Comment on bg-2021-259

The manuscript is a carefully detailed and well described study on pore network analyses of peat soils with a depth differentiated view. The aim is to use results of pore network analyses to help explain methane production potential in these environments. The level of language is very high, the text flow is very good, and it was a great pleasure to review. Although I am not that familiar with micro CT, image analyses and pore network simulations, the results are feasible, while not super surprising, as would be expected from the literature. Still, the manuscript is novel in its approach and comparisons.

The manuscript is a carefully detailed and well described study on pore network analyses of peat soils with a depth differentiated view. The aim is to use results of pore network analyses to help explain methane production potential in these environments. The level of language is very high, the text flow is very good, and it was a great pleasure to review.
Although I am not that familiar with micro CT, image analyses and pore network simulations, the results are feasible, while not super surprising, as would be expected from the literature. Still, the manuscript is novel in its approach and comparisons. I was left a little bewildered, what had happened to the discussion of methane (L371-383 gives some general statements on the importance and general conceptual discussion), in particular, since it was not explicitly modelled nor were the results contrasted against methane flux measurements from the field.
My recommendation is that, now with some distance, the authors re-assess the paper and whether or not the self set aims are fully fullfilled. Perhaps it might be a good idea to focus a little more on the strong technical part of the manuscript and limit the study a little more to the descriptive nature, and then discuss the methane production and diffusion from this vantage points in a more speculative manner. After all, the emerging methane emissions are mostly explaned by a conceptual model.

Major concern
What does this study have to do with methane emissions? This remained unclear to me. Either, the scope of the study should be a more quantitative Minor concerns L5 How can the formation of anaerobic pockets be conceptualized in a pore network approach? This is left unaddressed.
L53 like previous comments.
L 90 ff section 2.2: was the VGM model fitted to the averages of the replicates from each depth, respectively? Just a minor information to add. L94 Sentence not needed, but not harmful, either.
L97 in -> at L105 This is a rather bold statement. If samples were not saturated under co2 environment of vacuum, my impression is this is not actually correct. Please do not use this assumption.
L118 quantify the sample: What is meant by this? Please specify.
L122 is resolution meant, here?
L122 if this is the resolution, then the real micropores <10micron are not resolved. Thus, much of the area where anaerobia may continue to exist is not covered. Please address this limitation in the discussion. This, alongside the problem of dissecting organic from water.  (Table 1). Also, I expect that since the air filled porosity = 0 at saturation assumption is not warranted, the data points would be shifted to the left in x. This could be explored a little more. Also, what would the intercept in Figure     L384-385 repetition of introduction L393: a bit of a leap of faith or perhaps a rather general statement: the simulation provide support for the conceptual understanding to be ok. I think these hard earned results should perhaps be discussed a little more in acknowledgement to this (although I detect absolutely no oversell, here). L425: I see the potential to discuss the obtained pore space characterizing numbers in the light of other peoples results re: methane transport, or any other gas transport in particular. If this does not exist, I suggest to scope this section a little more carefully.
L448 mark you, many of the dead end pores might not have been resolved due to the micro CT technique. Perhaps this should be contextualize, too.
L486: How can a relative quantitative measure (anisotropy) determine the efficiency (a qualitative) absolute measure of gas diffusion.