Dear editor, dear authors,
I thank the authors for their feedback and the work on my comments. I observe that most of the specific comments, but less so the general comments, have been implemented. I think that the paper could have been significantly improved with some more general revision. However, I do not feel called upon to insist on the implementation of every single comment, and think that how the authors want to shape their paper manuscript is up to them. Overall, the specific comments have been well incorporated and the condition of the manuscript is satisfactory and good enough to publish. There are some minor points I would like to comment on; how the authors handle these is up to them.
(Note: As I am commenting on former comments, the lines of the first manuscripts are cited here, I did not look up what lines they changed to in the updated manuscript.)
40, now 43: RC: Naming something a key topic, more citations should be given to prove that. - AC: The citations of Levia et al. (2011) and Van Stan et al. (2020) are the latest published books on forest hydrology with emphasis on throughfall and stemflow effects. We do not think that more citations are needed. – RC2: I do not find it very convincing to evidence that “stemflow has become an active topic of research in recent years” (only) with a more than ten years old book on forest hydrology. There are much more recent and specific (on stemflow) papers and review papers, which I would find more fitting to illustrate an active research topic.
37: RC: “overland, preferential or subsurface flow” This combination is odd to me. Please reconsider what your point is. AC: We change the sentence to: “overland, preferential or subsurface matrix flow”. RC2: These categories still do not make sense to me. Preferential and matrix flow are both subsurface.
167 and following: RC: I would prefer using correct mathematical symbols and equations, meaning that one metric can not be symbolized by several letters (e.g. A_s instead of TSA). In any case, however, the quantities used in equations should be consequently printed in italics also outside of the equations. - AC We agree that the symbols should be all in italic, in both equations and text. However, it is not true that math symbols cannot have several letters. There is no such rule, indeed, the Cauchy number is an example of a symbol that has 3 letters. We have changed to upper and lower letters as suggested: for instance: DC to Dc. – RC2: You are right, there are no global rules to this. Some journals have rules, besides this, much depends on what is common in a field. I did not mean using lowercase instead of uppercase, but subscripts instead of abbreviations (the formatting got lost here). Using long abbreviations without subscripts just makes the formula much more unclear, and is also not standard practice. I want to reference to how formulas are put here: https://doi.org/10.1016/j.tplants.2020.04.003, https://doi.org/10.2136/vzj2015.09.0131. It is just a hint; if the authors are very attached to this formatting, let them keep it.
207, now 218: RC: “no relevant…” What does that mean, what are the implications for this study? No change in soil physical properties does not mean that no differences in hydrological processes will occur or nothing interesting will happen below this depth? – AC: We chose 30 cm because it was the maximum depth chosen for the excavation of the soil profiles after the experiment. Yes, no change in soil physical properties does not mean no differences in hydrological processes. However, we do not expect to find different results at deeper depths in the vadose zone. We changed “no relevant” to “no significant”. – RC2: I think it is fine to stop at a depth of 30 cm for the study, but it is wrong to argue with no changes in soil properties. It is not logical and sounds like an excuse where no excuse is needed. I personally would expect that processes change with depth, also with the same soil physical properties, and I am sure not the only one.
233, now 242: RC: Please use WRB instead of US SoilTax. When using a classification system, do not forget the reference. - AC: We are actually not using US SoilTax, but the USDA Soil Texture Classification. This is not the same. – RC2: You are right, I overlooked this. Still, I am missing a reference.
251, now 262: It would be great to have some measure of variance to being able to characterize and compare. – AC: Thanks for the suggestion, but as we only have one sensor per location and the water flow pattern is spatially variably, we do not have replicated measurements, and the variance for measurements cannot be calculated. Figure 5, Figure S1 and Table 1 provide an idea about the differences in water contents among sensors. – RC2: As you say, the pattern is spatially variable, and a measure of variability would give a number to quantify exactly that. You have n=16, which is enough to calculate a statistical variation. You could e.g. give a temporal evolution of the spatial variance in the two depths.
259: Please set the maximum difference in SWC in relation to pre-stemflow values. AC: This is what was done. “the maximum difference in SWC (i.e., difference between the max SWC and the pre-stemflow SWC” is shown in Table 1., and 264 ff.: RC: Please give absolute additional to relative values. – AC: These values are listed in Table 1., and 294: “SWC” Please again also give absolute numbers. – AC: Again, what would be the point of adding these values? The absolute values are listed in Table 1. – RC2: It is difficult to get a full picture of the observed processes, when you just name relative values or differences. Only the combination of both an absolute value (SWC at the beginning or end of the experiment) and a relative value (or difference) gives the reader the possibility to understand the processes (at a high pre-stemflow water content, a small max difference means something else than at a low pre-stemflow water content). You give all these results in the tables, but you name some of them in the text, too. The flow of your results text relies very much on these named results, and therefore it is good for them to offer the full picture. I hope I could clarify what I meant in those comments.
272: RC: “because…” This is a good thought. Maybe you can find more references to compare stemflow infiltration with and without throughfall and go into more detail here. - AC: Thank you for this wonderful suggestion, however, we are not aware of any studies that analyze stemflow infiltration with and without throughfall. If the reviewer is aware of any, please let us know as it would be of great interest. – RC2: As some stemflow studies investigated stemflow infiltration under natural rain events, and some applied stemflow artificially, you have the differentiation of inclusion and exclusion of throughfall.
307 (“The distribution…”) – 313: RC: I find this paragraph too long and the statement rather trivial. The flow mainly taking place laterally due to the low (non-existent) slope inclination can be said in one sentence and does not need to be compared with studies located on stronger slopes, because this is comparing apples with oranges. – AC: The sentences will be modified and shortened for better understanding as follows: “We observed the greatest dye coverage in the immediate vicinity of the tree (at 10-cm distance), which suggests that the majority of the stemflow infiltration water was directed vertically. This is likely a consequence of the flat area at our experimental site.” In addition, we disagree with the reviewer's comment "comparing apples with oranges". Relying on the observations of reviewer 1, it is certainly valid and useful to compare our results with the few available in the literature on trees on slopes. – RC2: You can compare different things, but then it is very important to name the differences. If you do not name the differences, then it is comparing apples and oranges. It is the same as it makes no sense to compare stemflow infiltration area, when you do not refer to stemflow amount and intensity (and tree species, soil type etc.). Without the preconditions, the numbers are not interpretable. And in your case, you can mention and discuss stemflow infiltration on slopes (I do not know what reviewer 1 said about this in particular), but it for sure makes more sense to compare your own results in a flat area (what, as I understood, it is) to other studies in flat areas. |
