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.

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.

Mowing for Monarchs – Extension Activities

Gabe Knowles has developed and piloted several data activities to accompany these Data Nuggets activities. For the first activity, Gabe developed an extension to bring his data into elementary classrooms. Using beautiful art created by Corinn Rutkoski, the following are materials to print and use the activity in your classroom:

This activity was first piloted at Michigan Science Teachers Association Annual Meeting in 2023.

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:

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.

Changing climates in the Rocky Mountains

Lower elevation site in the Rocky Mountains: Temperate conifer forest. Photo Credit: Alice Stears.

The activities are as follows:

Each type of plant needs specific conditions to grow and thrive. If conditions change, such as temperature or the amount of precipitation, plant communities may change as well. For example, as the climate warms, plant species might start to shift to higher latitudes to follow the conditions where they grow best. But what if a species does well in cold climates found at the tops of mountains? Because they have nowhere to go, warming puts that plant species at risk.  

To figure out if species are moving, we need to know where they’ve lived in the past, and if climates are changing. One way that we can study both things is to use the Global Vegetation Project. The goal of this project is to curate a global database of plant photos that can be used by educators and students around the world. Any individual can upload photos and identify plant species. The project then connects each photo to information on the location’s biome, ecoregion, and climate, including data tracking precipitation and temperature over time. The platform can also be used to explore how the climates of different regions are changing and use that information to predict how plant communities may change. 

Daniel is a scientist who is interested in sharing the Global Vegetation Project data with students. Daniel became interested in plants and vegetation when he learned in college that you can simply walk through the woods and prairie, collect wild seeds, germinate the plants, and grow them to restore degraded landscapes. Plants set the backdrop for virtually every landscape that we see. He thinks plants deserve our undivided attention.

Daniel and his team wanted to create a resource where students can look deeper into plant communities and their climates. Much of the inspiration for the Global Vegetation Project came from the limitations to undergraduate field research during the COVID-19 pandemic. Students in ecology and botany classes, who would normally observe and study plants in the field, were prevented from having these opportunities. By building an online database with photos of plants, students can explore local plants without having to go into the field and can even see plants from faraway places. 

Daniel’s lab is based in the Rocky Mountains in Wyoming, where the plants are a showcase in both biodiversity and beauty. These communities deal with harsh conditions: cold, windy and snowy winters, hot and dry summers, and unpredictable weather during spring and fall. The plants rely on winter snow slowly melting over spring and into summer, providing moisture that can help them survive the dry summers. 

The Rocky Mountains are currently facing many changes due to climate change, including drought, increased summer temperatures, wildfires, and more. This creates additional challenges for the plants of the Rockies. Drought reduces the amount of precipitation, decreasing the amount of water available to plants. In addition, warmer temperatures in winter and spring shift more precipitation to rain instead of snow and melts snow more quickly. Rain and melted snow rapidly move through the landscape, becoming less available to plants in need. On top of all this, hotter, drier summers further decrease the amount of water available, stressing plants in an already harsh environment. If these trends continue, there could be significant impact on the types of plants that are able to grow in the Rocky Mountains. These changes will have an impact on the landscape, organisms that rely on plants, and humans as well.

Daniel and his colleagues pulled climate data from a Historic period (1961-2009) and Current period (2010-2018). They selected two locations in Wyoming to focus on: a lower elevation montane forest and a higher elevation site. To study climate, they focused on temperature and precipitation because they are important for plants. They wanted to study how temperature and precipitation patterns changed overall and how they changed in different seasons. They predicated temperatures would be higher in the Current period compared to the Historic period in both locations. For precipitation, they predicted there would be drier summers and wetter springs.

Featured scientist: Daniel Laughlin from The University of Wyoming. Written by: Matt Bisk.

Flesch–Kincaid Reading Grade Level = 10.5

Additional teacher resource related to this Data Nugget:

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.

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:

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.

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: