Search Results for: lter

7.17.24

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 absorbed during photosynthesis. As plants photosynthesize, they take 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!

7.2.24

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.

9.27.23

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:

9.15.23

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:

8.3.23

Size matters – and so does how you carry it!

The activities are as follows:

Stalk-eyed fly copulation.

In the wild, animals compete for limited resources. Things like food, water, shelter, and even reproductive mates can be hard to come by. Animals with traits and behaviors that make them more likely to survive and reproduce are said to have higher evolutionary fitness. Some animals have evolved special traits that advertise their fitness to potential mates. Male deer, elk, and moose have large antlers that they use to compete with other males, which demonstrates their fitness to females. Another interesting example is the stalk-eyed flies, in which the males grow long eye stalks to attract a mate. In these cases, females are more likely to choose males with the biggest traits.

Scientists have long predicted that these traits come with both benefits and costs. Large antlers or eyestalks may help a mate notice you, but also come with some costs. Extra weight takes more energy to move around and could make it more difficult to escape from predators. And yet, many studies have failed to find any measurable costs to males having these seemingly impractical traits.

This scientific mystery puzzled Jerry and John, who study stalk-eyed flies. They had failed to identify and document any costs to having longer eyestalks, measured as the distance between the eyes, or eyespan. Common sense told them that having longer eye stalks should make flying more awkward for these flies. However, their data did not support this hypothesis. “When I started collecting data, I focused a lot on the performance costs and got kind of fixated on that,” John says of the team’s initial research. “It was frustrating when we couldn’t identify any actual decline in performance.”

John in the field when he first started his research – many decades ago!

The team began looking for an alternative explanation. They read about research supporting a new idea in a completely different kind of flying animal – barn swallows. Male barn swallows have long, ornate tails. These tails make male barn swallows less aerodynamic during flight. But males have also evolved to have larger wings relative to their body size. This could help them compensate for the extra burden associated with their long tails.

Jerry and John wondered if a similar thing might be at work in stalk-eyed fly wings. Perhaps the male stalk-eyed flies, like male barn swallows, had evolved to have larger wings relative to their body size to help them compensate for long eye stalks when flying. If this were the case, then they expected to see a positive correlation between wing size and eyespan. Could this be why they were unable to measure any disadvantage associated with having longer, more awkward eye stalks? In other words, male stalk-eyed flies with larger wings would be able to support longer eye stalks.

Eyespan (horizontal arrow) and body size (vertical arrow) of a stalk-eyed fly.

Jerry, John, and their team decided to test their new hypothesis by raising stalk-eyed flies in the lab to maturity, then collecting data about their body length, eyespan, and wing area.

To account for natural variation in body size among stalk-eyed flies, the team needed to use “relative” measurements based on body size. With these kinds of measurements, a value of zero (0) means that wing size or eyespan is exactly what you would predict for a fly of that body size. Negative values mean that wing size or eyespan are smaller than you would predict for that body size, while positive values mean that wing size or eyespan is greater than you would predict for that body size. For example, if a fly has a relative eyespan of -0.010, then the distance between the eyestalks was 0.010 millimeters shorter than expected based on its body size.

Featured scientists: Jerry Husak from the University of St. Thomas and John Swallow from the University of Colorado-Denver. Written by: Sam Holloway

Flesch–Kincaid Reading Grade Level = 8.8

Additional teacher resources related to this Data Nugget include:

You can find lessons to accompany many of John’s studies with insects on the Data Nuggets website! Check out the following Data Nugget activities!

A peer-reviewed journal article: Husak, J. F., Ribak, G., Wilkinson, G. S., & Swallow, J. G. 2011. Compensation for exaggerated eye stalks in stalk‐eyed flies (Diopsidae). Functional Ecology, 25(3), 608-616.

A video of a stalk-eyed fly in flight:

6.6.23

Trees and the city

A neighborhood with many tree species and a lot of tree cover.

The activities are as follows:

We often imagine nature as being a place outside of cities. But within our cities, we are surrounded by nature – in fact, most human interactions with nature happen within urban areas. Picturing a tree, we might imagine it in a remote forest, yet many trees are planted by residents and local governments within cities. Trees provide important benefits, such as beauty and shade. The number and types of tree species that are planted in a neighborhood can increase the benefits received from trees in urban areas.

When Adrienne first moved to the Twin Cities in Minnesota, she started exploring Minneapolis and St. Paul by bike. Biking is done at a slow enough pace that she can travel long distances but still make observations about neighborhoods in these cities. As an ecologist, she naturally found herself looking for patterns in trees. For example, she noticed some older neighborhoods in St. Paul have a lot of large trees that provide plenty of shade and tree cover. In other neighborhoods, Adrienne saw fewer types of trees and noticed that she spent less time shaded by branches and leaves.

Adrienne biking around Minneapolis-St. Paul.

Adrienne started conversations with her colleagues about their observations of differences in urban landscapes. They discussed the ways in which laws, policies, and practices (“the way things are done”) give advantages to certain groups of people over others. These advantages are woven into our cultural systems.

Adrienne and her fellow researchers expected that neighborhoods with wealthier and more white residents would have benefited from a long history of greater investment.

Therefore, these neighborhoods were expected to have greater tree cover from the large old trees that have been growing there for many years. They also expected these neighborhoods would have more types of trees. In contrast, the researchers expected that less wealthy neighborhoods and those with a greater percentage of Black, Indigenous, and other People of Color (BIPOC) would have less tree cover and fewer types of trees because of chronic lower investment in these neighborhoods.

To research these ideas, Adrienne and her colleagues combined three different sources of publicly available data:

  • U.S. Census data, used to estimate % BIPOC and average median household income per ‘Block Group’ (similar to a neighborhood).
  • Satellite images, which are often used to estimate % tree cover, measure the percent of land area covered by the tree canopy. Adrienne looked at tree cover in the Block Group areas used in the Census.
  • City data that include the location and species for each tree planted along public streets to calculate tree species richness in each Block Group. Tree species richness is the number of different tree species in an area and is a measure of tree biodiversity used by many ecologists.

Featured scientists: Adrienne Keller (she/her) from the University of Minnesota

The data in this activity are from the MSP Long-term Ecological Research Site. The focus of the research at this site is centered on ecological interactions in urban environments. You can learn more here.

Flesch–Kincaid Reading Grade Level = 9.4

Additional teacher resources related to this Data Nugget include:

  • You can have students read more about environmental justice research from the MSP LTER in this peer-reviewed article (email us at datanuggetsk16@gmail.com if you need a downloadable version):
    • Rebecca H. Walker, Hannah Ramer, Kate D. Derickson & Bonnie L. Keeler (2023) Making the City of Lakes: Whiteness, Nature, and Urban Development in Minneapolis. Annals of the American Association of Geographers, DOI: 10.1080/24694452.2022.2155606
  • This short video features Adrienne as she describes the motivation and process behind her research study.
6.1.23

Collaborative cropping: Can plants help each other grow?

The activities are as follows:

Alfalfa (middle) planted in a Kernza® field.

Most of the crops grown on farms in the United States are annual plants, like corn, soybeans, and wheat. Annual plants die every year after harvest and must be replanted the following year. Preparing farm fields for replanting every year can erode soils and hurt important bacteria and fungi living in the soil.

One way to change how we produce food is to grow more perennial crops. Perennial plants live for many years and don’t need to be replanted. Perennials stay in the ground all year and start growing right away in the spring before annual crops are even planted. This early growth also gives perennial crops a “head-start” in competing with annual weed species that emerge later in the season.

While there are potential benefits of perennial crops, they are not commonly planted because they tend to make lower profits for farmers than annual crops. Crop scientists are still examining potential options to make perennial crops work at a large scale for farmers. For twenty years, researchers at The Land Institute in Kansas and at the University of Minnesota have been looking at a new perennial grain, called Kernza®, that could be used as an alternative to wheat and rye annual crops. Kernza® comes from the seeds of a plant called intermediate wheatgrass. Because Kernza® is such a new crop, scientists still have a lot to learn about it. Before it can be widely used by farmers, they want to know what field conditions help the plants grow to ensure the crop makes money for farmers.

Dr. Jake Jungers taking a soil core in a Kernza® field.

One strategy to improve field conditions for perennial crops is to plant legumes in the field alongside them. Legumes can make nitrogen, a nutrient that plants need to grow, more available to the plants around them. Additionally, farmers can select legume species that typically don’t compete with the crop but may outcompete weeds.

Jake is an ecologist who uses his knowledge about plants to make agriculture more sustainable. Jake wanted to do some research into alfalfa, a type of perennial legume that might work well with Kernza®. Jake thought that growing alfalfa alongside Kernza® would lead to increased profit and yield for two reasons. One, because it would add nitrogen to the soil to boost crop growth. Two, because alfalfa would compete with agricultural weed species, making valuable resources available for the crop plants.

To test this idea, Jake set up an experiment with his team. Alfalfa was grown with Kernza® at three different locations in Minnesota in 2019. The study was replicated four times at each site, with the same amount of alfalfa and Kernza® planted into each field. At the end of the growing season, the fields were harvested, and the plants were sorted into three categories: Kernza®, alfalfa, and weed species. He further sorted Kernza® by grain, which can be used for food, and straw, which can be used for animal feed. Jake wanted to compare yield, or plant growth per unit area, across the plant categories. To do this, he weighed all the plants in each category to get the biomass and then divided by the area of the field.

Featured scientist: Jake Jungers (he/him) from the University of Minnesota

Written by Claire Wineman (she/her)

Flesch–Kincaid Reading Grade Level = 8.5

3.16.23

Benthic buddies

Danny and Kaylie sampling benthic animals

The activities are as follows:

Lagoons are areas along the coast where a shallow pocket of sea water is separated from the ocean most of the time. During some events, like high tides, the ocean water meets back up with the lagoon. Coastal lagoons are found all over the world – even in the most northern region of Alaska, called the High Arctic!

These High Arctic lagoons go through many extreme changes each season. In April, ice completely covers the surface. The mud at the bottom of the shorelines is frozen solid. In June, the ice begins to break up and the muddy bottoms of the lagoons begin to thaw. The melting ice adds freshwater to the lagoons and lowers the salt levels. In August, lagoon temperatures continue to rise until there is only open water and soft mushy sediment.

You would think these harsh conditions would make High Arctic lagoons not suitable to live in. However, these lagoons support a surprisingly wide range of marine organisms! Marine worms, snails, and clams live in the muddy sediment of these lagoons. This habitat is also called the bottom, or benthic, environment. Having a rich variety of benthic animals in these habitats supports fish, which migrate along the shoreline and eat these animals once the ice has left. And people who live in the Arctic depend on fishing for their food.

Ken, Danny, and Kaylie are a team of scientists from Texas interested in learning more about how the extreme seasons of the High Arctic affect the marine life that lives there. They want to know whether the total number of benthic species changes with the seasons. Or does the benthic community of worms, snails, and clams stay constant throughout the year regardless of ice, freezing temperatures, and large changes in salt levels? The science team thought that the extreme winter conditions in the Arctic lagoons cause a die-off each year, so there would be fewer species found at that time. Once the ice melts each year, benthic animals likely migrate back into the lagoons from deeper waters and the number of species would increase again.

Ken, Danny, and Kaylie had many discussions about how they could answer their questions. They decided the best approach would be to travel to Alaska to take samples of the benthic animals. To capture the changes in lagoon living conditions, they would need to collect samples during the three distinct seasons.

Benthic organisms from a sample

The science team chose to sample Elson Lagoon because it is in the village of Utqiaġvik, Alaska and much easier to reach than other Arctic lagoons. They visited three times. First, in April, during the ice-covered time, again in June when the ice was breaking up, and a final time in summer when the water was warmer. In April, they used a hollow ice drill to collect a core sample of the frozen sediment beneath the ice. In June and August, they deployed a Ponar instrument into the water, which snaps shut when it reaches the lagoon bottom to grab a sample. Each time they visited the lagoon, they collected two sediment samples.

Back in the lab, they rinsed the samples with seawater to remove the sediment and reveal the benthic animals. The team then sorted and identified the species present. They recorded the total number of different species, or species richness, found in each sample.

Featured scientists: Ken Dunton, Daniel Fraser, and Kaylie Plumb from the University of Texas Marine Science Institute

Written by: Maria McDonel from Flour Bluff and Corpus Christi Schools

Flesch–Kincaid Reading Grade Level = 8.9

Additional teacher resources related to this Data Nugget include:

11.14.22

Does more rain make healthy bison babies?

A bison mom and her calf.
A bison mom and her calf.

The activities are as follows:

The North American Bison is an important species for the prairie ecosystem. They are a keystone species, which means their presence in the ecosystem affects many other species around them. For example, they roll on the ground, creating wallows. Those wallows can fill up with water and create a mini marsh ecosystem, complete with aquatic plants and animals. They also eat certain kinds of food – especially prairie grasses. What bison don’t eat are wildflowers, so where bison graze there will be more flowers present than in the areas avoided by bison. This affects many insects, especially the pollinators that are attracted to the prairie wildflowers that are abundant in in the bison area. 

Not only do bison affect their environment, but they are also affected by it. Because bison eat grass, they often move around because the tastiest meals might be scattered in different areas of the prairie. Also, as bison graze down the grass in one area they will leave it in search of a new place to find food. The amount of food available is largely dependent upon the amount of rain the area has received. The prairie ecosystem is a large complex puzzle with rain and bison being the main factors affecting life there. 

The Konza Prairie Biological Station in central Kansas has a herd of 300 bison. Scientists study how the bison affect the prairie, and how the prairie affects the bison. Jeff started at Konza as a student, and today he is the bison herd manager. As herd manager, if is Jeff’s duty to track the health of the herd, as well as the prairie. 

One of the main environmental factors that affect the prairie’s health is rainfall. The more rain that falls, the more plants that grow on the prairie. This also means that in wetter years there is more food for bison to eat. Heavier bison survive winters better, and then may have more energy saved up to have babies in the following spring. Jeff wanted to know if a wet summer would actually lead to healthier bison babies, called calves, the following year.

Jeff and other scientists collect data on the bison herd every year, including the bison calves. Every October, all the bison in the Konza Prairie herd are rounded up and weighed. Since most of the bison calves are born in April or May, they are about 6 months old by the time are weighed. The older and the healthier the calf is, the more it weighs. Very young calves, including those born late in the year, may be small and light, and because of this they may have a difficult time surviving the winter. 

Jeff also collects data on how much rain and snow, called precipitation, the prairie receives every year. Precipitation is measured daily at the biological station and then averaged for each year. Precipitation is important because it plays a direct role in how well the plants grow. 

Jeff and a herd of bison on the Konza prairie.
Jeff and a herd of bison on the Konza prairie.
Konza LTER logo

Featured scientist: Jeff Taylor from the Konza Prairie Biological Station

Written by: Jill Haukos, Seton Bachle, and Jen Spearie

Flesch–Kincaid Reading Grade Level = 8.7

Additional teacher resources related to this Data Nugget include:

  • The full dataset for bison herd data is available online! The purpose of this study is to monitor long-term changes in individual animal weight. The datasets include an annual summary of the bison herd structure, end-of-season weights of individual animals, and maternal parentage of individual bison. The data in this activity came from the bison weight dataset (CBH012).
  • For more information on calf weight, check out the LTER Book Series book, The Autumn Calf, by Jill Haukos.
8.17.22

Mowing for monarchs, Part II

In Part I you explored data that showed monarchs prefer to lay their eggs on young milkweeds that have been mowed, compared to older milkweed plants. But, is milkweed age the only factor that was changed when Britney and Gabe mowed patches of milkweeds? You will now examine whether mowing also affected the presence of monarch predators.

A scientist measuring a milkweed plant.
A scientist, Lizz D’Auria, counting the number of monarch predators on milkweed plants in the experiment.

The activities are as follows:

The bright orange color of monarch butterflies signals to their enemies that they are poisonous. This is a warning that they do not make a tasty meal. Predators, like birds and spiders, that try to eat monarch butterflies usually become sick. Many people think that monarch butterflies have no enemies because they are poisonous. But, in fact they do have a lot of predators, especially when they are young.

Monarchs become poisonous from the food they eat. Adult monarchs lay their eggs on milkweed plants, which have poisonous sap. When the eggs hatch, the caterpillars chomp on the leaves. Young caterpillars are less poisonous because they haven’t eaten much milkweed yet. And monarch eggs are not poisonous at all to predators.

Britney and Gabe met with their friends, Doug and Nate, who are scientists. Doug and Nate thought that Britney and Gabe’s experiment might have changed more than just the age of the milkweed plants in the patches they mowed. By mowing their field sites they were also cutting down the plants in the rest of the community. These plants provide habitat for predators, so mowing all of the plants would affect the predators as well. These ideas led to another potential explanation for the results Britney and Gabe saw in their data. Because all plants were cut in the mowed patches, there was nowhere for monarch predators to hang out. Britney and Gabe came up with an alternative hypothesis that perhaps monarch butterflies were choosing to lay their eggs on young milkweed plants because there were fewer predators nearby. To test this new idea, Britney and Gabe went back to their experimental site and started collecting data on the presence of predators in addition to egg number. Remember that in each location, they had a control patch, which was left alone, and a treatment patch that they mowed. The control patches had older milkweed plants and a full set of plants in the community. The mowed patches had young milkweed plants with short, chopped plants nearby. For the whole summer, they went out weekly to all of the patches. They counted the number of predators found on the milkweed plants so they could compare the mowed and unmowed patches.

Predators of monarch butterflies.
There are many different species that eat monarch butterfly eggs and young caterpillars. These are just a few of the species that Gabe and Britney observed during their experiment.

Featured scientists: Doug Landis and Nate Haan from Michigan State University and Britney Christensen and Gabe Knowles from Kellogg Biological Station LTER.

Flesch–Kincaid Reading Grade Level = 8.2

Additional resources related to this Data Nugget:

  • A news article discussing declining monarch populations and the causes that might be contributing to this trend.
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