The Yin and Yang of N in Streams

Fall semester in the lab


Erin running samples on the GC

After a long summer of field work it was time to slip into our lab coats and start analyzing all the samples we collected.  Gas samples, collected during acetylene block assays, were run on the Gas Chromatograph (GC) to observe changes in nitrogen gas or N2O concentrations.  These changes would allow for quantification of nitrogen fixation and denitrification.  We ran water samples collected from chamber incubations of streams substrates using Membrane-inlet mass spectrometry (MIMS).  This allows us to determine N2-flux to understand whether there was a net nitrogen fixation or denitrification.


Michelle running samples through the MIMS


We also had to measure the concentrations of nutrients such as nitrogen, phosphorous, and carbon, within the stream as well as measure organic sediment content.


Ryan performing water chemistry analysis

We managed to complete most of this analysis and the coming semester will be comprised of analyzing our data, writing up our findings and preparing for the coming field season.