Kenneth Fortino edited ResultsOMMineralization.tex  about 8 years ago

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\subsection{Unleached Litter Experiment}  The sediments added to the mesocosms had an estimated dry bulk density that ranged between 0.25 to 0.26 g ml\textsuperscript{-1} and an organic matter content between 12.7 and 12.9\%. Using this information, we estimate that the sediments in the mesocosms contained between 3.16 and 3.33 g of organic matter. The mesocosms that received leaf litter each received between 0.04 and 0.08 additional g of organic matter with the added leaf litter, which would be the equivelent of 11.3 to 22.7 g coarse organic matter m\textsuperscript{-2}. In the lake from which the sediments were collected we measured between 57.3 and 163.0 g coarse organic matter m\textsuperscript{-2}, so the mesocosms used in the experiment contained at most 40\% of the coarse organic matter of the lake. However in the mesocosms all of the leaf litter was added to the surface of the sediments, while a portion of the leaf litter in the lakes was buried within the sediment.  The dissolved oxygen concentration of the overlying water in the bottles ranged from 80.09 to 275.80 $\mu mols$ O\textsubscript{2} L\textsubscript{-1} with a median of 224.80 $\mu mols$ O\textsubscript{2} L\textsuperscript{-1}. The dissolved oxygen concentration varied significantly over the course of the incubation and was the lowest on the initial day of the incubation (Fig. \ref{fig:DO_days}). Additionally, the bottles containing leaf litter had lower dissolved oxygen concentrations in the overlying water on day 0 and day 2 of the incubation (Fig. \ref{fig:DO_days}).  Over the course of the 21 days of incubation the total oxygen consumption of the bottles ranged between 360 and 2100 $\mu mols$ O\textsubscript{2} m\textsuperscript{-2} h\textsuperscript{-1}, with a median flux of 920 $\mu mols$ O\textsubscript{2} m\textsuperscript{-2} h\textsuperscript{-1}. Since the treatments with added leaf litter had more organic matter in the sediments than those without leaf litter, we normalized the oxygen flux to the estimated organic matter content of the sediments in the bottles. The organic matter normalized oxygen flux ranged from 7.34 to 42.54 $\mu mols$ O\textsubscript{2} (g organic matter)\textsuperscript{-1} h\textsuperscript{-1}, with a median flux of 18.97 $\mu mols$ O\textsubscript{2} (g organic matter)\textsuperscript{-1} h\textsuperscript{-1}.