The Effect of High Concentration of Carbon Dioxide on Plant Growth By Jeremy Tran

Hypothesis and Problem Problem Statement: What is the effect of high concentration of carbon dioxide on plant growth? Hypothesis: If there is a higher concentration of carbon dioxide, then the plant will grow faster.

Concepts Common Bean- Phaseolus Vulgaris Photosynthesis- The process of converting light energy to chemical energy and storing it in the bonds of sugar. Green house gases- Impact the growth of plants by controlling how much heat gets trapped on the earth’s surface. Carbon Dioxide- one type of green house gas. Plants use carbon dioxide so they can photosynthesize. PPM- Parts Per Million. Unit used to measure amount of carbon dioxide. Plant Growth- Number and size of flowers; number, size, and weight of seeds; number and size of fruits, and the amount of nitrogen in the seeds.” (Melville)

Regular Air (Approximately, 300 ppm of CO2) Design Diagram Levels 3000 ppm of CO2 1500 ppm of CO2 750 ppm of CO2 Regular Air (Approximately, 300 ppm of CO2) Trials 1 Sample Size 12 IV: Independent Variable- Amount of carbon dioxide DV: Dependent Variable- Plant’s growth rate, which the height of the plant will be measured in centimeters per day Constants: Soil, Plants, Amount of water (300 ml of filtered water per day), Amount of light (same location), Room temperature Materials: 48 bean plants (Phaseolus vulgaris), 4 Cardboard Boxes, Plastic wrap, Clear PVC tubing, Multiple plant trays,18 cm to 27 cm balloons, Soil of the same kind, Carbon dioxide tank, Metal clamps (To clamp tubing), Graduated Cylinder, Plastic funnel, Centimeter rulers, Filtered water, Drill (To drill holes in the PVC tubing)

Procedure Obtain a cardboard box and cut out the top and front sides of the box. Place equal amounts of soil into the plant trays. Next, place the plants into the trays and put the tray in the box. Tape plastic centimeter rulers along the back of the box, aligned with the tray. Repeat steps 1-3 for three additional box and trays. After, label each box. (A, B, C, and D) Measure the initial heights of each plant and record in the data table Drill two holes 10 centimeters apart on the right and left sides of the boxes. Prepare the tubing by drilling multiple small holes along the tubing. Place tubing across the boxes into the drilled holes. Attach metal clamps on each end of the tubing to prevent the water or air from entering or leaving. Using the plastic wrap, cover the two open sides of each box as tightly as possible to prevent outside air from entering. Drill holes into the plastic wrap only for one box labeled D, which is the control. Place each box in an area where adequate sunlight and room temperature can be obtained. Water each box by using the plastic tubing with 300 ml of filter water. For the three experimental groups, add different volumes of CO2 from the tank by using different size balloons. For box A, add four balloons full of CO2. For box B, add two balloons full of CO2. Finally for box C, add one balloon full of CO2. Place the opening of the balloon carefully on the tubing to allow the CO2 to enter each box. Measure the height of each plant in centimeters every other day and record. Repeat step thirteen to sixteen for ten days.

Data Plant 1 Plant 2 Plant 3 Plant 4 Plant 5 Plant 6 Plant 7 Plant 8 Box 1 3000 ppm 31 25 32 26 20 27 18 17 Box 2 1500 ppm 36cm 18cm 33cm 20cm 30 cm 27in 31cm Box 3 750 ppm 22cm 16cm 24cm 21 19 23 Box 4 Regular air 15cm 17cm 14cm 23cm

Averaged Data Box 1 Box 2 Box 3 Box 4 16.33 cm 22 cm 16.5 cm 15.33 cm

Statistical Analysis

Photo Documentation. Me watering a group of plants Me with one group plants at the end of the experiment Me watering a group of plants

ANOVA Results The ANOVA test shows that the results were not significant. Thus, the results could have occurred due to chance. The p value was > .05

Conclusion Carbon dioxide accelerated plants’ growth. However, the plants receiving the highest amount (3000 ppm) died. This may be due to the toxic side-effect of very high level of carbon dioxide.

Potential Sources of Error Inadequate sunlight- sunlight occurred in the same spot only for a few hours Could have used lights instead The seeds could have been bad Could have planted seeds first and used the ones that grew well to grow with the CO2 CO2 delivery Could have been delivered more accurately using a carbon dioxide scale

Extensions Test experiment with different plants Test experiment again more precisely with higher amounts of Carbon Dioxide The effect of sunlight on plant growth The effect of temperature on plant growth

Applications Is used by green houses to increase plant growth Could influence more people to growth more plants using a high concentration to maximize growth in a shorter period of time.

Acknowledgements Parents Ms. Pietrangelo People who accept this experiment