reviewed Publication

TOHOKU UNIVERSITY

 

IMAGE: AN ILLUSTRATION OF CROCONIC ACID AND AN IMAGE OF A HIGH-VOLTAGE ENVIRONMENTALLY FRIENDLY ORGANIC LITHIUM-ION BATTERIES. view more 

CREDIT: YUTO KATSUYAMA ET AL.

A joint research team from Tohoku University and the University of California, Los Angeles (UCLA) has made a significant advancement towards high-voltage metal-free lithium-ion batteries that use a small organic molecule, croconic acid. The breakthrough moves us closer to realizing metal-free, high-energy, and inexpensive lithium-ion batteries.

Unlike conventional lithium-ion batteries, which depend on rare-earth materials such as cobalt and lithium, organic batteries exploit naturally abundant elements such as carbon, hydrogen, nitrogen, and oxygen. In addition, organic batteries have greater theoretical capacities than conventional lithium-ion batteries because their use of organic materials renders them lightweight. Most reported organic batteries to date, however, possess a relatively low (1-3V) working voltage. Increasing organic batteries' voltage will lead to higher energy density batteries.

Itaru Honma, a professor of chemistry at Tohoku University's Institute of Multidisciplinary Research for Advanced Materials, Hiroaki Kobayashi, an assistant professor of chemistry at Tohoku University, and Yuto Katsuyama, a graduate student at UCLA, found that croconic acid, when used as a lithium-ion battery cathode material, maintains a strong working voltage of around 4 V.

Croconic acid has five carbon atoms bonded to each other in a pentagonal form, and each of the carbons is bonded to oxygen. It also has a high theoretical capacity of 638.6 mAh/g, which is much higher than the conventional lithium-ion battery cathode materials (LiCoO2 ~ 140 mAh/g). "We investigated the electrochemical behavior of croconic acid in the high-voltage range above 3 V using theoretical calculations and electrochemical experiments," said Kobayashi. "We discovered that croconic acid stores lithium ions at roughly 4 V, giving a very high theoretical energy density of 1949 Wh/kg, which is larger than most inorganic and organic lithium-ion batteries."

Although the theoretical capacity was not achieved in this study, the researchers are optimistic this can be enhanced by the development of stable electrolytes at high-voltage and chemical modifications to croconic acid. Since most electrolytes cannot stand for such a strong working voltage of croconic acid, developing new electrolytes is vital. Additionally, the structures of small organic molecules, including croconic acid, can be easily modified. Appropriate structural modification can stabilize the molecule, leading to greater capacity and reversibility.

---

JOURNAL

Advanced Science

DOI

10.1002/advs.202200187 

ARTICLE PUBLICATION DATE

10-Mar-2022

The triumph of secular individualism – A new mathematical model offers clear-cut answers to how morals will change over time

Peer-Reviewed Publication

INSTITUTE FOR FUTURES STUDIES

Corporal punishment of children, such as spanking or paddling, is still widely accepted in the world’s most influential country, the US. But public opinion is changing rapidly, and in the United States and elsewhere around the world this norm will soon become a marginal position. The right to abortion is currently being threatened through a series of court cases – but though change is slow, the view of abortion as a right will eventually come to dominate. A majority of Americans today reject the claim that parental leave should be equally shared between parents, but within 15 years public opinion will flip, and a majority will support an equal division.  

"Almost all moral issues are moving in the liberal direction. Our model is based on large opinion surveys continuously conducted in the US, but our method for analyzing the dynamics of moral arguments to predict changing public opinion on moral issues can be applied anywhere," says social norm researcher Pontus Strimling, a research leader at the Institute for Futures Studies, who together with mathematician Kimmo Eriksson and statistician Irina Vartanova conducted the study that will be published in the high-ranking journal Royal Society Open Science on Wednesday, April 13th.  

Applying the model to data on public opinion surveyed in 2018, the article presents year by year predictions for how public opinion will develop on a number of issues up until 2030. This allows for empirical tests of the model through comparisons with actual developments in the coming decade. The results of the first test, against data from 2020, are promising.   

"Our model did considerably better than all known methods for predicting opinion change. The key is to understand the mechanisms that underlie the change. How opinions change depends on the arguments used to argue for and against a certain stance. The model gives a clear picture of what societies will look like in the near future."  

Contact:   
Pontus Strimling (Principal Investigator), pontus.strimling@iffs.se, + 46 70 375 18 62 
Erika Karlsson (Communications Officer), erika.karlsson@iffs.se, + 46 70 604 58 55 

Read the article: 
The article "Predicting how US public opinion on moral issues will change from 2018 to 2020 and beyond" will be published here: https://royalsocietypublishing.org/journal/rsos on Wednesday, April 13:th.     

---

JOURNAL

Royal Society Open Science

DOI

10.1098/rsos.211068 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Predicting how US public opinion on moral issues will change from 2018 to 2020 and beyond

ARTICLE PUBLICATION DATE

13-Apr-2022

Austerity is worsening NHS waiting time inequality in Scotland

Peer-Reviewed Publication

SAGE

Research analysing the impact of the Scottish government’s initiative to reduce NHS waiting times concludes the programme of investment and reform is associated with a reduction in waiting time inequality, benefiting the most socioeconomically deprived patients. However, austerity measures introduced in 2010 are reversing these gains.

The researchers analysed three common elective surgery procedures, primary hip and knee replacements and knee arthroscopies, between 1 April 1997 to 31 March 2019. Hip replacements are commonly used to assess healthcare equity.

The Scottish NHS waiting time initiative was launched in 2002. The analysis shows that between 1 July 2002 and 31 March 2010 waiting time inequality between the most and least deprived patients fell. These gains were reversed between 1 April 2010 and 31 March 2019 during the period of austerity and budget cuts.

Inequality in mean waiting time for hip replacements increased by 1.07 days per quarter between 1 April 1997 and 30 June 2002; decreased by 1.26 days per quarter between 1 July 2002 and 31 March 2010; and increased by 0.58 days per quarter between 1 April 2010 and 30 June 2019.

The analysis was carried out by researchers at the Population Health Sciences Institute at Newcastle University. Senior research associate Graham Kirkwood said: “The drive to reduce waiting times in Scotland from July 2002 had the effect of reducing inequalities between the most and least socioeconomically deprived patients. This finding held true for each of the three elective procedures analysed: primary hip replacements, primary knee replacements and arthroscopies.

“Prior to this, for all three treatments, patients in the most deprived areas had longer waits than those in the least deprived areas. The introduction of austerity measures in 2010, with a real-term freeze on health spending, appears to have reversed the gains with waiting times increasing for all patients and the pre-2002 pattern of inequality returning.”

The authors say further research is needed to analyse, compare and contrast the trends and effects of the use of the private sector on waiting time inequalities in Scotland with England. Unlike Scotland, England has increased the proportion of elective surgery that is being outsourced from the NHS to the private sector under the patient choice programme and the numbers of patients paying to go private has also increased.

---

JOURNAL

Journal of the Royal Society of Medicine

DOI

10.1177/01410768221090672 

METHOD OF RESEARCH

Content analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Socioeconomic inequality, waiting time initiatives and austerity in Scotland: an interrupted time series analysis of elective hip and knee replacements and arthroscopies

ARTICLE PUBLICATION DATE

12-Apr-2022

Climate change will reshuffle marine ecosystems in unexpected ways, Rutgers study finds

Sophisticated model reveals how predator-prey relationships affect species’ ranges

Peer-Reviewed Publication

RUTGERS UNIVERSITY

 

IMAGE: LARGE PREDATORY FISH ARE EXPECTED TO LAG BEHIND TEMPERATURE SHIFTS DUE TO FOOD-WEB DYNAMICS. view more 

CREDIT: GERALD SCHÖMBS

Warming of the oceans due to climate change will mean fewer productive fish species to catch in the future, according to a new Rutgers study that found as temperatures warm, predator-prey interactions will prevent species from keeping up with the conditions where they could thrive.

The new study, published in the journal Proceedings of the Royal Society B, presents a mixed picture of ocean health. Not only will large species and commercially important fisheries shift out of their historical ranges as climate warms, but they will likely not be as abundant even in their new geographic ranges. For instance, a cod fisherman in the Atlantic might still find fish 200 years from now but in significantly fewer numbers.

“What that suggests from a fisheries perspective is that while the species we fish today will be there tomorrow, they will not be there in the same abundance. In such a context, overfishing becomes easier because the population growth rates are low,” said study coauthor Malin Pinsky, an associate professor in Rutgers’ Department of Ecology, Evolution, and Natural Resources. “Warming coupled with food-web dynamics will be like putting marine biodiversity in a blender.”

Previous studies of shifting habitat ranges focused on the direct impacts of climate change on individual species. While these “one-at-a-time” species projections offer insights into the composition of ocean communities in a warming world, they have largely failed to consider how food-web interactions will affect the pace of change.

The new study looked at trophic interactions – the process of one species being nourished at the expense of another – and other food-web dynamics to determine how climate change affects species’ ranges.

Using sophisticated computer models, the researchers determined that predator-prey interactions cause many species, especially large predators, to shift their ranges more slowly than climate.

“The model suggests that over the next 200 years of warming, species are going to continually reshuffle and be in the process of shifting their ranges,” said lead author E. W. Tekwa, a former Rutgers postdoc in ecology, evolution and natural resources now at the University of British Columbia. “Even after 200 years, marines species will still be lagging behind temperature shifts, and this is particularly true for those at the top of the food web.”

As climate warms, millions of species are shifting poleward in a dramatic reorganization of life on earth. However, our understanding of these dynamics has largely ignored a key feature of life -- animals and other organisms must eat. The researchers have filled this knowledge gap by examining how the basic need for nourishment affect species’ movements.

The researchers developed a “spatially explicit food-web model” that included parameters such as metabolism, body size and optimal temprature ranges. By accounting for climate change, their model revealed that dynamic trophic interactions hamper species’ ability to react quickly to warming temperatures. They also found that larger-bodied top predators stay longer than smaller prey in historical habitats, in part because of the arrival of new food sources to their pre-warming ranges.

“These dynamics will not only be in one place but globally,” Pinsky said. “That does not bode well for marine life, and this is not an effect that has been widely recognized.”

---

JOURNAL

Proceedings of the Royal Society B Biological Sciences

DOI

10.1098/rspb.2021.2755 

ARTICLE TITLE

Body-size and food-web interactions mediate species range shifts under warming

Beyond the honeybee: how many bee species does a meadow need?

Research led in part by UMD reveals the importance of pollinator diversity, highlighting the role of rare bees in wild ecosystems

Peer-Reviewed Publication

UNIVERSITY OF MARYLAND

 

IMAGE: UMD ENTOMOLOGIST MICHAEL ROSWELL COLLECTS BEES FOR A SURVEY OF POLLINATION NEEDS IN A NEW JERSEY MEADOW. HE AND COLLEAGUES FOUND 2.5 TO 7.5 TIMES MORE BEE SPECIES WERE IMPORTANT FOR POLLINATION THAN PREVIOUSLY DOCUMENTED. AND RARE SPECIES WERE MORE SIGNIFICANT THAN KNOWN. view more 

CREDIT: JAMES REILLY

A meadow’s lush array of flowers needs a full phalanx of bees to pollinate them—far more than just the honeybees and bumblebees that most people are familiar with, according to a new study by a team of researchers including University of Maryland entomologist Michael Roswell. A postdoctoral associate in the Department of Entomology, Roswell helped demonstrate that less common bees are much more important for ecosystem health than previously documented.

Previous research on bees as pollinators tended to focus on specific plants—frequently crops—or on entire communities of plants as if they were a single entity. This tended to over-emphasize the contribution of the most common bees, especially since 2% of the bee species provided 80% of the pollination in crops. But no previous work had asked the basic question: How many pollinator species are needed to pollinate all the species in a given community of plants? 

Roswell and his colleagues have now shown that the more plant species there are, the more bee species are needed for pollination. They found that the less common bees often visited specific plants others didn’t. Their findings shed new light on the role of rare species in ecosystems—critical to conservation efforts because rare species are most at risk of extinction from habitat loss, pollution, climate change and other factors. The study appeared April 13, 2022, in the Proceedings of the Royal Society B.

“Our work shows that things that are rare in general, like infrequent visitors to a meadow, can still serve really important functions, like pollinating plants no one else pollinates,” said Roswell, who studies diversity and pollination in the UMD Department of Entomology and is a co-author of the study.  “And that’s a really good argument for why biodiversity matters.”

CAPTION

A female Agapostemon virescens on an Echinacea purpurea flower.

CREDIT

Barry Rosenthall

The researchers surveyed 10 plots in New Jersey that included wild meadows and seeded fields over one year. They observed bees from over 180 species making nearly 22,000 visits to over 130 different plant species. The team used these encounters to estimate the pollination services each type of bee provided to each plant, because a plant’s most frequent floral visitors are typically its most important pollinators.

Their analyses showed that an entire meadow community relied on 2 ½ to 7 ½ times more bee species for pollination than a single typical plant species does. They also found that the locally rare species accounted for up to 25% of the important pollinator species, and that number was greatest in meadows with the most plant diversity. This suggests that at larger scales like entire ecosystems, the number of locally rare species that are important for pollination is even greater.

“We were looking at meadows that might be a few acres in size,” Roswell said, “but a typical bee flies over a couple of square miles, which is a really large and complicated landscape filled with lots of different kinds of plants that flower at different times and are visited by different insects. At that scale, even more diversity of pollinators is likely to be important.”

  

CAPTION

A female Ceratina bee visits a black-eyed Susan (Rudbeckia laciniata) blossom.

CREDIT

Barry Rosenthall

---

JOURNAL

Proceedings of the Royal Society B Biological Sciences

DOI

10.1098/rspb.2021.2689 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Many bee species, including rare species, are important for function of entire plant-pollinator networks

ARTICLE PUBLICATION DATE

12-Apr-2022