I've been collecting CO2 flux measurements at my thesis site each month throughout the winter. Since this is Jon's off-season for landscaping, he offered to take a break from his hectic climbing/skiing/netflix-watching schedule to be my winter assistant. Little did he know, once all of the brain-taxing study design is done and the field techniques are dialed, good science is synonymous with repetitive motion. Like in climbing, efficiency and good systems are key. I knew he'd be a natural...
So yesterday we drove out to the Kenai to see what was going on in the world of soil respiration. Believe it or not, there's still some going on! We have tubing running from the tip of this probe to an instrument that measures CO2. We can plunk this in each plot (the same places I've been measuring since May '08) and measure the CO2 at the bottom of the snow pack. Then we measure the CO2 at the top of the snow pack, how thick the snow is, and the snowpack density.
If you assume that the CO2 diffuses equally through the snowpack, you can calculate the rate of CO2 flux (umol CO2 m-2 s-1) coming from soil bacterial respiration. Neat, eh? There's no photosynthesis going on this time of year, so no plants are taking up CO2 but soil microbes are still giving off CO2. It's important to understand winter CO2 flux to really understand what's going on - some areas may be strong CO2 sinks in the summer, but lose so much over the winter that they're a CO2 source over the course of the year.
Thanks to Jon for all the field help... you measured the heck outta that flux.
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