6.17.22

Going underground to investigate carbon locked in soils 

Mineral-associated organic matter (MAOM) at the bottom of a test tube in a salt solution.

The activities are as follows:

Soil is an important part of the carbon cycle because it traps carbon, keeping it out of the atmosphere and locked underground. At a global level, the amount of carbon stored by soil is more than is found in all of the plants and the atmosphere combined. Carbon trapped underground does not contribute to the rising carbon dioxide concentration in our atmosphere that leads to climate change. For decades, scientists have been researching how much carbon our soils can store to understand its role in slowing the pace of climate change.

Carbon enters the soil when plants and animals die, and their organic matter is decomposed by soil bacteria and fungi. Sometimes it is broken down into very small molecules. These molecules become attached to minerals in the soil, like clay particles. We call this mineral-associated organic matter (MAOM). The carbon is connected to minerals with very strong chemical bonds. Because these bonds are hard to break, the carbon stays in the soil for long periods of time and accumulates on clay minerals. 

Some studies have shown that the carbon in MAOM can be trapped in soils for thousands of years! When more of the carbon in the soil is attached to minerals and locked in the soil for longer time periods, the ecosystem is serving an important role in keeping carbon out of the atmosphere. 

Ashley in the lab, using a saltwater solution to isolate mineral-associated organic matter (MAOM) from soil samples.

Ashley is working to understand how much stable carbon there is in soils, and the role of climate. Microbes work faster in warmer and wetter conditions, which results in quicker decomposition. Ashley thought this rapid decomposition would cause organic matter to be broken down into smaller particles sooner. Therefore, she thought that in warmer or wetter environments, more soil carbon would attach to minerals and become stable MAOM. In colder or drier environments, she expected this process to happen more slowly, leading to a smaller amount of MAOM in the soil.

To test these ideas, Ashley used soil samples from forests with different climates throughout the Eastern United States. Soil samples were collected from New Hampshire to Alabama by teams of researchers using the same sampling protocol. The samples were mailed to Ashley’s lab at Indiana University for analysis. Ashley measured the amount of MAOM in each soil sample by taking advantage of a key feature: MOAM is heavy! Ashley submerged each soil sample in a saltwater solution, and the parts that floated were discarded, while the parts that sunk to the bottom were classified as MAOM. She then rinsed the salt off and measured the amount of carbon in the MAOM with an instrument called an elemental analyzer. She compared this number to the amount of carbon in the whole soil sample to calculate what percentage of the total soil carbon was attached to minerals.

Featured scientist: Ashley Lang from Indiana University

Flesch–Kincaid Reading Grade Level = 10.8

Additional teacher resources related to this Data Nugget:

3.31.22

Salty sediments? What bacteria have to say about chloride pollution

Lexi taking water quality measurements at Cedar Creek in Cedarburg, WI.

The activities are as follows:

In snowy climates, salt is applied to roads to help keep them safe during the winter. Over time, salt – in the form of chloride – accumulates in snowbanks. Once temperatures begin to warm in the spring, the snow melts and carries chloride to freshwater lakes, streams, and rivers. This runoff can quickly increase the salt concentration in a body of water. 

In large amounts, salt in the water is harmful to aquatic organisms like fish, frogs, and invertebrates. However, there are some species that thrive with lots of salt. Salt-loving bacteria, also known as halophiles, grow in extreme salty environments, like the ocean. Unlike other bacteria and organisms that cannot tolerate high salinity, halophiles use the salt in the environment for their day-to-day cellular activities. 

Lexi is a freshwater scientist who is interested in learning more about how ecosystems respond to this seasonal surge of chloride in road salts. She thought that there may be enough chloride from the road salt after snowmelt to change the bacteria community living in the sediment. More salt would support halophiles and likely harm the species that cannot tolerate a lot of salt. 

By taking a water sample and measuring the chloride concentration, we can see a snapshot in time of how toxic the levels are to organisms. However, the types of bacteria in sediments take a while to change. Halophiles may be able to tell us a long-term story of how aquatic organisms respond to chloride pollution. Lexi’s main goal is to use the presence of halophiles as a measure of how much chloride has impacted the health and water quality of river or stream ecosystems. This biological tool could also help cities identify areas that may be getting salted beyond what is necessary to keep roads safe.

Lexi expected that there would be few, or maybe no, halophiles in rural areas where there are not many roads. She also thought halophiles would be widespread in urban environments where there are many roads. Because salt impacts the streams year after year, she expected that halophiles would become permanent members of the microbial community and increase in winter and spring. Therefore, she also wanted to track whether halophiles remain in the sediment throughout the year, increasing in numbers when salt levels become high. 

She began to sample sediments from two different rivers in Southeastern Wisconsin. The urban Kinnickinnic River site is in Milwaukee, WI, and the Menomonee River site is in a rural environment outside of the city. She selected these sites because they offer a good comparison. Because there are more roads, and thus saltier snowmelt, the Kinnickinnic site in the city should have higher chloride concentrations than the Menomonee site. 

When visiting her sites throughout the year, Lexi collected multiple water and sediment samples. Every time she visited, she also recorded important water quality characteristics such as pH, conductivity, and temperature of the water. She then brought the samples to the laboratory and analyzed each for its chloride concentration. To measure the quantity of halophiles in the sediment, Lexi used a process where the sediment is shaken in water to separate the bacteria from the sediment and suspend them in the water. Samples from the water were then plated on a growth medium that contained a very high salt concentration. Because the growth medium was so salty, Lexi knew that if bacteria colonies grew on the plate, they would most likely be halophiles because most bacteria do not thrive in salty environments. Lexi counted the number of bacteria colonies that grew on the plates for each sample she had collected.

Featured scientist: Lexi Passante from the University of Wisconsin-Milwaukee

Flesch–Kincaid Reading Grade Level = 12.0

Some videos about Lexi and her research:

Additional teacher resources related to this Data Nugget:

1.27.22

Ant wars!

Three pavement ants touch antennae to determine if they are nestmates. Photo courtesy Michael Greene.

The activities are as follows:

The ants crawling into and out of cracks along sidewalks are called pavement ants. They live in groups called colonies, which are made up of a few queens and many worker ants. A colony lives together inside a nest, a physical structure. Worker ants use their antennae to touch the bodies of other ants. Certain chemicals tell them if the ant is from their colony or a different colony. Nestmates are ants from the same colony, and non-nestmates are ants from other colonies. 

Neighboring colonies often compete for food, leading to tension. If an ant finds a non-nestmate, it organizes a large war against the nearby colony. This results in huge sidewalk battles that can include thousands of ants fighting for up to 12 hours! These ant wars often involve worker ants grabbing body parts of non-nestmate ants. 

Andrew, Jazmine, John, Mike, and Ken all work together to study the social and chemical cues that drive behaviors in animals. They were curious to learn more about the triggers that lead to colony wars. Worker ants don’t have a leader, so the scientists wanted to know how large wars are organized. The team started by reading lots of research articles and learned that there are several factors that may affect an ant’s decision to fight. These include the odor of other ants they meet, the size of the ant’s colony, and the season. The team also knew from their own experiments that if an ant meets a fellow nestmate before meeting a non-nestmate, it was more likely to fight.

A colony war involving thousands of pavement ants. Photo credit: Michael Greene.

All of this information helped the team realize that interactions with nestmates were an important part of the decisions that start ant wars with non-nestmakes. To build on this, they wanted to know whether the decision to fight was affected by ant density, which is the number of ants within an area. They thought that at higher densities the ants would be more likely to interact, leading to more fights with non-nestmates. If more wars are observed at higher ant densities, increased interactions with nestmates might be part of the story.

To answer their question, the team collected ants from different colonies in Denver, Colorado for two separate experiments. They brought them back to the lab to set up trials in a plastic tank arena.

Experiment 1: For the first set of behavioral trials, the researchers varied the number of ants in the tank, ranging from 2 to 20 ants. The size of the tank remained constant, and there were always equal numbers of nestmates and non-nestmates. This means the ratio of nestmates to non-nestmates was always 1:1, but the density varied by how many ants were included in the experiment. They performed 18 trials for each density treatment in their experiment.

At the start of every trial, ants from each colony were in separate areas so that they could interact with nestmates first. Earlier work had shown that when ants in each area interact, they touch antennae to another ant’s body. These interactions create a brain state that makes an ant more likely to fight an ant from another colony. Then the scientists removed a barrier revealing the ants from the other colony. They watched the ants for 3 minutes. During that time they recorded the number of ants that were fighting. This way they could compare how likely the ants were to fight at different densities. They predicted there would would be more fighting at higher ant densities.

Experiment 2: The scientists also wanted to measure the effect of density on the interaction rates between just nestmates. This experiment allowed the scientists to understand how the rate of interactions affected levels of neurochemicals in brains, creating the brain state that increased the likelihood that an ant would be aggressive. For these trials, they placed different densities of nestmate ants in a tank. They randomly picked an ant during each trial and counted the number of times it contacted a nestmate ant. Different groups of ants were used in each trial and each experiment. They observed the number of interactions at different densities and expected nestmate ants to have more interactions at higher densities.

Featured scientists: Andrew Bubak, Jazmine Yaeger, John Swallow, and Michael J. Greene from the University of Colorado-Denver; Kenneth Renner from the University of South Dakota. Written by: Gabrielle Welsh

Flesch–Kincaid Reading Grade Level = 9.0

Additional teacher resources related to this Data Nugget:

A news article about the research:

Looking at ant battles to learn about violence
1.26.22

David vs. Goliath

Stalk-eyed flies have their eyes at the end of long stalks on the sides of their head. These stalks are used by males when fighting for resources.

The activities are as follows:

Animals in nature often compete for limited resources, like food, territory, and mates. To compete for these resources, they use aggressive behaviors to battle with others of the same species. Aggressive behaviors are meant to overpower and defeat an opponent. The outcome of a battle depends on many different factors. In insects, one important factor is body size. Larger individuals are usually more aggressive and often win more battles. Chemicals in the brain can also influence who wins a fight. One chemical, called serotonin, can cause insects to have more aggressive behaviors. It is found in the brains of all animals, including humans.

Andrew had always been curious about what makes an animal decide to use aggressive behaviors in battle, or when to end one. He worked with researchers Nathan, Michael, Ken, and John to study the role that chemicals in the brain have on behaviors. The team was interested in how brain chemicals, like serotonin, affect aggression. They have been studying an insect species called stalk-eyed flies. These flies have eyes on the ends of long eyestalks that protrude from their heads. Male stalk-eyed flies use these eyestalks when battling each other. In a previous experiment, they found that serotonin can cause these flies to have more aggressive behaviors. They also knew that flies with shorter eyestalks usually lose fights to larger flies. 

This made them curious about whether extra serotonin could make flies with shorter eyestalks act more aggressive and help them win fights against flies with longer eyestalks. The team of researchers discussed what they knew from past research and predicted that if they gave serotonin to short eyestalk flies, it might help them win fights against long eyestalk flies. They thought this made sense because they already knew that serotonin make flies more aggressive, and more aggressive behaviors could help the shorter flies win more fights. 

The fighting arena where stalk-eyed flies battle. The camera is set up to help the scientists observe both the high intensity behaviors and retreats.

The team designed a lab study to look into this question about the importance of eyestalk length and serotonin for battles in stalk-eyed flies. First, the researchers raised male stalk-eyed flies in the lab. They made sure the flies were around the same age and were raised in a similar lab environment from the time they were born. Then, they measured the eyestalk length for each fly and divided them into two groups. One group had flies with longer eyestalks (Goliaths) and one group had flies with shorter eyestalks (Davids). They took the group of Davids with shorter eyestalks and fed half of them food with a dose of serotonin. This became the treatment group. They fed the other half of the Davids group food, but without serotonin. This was the control group. The treatment group and control group each had 20 flies.

To prepare the flies for battle, all flies were all starved for 12 hours before the competition to increase their motivation to fight over food. The researchers paired each David with a Goliath in a fighting arena. They observed the flies and recorded aggressive behaviors shown by each opponent. The researchers labeled any behavior where the fighting flies touch each other as a “high intensity behavior”. They labeled any behavior where the flies backed away as a “retreat”. Flies that retreated less than their opponent were declared the winners.

Featured scientists: Andrew Bubak, Nathan Rieger, and John Swallow from the University of Colorado, Denver; Michael Watt and Kenneth Renner from the University of South Dakota. Written by: Gabrielle Welsh.

Flesch–Kincaid Reading Grade Level = 9.3

1.11.22

Mowing for monarchs, Part I

A monarch caterpillar on a milkweed leaf.
A monarch caterpillar on a milkweed leaf.

The activities are as follows:

With their orange wings outlined with black lines and white dots, monarch butterflies are one of the most recognizable insects in North America. They are known for their seasonal migration when millions of monarch butterflies migrate from the United States and Canada south to Mexico in the fall. Then, in the spring the monarch butterflies migrate back north. Monarch butterflies are pollinators, which means they get their food from the pollen and nectar of flowering plants that they visit. The milkweed plant is one of the most important flowering plants that monarch butterflies depend on.

During the spring and summer months female butterflies will lay their eggs on milkweed plants. Milkweed plays an important role in the monarch butterfly’s life cycle. It is the only plant that monarchs will lay their eggs on. Caterpillars hatch from the butterfly eggs and eat the leaves of the milkweed plant. The milkweed is the only food that monarch caterpillars will eat until they become butterflies.

A problem facing many pollinators, including monarch butterflies, is that their numbers have been going down for several years. Scientists are concerned that we will lose pollinators to extinction if we don’t find solutions to this problem. Doug and Nate are scientists at Michigan State University trying to figure out ways to increase the number of monarch butterflies. They think that they found something that might work. Doug and Nate have learned that if you cut old milkweed plants at certain times of the year, then younger milkweed plants will quickly grow in their place. These new milkweed plants are softer and more tender than the old plants. It appears that monarch butterflies prefer to lay their eggs on the younger plants. It also seems that the monarch caterpillars prefer to eat the younger plants.

Britney and Gabe are two elementary teachers interested in monarch butterfly conservation. They learned about Doug and Nate’s research and wanted to participate in their experiment. The team of four met and designed an experiment that Britney and Gabe could do in open meadows throughout their community.

Britney and Gabe chose ten locations for their experiment. In each location they set aside a milkweed patch that was left alone, which they called the control.  At the same location they set aside another milkweed patch where they mowed the milkweed plants down. After a while, milkweed plants would grow back in the mowed patches. This means they had control patches with old milkweed plants, and treatment patches with young milkweed plants. Gabe and Britney made weekly observations of all the milkweed patches at each location. They recorded the number of monarch eggs in each of the patches. By the end of the summer, they had made 1,693 observations!

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:

  • This research is part of the ReGrow Milkweed citizen science project. To learn more, visit their website or follow them on Twitter at @ReGrowMilkweed.
  • Britney, one of the scientists in this study, wrote a blog post about her experience in the NSF LTER RET Program (National Science Foundation’s Research Experience for Teachers) working with Doug Landis.
  • Learn about how this group of scientists responded to the COVID-19 pandemic to pivot to a virtual citizen science program in this blog post.
  • A news article discussing declining monarch populations and the causes that might be contributing to this trend.
11.1.21

Round goby, skinny goby

An invasive round goby from the Kalamazoo River, Michigan.
An invasive round goby from the Kalamazoo River, Michigan.

The activities are as follows:

Animals often have adaptations, or traits that help them live in certain environments. For fish, that can mean having a body shape that allows them to feed on available prey, better hide from predators, or swim more effortlessly. When these traits vary within the same species from one location to another, they are called local adaptations. Such adaptations were once thought to only evolve slowly over hundreds or thousands of generations. However, new evidence shows that evolution can result in meaningful adaptations much more quickly than originally thought, sometimes in just a few generations!

Invasive species are those that have been moved by humans to areas where they do not usually exist and cause disruptions to native ecosystems. Because they have been moved to new places where they did not evolve, invasive species often have traits that aren’t matched to their new habitats. When mismatches occur, species may be able to adapt in just a few generations in their new locations.

Several invasive species have been problematic in the Great Lakes of North America. The round goby is a small invasive fish species that arrived in the Great Lakes around 1990. It is a bottom-dwelling species that is able to quickly reproduce and crowd out native fish species. Both avid anglers, Jared and Bailey observed the increasing numbers of round gobies during their time spent outdoors. They noticed that sometimes round gobies would even outnumber all other native fish in an area.

Originally appearing just in the Great Lakes themselves, the species is increasingly being found in rivers throughout the region. Jared and Bailey were surprised this species did so well in both river and large lake habitats since they are very different environments for fish to live. For example, water is constantly flowing downstream in rivers, whereas lakes can be still or have waves near the shore. Also, these two habitats have different predator and prey species living in them and differ in water chemistry characteristics. With the spread of more and more round gobies into rivers, Jared and Bailey set out to learn how this species is successful in both habitats. They thought that round gobies found in rivers would have adaptations to help navigate fast flowing waters. Fish with narrower body shapes can move more easily in flowing waters, giving narrow-bodied individuals an advantage over those with bulkier bodies. Over time, those individuals with such an advantage would be more likely to survive and reproduce in the rivers, eventually shifting the entire river-dwelling population to a narrow body shape. They predicted that round gobies from rivers would have shorter body depths and narrower caudal peduncles, which is the area between the fish’s body and tail. To test their idea, Jared and Bailey captured and measured hundreds of round gobies from both Great Lakes and inland river habitats.

Michigan State University researcher Bailey Lorencen fishing for gobies in a Michigan river.
Michigan State University researcher Bailey Lorencen fishing for gobies in a Michigan river.

Featured scientists: Jared Homola (he/him) and Bailey Lorencen (she/her) from Michigan State University

Flesch–Kincaid Reading Grade Level = 11.2

8.10.21

Trees and bushes, home sweet home for warblers

Matt, Sarah, and Hankyu – a team of scientists at Andrews Forest, measuring bird populations.

The activities are as follows:

The birds at a beach are very different from those in the forest. This is because each bird species has their own set of needs that allows them to thrive where they live. Habitats must have the right collection of food to eat, places to shelter and raise young, safety from predators, and the right environmental conditions like temperature and moisture. 

The vast coniferous forests of the Pacific Northwest provide rich and diverse habitat types for birds. These forests are also a large source of timber, meaning they are economically valuable for people. Disturbances from logging and natural events result in a forest that has many different habitat types for birds to choose from. In general, areas of forest that have been harvested more recently will have more understory, such as shrubs and short trees. Old-growth forests usually have higher plant diversity and larger trees. They are also more likely to have downed trees or standing dead trees, which are important for some bird species. Other disturbances like wildfire, wind, large snow events, and forest disease also have large impacts on bird habitat.

At the Andrews Forest Long-Term Ecological Research site in the Cascade Mountains of Oregon, scientists have spent decades studying how the plants, animals, land use, and climate are all connected. In the past, Andrews Forest had experiments manipulating timber harvesting and forest re-growth. This land use history has large impacts on the habitats found in an area. Many teams of scientists work in this forest, each with their own area of research. Piece by piece, like assembling a puzzle, they combine their data to try to understand the whole ecosystem. 

Collecting data on a warbler.

Matt, Sarah, and Hankyu have been collecting long-term data on the number, type, and location of birds in Andrews Forest since 2009. Early each morning, starting in May and continuing until late June, teams of trained scientists hike along transects that go through different forest types. Transects are parallel lines along which data are collected. At specific points along the transect, the team would stop and listen for bird songs and calls for 10 minutes. There are 184 survey locations, and they are visited multiple times each year.

At each sampling point, Matt, Sarah, and Hankyu carefully recorded a count for each bird species that they hear within 100 meters. They then averaged these data for each location along the transect to get an average number for the year. The scientists were also interested in the habitats along the transect, which includes the amount of understory plants and tall trees, two forest characteristics that are very important to birds. They measured the percent cover of understory vegetation, which shows how many bushes and small plants were around. They also measured the size of trees in the area, called basal area. 

Using these data, the research team is looking for patterns that will help them identify which habitat conditions are best for different bird species. With a better understanding of where bird species are successful, they can predict how changes in the forest could affect the number and types of birds living in Andrews Forest and nearby.  

Wilson’s Warblers and Hermit Warblers are two of the many songbirds that these scientists have recorded at Andrews Forests. Wilson’s Warblers are small songbirds that make their nests in the understory of the forests. Therefore, the team predicted that they would see more of Wilson’s Warblers in forest areas with more understory than in forest areas with less understory. Hermit Warblers, on the other hand, build nests in dense foliage of tall coniferous trees and search for spiders and insects in those coniferous trees. The team predicted that the Hermit Warblers would be observed more often in forest plots where there are larger trees.  

Featured scientists: Hankyu Kim, Matt Betts, and Sarah Frey from Oregon State University. Written with Eric Beck from Realms Middle School and Kari O’Connell from Oregon State University.

Flesch–Kincaid Reading Grade Level = 10.5

Additional teacher resource related to this Data Nugget:

7.19.21

Buried seeds, buried treasure

Marjorie (right) and David (left) digging up the seed bottle in 2021. This bottle was scheduled to be dug up in 2020, but the experiment was delayed one year due to COVID-19.

One of the world’s longest-running science experiments lies hidden in the soil beneath Michigan State University’s campus. Over 100 years ago, a scientist named William J. Beal had a question: how long do seeds survive underground? To find out, he started an experiment. In 1879 he filled 20 bottles with sand and seeds from local plants. William buried these bottles and created a map to document their location, hoping that future scientists would continue to dig them up to test whether the seeds would still grow long after his death.

These bottles and the map have been passed down from generation to generation, with each new scientist responsible for training their successor. To protect the seeds, only a select few scientists are let in on the secret. Today a team of four plant biologists hold the map, and they were the ones to dig up the most recent bottle in 2021. 

Early one Thursday morning, before the sun had risen, the team set out on their mission. Marjorie Weber, the first woman to be in charge of the study and currently the youngest team member, was the scientist who found the bottle and pulled it from the ground. This is a big deal, as back when William began the experiment women weren’t even allowed to be scientists!

Seeds of Verbascum blattaria germinating in 2021. This is the only species that germinated from the most recent collection.

Originally, the Beal Seed Experiment was designed to test seed viability, or how long seeds of different species stay alive in the soil and still germinate. Seeds don’t germinate as soon as they fall off their mother plant. They become part of a seed bank below the soil, waiting for the right conditions to tell them to sprout. William was working with local farmers in Michigan, and he was interested in helping them better understand how long weeds will continue to pop up in their fields after they start to plant crops. This is reflected in the fact that many of the species included in the experiment are weeds in agricultural fields. 

Despite all the changes that have taken place in the world since the seeds were buried 142 years ago, the main question remains the same: how long can seeds stay alive in the soil? In addition to helping farmers, Marjorie and the other scientists now have additional reasons for wanting to understand seed viability. Restoration of natural plant communities, conservation of endangered species, and removal of invasive plants from fragile ecosystems can all benefit from a knowledge of the seedbank. 

With this long-term study design, scientists can compare how many seeds sprout and which species are able to germinate through time. Originally, William dug up a new bottle every five years. Once scientists realized how long the seeds last, they made the interval between excavations longer; now they wait 20 years before digging up the next bottle. The experiment is set to go at least another 80 years. Imagine, future bottles will be dug up by scientists who are not even born yet!

Once a bottle is found and unearthed, it is taken back to the lab to see which species will germinate. Filled with sand and over a thousand seeds, each bottle contains the same mix of 50 seeds of 21 different species of plants. The contents are spread out on a tray filled with soil and are put into growth chambers. Scientists keep an eye on the trays to watch and see what germinates.

Featured scientist: Marjorie Weber from Michigan State University. 

Other scientists: Frank Telewski, David Lowry, Lars Brudvig, and Margaret Fleming.

Written by: Elizabeth Schultheis and Melissa Kjelvik.

Flesch–Kincaid Reading Grade Level = 9.7

Additional teacher resource related to this Data Nugget:

This experiment received a lot of press coverage. Have students check out these new stories and videos to learn more about the scientists and experiment:

YouTube video summarizing the search and the experiment:

6.18.21

Love that dirty water

Drew and students measuring river flow rate.

The activities are as follows:

Forests, wetlands, and other green spaces are natural filters for water; water is cleaned as it is used by plants and travels through soils. As green spaces are lost to make room for homes and businesses, ecosystems are less able to provide this service. Without natural filtration from green spaces, humans must build expensive water treatment systems or risk drinking contaminated water.

Impervious surfaces, like roads, buildings, and parking lots, do not allow water to pass through. When it rains or snows on an impervious surface, water cannot soak into soil or be used by plants. Instead, it quickly flows into nearby streams and rivers. If too much water runs off too quickly, it overwhelms local sewer systems, getting into rivers before it can be filtered. This dirty water may carry human waste and toxic materials. 

Impervious surfaces have become a major problem for both the health of river ecosystems, and the health of people who depend on them as a clean source of drinking water. How land is used in a watershed, or the network of land and rivers that flow to a single point as they empty out into the ocean, is an issue of great concern.

Jonathan is a scientist studying land use. He became interested in science after traveling around the country and working as a wilderness ranger and wildland firefighter. At the Harvard Forest, members of his lab study how land use decisions affect the environment. They used computer simulations to create maps of what New England’s landscape could look like under different possible futures. Their web-tool is called the New England Landscapes Futures Explorer. Johnathan’s lab works with Drew, a civil and environmental engineer who loves biking and hiking. Drew and his lab at Smith College are interested in the relationship between land use and water. Together, Jonathan and Drew’s labs teamed up to study how future increases in impervious surfaces from new development could affect water quality in New England. 

A team of scientists decided to use the web-tool to study the Merrimack River. The Merrimack is an important river for New England, and serves as a water source for more than 500,000 people in the region. It begins in New Hampshire, and flows through 117 miles of forests, farmland, and cities before emptying into the Atlantic Ocean.

To study the Merrimack, the scientists used their web-tool and data from two nearby similar watersheds to make predictions for the Merrimack. Combining research like this gives scientists, government organizations, and the public valuable information that can be used to help make decisions about how land should be used in the future.

Jonathan’s lab used their future land use predictions to estimate the percentage of impervious surface area in the Merrimack River watershed for three future scenarios in the year 2060. 

  1. Recent Trends: This scenario takes the historical rates and patterns of land use change from 1990-2010 and projects them through 2060.  This scenario imagines a future where we maintain current land use practices.
  2. Low Development: This scenario explores a future where the people of New England shift toward a lifestyle focused on “living local” and valuing reliance on local resources. This increases the urgency to protect local landscapes, including conservation of green spaces.  Rates of development are slightly lower than the Recent Trends scenario.
  3. High Development: This scenario explores a future with a rapid increase in human population in New England, because climate change has made life in many other places more difficult.  Rates of development are much higher than the Recent Trends scenario.

Drew’s team collected data from two watersheds adjacent to the Merrimack river (see map) and calculated the annual maximum daily flow, or the highest level that the river in each watershed would be expected to reach each day. Higher flows likely mean more human waste and toxic materials are getting into the river. These watersheds are similar to the Merrimack in some ways, but different in others. It is up to you to justify which watershed you think is most similar, and use the annual maximum daily flow data from that watershed to make your prediction for the Merrimack.

Featured scientists: Jonathan Thompson from Harvard University and Drew Guswa from Smith College. Written by Tara Goodhue and Joshua Plisinski. Supporting content by Amanda Suzzi.

Flesch–Kincaid Reading Grade Level = 11.3

Additional teacher resource related to this Data Nugget:

6.7.21

Blinking out?

A researcher collects data from a yellow sticky card at the MSU KBS LTER site. Photo Credit: K. Stepnitz, Michigan State University.

The activities are as follows:

The longest surveys of fireflies known to science was actually started by accident!

At the Kellogg Biological Station Long-Term Ecological Research Site, scientists work together to answer questions that can only be studied with long-term data. Their focus is to collect data in the same way over many consecutive years to look for patterns through time. One of these long-term studies, looking at lady beetle populations, was developed to keep watch on these important species. To count lady beetles, scientists placed yellow sticky card traps out in the same plots year after year. These data are used to figure out if lady beetle numbers are changing over time.

Because sticky traps catch everything small that flies by, other insect species get stuck as well. One day, a research technician noticed this and decided to add a few new columns to the data sheet. That way they could start recording data on the other insect species found on the sticky traps. Each year the technician kept adding to the record and over time, more and more data were collected. One of those new columns happened to record the number of fireflies caught. Though the exact reason for this data collection is lost to history, scientists quickly realized the value of this dataset! 

Several years later, Julia became the lab technician. She took over the responsibility of the sticky trap count, adding to the dataset. Christie joined this same lab as a scientist and stumbled upon the data on fireflies that Julia and the previous technician had collected. She wanted to take advantage of the long-term data and analyze whether firefly populations had been increasing or decreasing. 

Many people have fond memories of watching fireflies blink across open fields and collecting them in jars as children. This is one of the reasons why fireflies are a beloved insect species. Julia grew up in southwest Michigan and fondly recalls spending summers watching them blink over yards and open fields, catching them in jars to watch them for a little while. Christie did the same in her parent’s yard in rural Ontario! That fondness never really went away and both enjoy watching the fireflies around Northeast Ohio where they currently live. Fireflies are also an important part of the ecosystems where they live. Larvae spend most of their time in the soil and are predators of insects and other small animals, such as snails. 

All the insects collected on a yellow sticky card trap over the course of one week. Photo credit: Elizabeth D’Auria, Michigan State University.

Many scientists and citizens alike have noticed that they aren’t seeing as many fireflies as they used to. Habitat loss and light pollution could be causing problems for fireflies. This is where the importance of long-term data really comes into play. Long-term data are critical to identifying and understanding natural population cycles over long periods of time that we wouldn’t be able to see with just a few years of data. It also gives scientists opportunities to answer unanticipated research questions. In this situation, even though the data were collected without a specific purpose in mind, having the dataset available offered new opportunities! Christie and Julia were able to look at the long-term changes in southwest Michigan firefly populations, something they would not have been able to do before the research technician added those extra columns. In order to start answering this question, they compiled all of the years of firefly data and began to compare the average counts from year to year. Although data were collected in multiple different habitat types, they focused on data from open fields because fireflies use these areas to find mates.

Featured scientists: Christie Bahlai and Julia Perrone from Kent State University. Data from the Kellogg Biological Station LTER.

Flesch–Kincaid Reading Grade Level = 10.7

Additional teacher resources related to this Data Nugget include:

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