Sink or source? How grazing geese impact the carbon cycle

Tricia (left) installing carbon dioxide plots in the field.

The activities are as follows:

“If it wasn’t for the geese, you and I would not be here today because our ancestors would not have made it. When long, hard winters emptied people’s food caches early, starvation loomed. Return of geese in April saved us.” – Chuck Hunt, born and raised on the Yukon-Kuskokwim Delta

Spring geese are an essential food source for subsistence communities like Chevak, Alaska. Elders in western Alaska Native communities have observed a decrease in geese returning to their villages over time. These changes affect the local communities and could also affect the local ecosystem.

One way geese change their environment is by eating grass. In the Yukon-Kuskokwim Delta in western Alaska, birds from every continent on Earth migrate to this sub-Arctic habitat to lay their eggs and raise their young. Once they arrive, geese eat a ton of grass. They graze only in specific areas, called grazing lawns, leaving the rest of the vegetation alone.

When geese graze on wetland plants, they remove plant matter, potentially decreasing the amount of carbon dioxide, or CO2, that is released during photosynthesis. As plants photosynthesize, they absorb CO2 from the atmosphere and turn it into glucose (a sugar) and oxygen. Gross primary production is the total amount of energy that plants capture from sunlight to grow and live before they use up some of that energy for themselves. Plants can slow climate change by removing CO2 from the atmosphere and turning it into plant matter, like leaves and roots.

A scientist mimics geese grazing by clipping the grass.

Trisha is a scientist who became interested in ways that animals can affect the carbon cycle through their interactions with the environment. She wondered whether fewer geese returning to western Alaska could have global consequences that extend beyond remote communities. She thought that if geese ate enough grass, they may limit photosynthesis. This is important because it could change whether this ecosystem is a carbon sink or a carbon source. An ecosystem is called a carbon sink if it absorbs more CO2 through photosynthesis than it releases through respiration. Alternatively, an ecosystem can be a carbon source if more CO2 is released than absorbed. We want ecosystems to be carbon sinks because then they keep CO2 out of the atmosphere, where it contributes to global warming.

To test her idea, Trisha teamed up with fellow scientists Bonnie, Karen, and Jaron to take a closer look at how grazing grass influences whether the Y-K Delta ecosystem is releasing or absorbing CO2. To do their experiment they had to get creative. They considered getting a lot of geese, bringing them to an ungrazed area, and letting them chow down. However, it’s hard to capture geese and get them to graze exactly where you want. So instead, the research team simulated the effects of geese by cutting the grass to mimic nibbling and then gently vacuuming the pieces of grass to remove them.

The “Carbon and Geese” scientist team.

The team set up six different experimental areas. Inside each area were two plots: one that was left ungrazed, and the other which was artificially grazed. The research team then used a piece of equipment called a LI-COR to measure the quantity of CO2 in the air above each plot. They recorded the CO2 levels during the day and night. The comparison from day to night is one way to look at gross primary production and respiration in a system. At night, when there is no light, plants can’t photosynthesize, so the detected CO2 will be from respiration. The levels during the day represent a combination of CO2 absorption by plants and release from respiration.

To assess whether the ecosystem is a carbon sink or source, we need to determine the difference between respiration and gross primary production, or net ecosystem exchange (NEE). A negative NEE means the ecosystem absorbs more CO2 than it emits. A positive NEE means the ecosystem is releasing more CO2 than it is absorbing. In this way, scientists classify an ecosystem as either a carbon sink that is storing carbon or a carbon source that is releasing carbon into the atmosphere.

Featured scientists: Trisha Atwood, Karen Beard, and Jaron Adkins from Utah State University and Bonnie Waring from Imperial College. Written by Andrea Pokrzywinski.

Flesch–Kincaid Reading Grade Level: 8.9

Additional teacher resources related to this Data Nugget:

Check out this website created by teacher Andrea who participated in the research and wrote this Data Nugget. You will find additional lesson plans, videos, slides, and articles to use in the classroom!

Helping students hear the stories that data tell

Article Highlights

High school students work with a Data Nuggets module.
High school students work with a Data Nuggets module. Credit: Paul Strode
  • Michigan State University’s Data Nuggets program is starting its third round of funding from the National Science Foundation to improve data literacy in K-16 students.
  • The program, operated by the Kellogg Biological Station, also introduces real STEM professionals through storytelling, helping students better relate to their projects and engage more deeply with the program’s content.
  • In collaboration with Auburn University, the newest NSF grant will help Data Nuggets further that engagement and introduce students to a greater diversity of scientists.

A data literacy program that’s also changing students’ relationships with science and scientists is entering its third round of funding with a new $1.5 million grant from the National Science Foundation.

In collaboration with Auburn University, the Data Nuggets program at the W.K. Kellogg Biological Station, or KBS, will work to identify factors that improve equity and success in undergraduate STEM education.

Launched by Michigan State University in 2011, Data Nuggets is a curriculum development project designed to help students better understand and use data. The program shows how professionals in science, technology, engineering and math really work with data by sharing their stories, which also enables students to relate on a much more personal level.  

Data Nuggets challenges students from kindergarten through undergraduate levels to answer scientific questions using data to support their claims. The questions and data originate from real research provided by scientists whose studies range from physics to ecology to animal behavior. 

To add the personal element, Data Nuggets is collaborating with Project Biodiversify — another education program started at MSU — to add the scientists’ bios, which include information like hobbies and their lives outside of science. This helps students relate to the researchers and see them less as strangers in lab coats and more as scientific role models. 

“We’ve found that it’s the scientists that are engaging students in the activities,” said Elizabeth Schultheis, co-leader of the Data Nuggets program. “If they connect to the role model, then you can get students to do the data literacy activities because they know, ‘Oh, this is a real person. I relate to this person. And I’m working with authentic, real data. I’m not just doing busy work.’” 

Schultheis, who earned her doctorate in plant biology from MSU, is also the education and outreach coordinator for the Long-Term Ecological Research, or LTER, program at KBS, which supports Data Nuggets. Schultheis and co-leader, Melissa Kjelvik, developed and run the program, forming partnerships to research and fund the program.

“With our current research, we’re trying to figure out what is the special thing that’s really resonating with students in terms of the role models,” Kjelvik said.

“Our research will investigate how and why role models are critically important for students,” said Cissy Ballen. Ballen is an associate professor in the Department of Biological Sciences at Auburn, the lead institution on the NSF grant, which builds on the past success of Data Nuggets and will help ensure its future impact.

“The theory behind this is that students must be able to see a scientist’s success as attainable to relate to that scientist,” Ballen said. “My prediction is that students will find success most relatable when they see some scientists, like them, have struggled with science, but then were able to overcome that struggle.” 

Elizabeth Schultheis (right) and Melissa Kjelvik (left) lead the Data Nuggets program at Michigan State University’s W.K. Kellogg Biological Station.
Elizabeth Schultheis (right) and Melissa Kjelvik (left) lead the Data Nuggets program at Michigan State University’s W.K. Kellogg Biological Station.

Making data talk

Many students’ eyes gloss over when they hear terms like “data” or “science.” 

Even Schultheis admits she didn’t appreciate the significance of data until she was a grad student collecting her own. The problem, she said, is that kids are often taught how to make a graph, for example, but not why.

“I never really learned to care until I understood the reason I make a graph is because I want to answer a question,” Schultheis explained. “I need to see the data, what it looks like. And that’s why I make a graph.” 

Data Nuggets doesn’t change the skills that are taught in conventional curricula. Students still learn how to make and label axes, for example, and then how to plot data to create graphs. But they also get a more immersive introduction into why real people use these skills.

“Our purpose with these Data Nuggets modules is that everything is always given real context and always in service of a scientific question,” Schultheis said. “It’s always: Here’s a scientist. Here’s the question that they really care about and the reason they collected this data is because they want to answer this question. And you make the graph to visualize it so that you can see what the data is telling you.”

Data Nugget activities come in four levels, so instructors can use the ones best suited for their specific classes. Level 4 activities are designed for high schoolers and undergraduates, while level 1 activities are appropriate for elementary schools and higher grades looking for a refresher after a summer break, for example.

Teachers also have flexibility with how to present an activity based on their goals. For example, instructors can choose activities with completed graphs so students can focus on interpreting what they see to answer questions.

Or students can be given blank grids to give them experience in creating useful representations of data from scratch.

Connie High, a science teacher at Delton Kellogg High School about five miles from KBS, calls Data Nuggets “a game changer.”  

She said that her students, when they’re new to Data Nuggets, can usually make claims and find supporting evidence. The challenge is learning how to articulate the connection between the two.

“They really struggle with how to link claim, evidence and reasoning. They tend to just restate the evidence again,” High said. 

“With Data Nuggets, we definitely see an improvement from the beginning of the year to the end.” 

Humanizing data 

The Data Nuggets program started 13 years ago as a grassroots collaboration between KBS researchers — including Schultheis and Kjelvik, who were then grad students at KBS — and K-12 teachers, including High. 

More than 120 scientists have contributed more than 120 data literacy activities since then. Tens of thousands of people regularly use the Data Nuggets website. Links to various Data Nuggets stories can even be found in science textbooks. 

“Long-term relationship building is why we got such good insights from teachers about what their students needed, because they already had trust with us, and we went into their classrooms and learned from them,” Schultheis said. “And building relationships with scientists who trust us to tell their stories correctly, who are giving their own stories for students to read and learn about, continues to be critical to our success.”

But exactly how to best package and present the data stories falls to Schultheis and her colleagues. Previous research has supported the idea that focusing on the scientist and why they collected the data is essential. After all, data is just numbers. It’s human interaction that puts numbers in perspective, gives the scientific question context and engages students in the activity.

“Humanizing the data is at the crux of this work,” Ballen said. “Data Nuggets is such a successful resource because of the way they humanize the data component and contextualize it within the science itself and show that it’s being done by relatable scientists. They do that really well.”

With its third round of NSF funding, Data Nuggets is attempting to fine-tune how to best present the scientist role models and the stories to improve student engagement with science even more.

The goal is not only to increase the portrayal of under-represented groups among scientist contributors, but also for students to see that they share some things in common with the scientists they see. 

“We used to ask students to draw what a scientist looks like, and they all would draw someone who looks like Albert Einstein,” High said. “It’s incredibly important that they see there are scientists who look like them.”

“You can imagine if you were a student sitting in a classroom you might get an activity that features a scientist from a prestigious university with awards and that sort of thing, and that might not be very relatable,” Ballen said. “Success might not be perceived as attainable.”

Data Nuggets is working to combat that perception.

For example, there’s a Data Nugget called “Trees and the City”, featuring a photo of a smiling University of Minnesota ecologist named Adrienne Keller wearing a bike helmet and sunglasses. A video shows Keller riding her bike through neighborhoods in the Twin Cities as she describes her interest in tree patterns. She poses her dataset’s main question: “Are there differences in the total canopy cover or the number of tree species planted in a neighborhood based on residents’ income level or percentage of BIPOC — Black, Indigenous, and People of Color — residents?”

Another Data Nugget was written by a community scientist from Bayfield, Wisconsin, located on the south shore of Lake Superior. He’s pictured wearing shorts and gym shoes as he stands on ice. 

For his Nugget, he used historical data to answer his question if the winters were getting shorter and changing the dynamics of how people could travel in the area. 

He also happened to be a high school student.

“That’s the dream outcome,” Schultheis said, “that students realize how powerful data are, and they can be advocates for themselves and their communities because they can actually go to the source of information and ask and answer questions.” 


This story was written by Lynn Waldsmith, and was originally posted on the Michigan State University, College of Natural Science website here.

Seagrass survival in a super salty lagoon

A researcher in the Dunton Lab measures seagrasses underwater using a mask, snorkel, and a white PVC quadrat.

The activities are as follows:

Seagrasses are a group of plants that can live completely submerged underwater. They grow in the salty waters along coastal areas. Seagrasses are important because they provide a lot of benefits for other species. Like land plants, seagrasses use sunlight and carbon dioxide to grow and produce oxygen in a process called photosynthesis. The oxygen is then used by other organisms, such as animals, for respiration. Other organisms use seagrasses for food and habitat. Seagrass roots hold sediments in place, creating a more stable ocean bottom. In addition, the presence of seagrasses in coastal areas slows down waves and absorbs some of the energy, protecting shorelines.

Unfortunately, seagrasses are disappearing worldwide. Some reasons include damage from boats, disease, environmental changes, and storms. Seagrasses are sensitive to changes in their environment because they have particular conditions that they prefer. Temperature and light levels control how fast the plants can grow while salinity levels can limit their growth. Therefore, it is important to understand how these conditions are changing so that we can predict how seagrass communities might change as well.

Ken is a plant ecologist who has been monitoring seagrasses in southern Texas for over 30 years! Because of his long-term monitoring of the seagrasses in this area, Ken noticed that some seagrass species seemed to be in decline. Kyle started working with Ken during graduate school and wanted to understand more about what environmental conditions might have caused these changes. 

Manatee grass (Syringodium filiforme) located within the Upper Laguna Madre.

Texas has more seagrasses than almost any other state, and most of these plants are found in a place called Laguna Madre. During his yearly seagrass monitoring, Ken noticed that from 2012 – 2014 one of the common seagrasses, called manatee grass, died at many locations across Laguna Madre. Since then, the seagrass has grown back in some places, but not others. Kyle thought this would be an opportunity to look back at the long-term dataset that Ken has been collecting to see if there are any trends in environmental conditions in years with seagrass declines.

Each year, Ken, Kyle, and other scientists follow the same research protocols to collect data to monitor Laguna Madre meadows. Seagrass sampling takes place 2 – 4 times a year, even in winter! To find the manatee grass density, scientists dig out a 78.5 cm2 circular section (10 cm diameter) of the seagrass bed while snorkeling. They then bring samples back to the lab and count the number of seagrasses. While they are in the field, they also measure environmental conditions, like water temperature and salinity. A sensor is left in the meadow that continuously measures the amount of light that reaches the depth of the seagrass.

Kyle used data from this long-term monitoring to investigate his question about how environmental conditions may have impacted manatee grass. For each variable, he calculated the average across the sampling dates to obtain one value for that year. He wanted to compare manatee grass density with salinity, water temperature, and light levels that reach manatee grass. He thought there could be trends in environmental conditions in the years that manatee grass had low or high densities.

Featured scientists: Kyle Capistrant-Fossa (he/him) & Ken Dunton (he/him) from the U-Texas at Austin

Flesch–Kincaid Reading Grade Level 9.8

Additional teacher resources related to this Data Nugget:

There is another Data Nugget that looks at these seagrass meadows! Follow Megan and Kevin as they look at how photosynthesis can be monitored through the sound of bubbles and the acoustic data they produce.

Follow this link for more information on the Texas Seagrass Monitoring Program, including additional datasets to examine with students.

There are articles in peer-reviewed scientific journals related to this research, including:

National Park Service information about the Gulf Coast Inventory and Monitoring.

Texas Parks and Wildlife information on seagrass:

Auburn and MSU collaborate on NSF IUSE grant to determine what makes an effective scientific role model

Members of the Auburn and MSU research team sharing a meal.

Scientific role models increase student success in their science courses as well as inspire students to pursue science careers. The Ballen Lab at Auburn University has completed significant research demonstrating that role models with diverse identities are lacking in undergraduate biology classrooms. Students with identities that are not represented in their undergraduate science courses do not have many opportunities to see themselves in science careers and as scientific leaders.

“I am excited to collaborate with researchers at Michigan State University to identify factors that improve equity and success in undergraduate STEM education. Our research will investigate how and why role models are critically important for students,” said Cissy Ballen, associate professor in the Department of Biological Sciences.

The collaborative team, led by Ballen at Auburn and Elizabeth Schultheis at MSU, was awarded $1.5 million from the National Science Foundation’s Division of Undergraduate Education.

Robin Costello, a postdoctoral scientist in the Ballen Lab working to understand the relationship between role models and successful student outcomes, explained, “Featuring relatable scientist role models in classroom materials is a low-cost and accessible way to increase the recruitment and persistence of students with identities historically and currently excluded from STEM.”

The research team’s recent research showed a direct correlation between relating to scientific role models and student engagement. “These results led to more questions about the critical features of scientist role models that make them effective and served as the foundation for the recently awarded project,” Ballen explained. “Theory makes several predictions about why and how role models are critical to student success. With this support from NSF, we will conduct critical research that tests theory on what makes an effective role model.”

Costello added, “Our research will specifically explore how to tell scientists role model stories in ways that improve student outcomes.” The project is entitled “Collaborative Research: Sharing Scientist Role Model Stories to Improve Equity and Success in Undergraduate STEM Education.”

“Several popular resources have been created to combat the pervasiveness of the stereotypical scientist in biology and STEM curricular materials,” Ballen added. An important long-term result of the project are free, open-source materials for educators to use in their classrooms to nurture more inclusive environments where students can learn from a wide array of STEM leaders to whom they can relate.

These resources will develop biology data literacy curricular materials that teach quantitative skills while simultaneously highlighting the diversity of scientists in STEM. These resources will be based on two well-known educational resources: Data Nuggets, resources that are developed in a partnership between scientists and teachers, and Project Biodiversify, a site that offers education tools for diversity and inclusion in biology classrooms.


Our team will be recruiting instructors to implement the activities in classrooms. If you are interested in participating in this project, please contact mjb0100@auburn.edu. For the original story, written by Maria Gebhardt, visit the Auburn page here.

Eavesdropping on the ocean

Scientists heading out to the proposed wind energy site.

The activities are as follows:

Most of our energy in the United States comes from fossil fuels like natural gas, coal, and oil. These energy sources are efficient, but they release greenhouse gases into the atmosphere when burned. They are also non-renewable, meaning there is a limited supply. Renewable energy options collect energy from sources that are naturally replenished, such as sunshine, wind, and even ocean waves. By using renewable energy sources, we can fuel our lives without depleting fossil fuel supplies.

Windmills have been used by humans to capture energy from the wind long before electricity was discovered. Historically, they were used to pump water and grind grains to make flour. Today, they are used to generate electricity that can be used in your home. Most of these modern windmills (also known as turbines) are located on land, but researchers and engineers are exploring a new type of site – the ocean.

Offshore wind energy sites in the U.S. are usually at least 20 miles from land. Winds that blow over the ocean are much more consistent than on land, making offshore energy more reliable. In addition, land that can be used for windmills is limited, especially in areas where there are already a lot of people. Offshore wind energy could be a solution where there are a lot of people living along the coast.

Scientists attach a weight to the line and wait to get into position to deploy a drifting recorder

Careful planning goes into these large-scale projects. Before any construction begins, scientists want to make sure the benefits outweigh the costs. One topic of concern is marine mammals. Many marine mammals, like whales, are federally protected, and some are endangered species. Scientists are worried that the construction of offshore windmills could impact the whales that live or migrate through the designated wind energy areas.

Whales use sound transmitted through the water to survive. Just like many animals on land, they use sound to communicate, navigate, find food, and avoid predators or other threats. Noise from construction activities could cause whales to avoid the area. They may need to find a new area to find food, rest, or find mates. Whales typically migrate, so loud noises could also interfere with their migration route.

Shannon is an acoustic ecologist, meaning she uses sound and how it is transmitted to learn more about organisms and their environment. She works with Desray, who is a research biologist specializing in marine mammals. Together, they are leading a large project to collect sound data to assess the risks of a proposed offshore wind energy site off the coast of central California. One specific goal they have is to see whether it is possible to identify the best time of year to build the wind energy platforms with the least disturbance to marine mammals. To do this, they had to learn more about when whales are using and traveling through the area of the proposed site.

Acoustic ecology is a way to learn more about whales and their behavior through sound, which is important because visual detections are limited and take a lot of time out at sea. Instead, scientists can analyze acoustic data to detect which species are present. Each species makes different sounds with unique patterns, and by listening, we can identify which species are in the area. 

Shannon Rankin and Anne Simonis let out the line with the acoustic recorder and surface floats.

Shannon and a large team of supporting scientists worked together to design floating acoustic recorders. They partnered with Desray to deploy them in the proposed offshore wind energy area. Once the recorders are launched, the team uses satellite location to follow the movement of the recorders from shore. They let the recorders drift in the open ocean for several days before they board a large research boat and pick them up again. While the recorders are drifting, they are continuously recording the ocean sounds below. These drifting recorders cover a larger spatial area, for a longer time, than other types of passive acoustic monitoring methods. The team launched the acoustic recorders in different seasons to learn which whale species are using the proposed site throughout the year and to assess what time of year would have the lowest whale presence near the construction site.

Featured scientists: Shannon Rankin from the NOAA Southwest Acoustic Ecology Lab and Desray Reeb from the Bureau of Ocean Energy Management

Flesch–Kincaid Reading Grade Level 9.4

Additional teacher resources related to this Data Nugget:

  • The NOAA team members on this project have put together a blog series, called “Sound Bytes,” to share the stories and impacts of the ADRIFT research highlighted in this activity. This blog series features many perspectives showcasing how underwater sound, in the form of acoustic data, can be used to learn more about marine mammals.
  • Students can learn more about how acoustic data is analyzed and what it looks like visually by checking out the Ocean Voices project on Zooniverse. Here they can participate in a guided introduction to humpback whale and ship sounds from drifting acoustic recorders and help scientists classify sounds on the recordings.
  • These data were collected as part of the ADRIFT project, led by the Southwest Acoustic Ecology Lab run by the National Oceanic and Atmospheric Administration and the Bureau of Ocean Energy Management.
  • NOAA has a wide variety of lesson plans that you could use to supplement this activity. Here is a set of activities for elementary, middle, and high school on bioacoustics.
  • Lesson on bioacoustics by Seagrant and Woods Hole Oceanographic Institute.
  • For more lessons and activities about wind energy, check out the K-12 teaching materials by the Office of Energy and Renewable Energy.
  • A collection of videos that show the spectrograms and audio recordings for various marine mammals that you could share with students.
  • There is an extensive PowerPoint that has additional information about the ADRIFT acoustics project and other research being done.
Video of a drifting acoustic recorder launch. Turn on subtitles for information about the process.

This study was funded in part by the U.S. Department of the Interior, Bureau of Ocean Energy Management through Interagency Agreement M20PG00013 with the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NMFS), Southwest Fisheries Science Center (SWFSC).

The prairie burns with desire

Stuart showing an Echinacea flower setting seed.

The activities are as follows:

Fire plays a crucial role for prairie habitats across North America. Native Americans have long observed that lush and green pastures grow after a wildfire. In many areas, it is part of current and historical native culture to imitate this natural process by deliberately burning the prairie in a controlled way. This land management practice has many benefits, such as helping native grasses form seeds, thinning out plants, and enhancing habitat for prairie animals. By using controlled fires to cultivate these areas, Native Americans increase the availability of food and connect to the environment and their cultural traditions.

Some land management agencies plan prescribed burns to increase the health of prairie ecosystems. However, fire is still suppressed in many North American prairies due to the possible damage to human development. In these areas, scientists have observed that fire suppression contributes to local plant species extinctions, but we do not know why.

Stuart is a scientist interested in how fire can help prairie plants. In the late 1990s, Stuart was in central Minnesota searching for prairie plants in the Echinacea genus. The prairie was ablaze with flowers, so he had no difficulty finding plenty of plants. He tagged each plant so that he could study them again in the future. However, when he returned the following year, the field had almost no flowers! He kept returning to this same field. A few years later he found the site was again filled with flowers. That year there had been a prairie fire. Visually seeing the impacts of fire on the landscape is a memory he will not forget.

Stuart became interested in learning more about how fire affects the reproduction of native prairie plants. He knew that Echinacea plants grow in many places, but they have a hard time making seeds. This genus cannot self-pollinate, meaning they must be fertilized with pollen from a genetically different plant. Echinacea plants are also dependent on insects, such as bees, to pollinate them.

Echinacea flower

In 1996, a research team started collecting data on Echinacea plants in a large research site in Minnesota. This prairie site had a schedule for prescribed burns, or controlled fires that are started by experts to manage the land. These burns would happen every 4-6 years during the spring.

The team established a set of plot locations that they visited each summer. They searched for and mapped the location of all flowering Echinacea plants within these plots. They took measurements on each Echinacea plant – whether it was flowering, and the distance to its second closest Echinacea neighbor.

Stuart decided to take a new look at this long-term dataset. He had two ideas for how fire might be helping Echinacea plants. First, fire might help all the plants get on the same schedule and make flowers at the same time. This synchrony, or flowering at the same time, could help pollen get from one flower to another. Second, fire might remove competing plants from the area, opening up bare ground for new seeds to establish. This would allow Echinacea plants to be closer to one another, again making it easier for pollen to move between flowers.

With these data, Stuart could compare years with and without prescribed burns to see whether fire helped Echinacea flowering. To look at whether fire decreased the space between blooming Echinacea plants, he looked at the distance between a focal plant and its second-closest neighbor. To see whether fire increased the synchrony of flowering, Stuart used the data to calculate the proportion of Echinacea plants that were in bloom during the summer sampling period.

Featured scientist: Stuart Wagenius from the Chicago Botanic Gardens Written by: Harrison Aakre

Flesch–Kincaid Reading Grade Level = 8.6

Additional teacher resources related to this Data Nugget:

More information about the Echinacea project, based in Minnesota. There are additional datasets to explore, blog posts from the field, identification guides, and pictures of the experiments.

Article to learn about cultural perspectives that are traditionally not represented in textbooks. Native Americans have, and continue to incorporate ecology, observations, and making sense of patterns for millennia.

For more information about indigenous knowledges, or traditional ecological knowledge, check out the following websites:

Published journal article about this research. Wagenius, S. et al. 2020. Fire synchronizes flowering and boosts reproduction in a widespread but declining prairie species. Proceedings of the National Academy of Sciences.

Which tundra plants will win the climate change race?

Some arctic Tundra plant species monitored in this experiment.
Arctic tundra plant species monitored in this experiment.

The activities are as follows:

The Arctic, the northernmost region of our planet, is home to a unique biome known as tundra. While you might think of the arctic tundra as a blanket of snow and polar bears, this vast landscape supports a diversity of unique plant and animal species. The tundra is an area without trees that supports many species of plants, mammals, birds, insects, and microbes. 

Arctic environments present many challenges to plants. Temperatures only creep above freezing for about three months each year. This short arctic summer means that the species that live there only have a brief period to grow and reproduce. From mid-May to the end of July the sun doesn’t set, so there’s plenty of light available. Plants need this light for photosynthesis to make sugars for food. 

Even when there is light, plants need to wait until the snow has melted and the soil has thawed enough for them to grow. Tundra plants have short roots since they can’t grow through frozen ground. These roots try to get nutrients the plant needs from the soil. But with the soil so cold, decomposition is very slow. This means that microbes cannot easily convert dead plant material into nutrients that plants need such as nitrogen and phosphorus. For this reason, the growth of tundra plants is usually limited by nutrients.

Climate change is altering the arctic environment. With warmer seasons and fewer days with snow covering the ground, soils are thawing more deeply and becoming more nutrient-rich. With more nutrients available, some plant species may be able to outcompete other species by growing taller and making more leaves than other plant species. This means that climate change may alter the whole ecosystem game in the tundra. Instead of nutrients limiting plant growth, it may shift to a game of competition between plants reaching for light.

Gus (left) and Jim (right) set up a weather station to monitor air temperature and humidity on the tundra.
Gus (left) and Jim (right) set up a weather station to monitor air temperature and humidity on the tundra.

To simulate the environmental conditions, we can look at long-term data from two scientists, Gus and Terry, who started working at the Toolik Field Station in northern Alaska in the 1970s. They conducted a series of experiments and learned that two nutrients, nitrogen and phosphorus, limited plant growth in the tundra. Then, in 1981, they set up a new experiment where they added both nutrients to experimental plots every year. Gus and Terry compared plant growth between these fertilized plots and control plots that were not fertilized. They wanted to figure out how each plant species would respond to more nutrients over the long term and what would happen to the plant community to see if some species would outcompete others in the fertilized conditions. This experiment is one way to mimic future conditions and test hypotheses about what we might expect to see.

The fertilizer was added every year in early June after the snow melted off the plots. Beginning in 1983, other scientists, such as Laura and Ruby, began to sample these plots. They dug out small 20-centimeter by 20-centimeter samples of tundra and brought them back to the nearby Toolik Field Station. In the lab, the tundra sample was separated into individual plant species and “plucked” to sort by different plant tissue types: leaves, stems, and roots. Then these plants were dried and weighed to determine the biomass (mass of living tissue) of each species in the sample. The fertilized and non-fertilized plots were sampled and plucked six times between 1983 and 2015. This means that many of the scientists who sampled the plots in 2015 had not yet been born when the experiment started in 1981!

Featured scientists: Gus Shaver (he/him), Jim Laundre (he/him), Laura Gough (she/her), and Ruby An (she/her) from Toolik Field Station, Arctic Long-term Ecological Research Site

Flesch–Kincaid Reading Grade Level = 8.6

Additional teacher resources related to this Data Nugget:

The sound of seagrass

Underwater view of a seagrass meadow.

The activities are as follows:

Seagrasses are a type of plant that grows underwater. They have long, green leaves and form thick underwater meadows. Seagrass meadows have high plant productivity, or growth, which could help offset the effects of climate change. A major driver of climate change is excess carbon in the atmosphere. Plants can help by pulling carbon from the atmosphere during photosynthesis. Because seagrasses have such high productivity, a lot of carbon is stored in the sediment below them.

Megan and Kevin live in Texas, where these seagrasses are an important part of Gulf Coast ecosystems. Although Megan and Kevin are not ecologists, their expertise is in underwater sound. They are working with biologists to determine the value of applying sound-based methods to monitor the productivity of seagrass meadows.

If you know how to listen, seagrass meadows are full of sound! Sound sources include waves, wind, rain, shrimp, fish, boat engines… and the seagrass itself! It might be surprising that plants produce sound, but Megan and Kevin found that sometimes seagrasses are the main source of naturally occurring, or ambient, sound.

So where does this sound come from? Pulsating sounds are made when bubbles are released from the seagrass leaves. Seagrasses emit oxygen into the water during photosynthesis and most of the time this oxygen dissolves into the water. However, when the water has reached its limit and cannot hold more oxygen, bubbles are formed. Megan and Kevin wanted to see whether they could use these bubbles to monitor the photosynthesis levels in seagrass meadows through sound.

Megan and graduate students examining seagrass sound data in the field.

They started by developing a technique to record measurements of ambient sound in the underwater ecosystem. In the laboratory, they were able to use measurements of sound waves to determine a bubble’s size. However, when the ambient sound from seagrass meadows is recorded, there are many bubbles produced simultaneously. This means it is not possible to identify all the bubbles individually through sound recordings. Instead, Megan and Kevin decided to look at changes in the ambient sound level of the meadow as a measure of how much oxygen is produced.

Megan and Kevin wanted to see whether ambient sound levels were noticeably different during peak photosynthesis times. You can relate this to how the background noise changes throughout your school day. The ambient sound level in school is louder during lunchtime when many students are talking at the same time. It’s not possible to identify all the individual conversations taking place throughout the room, but the overall background sound level is higher during lunchtime than when you are doing schoolwork or taking a test.

Similarly, the sound of bubble production during photosynthesis is expected to increase the ambient sound level during periods of high productivity. Additionally, bubbles will be produced when the surrounding water is supersaturated with oxygen, indicated by the time the dissolved oxygen level is greater than 100%.

After they developed their methods, Megan and Kevin headed to the field! They placed a hydrophone (underwater microphone) in the seagrass meadow to record ambient sound data for a year. The hydrophone recorded thirty-second audio clips every ten minutes and they analyzed the clips for sound level, measured in decibels. They also installed a sensor that recorded the dissolved oxygen levels at the site.

Featured scientists: Megan Ballard (she/her) and Kevin Lee (he/him) from the University of Texas at Austin. Scientist team: Preston Wilson, Kenneth Dunton, Kyle Capistrant-Fossa, Colby Cushing, and Thomas Jerome

Flesch–Kincaid Reading Grade Level = 10.4

Additional teacher resources related to this Data Nugget include:

For an excellent teaching resource on underwater sound, check out the “Discovery of Sound in the Sea” website. You can have students explore the science of sound, sounds that animals make underwater, and how acoustic data can help society.

You can learn more about the Texas Seagrass Monitoring Project.

If you would like to give your students the opportunity to explore primary literature, there are several publications related to the research in this Data Nugget:

For more information about how bubbles are produced by underwater plants as a byproduct of photosynthesis:

  • Long, M. H., Sutherland, K., Wankel, S. D., Burdige, D. J., & Zimmerman, R. C. 2020. Ebullition of oxygen from seagrasses under supersaturated conditions. Limnology and Oceanography65(2), 314-324.
  • Freeman, S. E., Freeman, L. A., Giorli, G., & Haas, A. F. 2018. Photosynthesis by marine algae produces sound, contributing to the daytime soundscape on coral reefs. PloS one13(10).

Related research about what we can learn by collecting underwater acoustic sound data:

  • Spratt, K. S., Lee, K. M., & Wilson, P. S. (2018). Champagne acoustics. Physics Today, 71(8), 66-67.
  • Pettit, E. C., Lee, K. M., Brann, J. P., Nystuen, J. A., Wilson, P. S., & O’Neel, S. (2015). Unusually loud ambient noise in tidewater glacier fjords: A signal of ice melt. Geophysical Research Letters42(7), 2309-2316.
Underwater sounds from the seagrass meadows! Compare daytime and nighttime recordings and see if you can distinguish the sounds of photosynthesis bubbles!

A difficult drought

A field of switchgrass studied by biofuels researchers.

The activities are as follows:

Most people use fossil fuels like natural gas, coal, and oil daily. We use them to generate much of the energy that gets us from place to place, power our homes, and more. Fossil fuels are very efficient at producing energy, but they also come with negative consequences. For example, when burned, they release greenhouse gases like carbon dioxide into our atmosphere. The right balance of greenhouse gasses is needed to keep our planet warm enough to live on. However, because we have burned so many fossil fuels, the earth has gotten too hot too fast, resulting in climate change. Scientists are looking for other ways to fuel our lives with less damage to our environment.

Substituting fossil fuels with biofuels is one of these options. Biofuels are fuels made from plants. Unlike fossil fuels, which take millions of years to form, biofuels are renewable. They are made from plants grown and harvested every few years. Using biofuels instead of fossil fuels can be better for our environment because they do not release ancient carbon like burning fossil fuels does. In addition, the plants made into biofuels take in carbon dioxide from the atmosphere as they grow.

To become biofuels, plants need to go through a series of chemical and physical processes. The sugar stored in plant cells must undergo fermentation. In this process, microorganisms, like yeast, transform the sugars into ethanol that can be used for fuels. Trey is a scientist at the Great Lakes Bioenergy Center. He is interested in seeing how yeast’s ability to transform sugar into fuel is affected by environmental conditions in fields, such as temperature and rainfall.

When there was a major drought in 2012, Trey used the opportunity to study the impacts of drought. The growing season had very high temperatures and very low rainfall. These conditions make it more difficult for plants to grow, including switchgrass, a prairie grass being studied as a potential biofuel source.

Trey knew that drought affects the amount and quality of switchgrass that can be harvested. He wanted to find out if drought also had effects on the ability of yeast to transform the plants’ sugars into ethanol. Stress from droughts is known to cause a build-up of compounds in plant cells that help them survive during drought. Trey thought that these extra compounds might harm the yeast or make it difficult for the yeast to break down the sugars during the fermentation process. Trey and his team predicted that if they fed yeast a sample of switchgrass grown during the 2012 drought, the yeast would struggle to ferment its sugars and produce fewer biofuels as a result.  

To test their idea, the team studied two different sets of switchgrass samples that were grown and collected in Wisconsin. One set of switchgrass was grown in 2010 under normal conditions. The other set was grown during the 2012 drought. The team introduced the two samples to yeast in a controlled setting and performed four fermentation tests for each set of switchgrass. They recorded the amount of ethanol produced during each test.

Featured scientists: Trey Sato from the University of Wisconsin-Madison. Written by Marina Kerekes.

Flesch–Kincaid Reading Grade Level = 8.2

Additional teacher resources related to this Data Nugget include:

There are other Data Nuggets that share biofuels research. Search this table for “GLBRC” to find more! Some of the popular activities include:

The Great Lakes Bioenergy Research Center (GLBRC) has many biofuel-related resources available to K16 educators on their webpage.

For activities related specifically to this Data Nugget, see:

Lake Superior Rhythms

A sandy Lake Superior shoreline near Bayfield, WI.

The activities are as follows:

Gena and Ali are sisters who grew up in Bayfield, Wisconsin on the south shore of Lake Superior. When they were young, they spent many summer days sailing in the Apostle Islands National Lakeshore with their parents and friends. As they relaxed on the beach, they would watch how the lake changed. Even over a short period of time, they would see the landscape change. In just a few hours, a rock that was visible above the water’s surface when they arrived would slowly become submerged, only to reappear several hours later.

In high school, Gena and Ali set out to learn about the geophysical forces acting on Lake Superior. They wanted to investigate why they would sometimes see such dramatic fluctuations in water levels. They also wanted to know why water from rivers and streams would sometimes flow out into the lake, while other times it would flow back into the tributaries.

Ali presents research results on how the seiche changes the local water levels.

They learned that large lakes exhibit a phenomenon called a seiche (pronounced saysh). Like tides, a seiche is a periodic rising and falling of water levels. However, tides and seiches are caused by two different forces. Whereas tides are connected to the sun and moon, seiches are caused by changes in atmospheric pressure and strong winds.

Many atmospheric events can exert force on the water, including storms that come and go, heavy rain, cold fronts blowing through, or the calming of strong winds. You can think of Lake Superior as a giant bathtub, and the seiche is the water sloshing back and forth as it is pushed by a force and then released.

Gena and Ali realized that the seiche probably explained the water level changes they saw on Lake Superior. They became curious to learn more about the lake’s seiche pattern. An atmospheric event can cause the water to slosh from one side of the lake to the other several times. They predicted the seiche would look like a wave pattern as the water comes and goes.

The sensor with data recorder on the dock inside a boathouse.

To test their ideas, they decided to investigate how often the water switched directions and how much the water level changed because of the seiche. In other words, they wanted to measure the amplitude and period of the seiche. The amplitude is the height of a wave from its midpoint, or equilibrium. The amplitude can be calculated as half of the water level change from its highest and lowest point in a cycle. The length of time it takes to complete one full back-and-forth cycle is called the period. You can track the period of the seiche by how much time has passed from one peak to the next peak.

Over their summer break, Gena and Ali started to plan how they could document changes in water levels in their hometown. With permission, Gena and Ali placed a sensor inside a boathouse that was protected from wave action. The sensor measured the distance to the nearest object and was set to collect a data point every six minutes. Gena and Ali placed the sensor so that it faced the surface of the water. That way, it would document changes in the water level throughout time.

Featured scientists: Gena (she/her) and Ali Gephart (she/her), Bayfield High School.

Written by: Richard Erickson, Bayfield High School, and Hannah Erickson, Boston Public Schools.

Flesch–Kincaid Reading Grade Level = 8.8

Additional teacher resources related to this Data Nugget include:

  • Here is a link to learn more about the physics of waves.
  • Visit this NOAA website to learn more about seiche behavior and characteristics.