Like Musical Chairs
Getting a handle on the plots within sub-plots at the CiPEHR research site is perhaps one of the most important things to understand, yet for me has been the most difficult. And then yesterday, it got even more complex when we started playing musical chairs with the chambers! Let me see if I can explain it...
Mini Greenhouses
Within in each CiPEHR replicate plot, there are four sub-plots on each side of the snow fence. Two of the sub-plots will be controls where no treatment is applied. If the plots are located on the north side of the snow fence(winter-warmed), then the other 2 of the 4 sub-plots will have chambers placed placed on them to increase the air temperature within the plot, thus creating a mini-greenhouse effect. The chambers are made of plexiglass. The dimensions of these chambers are 60 cm by 60 cm by 60 cm.
How do the Plexiglass Chambers mimic the Greenhouse Effect?
Visible light passes through the plexiglass, and then is absorbed by plant material. The plants use some of this energy for photosynthesis, however most of the visible light energy is released by the plant as infra-red (heat) energy. The infrared energy is then absorbed by CO2. Thus, the air within the chamber is warmed. Two of the chambers have lids that periodically close for about a minute. During the closure time, the air within the chamber is sampled for CO2 concentration.
flux chamber on the tundra captures the CO2 flux
Moving Chambers to Remove Site Variability
Once each week the chambers are moved within the subplots to better remove variability from the data that might be an artifact of site variability.
Meghan Taylor Moving Chamber
Carrying Chamber to New Location
Moving Fluz Chamber
Gently Placing Flux Chamber
Once the chambers are successfully moved, then we have to check that the chambers that collect air samples for CO2 are functioning well. One of the tubes for the pnuematic arms that close the lids snapped, so Marguerite had to re-attach.
Repairing Pnuematic Arm Valve
All systems are now a go!
Mission Accomplished