The Effect of Wind on the Rate of Transpiration Nicole Chernavsky Nadia Zivkov Cassandra Zhi.

The Effect of Wind on the Rate of Transpiration

Nicole Chernavsky Nadia Zivkov Cassandra Zhi

Research Question

• How does wind strength* affect the rate of transpiration?

*Different fan distances of wind (40 cm, 70 cm, 100 cm, 130 cm, 160 cm)

Why is this important?• Certain species of plants require different amounts of water due

to different rates of transpiration, which vary depending on the wind level of the environment

• Plants in more windy environments will require more water• When there is too much wind, the stomata may even close• Too expensive to water certain plants• For farmers, it is too expensive to farm certain crops because of

the extensive amount of water needed to counter the excessive amount of transpiration caused by a windy environment

• Therefore, the wind level should be taken into consideration when farmers choose which crops to plant at different times of the year in order to prevent excess transpiration or closure of the stomata

Variables

• Independent variable: Distance of plant cuttings from fan (cm) (40, 70, 100, 130, 160 cm)• Dependent variable: Barometric

pressure (mm Hg) created by transpiration of plant cutting

Controlled VariablesControlled Variables How Method Allows for the Control of Key

Variables

Light distance All plant cutting were held 30 cm from the light source

Type of plant The same plant cutting species was used for all trials

Fan speed The same fan with the same wind setting (2-medium) was used for all trials

Time for data collection All trials were held for 10 minutes each and data was recorded every 10 seconds

Time for acclimation All trials were allowed 5 minutes to acclimate to new environment between

trials

Wattage of light bulb All lamps had 95 wattsGLX sensor The same GLX sensor was used to record

data

Materials• Materials:

– PASPORT Xplorer GLX– 3 PASPORT Barometer pressure sensors – 3 PASPORT extension cables– Large tub of water– 6 utility clamps– 3 plastic tubing clamps – 3 plastic tubings– 3 ring stands– 1 razor blade – 3 95-watt lamps – 1 metric ruler– 1 large fan– 3 plant cuttings– Flashdrive

GLX Sensor

Method

• Obtain 3 plant cuttings

Jar with water

Method cont.• Keep the clipped

ends of the plant cuttings submerged in water

• Cut plant at 45° angle and immediately place into open end of plastic tubing

Method cont.• Afterward, clamp plant

end with plastic tubing clamp

Pressurized tube with waterKeep thumb over top to

maintain constant pressure!

Method cont.

• Set up structure as shown in the photo (make sure to keep the barometer level with the plant cutting)

Plant cutting

Clamps

Barometer

Fan

Method cont.• Do 3 trials with 5 levels of

independent variable• The distance of the fan from

the plant cuttings is changed: 40 cm, 70 cm, 100 cm, 130 cm, and 160 cm from the plant cuttings

• For each variable, run trial for 10 minutes, letting GLX sensor measure every 10 seconds

Method cont.• Record data, process, and analyze data

Results-Tables

Distance of Plant Cutting from Fan (cm) Trial A Trial B Trial C Average: Final Average:

40 0.0602 -3E-15 0.0002 0.020133333 0.02

70 -0.00001 -0.00006 -0.0001 -0.000056667 none

100 -0.00001 -0.00007 -0.00004 -0.00004 none

130 0.0115 -0.0445 -0.0662 -0.033066667 -0.05535

160 -0.00006 -0.0237 -0.024 -0.01592 -0.02385

Data Table #1: Average Rate of Transpiration (in mmHg/10seconds) for Different Fan Distances from the Plant Cutting for Trials A,B, and C

Results- Graphs

40 70 100 130 160

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

Fan Distance From Plant Cutting (in cm. ) vs. the Average Rate of transpiration (in mmHg/10seconds)

Fan Distance From Plant Cutting (in cm.)

Ave

rage

Rat

e of

Tra

nspi

ratio

n (in

mm

Hg/

10 s

ecod

ns)

Graph #1: Fan Distance From Plant Cutting (in cm. ) vs. the Average Rate of transpiration (in mmHg/10seconds)

Results-Photos95 Watt Lamps

Clamp

Plant cuttings

Fan

GLX sensor

Conclusion• Too much wind is not good for transpiration• Stomata closes and causes little to no transpiration• Stomata close/wind strong= sensor reads positive pressure • For the plant cuttings placed 40 cm from the wind source, the

plants transpired slowly or not at all• The rate of transpiration, in this case, was actually positive 0.02

mmHg/10sec• Plants experiencing this much wind would thus starve • For the plant cuttings that were 70 cm and 100 cm from the wind

source, the data recorded was not viable to reach conclusions• An air bubble formed and the sensor could not measure pressure

changes

Conclusion cont.

• For the 130 cm, data showed that there was a transpiration rate of -0.05535 mmHg/10 sec

• This showed that at this wind level, transpiration rates were relatively high

• For the 160 cm, data showed that there was a transpiration rate of -0.02385 mmHg/10 sec

• This showed that at this wind level, transpiration rates were not as high as the 130 cm rate

• This is because there is less wind evaporating the water on the surface of the leaf, implying lower transpiration rates

• Overall, stronger wind leads to more transpiration, but too much wind causes no transpiration because stomata close

Evaluation

• Some errors include:– After the 100 cm trial, it was apparent that the plant

cuttings were no longer submerged in the water– The leaf cutting in the middle seemed to have more

wind directed toward it because it was placed directly in front of the fan as opposed to the other two leaf cuttings which were placed toward the sides of the fan

– During some of the trials, objects blocked parts of the fan (i.e. the power outlet blocked part of the fan during the 100 cm trial)

Thanks for Listening!