ALCA Members PLC Domains Data Standards Map Plan Curriculum Assessment Strategies

Do Trees Sweat More at Night or During the Day? Copy

Students will observe tree transpiration and compare the amount of water released during the day versus during the night. This activity provides a good review of the scientific method. Learners will be given opportunities to hypothesize, collect data, and draw conclusions.

Engaging Questions

  • How do the transpiration rates compare during different times of the day?
  • What are some reasons why the tree transpiration rate was higher for one particular time period?
  • How do the transpiration rates for the various time periods compare with other geographical locations?

Teacher Goals

  • By using the scientific method, learners will determine whether the rate of tree transpiration is greater at night or during the day.

Required Resources

  • Tree Transpiration: Day vs Night data collection sheet (attached in the Instructions)
  • Pencil
  • Plastic sandwich bags
  • Twist-ties
  • Balance
  • 10 ml graduated cylinder
  • Thermometer
  • GPS
  • Graph paper

Steps

  1. Make Hypothesis

    Write a hypothesis about whether a tree will transpire more during the day or night.

  2. Identify Tree

    Choose and identify the tree that will be used for the duration of this lab. Use the Optional Resource "What Tree Is That?" if necessary. Each student group should pick a different kind of tree. Record the tree type.

  3. Setup Water Collection

    Refer to the attached lesson Transpiration: Trees Have Water? for instructions to set up the water collection system. Repeat procedure for two equal time periods, one during the night and one during the day.

  4. Take Observations

    Use the data table (checklist) Night Verses Day Transpiration attached to record your observations. Record the observed weather conditions (temperature, relative humidity, and wind) in the same table.

  5. Calculations

    From your observed mass of water collected during the day and the number of leaves in the bag, determine the mass of water per leaf per day. Do the same for the night collections.

  6. Conclusion

    Write a conclusion based on your observations and on your classmates' results.

  7. Share Results

    Share your results by entering them into the data form Night & Day Transpiration.

Please enter a Registration Key to continue.