Effects of Varying Amounts of Sunlight on Plant Growth in Terraria

Nathaniel Routh

Hour 2

http://upload.wikimedia.org/wikipedia/commons/4/4f/Epipremnum_pinnatum_var.jpg

Abstract

• Hypothesis: If a terrarium receives more sunlight, then it will be warmer than a terrarium that receives less, and its plant will grow taller.

• Independent Variable: Amount of sunlight• Dependent Variable: Growth of plant• The plant which received nine hours of sunlight

grew 18mm, while the plant which received eight hours of sunlight grew 9mm.

Review of Literature

• Terrarium: A sealed container used for growing plants. – Invented in 1826 by Dr. Nathaniel Ward.– Allow plants to grow in harsh environments.

• Avoid placing in direct sunlight, which causes algal growth on the container

• Water inside mimics the water cycle• Air is recycled: plants use carbon dioxide during

the day, and create CO2 at night from free oxygen in the container.

Introducing the Problem

• What is the effect of varying amounts of sunlight upon plants in a terrarium?

• One would test this by exposing terrarium plants to different amounts of light

• If a terrarium receives more sunlight, then it will be warmer than a terrarium that receives less, and its plant will grow taller.

Materials

• A place with indirect sunlight of equal levels, with enough space for two terrariums

• Three paper grocery bags• Hyponex potting soil (3.63 kilograms)• Planting gravel• Three small pothos plants• Three plastic bowls to cover fishbowl openings• Three glass fishbowls with lids• Three rulers with metric measurements

Design

• Three terraria, side by side under a window

• Paper grocery bags used to cover• Terrarium C covered always• Terraria A and B covered at appropriate times

Procedure1. Gather materials2. Assemble three terrariums

a. Place gravel in the bottom of the fishbowlsb. Fill the bottom of the fishbowls with equal amounts of soilc. Plant pothos plants in the soild. Place rulers vertically with the plantse. Cover the top

3. Place two terrariums next to each other in an area where they will receive equal indirect sunlight, and the third where it will receive no sunlight.

4. Let Terrarium A receive eight hours of light each day. Let Terrarium B receive nine hours of light each day. Cover them with black cloths when they are not to receive light. Let Terrarium C (the control) receive no light, aside from that received when taking measurements.

5. Each day, before covering each terrarium, record height of plants. Take measurements for the control as well.

6. Continue this for fifteen days.7. Analyze data and draw conclusions

Results

• Terrarium A’s plant grew until Day 8, after which growth ceased until the last day

• Terrarium B’s plant grew steadily• Terrarium C’s plant grew one millimeter

Growth of Plants

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Days

Heig

ht in

Mill

imete

rs

Terrarium A Terrarium B Terrarium C

Analysis

• Terrarium A’s plant grew steadily until halfway, after which it ceased to grow

• Terrarium B’s plant grew steadily• Terraria A and B’s plants had a one millimeter

difference at the onset of the experiment, and finished with a ten millimeter offset

• Terrarium A had constant condensation after Day 4– May be due to a difference in air

temperature

Conclusion

• Terrarium B’s plant was taller than that of Terrarium A

• Terrarium A received one hour less of light per day.

• The results of the experiment support the hypothesis

• For future experiments:– More different amounts of light– More equal ambient temperatures– Different plants

Bibliography• (n.d.). Welcome to the best source for terrarium information.

Retrieved from <http://www.terrariums.com/>• "Terrariums." Science Weekly 19.7 (Nov 29, 2002): 1(12). General

OneFile. Gale. Shawnee Mission Kansas School District. 27 Oct. 2009  <http://find.galegroup.com/ips/start.do?prodId=IPS>.

• Trinklein, D. (2002, May). Terrariums. Retrieved from http://extension.missouri.edu/publications/DisplayPub.aspx?P=g6520

• Ward, N. (1842). On the growth of plants in closely glazed cases. London, England: Samuel Bently & Company.

• Weishan, M. (2002). Fern Fervor. Ebscohost. Retrieved 2009, October 27 from http://web.ebscohost.com/src/detail?vid=3&hid=6&sid=0e14c423-a50e-4561-9ae8-b75f9516f02b%40sessionmgr11&bdata=JnNpdGU9c3JjLWxpdmU%3d#db=ulh&AN=6344500

Acknowledgments

• Mr. David Routh and Mrs. Coleen Iverson-Routh provided funding and assistance

• Family Tree Nursery provided the pothos• Westlake Ace Hardware in Prairie Village

provided the soil• Wal-Mart provided the fishbowls and plastic

plates for the terraria