posted by Michelle:
As of Friday 17, July, all field sampling has been completed in high and low N deposition areas of Norway as planned (Egersund, Lillihammer, Rondane). Sediments collected from 28 lakes (14 high and 14 low N deposition). Zooplankton were collected from 30 lakes (15 high and 15 low N deposition) for alkaline phosphatase activity (APA). We were not able to collect sediments from 2 lakes because of heavy macropyhte growth (surprising at ~10m).
I have been conducting 48h enrichment experiments with sediments with the following treatments: organic carbon, nitrate, phosphate, and all three resources. I am also am conducting 24h incubations where I am measuring the relative flux of N2O (versus N2) during denitrification in response to additions of nitrate. We have access to a climate-controlled cold room at UiO, so I have been keeping the incubations at 12 degrees C, the approx. lake water temp at 10m. I will have about 1,500 gas samples when I am finished with the experiments and will analyze them by GC in late August/September.
Angie photographed 600 zooplankton from 30 lakes and has processed about half of the samples (for APA and protein) and still needs to determine the body sizes from the photos. More to come here.
The trip to Rondane as pretty uneventful (for field work) until we returned to Oslo. We had just filled up the rental car with petrol and were getting ready to return it to Rent-a-Wreck when it died. At least this didn’t happen at some remote lake without cell phone coverage, but rather at a gas station/McDonalds. The McDonalds staff was able to translate the “what to do in an emergency” instructions that came with the car. And a very nice tow truck driver from the Norges Automobil Forbund (kind of like AAA) was able to take us and the car back to the Rent-a-Wreck office.