The way animals behave can have a big impact on how big they grow and whether or not they survive. Sometimes there are advantages and disadvantages to acting risky (bold) AND advantages and disadvantages to acting timidly (shy). When there are costs and benefits for two different strategies, we call this a tradeoff. For example, when bluegill are young, they have to grow big enough so that they don’t fit into the mouth of their predators, the largemouth bass. The best habitat for young bluegill to get lots of food to grow is the open water areas of a pond or lake. But, the open water zone has very few plants for bluegill to hide in from predators, so it’s not safe when bluegill are small! Once a bluegill grows long enough to not fit in its predator’s mouth, it [...]

Animals can act very differently. The way they act can decide which habitats they use. There are two kinds of habitats that young bluegill use to find food: open water and cover. The open water habitat has more food. But, the open water habitat has very few places for bluegill to hide, so it’s not as safe! The cover habitat is in shallower areas where lots of plants grow for bluegill to hide in.  Scientists can look at what the fish were eating to see what habitats they were looking for food in. If a fish has a lot of zooplankton in their stomachs, they were probably using open-water habitat to look for food! Scientists at the Kellogg Biological Station wanted to know whether bluegill with different personalities were using different habitats. They brought young bluegill into an aquarium lab [...]

Every day we use a lot of energy to drive, to heat or cool our homes, and to use electronic devices. We get most of this energy from burning fossil fuels. However, burning fossil fuels releases carbon dioxide, which is the number one greenhouse gas contributing to climate change. Scientists are trying to figure out alternative ways to produce energy without releasing so much carbon dioxide. For example, biofuel is a type of a fuel produced from plant matter. Using plants as fuel can help reduce human impact on climate change because plants take up carbon dioxide as they grow. To figure out how to get the most fuel from plants, young scientists from Michigan set up two types of plots at ten schoolyards. They either planted switchgrass (1 species) or a mixture of prairie plants (16 species). They wanted [...]

Many factors can affect how well plants grow. In order to grow, plants need water, light, and carbon dioxide. Other organisms, such as plant pests, pollinators, and diseases, can also affect plant growth. How do scientists test whether these factors affect plants growth? To address this question, a group of young scientists in Michigan decided to focus on how soil moisture (amount of water soil holds) affects plant growth. They planted seeds in a 2m x 2m plot at each schoolyard and measured soil moisture once plants began to grow. They also collected plant growth above ground, not including roots, and dried it for at least one week. This is called biomass, and it is a measure of how much plants grew excluding the mass of water in the plants. The data they collected are summarized below and can be [...]

Everyday we consume a large amount of energy to drive, to heat or cool our home, and to use electronic devices. Most of this energy is produced by burning fossil fuels. However, burning fossil fuels releases carbon dioxide, the number one greenhouse gas contributor to climate change. Scientists are trying to figure out alternative ways to produce energy. For example, biofuel is a type of a fuel produced from plant matter. Using plants as fuel can help reduce human impact on climate change because plants take up carbon dioxide as they grow. Plants do release carbon dioxide when we burn them to make fuel, just fossil fuels release carbon dioxide when they are burned. However, the net carbon emission of plants is lower because plants also take up carbon dioxide when they grow (i.e., photosynthesis). Here we ask how the [...]

Everyday we consume a large amount of energy to drive our cars, to heat or cool our homes, and to use electronic devices. Most of this energy is produced by burning fossil fuels. However, burning fossil fuels releases carbon dioxide, the number one greenhouse gas contributing to climate change. Scientists are trying to figure out alternative ways to produce energy. For example, biofuel is a type of a fuel produced from plant matter. Using plants as fuel can help reduce human impact on climate change because plants take up carbon dioxide as they grow. Plants do release carbon dioxide when we burn them to make fuel, just fossil fuels release carbon dioxide when they are burned. However, the net carbon emission of plants is lower because plants also take up carbon dioxide when they grow (i.e., photosynthesis). If we want [...]

Invasive species, like zebra mussels and garlic mustard, are species that have been introduced by humans to a new area and negatively impact places they invade. Invasive species cost the United States over $100 billion per year by damaging habitats, displacing native species, and interfering with human interests. Researchers at the Kellogg Biological Station (KBS) are studying invasive plant species and how release from enemies (like disease, predators, and herbivores) may be a key factor explaining invasiveness. Scientists predict that invasive species may be more successful and aggressive than native species because, while native species get lots of damage from enemies, invasive species may not. For example, if a native plant species has tons of insects that can eat it, while an invasive plant species has few or none, this could explain how the invasive plants can take space away [...]

Insects that feed on plants, called herbivores, can have big effects on how plants grow. They can change the size and shape of plants, the number of flowers and seeds, and even what species can survive in a habitat. For this reason, scientists study how insects and plants interact, and how much damage insects to do plants. A plant with more herbivore damage will most likely grow smaller and produce fewer seeds. Plants can protect themselves from herbivores. For example, plants produce defense chemicals in their leaves or protect leaves with small hairs that make it hard for insects to take a bite. Native plants are species that naturally occur in an area. Native plants and insects have grown together for thousands of years, so native plant defenses tend to be effective. An exotic plant is one that people have [...]

A mutualism is a relationship between two species in which both partners benefit. One example exists between plants and a kind of bacteria, rhizobia. Rhizobia live inside root bumps, or nodules, of certain plants. They can convert nitrogen in the air to a form that is usable by plants; in return, plants provide the rhizobia with food and protection in the root nodule. Plants growing with rhizobia usually grow better than the ones growing without rhizobia. Mutualisms can affect what happens when a plant species moves somewhere it hasn’t been before. Invasive plants are moved from one location to another, and grow and spread quickly compared to other types of plants. Let’s consider three possibilities for an invasive plant with a mutualist partner: 1) a plant invades a new area without its mutualist – in this case, the plant is predicted [...]

Mutualisms are a special type of relationship in nature where two species work together and both benefit. Each partner “trades” a resource to the other species, while receiving a resource of their own. This cooperation should lead to each partner species doing better when the other is around – without their mutualist partner, the species will have a harder time getting a resource on their own. But what happens when one partner cheats and takes more than it gives? Scientists at the Kellogg Biological Station study a mutualism between clover (a type of plant) and rhizobia (a bacteria). The rhizobia live in small root bumps, called nodules, and receive protection and food from the plant. In return, the rhizobia give nitrogen to the plant, which plants need to photosynthesize and make new DNA. This mutualism functions well when nitrogen is [...]

When two species do better when they cooperate than they would on their own, the relationship is called a mutualism. One example of a mutualism is the relationship between a type of bacteria, rhizobia, and plants like peas, beans, soybeans, and clover. Rhizobia live in bumps on the plant roots, where they trade their nitrogen for sugar from the plants. Rhizobia turn nitrogen from the air into a form that plants can use. This means that legumes that have rhizobium living in their roots can get more nitrogen than those that don’t. However, some rhizobia are less cooperative than others. These less-cooperative bacteria are freeloaders: they fix less nitrogen, but still get sugars from the plant and other benefits of living in their roots.  Less-cooperative rhizobia are often found where the soil already has lots of nitrogen. When the plant [...]

Plant breeders are trying to develop new crops that are better for farmers and for the environment.  Most of the crops that farmers grow now are annuals, meaning that they die and have to be replanted every year. Recently, plant breeders created some hybrids between wheat plants and one of their wild relatives, a prairie grass called kernza.  A hybrid species is the offspring of parents of two different species.  Kernza is a perennial grass (it lives for more than one year).  By mating regular annual wheat with kernza, breeders created a new hybrid wheat that is perennial.  Breeders also created a hybrid between rye, a common grain that we make rye bread from, and one of its wild relatives, perennial rye, creating a new hybrid perennial rye. Breeders want to improve the ability of wheat and rye to do [...]

One potential explanation for high photosynthesis rates in plants is that their leaves could have more chlorophyll. Chlorophyll is the compound that gives leaves their distinctive green color. It absorbs sunlight and helps convert sunlight into chemical energy. Without chlorophyll, that conversion cannot take place. Therefore, some people have hypothesized that plants with more chlorophyll in their leaves should have higher photosynthetic rates.  Plants with more chlorophyll in their leaves are usually darker green. The worksheets are as follows: Teacher’s Guide Student Worksheet, Graph Type A, Level 4 Student Worksheet, Graph Type C, Level 4 Data provided by and written by GK-12 Fellow Nikhil S. Jaikumar

The goopy, mucky, (sometimes stinky!) mud at the bottom of a wetland or lake is a very important part of the ecosystem.  Mud is essentially wet soil, but because it is wet most of the time, mud tends to have different properties than soil.  Mud is usually dark brown because of it is high in partially decomposed plants, called organic matter.  We can measure the amount of organic matter in mud by weighing a sample of mud before and after burning up the organic matter.  Dead organic matter tends to build up in wetlands because it is decomposed more slowly under water, where microbes tend to use up all the oxygen they need quickly.  For this and other reasons, nutrients like phosphorus tend to build in mud, making mud an important source of these nutrients for algae and other plants [...]

One way to reduce the amount of greenhouse gases we release into the atmosphere could be to grow our fuel instead of drilling for it. Unlike fossil fuels that can only release CO2, biofuels remove CO2 from the atmosphere as they grow and photosynthesize, balancing the CO2 released when they are burned for fuel. However, the plants we grow for biofuels don’t necessarily absorb all greenhouse gas that is released during the process of growing them on farms and converting them into fuels – they’re generally not “carbon neutral”, meaning that if we release 10 units of CO2 to produce the biofuel, the plants during their lifetime will absorb perhaps 8 units. One reason that biofuels are not carbon neutral is that they must be fertilized, which results in the soil releasing N2O, a gas with global warming potential 298 [...]

If you dig through soil, you’ll notice that soil is not hard like a rock, but contains many air pockets between soil grains. These spaces in the soil contain gases, which together are called the soil atmosphere. The soil atmosphere contains the same gases as the atmosphere that surrounds us above ground, but in different concentrations. It has the same amount of nitrogen, slightly less oxygen (O2), 3-100 times more carbon dioxide (CO2), and 5-30 times more nitrous oxide (N2O, which is laughing gas!). Nitrous oxide and carbon dioxide are responsible for much of the warming of the global average temperature that is causing climate change. Sometimes soils give off, or emit, these greenhouse gases into the earth’s atmosphere. Currently scientists are figuring out what causes differences in how much of each type of greenhouse gas soils emit. During the [...]

Producing offspring (in other words, having babies) is how an animal passes on its genes to the next generation, and is an important part of the animal’s fitness or success. In many animals, males try to attract females to mate with through elaborate displays using colorful parts of their bodies like feathers or scales. Peacocks, for example, have very colorful tails, which they fan out and shake to attract female attention. In stickleback fish, males become very colorful when they are breeding and develop bright red throats. Stickleback males also court females with zig-zag swimming, where males move in a z-shaped pattern in front of the female, presumably showing off his reproductive colors.  This little dance is an example of a display behavior. Before male fish can get female fish to respond to them, males must gain a territory and [...]

In many animals, males fight for territories which they use to attract females for mating. Male stickleback fish fight each other to gain territories along the bottom of the shallow areas of a lake. In these territories, males build a nest out of sand, aquatic plants, and glue they produce from their kidneys. Males then attract females to their territories with courtship dances. If a female likes a male, she will deposit her eggs in his nest. Then the male will care for those eggs and the offspring that hatch. In this experiment, four males were kept together in a large (75-gallon) tank. Scientists watched the four fish every day for 10 days and recorded when the fish performed male competition behaviors, territory defense, and nest building.   Worksheets are as follows: Teacher’s Guide Student Worksheet, Graph A, Level 3 [...]

There is a lot more in river water than you might think!  This is because as the water flows it picks up bits of dead plants, algae (single-celled organisms that photosynthesize), and other living and non-living particles from the bottom, or bed of the river.  Scientists measure this stuff and call it total suspended solids (TSS).  Suspended solids in a river are a hodge-podge of many different kinds of materials, but are very important to the river ecosystem, and sometimes to the floodplain along the edges of a river.  Some suspended materials such as living algae or bits of broken down leaves are important because many organisms use them as a food source. However, too much sediment (dirt) in total suspended solids can bury the rocks where the organisms live.  The amount of total suspended solids in a river influenced [...]

There is a lot more in river water than you might think! This is because as the water flows it picks up bits of dead plants, algae (single-celled organisms that photosynthesize), and other living and non-living particles from the bottom, or bed of the river. Scientists call this “stuff” total suspended solids (TSS). Suspended solids in a river are a mix of many different kinds of materials, but are very important to the river ecosystem, and sometimes to the floodplain along the edges of a river. Some suspended materials such as living algae or bits of broken down leaves are important because many organisms use them as a food source. However, too much sediment (dirt) in total suspended solids can bury the rocks where the organisms live. The amount of TSS in a river is influenced by how fast the [...]

Just like individual people, individual fish differ from one another in the way they behave. For example, some fish may act boldly when in a dangerous situation while others may act timidly. In the same way, some fish are easier to catch on a fishing lure than others. These individual differences can impact a fish’s growth and survival, which is leading more scientists to study the effects of animal personalities. Researchers at Michigan State University were specifically interested in how fish personality influences which fish get caught by anglers. Scientists marked largemouth bass so that they could individually recognize them (like giving them a name) and then collected behavioral data on each fish in a laboratory. The scientists observed each fish’s actions for 10 minutes and recorded how often the fish behaved certain ways. Finally, the scientists put the marked [...]