New paper on cellulose isotope signals in grasses

Congratulations to Regina for her new paper that takes the MuSICA model to a new level by exploring the physiological and climatological signals recorded in the cellulose ¹⁸O/¹⁶O ratio of grasses. Using a new carbon growth and allocation scheme specific to grasslands, she demonstrated that the modelled isotopic signal agreed best with observations when 1) integrated over a 400 growing-degree-day period (the average leaf lifespan observed at the site); 2) the biochemical ¹⁸O fractionation between water and substrate for cellulose synthesis was temperature-sensitive (as previously reported for aquatic plants and heterotrophically grown wheat seedlings) and 3)  the proportion of oxygen in cellulose reflecting leaf water ¹⁸O enrichment was dependent on air relative humidity (as observed in independent controlled experiments with grasses). An early view version of the paper can be found here.