Experimental design:
We plan to have 20 cups containing 20 lemna plants (thalli)- 5 for each group. The first group is only going to have 20 thalli in pond water; this is our negative control. The second group is going to have lemna and food coloring. By doing this, we will be able to see the affect of food coloring on lemna, if any. The third group is going to have algae and food coloring. This will allow us to see the affect of putting the food coloring in the water, probably limiting algae growth. The fourth group is going to have lemna, algae, and food coloring. This group will allow us to observe if indeed lemna and algae competition is reduced due coloring the water so that blue light is not able to reach the algae, and thus the algae will not be able to photosynthesize.
Materials Needed:
- 20 lemna cups
- Lemna
- 20% pond water
- Algae
- Yellow, red, and green food coloring
Literature Cited:
Dickinson, Matthew B., and Thomas E. Miller. "Competition among small, free-floating, aquatic plants." The American Midland Naturalist. 140.n1 (July 1998): 55(13). Expanded Academic ASAP. Gale. Fairfield University. 19 Oct. 2008
<http://find.galegroup.com.libdb.fairfield.edu/itx/start.do?prodId=EAIM>.
Freeman, Scott. Biological Sciences. University of Washington; Pearson Education, Inc: 2008.
Annotated Bibliography:
Artetxe, U., Hernandez, A., and Garcia-Plazaola, J. “Do light acclimation mechanisms reduce the effects of light-dependent herbicides in duckweed (Lemna minor)?”
Weed Science. 2006: 230-6. 21 Oct. 2008. <
.fairfield.edu/hww/results/getResults.jhtml?_DARGS=/hww/results/ results_common.jhtml.20>.
This article discusses how different light intensities affects lemna's biological mechanisms to adapt to the light.
Cheng, J, L. Landesman, B.A. Bergmann, J.J. Classen, J.W. Howard and Y.T. Yamamoto. “Nutrient removal from swine lagoon liquid by lemna minor 8627.” Transactions _ of the Asae. 2002, vol 45,pp. 1003-1010. <>. Accessed October 21, 2008.
This article is mainly about the rates of nitrogen and phosphorus uptake by duckweed. It also talks about wastewater conditions and season climate conditions and their direct impact on the growth of duckweed. High light intensity and longer periods of warm temperature can increase the growth of duckweed.
Dickinson, Matthew B., and Thomas E. Miller. "Competition among small, free-floating, aquatic plants." The American Midland Naturalist.140.n1(July 1998):55(13). Expanded Academic ASAP. Gale. Fairfield University. 19 Oct. 2008
<http://find.galegroup.com.libdb.fairfield.edu/itx/start.do?prodId=EAIM>.
This article is about the competition between aquatic plants for nutrients.
Garcia-Plazaola, J., Hernandez, A., and Artetxe, U. “Regulation of the xanthophyll cycle pool size in duckweed (Lemna minor) plants.” Physiologia Plantarum. 2002: 121- 6. 21 Oct. 2008. < hww/ results/getResults.jhtml?_DARGS=/hww/results/results_common.jhtml.20>.
This article is about how different light intensities affects the ability of lemna to synthesize various pigments.
Hillman. “The Lemnaceae, or Duckweeds: A Review of the Descriptive and Experimental Literature.” Botanical Review. Gale. Fairfield University. 19 Oct 2008 <http://find.galegroup.com.libdb.fairfield.edu/itx/start.do?prodId=AONE>.
This article is about the structure of duckweed. It explains the growth of lemna.
Korner, S., Vermaat J., and Veenstra S. “The Capacity of Duckweed to Treat Wastewater: Ecological Considerations for a Sound Design.” Journal of Environmental _ Quality. 2003: 1583-90. 21 Oct. 2008. <.
fairfield.edu/hww/results/results_single.jhtml;hwwilsonid=T4DMJB3WYG 2LDQA3DILSFGOADUNGIIV0>.
This article discusses how duckweed are useful in treating wastewater. It discusses the impact of algae on nitrogen and phosphorus loss for lemna.
Lemon, Gordon D., and Usher Posluszny. "Comparative Shoot Development and Evolution in the Lemnaceae.” International Journal of Plant Sciences. 161.5 (Sept 2000): 733. Academic OneFile. Gale. Fairfield University.19 Oct. 2008
<http://find.galegroup.com.libdb.fairfield.edu/itx/start.do?prodId=AONE>.
This article is about the structure of lemna and its development. It explains how it grows and the different parts of the plant.
Paul C. Marino, "Ecological competition", in ,
<http://www.accessscience.com,DOI 10.1036/1097-8542.757554>.
This article is about plant competition and species coexistence. It talks about how competition is one of the most important forces structuring ecological communities.
Young, D.L.W., M.D. Wiegand, N.L. Loadman, S.A. Collins, A.J. Ballevona, and J.D. Huebner. "Effects of artificial ultraviolet-B radiation on growth and fatty acid composition of duckweed (Lemna minor). (Author abstract)." Freshwater Biology _ 51.11 (Nov 2006): 2029(12). Academic OneFile. Gale. Fairfield University. 21 Oct. 2008
This article is about Duckweed (Lemna minor) and how it was collected in the summer and early fall and was exposed under laboratory conditions to control (photosynthetically active and UV-A radiation) and experimental (control plus UV-B radiation) conditions. Growth and survival were determined by counting the number of green, and brown/white fronds following 1-5 or 11 days of irradiation. Growth of duckweed was impaired by exposure to UV-B radiation in the fall experiment but not in the summer.
