Dear Dr Perez-Quezada
Many thanks for your responses to comments made in the interactive discussion. All referees are supportive of your manuscript, and have made helpful comments to improve clarity of your main message, and detailed corrections. Your responses to referees adequately address these requests, and I’d like to ask you to implement the proposed changes in your manuscript for a final assessment.

It is clear from all referee comments that the issue of capturing diurnal variability remains a key challenge for field studies. Your proposed changes are welcome in further clarifying this. I think that you are right in stressing that there may not be a “right” window that should be used al every site, and the point that knowledge of diurnal variability and a targeted sampling strategy that takes account of this is required should be made carefully.

Your preference for using mass rather than molar units for annual respiration fluxes is fine, but please clarify whether you refer to grams of C or grams of CO2 in the figure. Using molar units avoids this problem, but when stating specifically what the mass refers to, this is acceptable.

With best regards,
Jens-Arne Subke

Dear Dr. Perez-Quezada,

Many thanks for the revised manuscript. I have read through your edits and they are all fine. In addition to these, however, I have a number of small requests, which I list below - please accommodate these in the final version, which should then be ready for publication.

I include one suggestion for adding a couple of papers for your overview of annual soil respiration studies in moist forests, which I hope is ok. If you feel strongly about not including these, that would also be fine. It may be worth indicating in the table caption in any case that this is an overview, but not exhaustive of all studies in moist forests.

With best wishes,
Jens-Arne Subke


Detailed comments:
P. 1, l .17: Delete “In this aim”; i.e. start with “We randomly selected…”

P. 1, l. 25: The phrase “In conclusion” comes too soon, as you follow this with further detail of our analysis. I suggest you delete here and may use the phrase for the last sentence (but it’s not obligatory there).

P. 2, l. 23: This should be “IRGAs”, as the A of IRGA stands for Analyser, so “IRGA analyser” doesn’t strictly make sense.

P. 2, l. 31/32: I propose different punctuation to make this clearer: “In the case of humid forests, both approaches are used, and in the case of annual estimates using manual chambers, measurements are usually done only once per day and during daytime (Table 1).”

P. 3, l. 3-5: Can I suggest a rephrasing also here to help clarity? “Temperate forests present ecosystems with a high degree of shading compared to ecosystems with sparser vegetation, including agricultural land uses. Nevertheless, variations of ±25% of the daily Rs flux have been reported for a temperate mixed hardwood forest, and mid-morning measurements identified as best suited to estimate daily mean fluxes (Davidson et al., 1998).”

P. 4, l. 13/14: Annual rainfall should be on the order of 2 m in these systems. Do you mean average daily rainfall here? Or should this in fact be “2,000 – 2,500 mm”? If you state this in metres, this avoids any confusion.

P. 4, l. 23: The depth of collars is an important issue for soil respiration measurements, as a deep insertion can affect root transport of carbohydrates to the rhizosphere. Please state here how deep the insertion of your collars was.

P. 6, equations 2 and 3: Please check this – your method of calculating standard deviations and RMSE seem identical.

P. 7, l. 11: Add units to values of soil moisture (2 instances in this line). Also please check the agreement of values stated here and Figure 4. The range shown in panel C of Figure 4 is much higher (in fact too wet to be realistic).

Table 1: In the first row, indicate what you mean by period (I presume it’s months?), and what M and A means for “Type of Sampling”.

I don’t normally request that authors cite my work, but I wonder if you consider our efforts to estimate annual soil respiration in a montane forest in Germany as fitting into your category of “humid forest”. If yes, you could include it too: (Subke J-A, Reichstein M, Tenhunen JD, 2003. Explaining temporal variation in soil CO2 efflux in a mature spruce forest in Southern Germany. Soil Biology and Biochemistry, 35, 1467-1483.) I don’t think there are implications for the text from this inclusion, and it’s purely for a more complete representation of studies in the table. Nina Buchmann estimated annual soil respiration using a non-continuous approach in the same stand (but a different year), which could also be included (Buchmann N, 2000. Biotic and abiotic factors controlling soil respiration rates in Picea abies stands Soil Biology and Biochemistry 32, 1625-1635).