EHS

Fertilizing biofuels may cause release of greenhouse gasses

Jan 182013
 

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 times higher than CO2! The fraction of fertilizer that is released as N2O may change depending on how much fertilizer is applied to the field

Scientists at Michigan State University decided to test this prediction by applying different amounts of fertilizer to fields of biofuels and measuring how much N2O the soil in each treatment produces over several years. In the table below we have two years of their data.

The worksheets are as follows:

Data provided by Leilei Ruan. Written by Sandy Erwin, Anne Royer, and Liz Schultheis

Does a partner in crime make it easier to invade?

Jan 172013
 

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 to grow badly; 2) a plant brings its mutualist friend along on the trip – we expect the plant to be successful at invading and grow well; 3) the plant finds a new mutualist partner it has never worked with before – we expect the mutualists to adapt to each other over generations, with the plants growing better and better over time.

A Michigan State University scientist tested these hypotheses using the invasive plant species, hairy vetch. She took soil samples, containing rhizobia, from three different sites with different histories of hairy vetch invasion: the vetch had never been there, it arrived recently (< 3 years), and it invaded a long time ago (> 10 years).  She then grew hairy vetch plants in each of the three soil types. Then, she counted number of nodules on the roots (an estimate of how many rhizobia the plant had) and plant biomass (how big the plants got).

The worksheets are as follows:

Data provided by and written by MSU undergraduate Yi Liu and GK-12 Fellow Tomomi Suwa, edited by Anne Royer

The Double Life of A Squirrel: Seed Disperser and Predator

Dec 142012
 

Because they cannot move, plants have developed a diverse range of strategies to spread their genetic material: from producing tasty fruits to entice birds and mammals to encasing seeds in structures that can be carried off by the wind. Small mammals, like squirrels and mice, can be both beneficial and destructive for plant seeds – they serve as dispersal agents, moving seeds far from parent plants and into beneficial habitats, or as predators, consuming seeds before they have had a chance to germinate. Using squirrels as a study system, we will explore importance of squirrel behavior human disturbance influencing seed dispersal.

In this lesson, we discuss dispersal and predation as major forces determining the fate of a seed. We will conduct an experiment where we measure squirrel removal of seeds from a seed trap to determine their activity in a variety of habitats – including forest and open field. Using this data, we will go through the scientific method, from hypothesis generation to conclusion. Students will be introduced to Project Squirrel, a citizen science database where students can submit and explore data on squirrel behavior.

At the conclusion of the lesson, students will be able to:
  • Understand how traits of a seed help it to disperse in its environment
  • Discuss the tradeoffs between remaining need the parent plant or dispersing too far away
  • Discuss the tradeoffs between attracting seed dispersers and being susceptible to seed predators
  • Generate a hypothesis and prediction, and understand how the experimental design addresses their hypothesis
  • Collect data from an experiment and put into a table
  • Convert a data table into a figure and draw conclusions

The following resources are available for this lesson:

Lesson Plan created by GK-12 Fellows Liz Schultheis, Tomomi Suwa, and Jakob Nalley

 Posted by on December 14, 2012 at 2:35 pm  Lessons

Why is there variation in personality type? Does fishing impact the variation?

Oct 032012
 


Students simulate bass populations with and without fishing pressure, gather data from the simulation, analyze it by making graphs, and draw conclusions about what maintains variation in personality type and how fishing could cause evolutionary change in personality in populations that are fished.

At the conclusion of the lesson, students will be able to:

  • List the three requirements for evolution by natural selection
    • Phenotypic variation in a trait exists within a population
    • The phenotypes must be heritable
    • Some phenotypes have higher fitness than others
  • Determine whether evolution happened in a given situation and how it happened.
  • Explain potential ecological and evolutionary effects of not using natural resources in a sustainable manner

Resources for this lesson include:

 Posted by on October 3, 2012 at 7:26 pm  Lessons

The Hunger Games: Hiding in Plain Sight – Exploring evolution using mimicry

Oct 032012
 

Evolution is one of the most fundamental concepts in biology.  The process of evolution by natural selection has produced some of the most spectacular traits found in living organisms.  In this lesson students will explore the concept of evolution by natural selection using mimicry as an example.  Mimicry refers to a similarity between more than one species for the purpose of protection.  For example, a non-poisonous species may closely resemble a poisonous species, and this resemblance protects the non-poisonous species from predators.  In this session, students will play a scavenger hunt game using Easter eggs to demonstrate the benefits of mimicry and the conditions under which mimicry can evolve.

At the conclusion of the lesson, students will be able to:

  • Understand the process of evolution by natural selection and be able to identify/explain its three components
  • Understand that populations evolve, not individuals
  • Understand that evolution occurs across generations, not within a generation
  • Understand the concept of mimicry and how it can evolve
  • Relate patterns to theory
  • Use evidence and reason to form a conclusion

Resources for this lesson include:

 Posted by on October 3, 2012 at 6:59 pm  Lessons

Geeked About Beaks: Inquiry learning about survival and reproduction

Oct 032012
 

In this lesson, students will learn about survival, reproduction, selection, adaptation, and evolution all while playing hands-on games and constructing their knowledge through experience. Students get to be birds and compete against their classmates to eat the most seeds. This activity demonstrates how small beaks are better at getting small seeds, whereas large beaks are better at getting large seeds. Next, students become part of a bird population with a variety of beak sizes. Depending on the weather, big, small, or medium seeds are common that year. Students observe how populations change over time based on the environment. Students explain why the population changes over time, and they also make predictions about what will happen to the population in future years.

At the conclusion of the lesson, students will be able to:

  • Describe how physical characteristics of an organism affect what it can eat, which then impacts its survival and reproduction
  • Explain why a population might change over time based on the environment
  • Make predictions about how a population might change over time based on the environment
  • Draw graphs from game outcomes, summarize patterns, and interpret what is happening to the population over time
  • Compare game outcomes and explain why populations look different depending on the environmental conditions they experienced over time

Resources for this lesson include:

Lesson plan written and created by GK-12 Fellow Alycia Lackey

 Posted by on October 3, 2012 at 6:42 pm  Lessons

Fair Traders or Freeloaders? – Cooperative and Uncooperative Bacteria

Sep 062012
 

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 doesn’t need to rely on rhizobia for its nitrogen, it doesn’t give as many sugars to the rhizobia, so the rhizobia become less cooperative as well.

Since farms use a lot of nitrogen fertilizer, researchers at KBS were interested in how different types of farming affected cooperating in rhizobia. They grew soybeans in a greenhouse and added rhizobia from three different farms: high N, low N, and organic (no N fertilizer).

The worksheets are as follows:

Data provided by and written by REU Jennifer Schmidt

Evolving to Invade – How can evolution by natural selection create invasive species?

Apr 302012
 

Many invasive species do not start to invade as soon as they are introduced into a new area; there is a “lag time” in most invasions where scientists predict they are evolving to their new habitat and waiting for beneficial genes to arrive, either through mutation or further introductions of new individuals from their native range. Through an interactive game, students will learn how evolution might create an invasive species. The game demonstrates the basic components of evolution (variation and selection) and how they can cause an introduced species to become invasive and outcompete native species.

At the conclusion of the lesson, students will be able to understand the basic concepts of evolution and biological invasions including:

  • Evolution by natural selection
  • Three factors required for evolution by natural selection to occur  (variation in trait, fitness differences, inheritance)
  • Source of variation (mutation, recombination and migration) and how these differ between native and invasive species
  • The definition of an invasive species
  • How evolution by natural selection can facilitate an invasive species

 

The following items are available for this lesson:

Lesson plan and game created by GK-12 Fellows Tomomi Suwa & Elizabeth Schultheis and Teacher in Residence Marcia Angle

 Posted by on April 30, 2012 at 4:16 pm  Lessons

Climate Change: the basis of belief

Mar 202012
 

In this lesson, students will examine claims made on global warming.  Students will use quantitative figures to critically evaluate each claim and they will decide which claim is best supported by the information in the figures. Students will interpret and analyze graphs and figures and then evaluate the reliability of the information in the figures.  Students will then evaluate the relevancy of each piece of information as it relates to the claims made and then students will make inferences to decide which claim is best supported by the evidence.

At the conclusion of the lesson, students will be able to:

  • Explain the main factors controlling climate and how changes in these factors would impact the earth’s climate.
  • Know what the current data on the causes of global warming show.
  • Communicate their position on global warming using evidence.

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Nick Ballew

 Posted by on March 20, 2012 at 3:52 pm  Lessons

Experimental Design and Communicating Scientific Findings

Mar 202012
 

Students will learn essential part of the experimental design (replication, randomization, and control). This will be especially useful for students conducting independent projects. Students will also learn how to present their scientific findings and practice by critiquing scientific posters.

At the end of the lesson, students will be able to:

  • Design experiment (randomization, replication and control)
  • Communicate scientific findings (general structure)
  • Make a poster and evaluate constructively

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellows Tyler Bassett and Tomomi Suwa

 Posted by on March 20, 2012 at 3:28 pm  Lessons

Invasion: Total Take-Over! Exploring invasive species and the methods to control them

Mar 202012
 

Invasive tree Norway maple, growing near KBS

Invasive species are non-native, introduced species that have a negative impact on the habitats they invade. Invasive species can be plants, animals, or microorganisms, and the damage they can cause to native ecosystems can be devastating. What is it about these species that allow them to successfully invade different habitats? Does the environment itself also play a role in how likely it is that an invasion will take place? In this lesson plan students will explore what it means to be an invasive species. They will learn what traits make a good invader as well as what environmental conditions favor invasion. Students will also get a chance to observe and interpret graphs and figures from real world research on invasive species. Finally, students will have the opportunity to play a game that simulates an invasive species spreading through Michigan, and students have to implement different methods to control its spread.

At the conclusion of the lesson, students will be able to:

  • Explain what an invasive species is and provide several local examples of invasivespecies
  • Understand what traits help invasive species spread
  • Understand what environmental factors facilitate invasion
  • Interpret graphs and figures of real world data from several invasive species
  • Understand the different methods that have been used to control the spread of invasive species

The following resources are available for this lesson:

Lesson plan and game created by GK-12 Fellows Kate and Mike

 Posted by on March 20, 2012 at 2:33 pm  Lessons

Biotic Resistance – What can stop invasive species?

Mar 202012
 

Biotic resistance is the ability of a native community to keep out invasive species. Land managers want to promote biotic resistance because of the harmful effects of invasive species once they have established. Several aspects of a community might make it better able to resist invasion such as high diversity, low nutrient levels, and low disturbance. In this activity, students will be able to make and test hypothesis based on invasive species success and biotic resistance. Factors promoting biotic resistance are manipulated in our BEST Bioenergy Plots and so similar questions can be asked through this activity and the data that we will be collecting through the entire GK-12 district network.

At the conclusion of the lesson, students will be able to:

  • Discuss several examples of invasive species in Michigan, and why biologists are concerned about their introduction.
  • Define biotic resistance and qualities of a community that can repel or facilitate invasion.
  • Link biotic resistance to the treatments that are being applied to the BEST Bioenergy plots at their school district.
  • Make predictions about where we’ll find the most invasive species in the plots.
  • Graph and interpret data, using evidence to support their claims.
The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Elizabeth Schultheis

 Posted by on March 20, 2012 at 2:09 pm  Lessons

BEST Plots Lesson Plans

Mar 202012
 

Here you will find our Fellow-developed lesson plans that relate to the three categories of protocols we’ve developed: biomass/biodiversity, landscape level, and soils. Each lesson plan takes one or more of those protocols, provides background for teachers and students, and relates the protocol to Michigan grade-level content standards.

Introducing the Plots

Plant Biodiversity Protocols

Invertebrate Biodiversity Protocols

Soil Protocols

Lessons on Plot Data Analysis
  • Data Analysis Lesson Plan – What will you do with all these data?, Middle and High School level
  • Exploring patterns and drawing conclusions from data – Elementary level, invertebrate data

How seeds get around – Inquiry learning about seed dispersal

Mar 202012
 

In this lesson, students will learn the characteristics that help seeds to disperse and the variety of ways that seeds can get around! Dispersal is important for plants (and animals, too) because it helps young organisms to avoid competing with their parents for resources and to escape seed predators. Different species of plants produce seeds with different adaptations for dispersal. Some seeds, like those of the dandelion, rely on the wind to carry them. Other seeds are encased in fruit, and rely on animals to eat them and deposit their seeds elsewhere. This topic connects to many K-4 topics, including organism’s needs in their environments, competition, adaptation, survival, reproduction, and plant life cycles. Additionally, this lesson helps students practice multiple important inquiry skills that encompass many steps of the scientific method.

At the conclusion of the lesson, students will be able to:

  • Describe different adaptations seeds have that help them to disperse
  • Make predictions about how a seed is likely to disperse
  • Collect data and record findings in simple charts
  • Summarize data from charts into sentences
  • Compare findings among types of seeds
  • Compare findings between groups that may have tested the same or different types of seeds
  • Recognize that repeating a test should provide similar results to previous tests

 

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellows Elizabeth Schultheis & Alycia Lackey

 Posted by on March 20, 2012 at 1:48 pm  Lessons

Take students on a field trip to do a forest walk!

Mar 192012
 

These materials can be a guide for exploring nature, with focus on Michigan species. Use the scavenger hunt to help your students identify particular types of organisms and organism-environment interactions. The “picture review” shows how Jim Eckert’s class at Wattles Park Elementary School in Harper Creek exploring the Ott Biological Reserve. The “tree identification” and “animal tracks” documents focus on Michigan species your students might be able to find.

Enjoy the outdoors!

GK-12 Fellow Alycia out with students doing a forest walk!

Resources available for this field trip include:

Field trip idea by GK-12 Fellow Alycia Lacky

 Posted by on March 19, 2012 at 10:37 pm  Lessons

Survivor: Who will be the best competitor?

Mar 192012
 

Students explore the effects of the environment on competition between species. Students play a game where two different species forage for prey. Species differ in vision, simulated by light-filtering goggles, which affects their
ability to forage on particular food items that differ in color. Students gather data, make tables and graphs, and make comparisons between outcomes for different species and in different environments. Students develop new
questions to test within the framework of the game. They make predictions, develop methods, gather data and interpret results from their questions. Connections to evolution, competition, predator-prey dynamics and food webs
can be made.

At the conclusion of the lesson, students will be able to:

  • Understand that organisms require resources from their environment.
  • Understand that organisms compete for resources in their environment.
  • Become familiar with examples of competition between species.
  • Understand that changes to the environment change competition between species through a game.
  • Become familiar with examples of change in environments that cause change in competition between species.
  • Make applications to real world situations of environmental change and competition (including applications to bioenergy plots).
  • Make tables and graphs of data collected.
  • Interpret data from graphs and make comparisons between graphs from different scenarios and species.
  • Develop new questions, make predictions, design methods, test question, collect and interpret data.

The following resources are available for this lesson:

Lesson plan and game created by GK-12 Fellow Alycia Lackey & teachers Steve Barry and Sandy Erwin

 Posted by on March 19, 2012 at 10:28 pm  Lessons

The Marvels of Mud

Mar 192012
 


Mud, or sediment, is an active part of aquatic ecosystems. Sediment varies widely within and among ecosystems in its biotic and abiotic characteristics. In many ecosystems sediment can release excess phosphorus (a common aquatic pollutant) into the water column causing internal eutrophication

At the conclusion of the lesson, students will be able to:

  • Observe and describe abiotic and biotic characteristics of sediment
  • Recognize that the sediment and water in a lake carry phosphorus, which is necessary for life, but can have negative ecosystem effects at high levels
  • Describe the difference between experimental control and treatment groups
  • Use observations to support conclusions

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Lauren Kinsman & teacher Liz Ratashak

 Posted by on March 19, 2012 at 10:17 pm  Lessons

Do herbivores prefer local or exotic foods?

Mar 192012
 
Purple loosestrife

Purple loosestrife, photo by EHS

In this lesson, students will examine herbivory on exotic vs. native tree species planted into plantations in the Kellogg Forest. We will use our data to test the Enemy Release Hypothesis, which posits that exotic species escape from specialized natural enemies in their invaded range, contributing to their success. Students
will develop predictions, design experimental sampling methods, collect data, and create graphs to summarize data.

At the conclusion of the lesson, students will be able to:

  • Give reasons why invasive species are so successful in their introduced range and can displace native species
  • Compare ecosystem processes acting on native and exotic species
  • Identify new plants species and different types of herbivore damage
  • Present data in visual format for interpretation

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Elizabeth Schultheis & teacher Marcia Angle

 Posted by on March 19, 2012 at 10:12 pm  Lessons

Who wants to fish for bass that won’t take the bait?

Mar 192012
 

Students explore the effects of fishing on fish populations. Students simulate fishing pressure, gather data from the simulation, analyze it by making figures, and draw conclusions about how fishing could cause quick evolutionary change in only a few generations of the population being fished.

At the conclusion of the lesson, students will be able to:

  • List the three requirements for evolution by natural selection
    1. Phenotypic variation in a trait exists within a population
    2. The phenotypes must be heritable
    3. Some phenotypes have higher fitness than others
  • Determine whether evolution happened in a given situation
  • Explain potential ecological and evolutionary effects of not using natural resources in a sustainable manner

A male bass guarding his nest

The following resource is available for this lesson:

Lesson plan created by GK-12 Fellow Nick Ballew & teacher Terri Morton

 Posted by on March 19, 2012 at 10:03 pm  Lessons

N2O: It’s No Laughing Matter!

Mar 192012
 

Biofuel crops are being considered as an option for reduction of global warming.  However, biofuel crops are not 100% carbon neutral.  There are three agriculture related greenhouse gases: carbon dioxide, methane, and nitrous oxide, N2O. Nitrous oxide is an important greenhouse gas that is often overlooked by the non scientific community.  60% of nitrous oxide emissions are produced by agriculture ecosystems.  Input of fertilizer greatly stimulates nitrous oxide emissions.

At the conclusion of the lesson, students will be able to:

  • Describe certain processes in nitrogen cycling (specifically, denitrification, nitrification)
  • Understand that an increase in fertilization of biofuel crops will increase the release greenhouse gases
  • Know how nitrous oxide can counteract the greenhouse gas reduction effects of using biofuels as a means of reducing greenhouse gas emissions
The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Leilei Ruan & teacher Sandy Erwin

 Posted by on March 19, 2012 at 9:53 pm  Lessons

Sounds of Selection

Mar 192012
 
Gray tree frog

Gray tree frog, photo by DNR

This lesson will span both Middle and High School Michigan Standards making connections to wetland ecosystems and natural selection.  Students explore gray treefrog morphology and behavior, focusing on how these frogs are adapted to their environment.  Students will be asked to describe their preconceptions of what makes a frog.  Students will engage in an activity demonstrating what a frog needs to survive in the wild.  Students will also examine several species of MI frogs taking notes of their similarities and differences and learning to identify the calls of MI frogs.  Finally, students will also play a card game simulating the pros and cons of different reproductive strategies.

At the conclusion of the lesson, students will be able to:

  • Identify food chains and food webs in a wetland incorporating the Michigan gray treefrogs
  • Understand how the environment and human activity can influence populations.
  • Understand that all plants and animals have a definite life cycle, and adaptations to accomplish specific life functions.
  • Understand that inherited traits can be influenced by changes in the environment and by genetics
  • Understand that characteristics of mature animals may be inherited or acquired and that only inherited traits are passed on to their young.
  • Understand that there are different strategies that can be used to try to maximize reproduction

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Mike & teacher Marty

 Posted by on March 19, 2012 at 9:47 pm  Lessons

How do mutations and invasions affect populations?

Mar 192012
 

Students participate in an activity that models natural selection or the introduction of an invasive species by competing for limited “resources,” and observing how the presence of an advantageous trait can change the class population over time.  Students graph the population’s change over time and participate in a guided discussion about factors that may influence natural selection.

 At the conclusion of the lesson, students will be able to:

  • Describe the effects of natural selection on a population, or the effects of an invasive species on a native population
  • Understand the factors contributing to extinction, including displacement and competition
  • Discern patterns of population growth, including exponential growth and the relationship between a population’s environment and its carrying capacity
  • Construct and interpret graphs relating to population growth
  • Relate patterns to theory
  • Use evidence to reason and draw conclusions
  • Differentiate between a theory, hypothesis, and observation

Example graph from the activity

The following items are available for this lesson:

Lesson plan created by GK-12 Fellow Kate Steensma & teacher Marty Beuhler

 Posted by on March 19, 2012 at 9:44 pm  Lessons

What Happened to My Apples?

Mar 192012
 

Students will explore the connections between plant diversity and “ecosystem services” in general, and pollination in specific. Greater plant diversity is predicted to support greater insect diversity, and we will directly test this hypothesis. We will sample the pollinating insect communities found in three different fields at KBS. Students will collect, analyze and graph data.

At the conclusion of the lesson, students will be able to:

  • Recognize that higher levels of plant diversity support higher insect diversity
  • Distinguish between high and low diversity and appreciate differences between taxonomic groups (species or families)
  • Sample (pollinator) insect community

 

The following items are available for this lesson:

Lesson plan created by GK-12 Fellow Tyler Bassett & teachers Jennifer Boyle and Kim Clancy

 Posted by on March 19, 2012 at 9:25 pm  Lessons

Mutualism in Action

Mar 192012
 

Students will learn about the mutualistic relationship between plants and nitrogen fixing bacteria.  The effect of environmental conditions on this relationship will be investigated in two inquiry activities.

At the conclusion of the lesson, students will be able to:

  • Define mutualism.
  • Describe the mutualistic relationship between nitrogen fixing bacteria and legumes. (biotic interactions)
  • Describe how changing environmental conditions can alter the relationships between organisms. (abiotic interactions)

 

The following resources are available for this lesson:

Lesson plan created by GK-12 Fellow Tomomi Suwa & teacher Sandy Breitenbach

 Posted by on March 19, 2012 at 9:18 pm  Lessons

Invasive Species Game

Mar 192012
 

In this lesson and game, students will learn about invasive species in Michigan, characteristics that make species good invaders, factors that can influence plant community assembly, and the role that people play in causing and proliferating invasions.

At the conclusion of the lesson, students will be able to:

  • Provide examples of invasions causing economic and ecological concerns in Michigan
  • Identify characteristics (traits) that are common among many invasive species
  • Present information on the role that people play in the establishment and spread of invasive species
  • Recognize some common native and invasive plant species in Michigan
  • Talk about populations, communities, and the niche

 

The following items are available for this lesson:

Lesson plan and game created by GK-12 Fellows Elizabeth Schultheis & Melissa Kjelvik

 Posted by on March 19, 2012 at 8:46 pm  Lessons

Do insects prefer local or foreign foods?

Dec 142011
 
herbivore

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 moved into new areas, and has the potential to become an invasive species that can take over habitats. An exotic plant may not have defenses against the insects occurring in its new range, and therefore may receive more damage than native species. More damage could result in exotic plants not doing very well compared to native plants. However, we know invasive plants grow very well, so perhaps they will be less damaged compared to native plants, which could explain how they are able to grow fast and make many seeds.

Screen Shot 2013-03-26 at 2.21.20 PM

Scientists at the Kellogg Biological Station (KBS) are studying the interaction between herbivores and native, exotic, and invasive plants. Scientists predict that herbivores may damage exotic plants more than natives, because exotic species have not evolved defenses against them, and so are unprotected. They also predict that invasive plants will receive less herbivore damage than native species, which might explain why invasives can take over habitats. To address these predictions, scientist Liz collected data on native, exotic, and invasive plant species in Kalamazoo County, MI. She measured what percentage of leaves on each plant had damage from herbivores. A portion of her data is found in this Data Nugget and can be used to test which type of plant gets the most damage.

The worksheets are as follows:

Data provided by and written by GK-12 Fellow Elizabeth Schultheis

Marvelous Mud

Aug 232011
 

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 that need them to grow.  Under the right conditions, mud can act like fertilizer for a wetland.

Although most mud is high in organic matter and high in nutrients, all mud is not created equal!  The amounts of organic matter and nutrients, as well as how quickly these materials enter or leave the mud may change from one ecosystem to another, and are often even different from one place to the next in the same ecosystem.

You can tell that the mud in this picture is high in organic matter because it is dark brown and mucky (in real life you’d be able to smell it, too!)

The worksheets are as follows:

Data provided by and written by GK-12 Fellow Lauren Kinsman-Costello

Cheaters in nature – are mutualisms always beneficial?

Aug 232011
 

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 rare in the soil – rhizobia benefit the plant because it is hard for plant roots to find nitrogen on their own. However, what happens when humans fertilize the soil, such as in gardens and farm fields? Now nitrogen is freely available in the soil and plants have all they need. With high nitrogen, rhizobia no longer benefit the plant, and so the plant may start to trade less with rhizobia. In response, rhizobia from high nitrogen areas will try harder to get food from the plant and both species will no longer be acting as mutualists.

Clover plant in the field growing with rhizobia mutualist

Rhizobia growing on a Petri Dish in the lab

To test whether high nitrogen can eliminate this mutualism, a lab at KBS grew two species of clover with two types of rhizobia – one from a high nitrogen environment, and one from low nitrogen. Some of the clovers were not inoculated with any rhizobia as a control. Researchers collected data on leaf number for each clover plant. Plants with fewer leaves are considered less healthy.

The worksheets are as follows:

Data provided and written by REU Iniyan Ganesan and edited by GK-12 Fellow Elizabeth Schultheis

Dangerously Bold

Aug 192011
 

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 can search for food in the open water zone without risking being eaten.

Scientists at the Kellogg Biological Station wanted to know whether acting bold or acting shy was better for bluegill growth (how big they get) and survival (whether or not they get eaten by predators). They brought young bluegill into an aquarium lab to determine whether each individual was bold or shy. Boldness was determined by watching whether or not bluegill ate food while there was a predator behind a mesh separator during a trial (Figure 2). They then marked them (by clipping a right fin for bold or a left fin for shy) and placed 100 bold and 100 shy young bluegill into a pond with one largemouth bass. After two months, they drained the experimental pond and collected all remaining young bluegill.

By Eric Engbretson, U.S. Fish and Wildlife Service

The worksheets are as follows:

Data provided by and written by GK-12 Fellow Melissa Kjelvik

Float Down the River Part 2: Discharge and Total Suspended Solids

Aug 192011
 

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 water in the river is flowing. Scientists measure this as discharge, which is the volume of water that passes by a particular point over a certain amount of time. You can think about discharge as the number of cubes (one foot on each side) filled with water that pass by every second.

To investigate how discharge changes over the course of the year, researchers at KBS took several measurements of discharge and TSS.

Map of Kalamazoo River

The worksheets are as follows:

Data provided by and written by GK-12 Fellow Leila Desotelle

Let the Sun Shine In Part 2: Photosynthesis of Annual and Perennial Crops

Aug 192011
 

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.

photo credit: J.E.Doll/MSU-KBS

The worksheets are as follows:

Data provided by and written by GK-12 Fellow Nikhil S. Jaikumar
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