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Volume 9
Climate Change Summit 2018
Journal of Earth Science & Climate Change | ISSN : 2157-7617
November 19-20, 2018 Paris, France
6
th
Global summit on
Climate Change
Effects of elevated atmospheric CO
2
and nitrogen fertilization on nitrogen cycling in experimental riparian wetlands
Theresa Oteng Apreku
Hohai University, China
S
tudies on the relationship between plant nitrogen content and soil nitrogen reduction under elevated CO
2
conditions and
with different nitrogen additions in wetland ecosystems are lacking. This study was meant to assess the effects of elevated CO
2
concentrations and inorganic nitrogen additions on soil and plant nitrogen cycling. A cultured riparian wetland, alligator weeds, and
two duplicated open top chambers (OTCs) with ambient (380 μmol/mol) and elevated (700 μmol/mol) CO2 concentrations at low (4
mg/L) and high (6 mg/L) nitrogen fertilization levels were used. The total plant biomass increased by 30.77% and 31.37% at low and
high nitrogen fertilization levels, respectively, under elevated CO
2
conditions. Plant nitrogen content decreased by 6.54% and 8.86%
at low and high nitrogen fertilization levels, respectively. The coef cient of determination (R2) of soil nitrogen contents ranged from
0.81 to 0.96. Under elevated CO2 conditions, plants utilized the assimilated inorganic nitrogen (from the soil) for growth and other
internal physiological transformations, which might explain the reduction in plant nitrogen content. A reduction in soil dissolved
inorganic nitrogen (DIN) under elevated CO
2
conditions might have also caused the reduction in plant nitrogen content. Reduced
plant and soil nitrogen contents are to be expected due to the potential exhaustive use of inorganic nitrogen by soil microorganisms
even before it can be made available to the soil and plants. The results from this study provide important information to help policy
makers make informed decisions on sustainable management of wetlands. Larger-scale eld work is recommended in future research.
J Earth Sci Clim Change 2018, Volume:9
DOI: 10.4172/2157-7617-C5-052