Dear Authors

thank you for your response to the reviews and your marked up revised ms. I have some outstanding issues that are listed below. Please can you respond to these and revise your manuscript accordingly.

I agree with author 1 that the abstract could be improved. Please revise this text in line with the reviewer’s recommendations.

2.3. I agree with the reviewer 2 that the term "seasonal drought' is not appropriate. Please use 'dry season' instead. Please also clarify the timing of dry season at both sites to support your assertion of similar expected NEP dynamics (using figure 2).

2.4. Change “Since” to “Because”.
Please make clear here your use and comparison of the two Rhet schemes in the simulations.

Section 3. This would benefit from improved use of topic sentences to open each sub-section and paragraph. E.g. sections 3.1, 3.2, 3.3, 3.4 and 3.5 all have weak opening sentences. Please improve these to make your key point right at the start.

3.2 Break this section into two – one on C fluxes, another on Energy fluxes – to improve structuring.

3.4 I understand the concerns of the reviewer 1 about soil moisture offset between model and observations. The main message of the paper is that soil moisture controls on processes must be included in effective models. So any bias in a key variable must be a concern. I understand that observations and models must be carefully compared, but soil moisture is a relatively straightforward variable. As I said in my response to your initial submission “The mismatch between model and data in fig 7d looks significant to me, and needs careful discussion.” Please revise your text accordingly and add a section on this to the discussion.

4. Please add headings to this section to improve the structure and readability. I asked for this structure after your initial submission, so please take this seriously now.

A key issue relates to upscaling. Knowledge of the soil types and their parameterisation across the Amazon is sparse. Please discuss this scaling challenge for modelling. Also please discuss the various alternative matric models, and how they might affect your results. See for instance:

Fisher, RA, M Williams, M de Lourdes Ruivo, A L da Costa & P Meir (2008) Evaluating climatic and edaphic controls on dry season gas exchange at two Amazonian rain forest sites. Agricultural and Forest Meteorology 148: 850-861.



In a survey we made of soils around Tapajos we found very significant shifts in soil texture occurring frequently and over short distances. How can a model cope with this challenge?

Williams, M., Y.E. Shimabukuro, D.A. Herbert, S. Pardi Lacruz, C. Renno and E.B. Rastetter (2002) Heterogeneity of soils and vegetation in eastern Amazonian rain forest; implications for scaling up biomass and production. Ecosystems, 5: 692-704.


Fig. 3. Please make clear which of the Rhet models was used in the simulations (i.e. I think you used the standard scheme here).


Best wishes


Mathew Williams

Dear Authors

thank you for the changes you have made the ms, and your responses to my queries. The manuscript can now be accepted and published - congratulations.
Many thanks for your submission
best wishes

Mathew