Journey North International Plant Study Spring 2005

Tulip Garden Update: February 18, 2005

Today's Report Includes:

A Red Valentine Bloomer!
What is a Typical Spring? Mapping Discoveries
Challenge Question #4
Hazaa! Tulip Garden Emerges!
Digging Deeper into Temperature Studies
Try This!: Growing Degree Days
Draw Your Own Wave of Spring
The Scientific Method: Answering Challenge Question #3
Bending Over Backward for Light

A Red Valentine Bloomer!

This week we were surprised by our first blooming garden on St. Valentine’s Day! This first BLOOMING report for 2005 is 2 weeks ahead of the first to bloom in 2004!
Southside Elementary students from Denham Springs, LA, wrote, “We had a Valentine tulip. Our first tulip bloomed today. It was beautiful. We thought it looked like a heart from our classroom window.”

Study our weather maps this week for clues to why this might have happened. Predict which gardens may be next.

What is a Typical Spring? Mapping Discoveries
Our first blooms are now on the map, but are we 2 weeks ahead of last year. What is normal? Defining a normal or typical spring can be tricky. Lucky for us the U. S. Weather Service keeps all kinds of weather records each year so we can study them for clues. Let's compare this year's weather and tulip maps with last year's maps.

Journey North Tulip Maps

Today's Tulip Garden Map (02/18/05)	Last Year's Tulip Garden Map (02/20/04)

Departure from Normal Temperatures

Take a good look - then try these questions:

What does this mean, “Departure from Normal?”
What do the colors in the weather map key represent (especially red and purple)?
In which year was it colder?
What temperature is the aqua blue color?
How does the temperature change as you travel into the central US in both maps?
Which year do you see more tulip gardens emerged (green triangles)?
How would you describe the pattern of green triangles in each map?

Challenge Question #4:
"What statements can you make about weather and the emerging tulips?"

(To respond to this question, please follow the instructions below.)

Hazaa! Tulip Garden Emerges!
If Journey North published a newspaper, today’s headline would read

“Hazaa!! Today our first 3 Journey North tulips Emerged”

Sixth graders at Seven Oak Middle School in Lebanon, OR, spread the news that they have emergence. Their announcement comes along with their predictions and observations.
Students began with predictions; “We predicted that the average soil temperature in our study area would be approximately 50 F/10 C when our tulips first began to emerge.” AND “We predicted that the average air temperature in our study area would be approximately 50 F/ 10 C.”

What actually happened? Read all about it!

Journey North Field Data

Digging Deeper into Temperature Studies

credit Gayle Kloewer

Students eager to understand the events that lead to the first flush of spring growth have taken to their thermometers. We challenge you to think beyond a single day’s temperature and explore what scientists call “growing degree days.”
Scientists have discovered that you can actually measure the amount of heat it takes to make some spring events occur. Like in baking a cake, the oven must be set at a certain temperature--and the cake must remain in the oven for a certain length of time--in order for it to bake properly. Plants respond similarly.

Try This!
Using a simple formula and a base temperature you can measure the amount of accumulated heat in units called "Growing Degree Days (GDDs)."
Put your knowledge to work by measuring, calculating and recording temperatures in your tulip garden.

Growing Degree Days

AND Try This!
Investigate the microclimate of your tulip garden this spring. You can start to measure when the daytime temperatures reach the base temperature of 40 degrees F. Each day's data will help you to analyze the role temperature plays in setting the pace of spring's arrival. Place a thermometer (a minimum/maximum thermometer is ideal) in the garden site and take daily readings.

Record using this chart (or make your own):

Compare these temperatures with your daily newspaper's temperatures (published a day later). How do the temperature data compare? What do these data show you about your garden microclimate?

Draw Your Own Wave of Spring
As tulips begin to grow and bloom this spring, you may be surprised to see when and where they bloom. On your classroom map draw the "waves" of spring by connecting each week's garden data points with a line called an isopleth ("Isopleth: A line on a map connecting points at which a given variable has a specified, constant value".) As the weeks go by you will begin to see a picture of the advance of spring. For more tips go to:

Mapping the Green Wave of Spring

Teacher Tips
Use a clear plastic/transparency overlay on top of your classroom map to draw the isopleth map. Have a separate plastic sheet for emerging and blooming isopleths. At the end of the season study and compare the two sets of lines.
OR Try drawing your isopleth lines using a transparent map and a clear overlay to project a large format with your overhead projector.

The Scientific Method: Answering Challenge Question #3

Look how Felix's plant grew in the dark closet!
-credit Pam Masters

Could you set up an experiment to test Felix’s theory that plants grow taller without sunlight? How would you design your experiment?
Many students submitted plans for designing this kind of experiment. A good experimental design uses light as the single variable. All other factors should remain the same. Extra credit to those who mentioned the need for careful labeling and measuring.
Why not try this experiment and share the results with your school?

Thanks to Ashley, Kaylah, Carley and Joe for your experimental plans!

Bending Over Backward for Light
What makes plants lean toward the light? Even though plants are firmly rooted in the ground, they can still move as they respond to changes in their environment. Light is so important for plant growth that plants actually 'bend over backwards' to get their share!

Read on to learn more about light, plant physiology, and a big word – phototropism. Watch a video clip of seedlings growing in light and dark environments.

Auxin’s not a Toxin: How Plants Grow

How to Respond to Today's Challenge Questions:

IMPORTANT: Answer only ONE question in each e-mail message.

1. Address an e-mail message to: jn-challenge-tulip@learner.org
2. In the Subject Line of your message write: Challenge Question #4.
3. In the body of EACH message, give your answer to ONE of the questions above.

The Next Tulip Garden Update Will Be Posted on February 25, 2005.