Empirical Approach for Modelling Tree Phenology in Mixed Forests Using Remote Sensing

Round 1

Reviewer 1 Report

In this manuscript, the authors applied proper methods modeling the start of season (SOS) and the end of season (EOS) of different tree species in Slovenian mixed forests. The above methods were very reasonable, and in some sense very skillful in dealing with the multi-source data in this manuscript. I believe it is timely to readers who are interested in phenological modeling for mixed forest. The verification was relatively sufficient and most of the conclusions were reliable. I would like to suggest a minor revision decision for the manuscript. However, I have the following concerns need to be addressed by the authors.

 

My major concerns include:

1. The substitute stands were chosen by the criteria [altitude ± 200 m, slope ± 10° and aspect ± 1 class]. Why do these conditions ensure that the phenology of the substitute stand and the observation station are consistent? The reason is 200m difference in altitude may lead to more than 5 days’ error in SOS, according to “Hopkins biometeorology law”.
2. How to consider the influence of undergrowth vegetation change in mixed forest studies? Undergrowth may also affect the optimal thresholds for phenological phase extraction.

 

I have also some minor points:

1. It is suggested to add some summaries of recent studies on phenology of mixed forests in the introduction.
2. Line 145-146, does it mean the interested species present as a secondary species in the rest of the pixel? Then, what is the dominant species, and why isn’t the dominant species contributing substantially to the pixel value.
3. Figure 5, how to get the fractional land share of each land cover type. It shows that species of interest have relatively low land share, so it may not contribute substantially to the pixel value.
4. Figure 6, It is suggested to unify the ordinate to make it more clear.

Author Response

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Reviewer 2 Report

Attached

Comments for author File: Comments.pdf

Author Response

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Reviewer 3 Report

Dear all,

Thank you for the opportunity to read this paper.

I think this paper is well structured even if some aspects should be clarified. Specifically, the below aspects should be addressed by the author before publication.

SPECIFIC COMMENTS:

Abstract: Could the authors reword the initial sentence in line 11? I think it needs to be clarified and explained better.

Could authors report in the Abstract the novelty of the study?

Line 36: I think it is effective in the introduction to add a brief description of what is meant by phenological observations and explore how they are used to study climate change.

Line 58: Some references?

Line 109: Is there a reason for the choice of these species? Can it be reported?

Line 130: How were they geolocated? Always by satellite?

Author Response

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Author Response File: Author Response.docx