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.



Comments are closed