Date of Award
Bachelor of Science
moss, peat, ecosystems, acid, environment, speciation
Sphagnum mosses often dominate peatland ecosystems. Because of the low availability of nutrients in these environments, Sphagnum mosses have developed a cation exchange system within their cell walls to take up nutrients using polyuronic acids (PUA). Increasing amounts of PUA may come at a physiological tradeoff and cause decreasing photosynthetic rates. The objectives of this study were 1) to assess variation in polyuronic acid content and structure by analyzing component monomers from three different Sphagnum species representative of different microhabitats, 2) to investigate how this variation affects the cation exchange capacity of the peat moss species, and 3) to evaluate whether uronic acid concentrations show a negative association with maximum photosynthetic rates. Maximum photosynthetic rates were lowest among species that grew in nutrient poor environments. Cation exchange capacity was measured, with the species that grew in less nutrient poor having the lowest capacity. Cell walls were isolated, hydrolyzed, and an evaluation of monomer concentrations was done. The data from this experiment was inconclusive. While the protocol was shown to be an effective method to quantify the uronic acid content of the species, the analytical techniques may have been too simplistic causing the results to be skewed.
Danise, Michael J., "The tradeoff between polyuronic acid content and photosynthesis rates in Sphagnum" (2011). Honors Theses. 962.