Dear Authors
Thank you very much for taking the time for carefully responding to the two reviews and changing the manuscript accordingly. Many of the requested changes and explanations overlapped among the two reviews and you used these comments to improve the presentation of the method and the data used.
In some cases I was not sure that your explanations answered the questions very well, and for this reason I decided to ask one of the reviewers for evaluation. But in addition to what might come I’d like to ask you to carefully consider the following points:
1- I was missing the critical discussion of the implicit assumption that one single model should be able to describe phenology across an entire continent, i.e. comprising different species and climates and ecological factors. That phenology at different locations and in differing species is driven by different drivers in differing ways is at least more likely.
2- Now, after you have mapped some model residuals, you should also use the information to critically discuss your work in the main text. If I interpret your supplementary graphs correctly they show distinct patterns, which shows that there is still systematic bias which needs to be carefully analysed, explained and discussed. This discussion should also include that the observed distribution of residuals might be and expression of heteroscedasticity which compromises the estimation of unbiased regression parameters.
3- The figure captions in the supplementary material are by far nor complete enough for understanding the figures (units, data sources, which test? ...). If you don’t exactly explain what you present, the presentation is useless. Please make sure that if it should come to a third revision to present it in appropriate quality.
4- I was surprised that the residuals maps are only limited to a small number of points, I guess, where you have ground observations. You trained the model with the satellite derived LSPs, so why don’t you present the residual maps that cover the entire continent.
5- Supporting strongly the point of Reviewer 2 on model selection (ref Figure 3): a) The selection of additional models should be depending on the gain of model performance (not necessarily on R^2 only). If the performance does not increase with increasing degrees of freedoms, using more complex models doesn’t make sense. b) Do you have any indication for the distribution of residuals or the RMSE having improved using more complex models.
6- In Figures 5 the regressions are performed including two separated data domains (positive, negative fluctuations) . a) Why did you not use the entire data set including small and zero fluctuations? b) Please give the regressions for the variation within the domains. You will see the difference and will look at your results in a different way.
7- When you speak of ‘temporal variability’, it is interannual variability that you mean?
8- You speak several times of ‘biological scales’, without defining or explaining what you mean. In fact I don’t exactly understand what you want to say with this.

Best wishes,
Andreas Ibrom, Associate Editor

Dear Authors
I have now received an external review on your revision. The reviewer has acknowledged improvement but still has some urgent questions, which I ask you to clarify.
Sincerely,
Andreas Ibrom

Dear Authors

thank you for your very satisfying response to the second review of reviewer 1.

Please include these clarifications in the text of the discussion to help readers understanding the difference when looking at relative fluctuations as compared to looking at exact absolute timing.

After you have done this, please provide me with a with a marked-up manuscript version relative to the latest version that has been reviewed (track changes in Word, latexdiff in LaTeX, converted into a *.pdf , see http://www.biogeosciences.net/for_authors/manuscript_preparation.html)

With kind regards,
Andreas Ibrom, Associate Editor

Dear Authors,

thank you for your patient and careful responses to the reviewer comments and respective improvements of the manuscript.

I'm pleased to inform you that your manuscript is now accepted for publication in Biogeosciences.

With kind regards,
Andreas Ibrom, Associate Editor