Impact of Rhabdocline pseudotsugae and Phaeocryptopus gaeumannii on the Selection of Suitable Provenances of Douglas Fir in Central Europe

Round  1

Reviewer 1 Report

The manuscript presents some new and valuable data on the impact of two important pathogens, Rhabdocline pseudotugae and Phaeocryptopus gaeumannii, on different provenances of Douglas fir, which could be used to choose provenances better adapted for certain areas. The manuscript is well researched and written, the methodology well described and the results and discussion clear and adequate. The English language should be checked for minor errors, and both introduction and discussion could be shortened a bit.

Several minor points should be addressed:

Line 16: add scientific name for Douglas fir

Line 19: write out full name for IUFRO

Line 38: The sentence: The occurrences needle casts…  is not clear.

Figure 1: the map could be improved by inserting prominent geographic landmarks, e.g. major cities such as Vancouver, Seattle and Portland; or the international border Canada-USA

Lines 160-163 and Table 3: 3,700 nursery-raised saplings were planted in 1971, but only 704 mature trees used for assessment of growth and defoliation.  Please explain when and why numbers decreased (thinning, poor growth, diseases?).

Line 226-227: Please explain why sporulation of P. gaeumannii occurred at lower temperatures than R. pseudotugae. According to Table 2, P. gaeumannii was found mainly in July, which in most European countries is the warmest month.

Line 238-239: Don’t use the expression “entirely dead”: trees are dead or alive.

Discussion: Are there any data available on the genetic structure of the different Douglas fir provenances? And if so, are they in agreement with the observed differences in disease susceptibility?

Line 343: “The defoliation of crowns was most affected by volume. “  The sentence should be changed to reflect that the volume is not the direct cause of defoliation, but most probably only indirectly correlated to it.

Lines 359-361: 1025 is a maritime provenance, and therefore most probably it’s not surprising that it grows well in the Netherlands.

Lines 409 ff: The authors discuss the possible impact of climate change on future Douglas fir growth in Central Europe.  In this regard it would be interesting to analyze how much the climate changed already since the trees were planted in Hurky in 1971, and if any changes in tree growth vigor and disease susceptibility were observed.

 Author Response

Thanks for the overall comments. We appreciate that.

English issue: The modified version of the manuscript is now read by a native english speaker and we have incorporated his suggestions carefully . We have also checked our manuscript text via professional grammarly software to avoid typographic errors. (Please refer acknowledgement).

In the following document, we have addressed the comments, and the required changes were made in the revised version of the manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript “Impact of Rhabdocline pseudotsugae and Phaeocryptopus gaeumannii on the selection of suitable provenances of Douglas fir in Central Europe” studies the infection from two pathogens on a Douglas fir provenance trial established as a part of IUFRO experiments. The authors measured sporulation on the stand during one season, and for all provenances DBH, height, diameter difference after 5 years, dominance class and rate of defoliation. The results show that smaller trees are more susceptible to needle cast. The statistical analysis are well conducted and significant effects of the pathogens could be identified.

I had however extreme difficulties to follow the whole text which is too long and unfocused, and mostly only interesting to readership working on that specific species. The main results are not clearly stated and discussed, and the authors more or less structured their discussion on the reporting of the results from other studies. I would rather see clearly each significant result discussed one after the other, and this was only partially done at the beginning of the discussion:

-          the effect of volume on defoliation

-          the effect of defoliation on the growth

-          the difference in pathogen attack among provenances

-          growth performance of the different provenances taking into account or not needle cast

-          performance of coastal vs inland subspecies: recommendations for Central Europe

-          comparison of same provenances with other stands

This might imply that the results could be presented differently, for example separating coastal and inland provenances in the figures. I would also in the text indicate from which region of origin are the suitable or unsuitable provenances if there is any geographical pattern, that would be easier for the reader than the provenance IDs. To sum up, the manuscript requires substantial rewording before being suitable for publication.

 Specific comments:

Figure 1: the map should be in a GIS program instead of googlemaps, the labels would be easier to read, especially if the reader do not use a color copy

Figure 4 is difficult to understand

Author Response

We appreciate your comments on our manuscript.

English issue: The modified version of the manuscript is now read by a native english speaker and we have incorporated his suggestions carefully . We have also checked our manuscript text via professional grammarly software to avoid typographic errors. (Please refer acknowledgement)

In the following document, we have addressed your comments, and the required changes have been made in the revised version of the submitted manuscript.

Author Response File: Author Response.pdf