In December, I presented my research on the global temperature responses of leaf respiration at AGU in San Francisco. This was my second time at the conference, and first time giving a talk. I was invited to speak in a session entitled "Photosynthesis and Respiration at Leaf, Ecosystem, Regional, or Global Scales: Constraints, Measurements and Modeling" - which was a perfect setting to present this work.
The earlier morning part of this session was filled with excellent research on new advances in chlorophyll fluorescence measurement across scales, and how this could be modified by leaf development (as in Loren Alberts talk on sunflower leaves), drought (as in Ying Sun's talk that compared types of drought), as well as tracked through the season and related to canopy carbon exchange (as explained by my friend Xi Yang, on his work in Harvard Forest).
This session also probed deeply into the use of carbonyl sulfide to measure real-time stomatal conductance and therefore estimates of realtime carbon uptake through the canopy. COS (or OCS, depending on who you are) is also taken up by soils, so knowing the day and night-time baseline of this activity is necessary for determining leaf-level exchange (which was discussed by Rick Wehr, and others). The soil rates seemed constant in Harvard Forest (as presented by Rick Wehr), but according to this and other research, were modified by the presence of water - both on leaves in the form of dew, and in soils.
The second half of the session was kicked off by my talk, and then followed by Paul Gauthier, my bizarro post-doc colleague (we have been hired by the same people, but never lived or worked in the same place at the same time). It was great to finally meet Paul and chat RLight, modeling, and the Kok effect nitty gritty in person. Paul presented a great talk on his work with Michael Bender at Princeton, where they used stable isotope measurements to determine which element of the respiratory process most contributes to the light inhibition of respiration (pro-tip: it's PDH!). The patience and fine-scale work that this requires is astounding when you are used to measurements in the field.
The following talks in the session really honed in on current research in COS - and included excellent talks by Mary Whalen (who also found more soil uptake under wet conditions), and a deeper look into carbonic anhydrase, the enzyme that breaks down COS by Lisa Wingate. Overall, I was really thankful and pleased to be a part of this great session - it was exactly what I found missing from my previous experience at AGU - talks that use real measurements and experiments to scale photosynthesis and respiration.
Like all conferences at this stage, it was great to see old friends from Alaska, grad school, collaborations, and various field work. And some of the best learning moments happened in casual meetings with colleagues and future collaborators rather than in the sessions. Looking forward to the writing motivation boost from AGU to carry over into January!