The program is open to students who want to apply for an MS or PhD in the Earth sciences or who have applied previously to a graduate program. Bridge programs like AGU’s are part of a raft of larger efforts to broaden participation in a field whose makeup does not reflect the U.S. population or other science professions.

The geosciences are the least diverse among all STEM fields, according to recent surveys of graduate degrees conferred, and faculty of color hold a mere 3.8% of tenured or tenure-track positions in the top 100 Earth science programs in the U.S. More troublingly still, these trends show little improvement over the last 40 years, so funders like NSF and professional societies like AGU are redoubling efforts to better connect to, recruit, and serve students from ethnic and racially diverse backgrounds.

“We in the biogeosciences have to do better when it comes to not just recruiting, but supporting scholars from marginalized communities throughout their careers,” said assistant research professor Mariah Carbone, one of the leads on the Ecoss AGU Bridge team. “The AGU Bridge Program will help our center better serve students from minoritized communities by sharing best practices and trainings, and by connecting us with these researchers who are a vital part of our field’s future.”

“We’re looking forward to working with students in this program at NAU,” said Ted Schuur, a Regents Professor in biology and Ecoss who led efforts to join the AGU Bridge Program. “Students accepted into the program will have the support of a nationwide peer network, and the program allows us to learn mentoring strategies from other institutions across the U.S.”

“A critical part of NAU’s mission is to make concerted, collaborative efforts to increase diversity, including recruiting students from historically underserved and underrepresented groups and diverse life experiences and backgrounds,” NAU president José Luis Cruz Rivera said. “Ecoss’ collaboration with the AGU Bridge Program is an important step in that process, and I’m excited to see this increased focus to increase participation in these fields so they are more representative of our communities.”

Learn more about the AGU Bridge Program and its partners here.

The team, which includes researchers from NAU, University of California-Berkeley, Lawrence Livermore National Laboratory, and University of Nebraska-Lincoln, will conduct experiments in rivers in Arizona and California. By manipulating nutrients and sunlight, they will look for the biological “switches” that get turned on and off by organisms living in the algal mat, a laminate composed of algae, bacteria, fungi, and tiny animals that grows on rocks and sediments of riverbeds.

“When does productive algae become toxic strains of Cyanobacteria, which can be really harmful to marine life, dogs, and humans, and what are the biological switches that flip?” said principal investigator Jane Marks, professor in biology in the Center for Ecosystem Science and Society at NAU. “Even in a relatively pristine river like the Eel, we get these very sudden shifts from productivity to toxicity, and we don’t really understand the tipping points.”

Because algal mats are long-studied and relatively accessible to observe, the team will use them as models to better learn how microbial communities beyond rivers behave. The team will combine field experiments with high-tech molecular tools and machine learning to unravel the complex interactions among bacteria and algae into a set of predictive rules. The experiments they conduct and computer models they develop will illumine which interactions among micro-organisms have the power to change the health of a river or a human gut.

“I’m excited to gather new kinds of measurements with this team, like species-specific carbon and nitrogen uptake rates,” said Toby Hocking, assistant professor in the School of Informatics, Computing and Cyber Systems at NAU and co-principal investigator on the project. “Most previous work has been limited to measurement of abundance data, which means counting the individuals of a species in a population. But having only abundance data makes it very difficult to infer more complex interactions such as mutualism and predation. Combining our metabolic data with abundance will reveal new details about interactions and relationships between species in these microbial communities.”

“Since we can’t walk through an algal forest to map out where nutrients are going, we need to use isotopic tools like qSIP (quantitative stable isotope probing) and NanoSIMS (nano secondary ion mass spectrometry), which allow us to follow carbon and nitrogen as it moves through the system,” said Marks.

“Pulling nitrogen into the river food web, as the diatom Epithemia does, is hugely important for fish like salmon and other riverine consumers,” said Mary Power, a professor at University of California-Berkeley and co-principal investigator on the project. “Using the sophisticated technology Ecoss developed, we can track how Epithemia—the Greek word for desire—and its amazing endosymbiont bring nitrogen into the river.”

The NSF award will support training 10 undergraduate students, two postdocs, and four graduate researchers at NAU. The team will collaborate with tribal community partners and citizen scientists to conduct field trips called “algal forays,” and plans to share what they learn about the algae microbiome through community art and science collaborations like Parched: the Art of Water in the Southwest.

For Marks, who studies how freshwater food webs respond to environmental change, this project represents a return to her first scientific love: exploring life underwater.

“Jane first taught me to recognize Epithemia when she began her dissertation work in the Eel River three decades ago,” said Power. “Now we’re back on its trail, learning how changes in river temperatures, flows, and other factors can turn this algae from an excellent food source for salmon-bearing food chains into a victim of overgrowth by other toxic algae and Cyanobacteria.”

“I have loved algae for many, many years,” said Marks. “It’s green and slimy, but when you put it under the microscope, you enter this secret world. There are epiphytes of all colors and shapes, and structures that rival the planet’s densest forests. I love getting to go back there with new questions.”

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Other co-principal investigators from NAU include Greg Caporaso of the School of Informatics, Computing and Cyber Systems and Bruce Hungate of the Center for Ecosystem Science and Society.

“Our fate is bound up with soil carbon, and its fate is bound up with these intricate microbial communities, whose individual capabilities and interactions we are only beginning to understand,” said Jennifer Pett-Ridge, the lead investigator and Environmental Isotope Systems Group Leader at LLNL. “Using new tools, some of which this team developed, we are asking: how can understanding the microbial lives unfolding in soil tell us about the future of carbon?”

These microscopic lives, the researchers say, are highly sensitive to soil moisture, and undergo significant changes as the weather patterns of our climate (rainfall, temperature) are changing. Pett-Ridge and others are mimicking shifts in California’s climate and tools linking metagenomics with stable isotope tracers to see how microbes respond to these changes. By observing who is actively growing, who is dying, and how the genes expressed in the microbiome change as a result, the research team will learn which functions of microorganisms are most relevant to keeping carbon in the soil, and what indicators predict when it will be released into the atmosphere.

“Some microbial communities seem to respond to drought like many plants and animals do: by waiting for a better year,” said Bruce Hungate, director of the Center for Ecosystem Science and Society at Northern Arizona University (NAU) and a collaborator on the project. “By studying wild microbes, outside of the lab and in their home soils, we’re beginning to understand how dynamic and nuanced these communities really are.”

The team, which includes researchers from LLNL, NAU, University of California-Berkeley, Lawrence Berkeley National Laboratory, University of Minnesota, Pacific Northwest National Laboratory, and University of California-Davis, has been asking questions about the way soil water patterns shape microbial communities, and this new “Microbes Persist” award allows it to ask new questions about how microbial capabilities change with soil depth and over time. A recent study published by the team, the first to apply quantitative stable isotope probing (qSIP) to all the different organisms in soil simultaneously, revealed that soil viruses that infect bacteria near plant roots were among the most active entities in the soil microbiome.

Alexa Nicolas, a graduate student on the project from UC Berkeley, says this project “opens a window into the life and death of soil microbes, to see their molecular afterlives. We can measure this by tracing molecules through microbial life and death along paths shaped by the DNA of the whole soil community.”

“We are now seeing the effects of climate change in our day to day lives, whether it’s wildfire smoke or a drought-depleted reservoir,” said Pett-Ridge. “Microbes are experiencing stresses from some of the same effects. We want to understand how that stress alters their living, growing, and dying, and what that means for the huge reservoirs of nutrients and carbon held in soils.”

The research is funded by the Department of Energy, Office of Science – Office of Biological and Environmental Research and the Genomic Science Program LLNL “Microbes Persist” Soil Microbiome Scientific Focus Area.

That’s why she created a user interface called “MIDA”—model-independent data assimilation—which allows a scientist to improve a model with data without extensive coding experience. The resulting study, “A model-independent data assimilation (MIDA) module and its applications in ecology,” was published in Geoscientific Model Development and is Huang’s first lead-author publication.

“A model is a powerful tool to approach the future with, which is why we wanted to expand access with this software,” said Huang. “In this data-rich era, we use data assimilation to integrate abundant observations into models. If an ecologist wants to train a model but doesn’t have extensive programming experience, they might run into technical issues. This software aims to remove that barrier.”

Huang is a member of Yiqi Luo’s EcoLab, where she and her colleagues work to make earth system models faster and more accurate through data assimilation and the matrix approach. “Even if a model is perfect, we need observations to constrain it. So data assimilation is a tool we use to bring the model and our observations together, to create a clearer picture of what the future looks like.”

Huang, who received her masters from Tsinghua University in China, said publishing in Geoscientific Model Development means a great deal to her, since the journal is a gold standard in her field. The paper was co-authored by research associate Lifen Jiang, postdoctoral fellow Enqing Hou, and Regents’ professor Yiqi Luo of the Center for Ecosystem Science and Society, and assistant professor Igor Steinmacher and Regents’ professor Andrew Richardson of the School of Informatics, Computing, and Cyber Systems.

What’s next for Huang? She plans to use MIDA and data from the SPRUCE project in northern Minnesota to improve ecological forecasting.

“Climate forecasting, like weather forecasting, comes with uncertainty,” Huang said. “When we talk about modeling future aspects of the climate, this uncertainty is huge, especially around the nature of carbon sources and sinks and the processes that drive them. This is the work I want to dive into next.”

The terrestrial biosphere—the activity of land plants and soil microbes—does much of Earth’s ‘breathing,’ exchanging carbon dioxide and oxygen. Ecosystems across the globe pull in carbon dioxide through photosynthesis and release it back to the atmosphere via the respiration of microbes and plants. Over the past few decades, the biosphere has generally taken in more carbon than it has released, mitigating climate change.

But as record-breaking temperatures continue to spread across the globe, this may not continue; the NAU and Waikato researchers have detected a temperature threshold beyond which plant carbon uptake slows and carbon release accelerates.

Lead author Katharyn Duffy, a postdoctoral researcher at NAU, noticed sharp declines in photosynthesis above this temperature threshold in nearly every biome across the globe, even after removing other effects such as water and sunlight.

“The Earth has a steadily growing fever,” said Duffy, “and much like the human body, we know every biological process has a range of temperatures at which it performs optimally, and ones above which function deteriorates. So we wanted to ask, how much can plants withstand?”

This study is the first to detect a temperature threshold for photosynthesis from observational data at a global scale. While temperature thresholds for photosynthesis and respiration have been studied in the lab, the Fluxnet data provide a window into what ecosystems across Earth are actually experiencing and how they are responding.

“We know that the temperature optima for humans lie around 37^oC (98^oF),” Duffy said, “but we in the scientific community didn’t know what those optima were for the terrestrial biosphere.” She teamed up with two researchers at the University of Waikato in New Zealand who recently developed a new approach to answer that question: MacroMolecular Rate Theory (MMRT). With its basis in the principles of thermodynamics, MMRT allowed the researchers to generate temperature curves for every major biome and the globe.

The results were alarming.

The researchers found that temperature “peaks” for carbon uptake —18^oC for the more widespread C3 plants and 28^oC for C4 plants— are already being exceeded in nature, but saw no temperature check on respiration. This means that in many biomes, continued warming will cause photosynthesis to decline while respiration rates rise exponentially, tipping the balance of ecosystems from carbon sink to carbon source and accelerating climate change.

“Different types of plants vary in the details of their temperature responses, but all show declines in photosynthesis when it gets too warm,” said NAU co-author George Koch.

Right now, less than 10 percent of the terrestrial biosphere experiences temperatures beyond this photosynthetic maximum. But at the current rate of emissions, up to half the terrestrial biosphere could experience temperatures beyond that productivity threshold by mid-century—and some of the most carbon-rich biomes in the world, including tropical rainforests in the Amazon and Southeast Asia and the Taiga in Russia and Canada, will be among the first to hit that tipping point.

“The most striking thing our analysis showed is that the temperature optima for photosynthesis in all ecosystems were so low,” said Vic Arcus, a biologist at the University of Waikato and co-author of the study. “Combined with the increased rate of ecosystem respiration across the temperatures we observed, our findings suggest that any temperature increase above 18^oC is potentially detrimental to the terrestrial carbon sink. Without curbing warming to remain at or below the levels established in the Paris Climate Accord, the land carbon sink will not continue to offset our emissions and buy us time.” 

Funding for this research was provided by the National Aeronautics and Space Administration (grant NNX12AK12G), National Science Foundation (NSF) East-Asia Pacific Summer Institute Fellowship (1614404), the Royal Society of New Zealand Foreign Partnership Programme (EAP- UOW1601) and the New Zealand Marsden Fund (grant 16-UOW-027). This work used eddy covariance data acquired and shared by the FLUXNET community, including AmeriFlux, AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada, GreenGrass, ICOS, KoFlux, LBA, NECC, OzFlux-TERN, TCOS-Siberia, and USCCC networks.

“The Bumpy Road to Net Zero: Paths to Carbon Neutrality in Uncertain Times” features experts in nine major areas of campus carbon reduction, including campus efficiency improvements, biomass energy, cross-sector partnerships, carbon offsets, power purchase agreements, and financing. Panels over the three-day conference will also discuss the importance of student engagement and leadership in achieving climate goals, and accountability and organizational tools that are key to their success. The event is backed by the Center for Ecosystem Science and Society (Ecoss) and the McAllister Program on Community, Culture, and the Environment at Northern Arizona University in partnership with the NAU Office of Sustainability.

Speakers from diverse campuses, including the University of California-Davis, University of Wisconsin, Brown University, Colorado State University, Ohio State University, and Stanford University, will discuss some of the obstacles and opportunities they have encountered, including budgetary constraints and energy savings realized during the Covid-19 pandemic. Northern Arizona University has recently renewed its climate action planning process and will be finalizing its own carbon reduction goals in spring 2021.

“We know getting to carbon neutrality is a challenging road,” said George Koch, associate director of Ecoss and one of the event’s lead organizers. “Why have some campuses made it farther than others? How does a campus engage its full community on this journey? And importantly, how well must we know the route before committing to reaching the destination? By creating a forum for sharing lessons learned, we hope to begin to answer some of these questions together.”

Since the Presidents’ Climate Leadership Commitment was initiated in 2006, more than 450 colleges and universities across the nation have made carbon reduction and neutrality commitments. A few have achieved carbon neutrality ahead of their target date, while others are redoubling efforts to meet their goals; still others are establishing new targets. According to Second Nature, a non-profit that supports climate action in higher education and helped develop the 2006 climate commitment, nine U.S. institutions have achieved carbon neutrality as of this fall.

“Achieving carbon neutrality is not an easy feat,” said Tim Carter, president of Second Nature, who will deliver opening remarks at the event. “It requires making the commitment, creating a plan, and doing the hard work. Hundreds of higher education institutions of all sizes and structures have made this commitment and are doing the work to reach their carbon neutrality goals. They understand that there is no other option, because climate change doesn’t just affect their campuses and communities, but is a global crisis that we need to solve together. Which is why opportunities like this one being hosted by Northern Arizona University—opportunities that bring together college and university leaders to share and cultivate climate solutions, and to provide peer-to-peer support to one another—are so crucial.”

“As institutions committed to serving future generations, we know we must address the climate crisis now,” said Bruce Hungate, director of Ecoss and chair of the McAllister Program on Community, Culture, and the Environment. “We hope these conversations can foster some of the community, creativity, and urgency needed to navigate the way forward.”

Registration is free and required to attend the sessions. Learn more about the speakers and register at the conference website.

Participants include representatives from: Northern Arizona University, Arizona State University, Brown University, Colorado College, Colorado State University, Duke University, Ohio State University, Stanford University, University of California – Davis, University of California-Berkeley, University of Colorado – Boulder, University of Idaho, University of Illinois – Urbana-Champaign, University of Minnesota – Morris, University of Montana, University of Northern Iowa, University of Utah, and University of Wisconsin – Madison.

As Arizona confronts the impacts of a hotter world, Northern Arizona University is joining partners from Arizona State University, the University of Arizona and communities from throughout the state to convene the first statewide, solutions-focused climate summit.

Climate 2020: Seven Generations for Arizona is a two-day event that will bring together youth, community leaders, decisionmakers and researchers Nov. 15-16 in Flagstaff. The summit will feature nationally-recognized voices on climate issues including Texas Tech scientist Katharine Hayhoe, hip-hop artist Xiuhtezcatl Martinez, and former Governor of Arizona and Secretary of the Interior Bruce Babbitt.

“Arizonans have a long tradition of coming together in moments of urgency, and our quickly changing climate presents us with another one: larger and more frequent wildfires, prolonged drought, extreme heat and reduced snowpack are already changing life in this state,” Babbitt said. “Climate 2020: Seven Generations for Arizona offers Arizonans a chance to meet at a critical junction in our state’s life and ask each other: What do we love here? And what are we willing to do to keep the state we love healthy and habitable for our children, and the grandchildren of their grandchildren?”

“Climate change is already affecting us, here and now, and as a climate scientist, I know that the choices we make today will determine our future,” said Hayhoe, who has served as an expert reviewer for the Intergovernmental Panel on Climate Change and writes the digital short series Global Weirding. “That’s why it’s so important to talk about how we can build resilience and transition to clean energy while investing in our kids and our future.”

Bruce Hungate, director of the Center for Ecosystem Science and Society (Ecoss) at NAU, which is one of the sponsors of the summit, spoke about the importance of addressing these issues in Arizona.

“We know that the changes happening globally affect Arizona, and we’re observing them everywhere: under the microscope, on our farms and in our front yards,” said Hungate, who also is chair of the McAllister Initiative on Community, Culture, and the Environment. “It’s time for a new kind of conversation, one that brings all of our voices to bear on the big question: What do we want to do now?”

Bringing together more than 30 speakers on a broad range of issues including rural resilience, community climate action and wildfire response and management, Climate 2020: Seven Generations for Arizona draws on the Iroquois principle of making resource decisions that will be sustainable for the next seven generations. Students will deliver keynotes and lead breakout sessions and panels throughout the summit. A climate action town hall on Nov. 16 will feature members of Arizona Youth Climate Strike and Our Children’s Trust.

The summit also will address how the shifting climate threatens Arizonans’ health. More extreme temperatures and more frequent heat waves exacerbate chronic conditions; in particular, worsening air quality from dust storms, wildfires and particulate emissions aggravate asthma and respiratory illnesses. Climate disruptions and altered habitats are changing the way infectious diseases spread in the state. Heat-associated deaths scar families and communities, and Arizona can anticipate increases in those largely preventable tragedies. All these risks disproportionately affect the most vulnerable: children, the elderly, migrant farmworkers and people in low-income, rural and tribal communities.

Arizona is uniquely situated to respond to these challenges. Communities and resource managers have experience contending with the hotter and drier conditions the state is experiencing, and the state has been recognized for a culture of listening to diverse perspectives to make sound decisions for its future. 

“In Phoenix metro, city planners, sustainability directors, community leaders, and scientists have been developing positive visions for central Arizona that take into account these climate futures,” said Nancy Grimm, co-director of the Urban Resilience to Weather-Related Extreme Events Sustainability Research Network (UREx SRN) and a professor at Arizona State University. “We hope to engage in this kind of hopeful conversation at the climate summit.”

Climate 2020: Seven Generations for Arizona aims to transform the conversation, moving beyond drought contingency plans and into a comprehensive and future-oriented framework of creative and science-driven decision-making. The summit is organized by Ecoss (NAU), the Institute for Tribal Environmental Professionals, the Center for Health Equity Research (NAU), the Green Fund (NAU), the Sustainability Program at the City of Flagstaff, Vitalyst Foundation and other partners.

Climate 2020: Seven Generations for Arizona will take place at High Country Conference Center in Flagstaff on Nov. 15-16. Summit registration is free to Arizona college and university students who wish to volunteer. To learn more or to register, visit https://climate2020arizona.nau.edu/

As trees across the U.S. continue their picturesque march toward autumn, one 100-year-old oak tree in Massachusetts is attracting a crowd of admirers online. The tree is a scientific wonder—not because of its unique looks or a special way it grows, but because of its voice.

The idea for the Harvard Forest Witness Tree, a social media outreach project led by post-doctoral fellow Tim Rademacher of Northern Arizona University and Harvard University, began as a public outreach component of a study investigating the effect of environmental changes on wood growth, funded by the National Science Foundation.

“The tree is wired with sensors that measure its growth, sap flow, local climate, and other factors in real-time,” says Rademacher. “Because we were measuring these things anyway, we thought, why not use the data to give the tree a voice?”

Since the tree’s Twitter account launched in July 2019, it has attracted over 7,700 followers, who regularly share the tree’s messages and ask it questions (which it answers). The Twitter account – and as of this week, the Facebook account – for the Witness Tree is the first of its kind in North America.

Helping a tree to trend on social media was a process two years in the making. In summer 2018 and 2019, Rademacher worked at Harvard Forest with undergraduate interns Kyle Wyche of University of Pittsburgh and Shawna Greyeyes of Coconino Community College to deploy the sensors and write analytical code that would connect data streams from the tree to public messages on Twitter and Facebook.

Wyche helped to write and test some of the first computer code for the Witness Tree, and says he is thrilled it has now come to fruition online. He notes the team made a choice early on about the tree’s name – “a witness tree” instead of “the witness tree” – signifying that this tree is one of trillions experiencing environmental change. “We want people to understand that every tree bears witness to the changing world,” says Wyche.

Greyeyes worked on message coding and a website for the tree in summer 2019. “I kept several things in mind while creating the messages,” she says. “We went with a first-person narrative, with context and visuals that are hopefully easy to understand and connect with.” This year, Greyeyes is a SEEDS SPUR Fellow for the Ecological Society of America and will present her research on the Witness Tree at the society’s national conference in summer 2020.

Andrew Richardson, Professor at Northern Arizona University’s Center for Ecosystem Science and Society, and the principal investigator on the research, says he hopes the project helps those who may never visit Harvard Forest to connect with the Witness Tree and the long history written into its rings.

“Individual trees have held deep meaning for people across time, and it’s exciting that Tim and Shawna have imagined a new way, in our hyper-technological moment, for people to connect with trees, and nature,” he says.

Rademacher points out that many other social media accounts online represent non-humans: pets, landmarks, or even other trees, but this project is unique because no humans are doing the tweeting.

“We are not sitting there at the computer tweeting for the tree,” he says. “When it’s hot, the data tells us through the tree, not the other way around,” says Rademacher, who built the tree’s computer program to work automatically.  Twenty-four hours a day, several times a minute, the program scans the data coming out of the tree’s sensors and cameras, watching for thresholds that signal something ecologically significant in the tree’s life: a surge in growth, a heatwave, heavy rainfall, or seasonal changes in leaves. The tree often tweets in these unique moments, and it also posts photos of visits from wildlife, and monthly summaries of its growth and local climate.  

“In most parts of the world, trees are our neighbors,” says Clarisse Hart, Director of Outreach & Education at Harvard Forest and the communications lead for the project. She says she hopes the project will help people recognize the vital role of trees and forests in our everyday lives and encourage them to be good stewards. “The first step is noticing,” she says.

The tree first came into the spotlight as the subject of a popular book about climate change research, called Witness Tree, by science writer Lynda Mapes. “Our goal has been to carry that storytelling mission forward,” adds Hart. 

Rademacher says the next steps for the project will depend on new funding and include do-it-yourself tweeting tree kits for educators to deploy in their local communities. They also hope to translate the tree’s messages into French and Spanish to expand its audience around the world.

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Learn more about the project and download photos for use in news media at https://harvardforest.fas.harvard.edu/press-resources-witness-tree-social-media.

The Center for Ecosystem Science and Society at Northern Arizona University studies how ecosystems respond to and shape environmental and climate change and works to communicate those discoveries in new ways to local and global communities. Collaborating with national laboratories and state-of-the-art research facilities such as the Colorado Plateau Stable Isotope Laboratory (CPSIL), Ecoss trains scientists to apply broad trans-disciplinary thinking and leading-edge methods to the pressing challenges facing Earth. Learn more at https://ecoss-nau.org/.

The Harvard Forest, founded in 1907 and located in Petersham, Mass., is Harvard University’s outdoor laboratory and classroom for ecology and conservation, and a Long-Term Ecological Research (LTER) site funded by the National Science Foundation. Its 4,000-acre property is one of the oldest and most intensively studied research forests in the U.S.  Open to the public year-round, the site includes educational and research facilities, the Fisher Museum, and recreational trails.  Learn more at http://harvardforest.fas.harvard.edu.

Other links: https://www.grandcanyontrust.org/projects-climate-change-research