Seasonal Pattern of Stem Diameter Growth of Qinghai Spruce in the Qilian Mountains, Northwestern China

Round 1

Reviewer 1 Report

Fig. 1. Incorrect color scale in the drawing, usually high areas are represented in orange-red-brown, and here green and blue are high above sea level - this should change

line 130 Eq. 4 explain what e means

line 158 CMr does not appear in the formula 5 (Eq. 5)

line 172 -173- 174 at what depth (soil temperature)?

Table 2 explain  what SE means

Fig. 4. it is worth providing an explanation why in Phases 2 and 3 for 2015 and 2016 we have opposing correlations (statistically significant) in the same months

Author Response

Dear Sir/Madam,

      Please see the attachment.

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Reviewer 2 Report

Well structured paper with a classical form.

Objectives are clear but they were more to describe the seasonal pattern than to verify an hypothesis.

Material and methods are good. The only weakness of the study is the low number of trees measured and the fact that the observations were done on only two years in an highly variable climatic environment as shown by the results. also, the age of the trees cover a large span and nothing in the disussion was found about a possible effect of the age on the growth rate of the trees. The soil description is very limited with no reference to the soil classification system used and, which is more worrying, no mention of the texture of the souil. texture is important to asses soil water holding capacity and may be important to explain the pattern of growth, especially when soil moisture is identified as a key factor. Methods and data analysis are well explained.

Results. Section 3.1 shows that the 2 years of observation were really different in terms of climatic conditions. This shows the necessity to follow the trees with more years of observations (which is mentioned in the discussion). Take care to how the word "significantly" is used (line 182), is it in statistical terms or simply an observation that 2015 and 2016 climatic patterns were really different.

In section 3.2 one interesting observation is missing: the day of maximum growth was reached after 34 and 32 days after the growth initiation respectively. This shows a certain determinism in growth even if the growth initiation started almost a month later on the second year.

Discussion is good and quite complete. However, no mention is made about the variability of growth in function of the diameter of trees or re4lative to their age. Smaller trees may have less access to light and this may induce a lower growth rate. The same appies to the older trees that may have more needs in water, therefore are more sensitive to water deficit in soil, or may show a growth decline relative to senescence. 

Important thresholds are well identified and comparison with litterature is correct.

We agree with authors that observation on more trees and for more years is necessary due to the high variability of the patterns observed in 2015 and 2016. Section 4.3 is very good.

References are relevant and cover different ecosystem with similar problematics.

Two typographic correction needed:

Line 427 : Duchesne L. (instead of Duchesnea L.).

Line 472 : 2003 should be in bold.

 

Author Response

Dear Sir/Madam,

      Please see the attachment.

Author Response File: Author Response.docx