BG-2018-120

Dear Gustaf Granath,

First of all I would like to thank both reviewers for their constructive comments and you for your reply. I agree with the reviewers that some parts of the manuscript need a bit of attention and I am happy t read that you agree. So I would like to ask you to make the changes as suggested by the reviewers and a indicated by you. I agree with you that the 18O precipitation model depends on sampling density and interpolation between the measurement points and that is therefore possible that certain areas are not covered as well as others, potentially NWT is such an area. As for the carbon isotope data, I am not sure if CO2 transport within Sphagnum to the Chloroplasts plays a crucial role, I have the impression they have this uptake/transport issue under control? For unicellular organisms fractionation is determined by growth rate versus CO2 availability/concentration and an uptake factor as the result of cell surface versus volume. I am assuming that growth rate is related to temperature and CO2 availability, for instance by being submerged or not. The isotopic composition of dissolved CO2 is also, slightly, different from CO2 in air. On top of that there is recycled CO2 coming from the breakdown of organic matter which is related to oxygen availability and therefor water table and degradation is also related to temperature. I can see that the carbon isotopic composition might me a more complex story than the oxygen isotopic composition. I am looking forward to reading your final comments and revised manuscript.

Success,

Marcel

Dear Gustaf Granath and co-authors,

First of all thank you for your rebuttal and revised manuscript. It is an impressive and interesting dataset, having read the revised version I definitely think it should be published in Biogeosciences after some minor issues have been addressed.

Best regards,

Marcel