Sustainable biomass production capacity could triple US bioeconomy, report finds

Reports and Proceedings

DOE/OAK RIDGE NATIONAL LABORATORY

 

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THE 2023 BILLION-TON REPORT IDENTIFIES FEEDSTOCKS THAT COULD BE AVAILABLE TO PRODUCE BIOFUELS TO DECARBONIZE THE TRANSPORTATION AND INDUSTRIAL SECTORS WHILE POTENTIALLY TRIPLING THE U.S. BIOECONOMY. THE MAP INDICATES A MATURE MARKET SCENARIO, INCLUDING EMERGING RESOURCES. CREDIT: ORNL/U.S. DEPT. OF ENERGY

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CREDIT: ORNL/U.S. DEPARTMENT OF ENERGY

The United States could triple its current bioeconomy by producing more than 1 billion tons per year of plant-based biomass for renewable fuels, while meeting projected demands for food, feed, fiber, conventional forest products and exports, according to the Department of Energy’s latest Billion-Ton Report led by Oak Ridge National Laboratory.

The 2023 Billion-Ton Report, or BT23, announced by DOE, is the fourth in a series of national biomass resource assessments spanning two decades. The report identifies feedstocks that could be available to produce biofuels to decarbonize transportation and industrial processes.

The report examines different levels of market maturity to assess the quantity of biomass that could be produced, its price, geographical density and distribution. The report covers biomass production capacity from some 60 resources, including winter oilseed crops, trees and brush harvested to prevent forest wildfires, purpose-grown energy crops, macroalgae such as seaweed cultivated in ocean farms, waste captured from cities and carbon dioxide from industrial plants. Harnessing emerging resources, such as algae, could boost biomass availability by another 250 million tons per year, depending on price, the report found.

The United States currently uses about 342 million tons per year of biomass to generate 5% of the nation’s energy. In a mature market where between 1.1 and 1.5 billion tons per year of biomass is available, the nation could produce 60 to 85 billion gallons per year of sustainable aviation fuel, reaching the goal of meeting 100% of the sector’s demand by 2050. Another use would be producing enough electricity to replace the power currently generated with fossil fuels.

No single source of biomass can supply all that’s needed, and the report identifies opportunities for biomass production down to the county level based on local conditions and evolving technologies. These resources and easy-to-use tools are available on DOE’s Bioenergy Knowledge Discovery Framework website.  

“An economy based on clean, sustainable biotechnologies and biomanufacturing is within reach,” said ORNL Director Stephen Streiffer. “The latest Billion-Ton report provides invaluable information to develop science-based solutions for a greener, more prosperous future. ORNL is excited to be part of that.”

“The report describes biomass production capacity in response to different market demand and pricing scenarios. The results show resources that would be accessible within economic and environmental constraints, including protecting food production,” said Matthew Langholtz, natural resources economist at ORNL and the project lead. “Even with these constraints, in a mature market with sufficient supply and demand, we could produce 1.5 billion tons of biomass annually, and even more with the new resources we identify.”

Farmers and bioeconomy stakeholders can use the report as a first step to identify biomass production opportunities. Hardy perennial crops such as poplar trees and switchgrass that need less water and fertilizer, and winter oilseed crops like carinata and pennycress can provide additional farm income. Cities could capture waste discarded in landfills, supporting a circular economy.

The report follows the 2005 U.S. Billion-Ton Study, the 2011 U.S. Billion-Ton Update and the 2016 U.S. Billion-Ton Report, all managed by ORNL researchers. The new assessment includes contributions and reviews by 52 experts from 11 federal agencies, national laboratories, universities and industry.

“Data behind the new Billion-Ton Report — as well as data from past reports — can be used to drive local, regional and national decision-making,” said Maggie Davis, natural resources data scientist at ORNL. “We leveraged modern data methods to make accessing and using the data easy for government decision-makers, industry leaders, farmers, researchers and other stakeholders who support the bioeconomy. The information can also be used to chart a course for larger investments in support of strategically targeted scientific research.”

The 2023 report “is the culmination of 20 years of meticulous analysis taking into account the potential from croplands, forests and new sources of biomass along with economic and environmental considerations, transportation and logistics and evolving technologies. We identify pathways to boost both rural and urban bioeconomies in support of a cleaner future,” said Erin Webb, lead for the Bioresource Science and Engineering group and relationship manager for DOE’s Bioenergy Technologies Office at ORNL.

ORNL’s biomass resource expertise, including Billion-Ton data and analysis, also supported the Roads To Removal national report released in December 2023 that identified 1 billion metric tons of carbon dioxide removal potential in the United States, charting a path toward the goal of a net-zero emissions economy by 2050.

UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

The United States could triple its current bioeconomy by producing more than 1 billion tons per year of plant-based biomass for renewable fuels, while meeting projected demands for food, feed, fiber, conventional forest products and exports, according to the Department of Energy’s latest Billion-Ton Report led by Oak Ridge National Laboratory.

The 2023 Billion-Ton Report, or BT23, announced by DOE today, is the fourth in a series of national biomass resource assessments spanning two decades. The report identifies feedstocks that could be available to produce biofuels to decarbonize transportation and industrial processes.

The report examines different levels of market maturity to assess the quantity of biomass that could be produced, its price, geographical density and distribution. The report covers biomass production capacity from some 60 resources, including winter oilseed crops, trees and brush harvested to prevent forest wildfires, purpose-grown energy crops, macroalgae such as seaweed cultivated in ocean farms, waste captured from cities and carbon dioxide from industrial plants. Harnessing emerging resources, such as algae, could boost biomass availability by another 250 million tons per year, depending on price, the report found.

The United States currently uses about 342 million tons per year of biomass to generate 5% of the nation’s energy. In a mature market where between 1.1 and 1.5 billion tons per year of biomass is available, the nation could produce 60 to 85 billion gallons per year of sustainable aviation fuel, reaching the goal of meeting 100% of the sector’s demand by 2050. Another use would be producing enough electricity to replace the power currently generated with fossil fuels.

No single source of biomass can supply all that’s needed, and the report identifies opportunities for biomass production down to the county level based on local conditions and evolving technologies. These resources and easy-to-use tools are available on DOE’s Bioenergy Knowledge Discovery Framework website.  

“An economy based on clean, sustainable biotechnologies and biomanufacturing is within reach,” said ORNL Director Stephen Streiffer. “The latest Billion-Ton report provides invaluable information to develop science-based solutions for a greener, more prosperous future. ORNL is excited to be part of that.”

“The report describes biomass production capacity in response to different market demand and pricing scenarios. The results show resources that would be accessible within economic and environmental constraints, including protecting food production,” said Matthew Langholtz, natural resources economist at ORNL and the project lead. “Even with these constraints, in a mature market with sufficient supply and demand, we could produce 1.5 billion tons of biomass annually, and even more with the new resources we identify.”

Farmers and bioeconomy stakeholders can use the report as a first step to identify biomass production opportunities. Hardy perennial crops such as poplar trees and switchgrass that need less water and fertilizer, and winter oilseed crops like carinata and pennycress can provide additional farm income. Cities could capture waste discarded in landfills, supporting a circular economy.

The report follows the 2005 U.S. Billion-Ton Study, the 2011 U.S. Billion-Ton Update and the 2016 U.S. Billion-Ton Report, all managed by ORNL researchers. The new assessment includes contributions and reviews by 52 experts from 11 federal agencies, national laboratories, universities and industry.

“Data behind the new Billion-Ton Report — as well as data from past reports — can be used to drive local, regional and national decision-making,” said Maggie Davis, natural resources data scientist at ORNL. “We leveraged modern data methods to make accessing and using the data easy for government decision-makers, industry leaders, farmers, researchers and other stakeholders who support the bioeconomy. The information can also be used to chart a course for larger investments in support of strategically targeted scientific research.”

The 2023 report “is the culmination of 20 years of meticulous analysis taking into account the potential from croplands, forests and new sources of biomass along with economic and environmental considerations, transportation and logistics and evolving technologies. We identify pathways to boost both rural and urban bioeconomies in support of a cleaner future,” said Erin Webb, lead for the Bioresource Science and Engineering group and relationship manager for DOE’s Bioenergy Technologies Office at ORNL.

ORNL’s biomass resource expertise, including Billion-Ton data and analysis, also supported the Roads To Removal national report released in December 2023 that identified 1 billion metric tons of carbon dioxide removal potential in the United States, charting a path toward the goal of a net-zero emissions economy by 2050.

UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

The 2023 Billion-Ton Report identifies emerging resources that could triple the U.S. bioeconomy, producing as much as 1.5 billion tons per year of biomass in a mature market. 

CREDIT

U.S. Department of Energy

 

Reimagining the future of solar energy

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

 

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SIMULATION RESULTS OF LIGHT CONCENTRATING DEVICES AROUND THE WORLD

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CREDIT: DR. TOMI BAIKIE, CAVENDISH LABORATORY, UNIVERSITY OF CAMBRIDGE

Scientists are always on the lookout for ways to make our world a better place, and one area they're focusing on is solar energy. One idea in this area is to make solar cells more efficient by concentrating more solar light onto them. While investigating this recently, a group of scientists at the Cavendish Laboratory and AMOLF (Amsterdam NL) have found that improving solar cells efficiency in this way is harder than we might think but have discovered other avenues by which it might be possible to improve solar energy capture anywhere on the planet.

The researchers were interested in finding out if solar cells, devices that turn sunlight into electricity, could be tweaked to perform better in different parts of the world, where concentration of solar light may be higher. To examine this, they used machine learning models and neural networks (AI) to understand how the sun’s radiation would behave in different spots on Earth.

They integrated this data into an electronic model to calculate the solar cells’ output. By simulating various scenarios, they could predict how much energy the solar cells could produce at various locations worldwide.

Their findings published in Joule, however, revealed a surprising twist. “Making solar cells super-efficient turns out to be very difficult. So, instead of just trying to make solar cells better, we figured some other ways to capture more solar energy,” said Dr. Tomi Baikie, first author of the study and Research Fellow at the Cavendish Laboratory and at Lucy Cavendish College. ”This could be really helpful for communities, giving them different options to think about, instead of just focusing on making the cells more efficient with light.”

Imagine solar panels that can flex and fold like origami or become partially transparent to blend seamlessly into surroundings and make them easy to install. By enhancing the durability and versatility of these panels, they could be integrated into a wide range of settings, promising longevity and efficiency.

“We suggest a different plan that can make solar panels work well in lots of different places around the world,” said Baikie. “The idea is to make them flexible, a bit see-through/semi-transparent, and able to fold up. This way, the panels can fit into all kinds of places.”

Furthermore, the researchers advocate the use of patterning the solar capture devices with the aim to optimise their arrangement for maximum sunlight absorption. This approach holds the potential to improve the design of solar arrays, increasing their effectiveness in harnessing solar energy.

“This realisation means that we can now focus on different things instead of just making solar cells work better. In future, we're going to examine solar harvesting pathways that includes tessellation. It's like a puzzle pattern that could help us capture even more sun power,” concluded Baikie.

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Photo of a light concentrating device outside the Maxwell Centre at Cambridge 

CREDIT

Dr. Tomi Baikie, Cavendish Laboratory, University of Cambridge

JOURNAL

Joule

DOI

10.1016/j.joule.2024.01.018 

 

Air quality in Lombardy region: livestock farming responsible for up to a quarter of pollution

CMCC FOUNDATION - EURO-MEDITERRANEAN CENTER ON CLIMATE CHANGE

Agricultural activities and livestock farming are key contributors to the concentrations of hazardous pollutants for health and the environment in the atmosphere, but the potential action in these sectors is often overlooked in public debate.

The recent pollution alarm in Northern Italy has brought attention to the Lombardy region, one of the most critical areas in Europe in terms of air quality. The new study “Exploring the impact of livestock on air quality: A deep dive into Ammonia and particulate matter in Lombardy,” conducted with the participation of CMCC authors, provides a framework for studying the impact of farming on air pollution in the area and supports the need for integrated policies in the agricultural sector.

The study was conducted in the context of the INHALE project (Impact on humaN Health of Agriculture and Livestock Emissions), funded by Fondazione Cariplo, coordinated by Università Bocconi and carried out in partnership with the CMCC Foundation and Legambiente Lombardia. Scientists studied the extent to which emissions from agriculture contribute to high concentrations of particulate matter and, consequently, may lead to a related increase in health risk for the population in Lombardy. The research shows the need for pollution reduction policies not to ignore emissions from agro-livestock sources (ammonia), while at the same time acting on traffic pollutants (NOx).

“The Po Valley is infamously known for the poor quality of the air its inhabitants breathe” says Jacopo Lunghi from Bocconi University and CMCC, lead author of the paper. “Its record levels of particulate matter, especially during winter, make it one of the most polluted areas in Europe. Investigating the sources of such unhealthy air is vital to decrease pollution and increase the wellbeing of individuals through effective policy action.”

The contribution of ammonia (NH3) emissions to the levels of particulate matter recorded in the Po Valley is substantial, and agriculture, especially the management of livestock manure and the use of fertilizers, is the main source. Animal husbandry operations are responsible for large releases of ammonia, a gaseous compound that serves as a precursor in secondary particle formation. From reactions with other compounds, such as sulfur oxides (SOx) and nitrogen oxides (NOx), ammonia contributes to a major part of the inorganic composition of PM2.5. This explains why air pollution from livestock farms is associated with airway obstruction diseases and severe pneumonia.

Specifically, an increase of 1,000 units in livestock triggers a corresponding daily increase in ammonia and particulate matter concentrations in Lombardy quantified at 0.26 and 0.29 μg/m3 for bovines (about 2% and 1% of the respective daily averages) and 0.01 and 0.04 μg/m3 for swine. The study also suggests that bovine and swine farming could account for up to 25% of local pollution exposure.

The paper contributes by establishing a necessary step to evaluate the nature of the direct correlation between changes in livestock levels and the impact on human health due to air pollution. The use of causal inference methods is a novel approach to this type of analysis.

“The Po Valley suffers from an unfortunate combination of unfavorable orographic conditions, high population density and high industrial and agricultural intensity” affirms CMCC researcher Lara Aleluia Reis. “Much is being done to mitigate the power and the transport sector and to some extent also the residential sector. Agriculture, more specifically the sector of livestock, cannot be left aside and must also be included in more stringent air pollution mitigation policies.”

Maurizio Malpede from University of Verona says: “Understanding the environmental impacts of intensive livestock farming can pave the way for a less polluted environment. Our research can help us develop sustainable farming practices that not only minimize environmental harm but also mitigate public health risks. By optimizing resource use and reducing waste, we can ensure more efficient and sustainable production systems. Additionally, our research findings can guide policy decisions to protect ecosystems and public health while increasing consumer awareness about the consequences of their dietary choices, which can contribute to global efforts to mitigate climate change.”

 

For more information: 

• The study: J. Lunghi, M. Malpede, L. Aleluia Reis, Exploring the impact of livestock on air quality: A deep dive into Ammonia and particulate matter in Lombardy, Environmental Impact Assessment Review, Volume 105, 2024, 107456, ISSN 0195-9255, https://doi.org/10.1016/j.eiar.2024.107456.
• Video of the INHALE project

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DOI

10.1016/j.eiar.2024.107456 

ARTICLE TITLE

Environmental Impact Assessment Review

 

Rapid study of Kakhovka Dam breach impacts will support biodiversity’s recovery

UK scientists use cutting-edge technologies for unprecedented assessment

UK CENTRE FOR ECOLOGY & HYDROLOGY

 

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FLOODING IN KHERSON FOLLOWING THE DAM BREACH.

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CREDIT: ДМИТРО ЗАВТОНОВ / АРМІЯINFORM, CC BY 4.0

UK scientists’ unprecedented rapid assessment of the environmental impacts of the Kakhovka Dam’s breach will support international action to restore a biodiversity hotspot.

With the area in southern Ukraine in a warzone, the UK Centre for Ecology & Hydrology (UKCEH) and HR Wallingford used cutting-edge technologies to carry out the first independent assessment of the impacts within weeks of the dam being breached in June.

It estimated that half a million hectares of protected freshwater and terrestrial habitats have been exposed to a range of hazards, including nutrients, pollutants from 1,000 sites and the erosion of sediment. This follows widespread flooding downstream and the near-emptying of the upstream Kakhovka Reservoir.

Environmental assessments have previously taken place only after a war, when it is safe for scientists to carry out in-depth field studies, but this has limited the scope of targeted biodiversity restoration within post-conflict recovery planning.

The Kakhovka study, commissioned by the Foreign, Commonwealth and Development Office (FCDO), combined hydrological and digital modelling with satellite imagery and a study of data on the region’s ecology. This enabled the identification of protected habitats and species likely to be impacted by the breach, setting a precedent for early action in future conflicts.

The report’s key findings were:

• Around 83,000 hectares of land, an area the size of Kyiv, was flooded downstream of the dam. The discharge of water was 30,000 m3 per second immediately after the breach, compared to a daily average of 2,600 m3/sec
• The Kakhovka Reservoir was almost completely emptied, leaving thousands of fish washed out or stranded. This included an estimated 28,000 crucian carp, totalling 95,000 tonnes with an estimated commercial value of US $108 million
• There were more than 1,000 potential sources of pollution from flooded sites, including wastewater treatment works, petrol stations, landfills and industrial sites
• The erosion of sediment following the flood might also have released historic pollutants, such as metals, stored in sediments
• The breach affected over half a million hectares of habitats of national or international importance, upstream and downstream of the dam, including the Black Sea Biosphere Reserve
• Some 28 of the 567 species affected by a range of hazards are globally threatened or worse, including the Great Bustard, Pontic Shad, Harbour porpoise, Donets ruffe, the Steppe Polecat, the European mink and the slender-billed curlew, the latter being on the verge of extinction.

Professor Bryan Spears of UKCEH says: “We hope that our assessment provides a baseline against which to assess biodiversity and habitat impacts and recovery related to the Kakhovka Dam breach. It is now important that the results of this and other assessments are scrutinised fully by the wider scientific community, allowing biodiversity restoration to be incorporated within post-conflict recovery planning at an early stage.”

Emma Brown, technical director at HR Wallingford, adds: “I am very proud of the work we’ve done with UKCEH to assess the environmental impacts of the Kakhovka Dam breach. Combining our expertise in dam breach modelling, hydrology and earth observation with UKCEH’s expert biodiversity knowledge enabled the team to produce a detailed report in just 16 days, which I hope will be instrumental in helping with recovery efforts in the region.”

The report, which informed a wider report by the UN Environment Programme, also identified potential long-term effects on the environment, human health and economies. It said the flooding would have worsened water infrastructure and quality, affecting drinking water supply and irrigation for agriculture. The authors made several recommendations for future action (see Notes).

Professor Harry Dixon, Associate Director of International Research and Development, UKCEH, comments: “This significant work undertaken in a timely way using cutting-edge technologies highlights the importance of using science from organisations to inform humanitarian and environmental response to disasters and emergencies across the globe.”

The report is available on the Zenodo website and a commentary by Professor Spears has been published in the journal Nature, Ecology & Evolution (DOI: 10.1038/s41559-024-02373-0).

- Ends -

 

Media enquiries

For interviews and further information, please contact Simon Williams, Media Relations Officer at UKCEH, via simwil@ceh.ac.uk or +44 (0)7920 295384.

 

Notes to editors

Report authors’ recommendations

The report by UKCEH and HR Wallingford recommends an assessment of the sources of radioactive and munitions waste, and their movement down the Dnipro River to the Black Sea. This would support clean-up efforts, reduce the risks to human health associated with eating contaminated fish, shellfish and crops and safeguard a key global grain shipping route if there are unexploded arms in the area.

The scientists at UKCEH and HR Wallingford are now encouraging the international scientific community to work together to build on their initial assessment, to quantify the ecological impacts, provide monitoring programmes, and ensure open access of relevant data.

They call for the rapid development of habitat recovery plans to support species of high conservation, cultural and commercial interest, saying an international scientific response will be required.

 

About the UK Centre for Ecology & Hydrology (UKCEH)

The UK Centre for Ecology & Hydrology is a world-leading centre for excellence in environmental sciences across water, land and air. Our 500-plus scientists work to understand the environment, how it sustains life and the human impact on it – so that together, people and nature can prosper.

We identify key drivers of biodiversity change, develop tools and technologies for monitoring biodiversity, and provide robust socio-economic and environmental solutions for restoring biodiversity. We investigate the dispersal, fate and behaviour of chemicals and polluting substances in terrestrial and freshwater environments.

The UK Centre for Ecology & Hydrology is a strategic delivery partner for the Natural Environment Research Council, part of UK Research and Innovation.

www.ceh.ac.uk / X: @UK_CEH / LinkedIn: UK Centre for Ecology & Hydrology

 

About HR Wallingford

We design smart, resilient solutions across the natural and built environments to help everyone live and work more sustainably with water.

By harnessing research, data insights and the power of our collective expertise, we help the world to better understand the changing influence and impact of water.

Drawing on our unique capabilities in science, technology and engineering, we invest in knowledge and innovate to address future challenges and opportunities.

We are the global leaders and independent experts in how to live and work sustainably with water.

www.hrwallingford.com / X: @hrwallingford / LinkedIn: HR Wallingford

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METHOD OF RESEARCH

Computational simulation/modeling

ARTICLE TITLE

A rapid assessment of the immediate environmental impacts of the destruction of the Nova Kakhovka Dam, Ukraine’

ARTICLE PUBLICATION DATE

18-Mar-2024

 

Lehigh University researchers awarded $2 million DOE grant to develop and demonstrate lower greenhouse gas cement ingredient

LEHIGH UNIVERSITY

A research team at Lehigh University led by John T. Fox, an associate professor of civil and environmental engineering, has been awarded a $2 million, three-year grant from the Department of Energy’s Industrial Efficiency and Decarbonization Office (IEDO) for its proposal, “Decarbonizing Concrete: Low-Temperature Calcined Clays as an Alternative Concrete Binder, ​Achieving Durability with Clay Beneficiation.” The team also consists of Clay Naito, a professor of civil and environmental engineering, Paolo Bocchini, a professor of civil and environmental engineering, and Carlos Romero, director and principal research scientist of Lehigh's Energy Research Center.

IEDO states that the purpose of the award is to “drive improvements in energy, materials, and production efficiency, and to accelerate decarbonization across the industrial sector.” Fox’s project has the potential to speed up the process of developing low-carbon or net-zero technology for commercialization in the concrete industry. The Lehigh team will focus on the processing and testing of calcined clay to develop a material that has properties similar to those of ordinary Portland cement, but without the greenhouse gas (GHG) emissions typical of its production. 

The research project also involves Buzzi Unicem USA, a leading cement manufacturing company based in Bethlehem, PA, which has previously collaborated with Lehigh researchers on other projects. Shamim Pakzad, professor and dhair of the Department of Civil and Environmental Engineering, is optimistic about the partnership between industry and academic research. “This grant shows the opportunities of synergy between academia and industry, and how it could lead into high level and impactful research," he says. "I am particularly excited about the expansion of the research portfolio of CEE departments into this area of greener cement, which opens many opportunities for future research and implementation in industry.”

The cement industry presents a huge opportunity for lower-emission innovation, because its traditional production methods can be environmentally harmful and because it is used in so many ways, particularly in construction. Concrete is generally made by adding water to cementitious materials to form a binder which is mixed with sand and stone aggregate. The most popular modern binder relies on Ordinary Portland Cement (OPC), which is produced by heating limestone to extreme temperatures (over 2,500 degrees F). OPC contributes to carbon dioxide emissions in two ways during production: first, the heating process uses fossil fuels, which form carbon dioxide during combustion; and second, limestone undergoes a chemical transformation called calcination that directly releases carbon dioxide during heating. Due to the significant volume of cement used and carbon intensity of production, Ordinary Portland Cement production is responsible for 4% to 8% of the world’s carbon dioxide. Because of this tremendous scale, finding a replacement for the OPC is crucial to creating a net-zero economy.

Fox and his team will work with a possible replacement, low-grade calcined clay. This lower-cost and more available limestone-free clay does not directly emit carbon dioxide during heating and can be calcined at lower temperatures than limestone. A variety of low-grade clays are available within the U.S. for the research effort. Part of the team’s testing will involve cleaning, milling, and appraising the properties of these different clays, as well as measuring the carbon footprint of each.

Buzzi will supply several varieties of low-grade calcined clay. The team at Lehigh will combine these clays in various mixes, create mortar cubes, and test their performance in multiple tests for compressive strength and for mechanical and durability qualities, such as freeze-thaw cycle, abrasion resistance, and chloride migration.

The project’s overall goal is to produce an economically viable calcined clay that, when mixed, produces half the CO2 of traditional mixes. Considering that concrete is the second-most used material in the world (after water), this would be a big step toward the reduction of carbon dioxide emissions.

 

Artificial streams reveal how drought shapes California’s alpine ecosystems

Researchers used a series of channels in the Eastern Sierra Nevada to mimic the behavior of headwater streams under present day conditions and future climate change scenarios

UNIVERSITY OF CALIFORNIA - BERKELEY

 

IMAGE: 

UNIVERSITY OF CALIFORNIA, BERKELEY, RESEARCHERS USED A NETWORK OF ARTIFICIAL STREAM CHANNELS TO MIMIC THE BEHAVIOR OF HEADWATER STREAMS UNDER PRESENT DAY CONDITIONS AND FUTURE CLIMATE CHANGE SCENARIOS. THE ZIG-ZAGGING CHANNELS, EACH 50 METERS LONG AND 1 METER WIDE, RESEMBLE A MOUNTAIN HEADWATER STREAM. THE CHANNELS DIVERT FRESH WATER FROM NEARBY CONVICT CREEK AND ARE EQUIPPED WITH GATES TO CONTROL HOW MUCH WATER FLOWS THROUGH EACH CHANNEL.

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CREDIT: THE RUHI LAB, UC BERKELEY

Berkeley — A network of artificial streams is teaching scientists how California’s mountain waterways — and the ecosystems that depend on them — may be impacted by a warmer, drier climate.

Over the next century, climate change is projected to bring less snowfall to the Sierra Nevada. Smaller snowpacks, paired with warmer conditions, will shift the annual snowmelt earlier into the year, leaving less water to feed streams and rivers during the hot summer months. By 2100, mountain streams are predicted to reach their annual base, or “low-flow,” conditions an average of six weeks earlier in the season than now. 

In a new study, University of California, Berkeley, researchers used a series of nine artificial stream channels off Convict Creek in Mammoth Lakes, California, to mimic the behavior of headwater streams under present-day conditions and future climate change scenarios.

Over the course of a summer, the researchers monitored the populations of algae, aquatic insects and other organisms growing in and around the stream channels. They found that shifting the timing of the low-flow conditions also shifted the life cycles of many of these organisms and the relative abundance of different species. It also caused pulses of midges, the dominant insect group, to nearly double in magnitude.

However, because species adjusted to the shifts in a variety of ways, the stream ecosystems were generally resilient to the changing conditions.

“We were surprised to see such a clear example of how biodiversity can stabilize ecosystems,” said study first author Kyle Leathers, a graduate student in the Ruhi Lab at UC Berkeley. “It’s similar to having a balanced financial portfolio — because different species respond in different ways to warming, the more species a river has, the more likely it is that warming will not drastically impact an ecosystem process that is key for the broader food web.”

The study appears this week in the journal Proceedings of the National Academy of Sciences.

Changing the rhythm of the seasons

Ecosystem processes follow natural seasonal rhythms, and animals, plants and other organisms are adapted to these seasonal changes. For example, aquatic insects disperse, reproduce and grow along fixed developmental timelines — and their success depends on factors such as water temperature and nutrient availability. Their predators, likewise, are cued to expect abundant populations of insects at specific times of year. 

Leathers and senior study author Albert Ruhi, an associate professor of environmental science, policy and management at UC Berkeley, wanted to understand how earlier low-flow stream conditions might impact these natural rhythms.

“When you only study annual averages, you may not get the full story because important changes are happening on a much finer scale,” Ruhi said.

The system of artificial stream channels, maintained by the UC Sierra Nevada Aquatic Research Laboratory, offered an ideal location for studying these fine-scale changes. Originally built by researchers at the U.S. Fish and Wildlife Service, the channels divert fresh-flowing water from nearby Convict Creek. Each of the nine channels is 50 meters long and 1 meter wide — approximately the size of a small mountain stream — and equipped with a gate to control how much water flows through the channel.

The outdoor stream channels allow for natural colonization of insects, algae and other nutrients. They also reflect natural fluctuations in temperature, dissolved oxygen and other variables — all of which can be monitored via modern sensors.

“At this scale, this is the only system that uses natural water, not recirculated water, and the water comes from the actual snowmelt in the watershed.” Ruhi said “We could potentially run a similar study by comparing dry and wet years in natural waterways, but it's almost impossible in nature to have nine nearby, identical streams where some are under low flow and others are not.”

During the summer of 2019, the researchers set three of the nine channels to mimic low-flow conditions starting in early August, which is when streams usually reach low-flow in this region. They set an additional three channels to low-flow three weeks earlier, in early July, and set a final three to low-flow six weeks earlier, in mid-June.

As the summer progressed, Leathers and other members of the research team took periodic measurements of various stream conditions, from water temperature and dissolved oxygen levels to the number of insects in the stream channels. They found that the channels responded almost immediately to low-flow conditions with rising water temperatures, changes in algae metabolism and earlier emergence of insects.

These shifts could have significant consequences not only for the fish, but also for terrestrial predators like birds, bats and lizards that rely on pulses of aquatic insects for food. The boom in midges, for example, attracted nearby Brewer’s blackbirds, which collected the nutritious insects to feed their young.

“It is remarkable that despite the stability at the broad ecosystem level, even slight changes can be consequential,” Ruhi said. “We did not expect that early snowmelt would control the abundance of stream insects metamorphosing, leading to earlier, more abundant pulses of flying bugs that in turn attracted riparian birds. This type of cross-ecosystem linkage is something we just had not envisioned, and we would have never captured in a laboratory setting. It underlines that timing is everything”. 

The Ruhi Lab is now expanding on this work to understand how climate change may lead to mismatches — or new matches — in aquatic food webs.

“Ecologists often think of climate change leading to predator-prey mismatches, because predators and their prey shift their life cycles at different rates, or even in different directions, resulting in starved predators,” Leathers said. “The notion of novel matches may be underappreciated, but important.”

Additional co-authors include David Herbst of the Sierra Nevada Aquatic Research Laboratory and Guillermo de Mendoza and Gabriella Doerschlag of UC Berkeley. This research was supported the Sequoia Parks Conservancy, the UC Valentine Eastern Sierra Reserves and the Margaret C. Walker Fund.

University of California, Berkeley, researchers used a network of artificial stream channels to mimic the behavior of headwater streams under present day conditions and future climate change scenarios. The outdoor stream channels allow for natural colonization of insects, algae and other nutrients. They are also equipped with sensors to monitor natural fluctuations in the temperature and dissolved oxygen levels of the water. The wooden-framed screen in the foreground prevents fish from entering the channel.

University of California, Berkeley, researchers used a network of artificial stream channels to mimic the behavior of headwater streams under present day conditions and future climate change scenarios. In this image, lead researcher Kyle Leathers uses a home-built device to capture insects as they emerge from their nymphal stage, which they spend in the water, into their adult stage, which they spend on land or flying in the air. The team built the device using PVC pipes and mesh, and added pool noodles to help it float.

CREDIT

The Ruhi Lab, UC Berkeley

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JOURNAL

Proceedings of the National Academy of Sciences

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

Climate change is poised to alter mountain stream ecosystem processes via organismal phenological shifts

ARTICLE PUBLICATION DATE

18-Mar-2024