This manuscript evaluates the role of initial litter traits in influencing patterns of temporal N release from litter and determining the fate of N in soi. Although there are several studies evaluating the dynamics of litter N in different species, very few relate it to the fate of this nutrient in soil fractions and soil solution. For the latter, this is a novel manuscript with a relevant question and a well-designed experiment. However, too many results are presented and the messages are not entirely clear. In my opinion, it still needs to organize and condense the results to arrive at novel messages. There are many main and supplementary figures, I do not think all of them are necessary, some are redundant (e.g. Fig. 2 and S2, Fig 5 c and b). I think there are two aspects to distinguish, on the one hand, the general patterns and, on the other hand, the variability between species. It is also confusing that sometimes N is discussed in terms of absolute values of N and sometimes in terms of relative values, leading to opposite conclusions. Improving these aspects would make it easier to read and convey clear messages. Although generally well written, the English could be improved. There are long sentences that could be simplified and shortened.

In particular, there is an error in the way they calculated litter-derived soil N (Fig. 2c). Strictly speaking, if the litter fragment is larger than 2 mm, it is not POM (soil), but rather litter. I understand that you measured the 𝝳15N in the soil-litter fragment mixture to calculate the litter-derived soil N over time, but if you did not separate the fragments > 2 mm, you will overestimate the litter-derived soil N (see specific comments below). To calculate litter-derived soil N, you should have used the 𝝳15N of the POM, MAOM and soil solution for the 𝝳treat, as you do at the end of the experiment.

Specific comments:
The introduction provides a good conceptual framework for the research question. However, they should reconsider the order of the paragraphs based on the processes they describe. In my opinion, it is more intuitive to start with the dynamics of litter decomposition, continue with the fate of N in POM and MAOM and soil solution, and finally mention the decomposition of SOM fractions and soil N mineralization.

L 93-96 This is relevant. Please briefly describe the results found in these papers.

L130 Mention which nutrients

L134-136 There are many comparisons in these hypotheses, they must be simplified

Table 1 The low C/N values catch my attention. Were you compared to unfertilized plants?

L200 Why did you put in resin capsules? It will be understood later, but it would be good to explain it here.

L211-212 did you analyze 𝝳15N of the soil-litter fragment mixture? or did you separate the litter fragments first (L221)? see comment in L267?

L246-247 It is not clear how you calculated the remaining mass. Did you use the 10 g sample mentioned in L221?

267 You should have used the 𝝳15N of the POM or the MAOM for the 𝝳treat. Soil N should be calculated as the sum of the N in the POM and MAOM and that of the solution.

Figure 2 There is a lot of information in this figure. I do not think it is necessary to show the N in the resin capsules in the control soil (it could be a supplementary figure). Panel c, based on the previous comment, I would not call it soil N, and I do not know if it is a relevant variable, maybe it would not be shown either.

Figure 3 Although I think it is interesting to fit these models, it was difficult for me to understand the importance in the analysis. Perhaps it needs to be made more explicit in the text. Can you report a measure of model fit? According to Figure 2, there is a lot of variability between species. Are not we losing it in this figure?

L378 Simplify the writing of this section

L391-392 Cite Figure 3. 196 vs. 394 days in leaf and root litter, respectively?

Figure 4 Why is it important to show the relationship between POM-N, MAOM-N and N in resin capsules? I find it better to have a bar graph or box plot for POM-N, MAOM-N showing the differences between spp and between soil fractions.

Figure 5 Why not combine panels a and b into one? The results from panel c are repeated in panel b. Why not show panel c in absolute terms and leave the relative values for d?

L462-465 To what figure or table do these results correspond? Perhaps this sentence should go next to the paragraph above.

L469 I see initial litter N and Mn, but not C in figure 6

L479-486 These two paragraphs are vague. In my opinion, what indicates the effect of initial litter quality on temporal patterns of organic N and fates are the relationships, not the variability. The fact that they used a wide variety of litter allowed us to find these relationships. What are the differences between the effects of leaf and root litter on N dynamics? How do they vary across surfaces? The latter is important, but they do not evaluate it, perhaps I would leave it for later discussion.

L487 This section is not about litter identity, but about general patterns and their implications for ecosystem functioning.

L488-489 This sentence is vague, I think this was already known. Emphasize here what this study contributes that has to do with the fate of N in solution and in the different fractions of the soil.

L521 This sentence: "We further found some evidence for a higher N release (Tab. S3)” is unfinished and disconnected from the previous sentence, which is also very long.

L597-602 The positive effect of lignin concentration on POM-N could be due to chemical rather than physical protection, due to the recalcitrance of the litter; with more lignin, the N would remain as POM in the soil.

L615-617 In which figure are these results shown?

In my opinion, you should return to the hypotheses in the discussion to discuss them in more detail. In the conclusion section, the main contributions of the work are not clear.

L633-634 I am not sure that the goal of the study is to predict the fate of N from the traits. For example, there is no trait that explains much of the amount of N in MAOM. In addition, there are general patterns across species that are interesting and should be highlighted (Fig. 3).

L639-641 This is important and could be discussed above, but I would expect a stronger message for the last sentence of the manuscript.

The manuscript addresses an interesting and little studied question. The experiment is novel and well designed. The conclusion is clear and relevant: highly degradable litter promotes rapid N cycling, immediate N availability to plants but potentially higher losses and long-term storage as MAOM-N, whereas poorly degradable litter promotes longer and lower N release and increased POM-N formation. In my opinion, the manuscript could be improved. In particular, the results need to be better linked to the discussion and the main messages. Figures 3b, c and d together give a very complete and interesting view of the dynamics of N in the litter-soil system. I think the three can be integrated and linked to the feature results in the text. I am not convinced by the variable in Figure 3c (see specific comment, L408-413), I am not sure how to interpret it. The wording needs to be improved, some sentences are long and/or confusing.

L44. I like figure 1. Why does microbial turnover go to POM? What would be the mechanism by which microbial turnover would form POM?

L84-91 I think this paragraph should give a good description of the two soil fractions and highlight their differences. I find some mistakes and missing information. See Lavallee et al. 2020. Global Change Biology. Conceptualizing soil organic matter into particulate and mineral‐associated forms to address global change in the 21st century

L145-148 “The overall distinct trait syndrome of leaf vs. fine-root litter results in different N dynamics during decomposition” and fates.

L154 Reference missing

L262 Remaining litter N alone (without initial N) does not indicate N release from decomposing litter.

L279-282 very long and confusing sentence

L365 “ across all litters” Do they refer to litter types or species? or both?

L408-413 In my opinion, litter-derived soil N is confusing and can be misinterpreted. If it includes litter N, it is not just soil N as the label says. Couldn't the remaining litter N (Fig. 3b) be subtracted to calculate the soil N? The increase in litter N in the first 10 days is quite obvious, it is simply due to the addition of litter. More interesting is the comparison between leaves and roots. My interpretation is that more (and slower) N is retained in soil and litter for roots than for leaf litter. There may be a better way to show this, as it overlaps with Fig. 3b.

L410-413 very long and confusing sentence

L430-432 and in absolute values?

L480-483 What figure/table does this paragraph refer to?

L491 What does "This dichotomy" refer to?

L494-497 This is very interesting and makes a lot of sense, but I don't understand the reasoning behind this conclusion at this point in time. I think I missed something in between the results and this conclusion. Maybe this is a bit speculative, but the way it's written, it doesn't seem like it.

L500-502 cite figures that show this

L502-503 What is the difference between this and the previous sentence?

L542-543 cite figure/table/s

L557-559 This sentence contradicts the previous one

576-578 The two phrases in this sentence are not contradictory. Rephrase without "despite

L587 The figure can be improved a little to make the message more visual. I wonder if, over a longer period of time, the retention and loss in the two scenarios might be different because MAOM has a longer residence time than POM. On the other hand, the soil has very low clay content and moderate CIC. Could the N losses be much lower if there is more clay content to form MAOM? I think this needs to be discussed in this section.

616-618 I would have liked to know this much earlier, in the methods section perhaps.

644-647 Too long sentence

649-650 Confused sentence. What do you mean with differential fate here?