Field Notes

<--2017-07-12 09:30:00 | 2017-07-17 14:00:00-->
Other sites visited today: East End

East End: 2017-07-17 09:30:00 (DOY 198)
Author: Elke Eichelmann
Others: Ada Chang

Summary: Took Li-6400 leaf level photosynthesis measurements

Ada and I arrived at East End wetland at around 9:30. We met there with Sophie Taddeo from Iryna Dronova's lab. She was doing a survey of East End with a few helpers looking at standing biomass, species composition, LAI, etc.

It was a sunny and clear day and it got very hot around noon. We used the borrowed LI-6400 from Whendee Silver's lab with our slightly modified clear conifer chamber head for leaf level photosynthesis and water exchange measurements.

I forgot to match the IRGAs at start, but we checked the match at the end after all measurements were done. The CO2 concentration in the reference cell IRGA was 367.9 compared to 365.4 in the sample IRGA. I think this difference is small enough to not have significantly affected the measurements at the high photosynthesis rates we were seeing.

We took 29 measurements in total, although some of these were accidental double measurements.

On the first 5 cattail leafs we repeated each measurement with the leaf turned upside down in the chamber.
After that we took 5 measurements on tule, then 5 on cattail without turning the leafs upside down, then 5 on tule again, leaving us with a total of 10 different cattail leaf measurements and 10 different tule measurements. We took the measurements off the boardwalk a few meters north of the EC tower. Most measurements were taken along the top third of the plants, and all in the top half of the plants.

We used full bypass for both CO2 scrub and desiccant on all measurements. For all measurements we held the leafs horizontally, regardless of how they were oriented in the field. This lead to some leafs being bent so far that they would show a fold. We did not take any measurements on plants that already had a fold in them before we started.

The 29 measurements took about 4 hours in total. We left around 14:30.

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11 sets found

14 EE_met graphs found