Effects of Planting Position, Seedling Size, and Organic Nitrogen Fertilization on the Establishment of Scots Pine (Pinus sylvestris L.) and Norway Spruce (Picea abies (L.) Karst) Seedlings

Round 1

Reviewer 1 Report

It is an interesting work with valuable information. The authors tested different plantation methods according to the preparation of the surface soil, this is the O and the A horizon. They also included treatments with N-fertilization and explained their results according to the frequency of attack by Hylobius abietis.

It is a study with two species, nine planting treatments and additionally the plant used for in field was produced in three container sizes. In this way the size of the seedlings was another study factor. This complexity results in a very long document and for this reason authors should use more direct language and try to make a shorter document, highlighting only the most important.

Specific suggestions are included in the attached pdf document.

Comments for author File: Comments.pdf

Use direct language. Avoid introductory sentences.

Author Response

Dear reviewer 1,

Thank you for considering this work for publishing, and for the many useful comments that improved the manuscript.

I have now shortened the document, highlighting only the most important results. For this reason, I removed some results from the main document result section that did not add any specific additional information regarding the effects of planting positions and effect of arginine-phosphate addition on establishment of the seedlings to make it more available for the reader, and re-wrote some sections:

• I removed results regarding the harvested seedlings root + shoot dry-weights (for the reader that want to know more about this, the separate analyses of root dry-weight and shoot dry-weight are available in the appendix).
• I removed results regarding multiple top shoots on pine and the discussion part regarding this topic since this was not a result related to the hypotheses.
• I removed the percentage growth increase from the original seedlings’ sizes (since this table do not present a statistical analysis and the seedling sizes are not directly compared regarding growth measurements), and also where this previously was mentioned in the discussion and conclusion.
• I removed the information of analyses of pine weevil damage effect on growth from the material and methods section since this was not included in the results.
• I rationalized information of seedling development records, removing information that were not related to the presented results.
• For the figures, I rationalized previous figure 3 and 4 to one figure since it was no effect of seedling size.
• I rationalized the text describing the results for survival to match the new figure 3, lines 289-292 (previously lines 325-335) as well as moving the text section before table 4.
• I replaced all figures, making the graphs larger to make them more readable.
• I renumbered all figures following figure 3, due to the change in number of figures.
• I re-wrote the growth results in a shorter, more straight-forward way.

Further, I have adjusted in the text accordingly to most suggestions in the pdf. Below follows answers to the comments where I did not use the direct suggestion:

• Line 4 (Title), the suggestion of “plantations” was not used, since in regenerated forest is not referred to as plantations in Swedish forestry. Instead, I wrote “seedlings”.
• Line 40, I switched from the suggested “…soil nutrients and water…” to “…water and soil nutrients…”.
• Line 66-67 (previously line 73) where the previous text (“Furrows, patches, and the patch/depression”) was highlighted without suggestion of replacement, I re-formulated the first part of that sentence from “Furrows, patches, and the patch/depression adjacent to mounds present exposed mineral soil…” to “The exposed mineral soil areas adjacent to the capped mounds provide…”
• Line 97 (previously 98) there was a suggestion of replacing “hinge” with “shoulder”. I did not replace it because it is called “gångjärn” (= hinge in Swedish), and I would like to keep that description to stay coherent with Swedish translations. “Shoulder” is more likely to be mistaken to be at any side of the capped mound, while “hinge” more clearly describe that it is the position where the moved soil package was turned up from.
• Line 123 (previously line 124) I replaced “mesic” with “moister” instead of the suggested “wettest”, as it was not really wet, but not as dry as the area described as drier in the previous sentence.
• Line 142 (previous line 143), in figure 2, I replaced the illustration of the planting positions with a better one and marked up the positions with names in the illustration as suggested. Photos of the positions are less illustrative; it is often not easy to see which position is which since they ideally are all covered by mineral soil. All capped mounds also look very different; hence one single photo would not be representative to illustrate the principle of the positions. However, I added a photo in figure 2 as an example of how the planting positions could look in the field as a compelemt to the schematic illustration. I also added photos of different seedling sizes and the Potiputki pipe with argrow dispenser as more photos was asked for by reviewer 2.

• Table 2 (previously lines 196-201) is now removed, since the classification assessment was described overly detailed and made the methods section difficult to understand.

I for this reason now also re-written how the positions was assessed (line 181-195) and shortened it to that positions where organic material was close to the seedling were sorted aside as a separate low-quality group due to the higher amount of pine weevil damage for the seedlings planted in this position instead of describing the detailed 1-9 assessment classes. I have also removed all references to the 1-9 classification system in captions. I also removed table 3 (previously line 203), since this was also details of the classification 1-9 system (number of seedlings planted per class).

• Previous lines 298-300 were underlined, but with no comment on why. This part is removed now since the effect of pine weevil damage of growth was not a main interest of the study.
• Lines 268-269 (previously lines 312-313) the suggested change of the sentence (..results were more focused on the technical details than on the best economical effectiveness) do not reflect the intended meaning, the trial is as many trials biased in the way that more care has been taken to assure good results than in commercial planting, so yes, maybe economically effectiveness for the planters but as the regeneration results may be poorer it is not economical effectiveness for the forest owner. So, eventually I only added the word “regeneration” instead of replacing the sentence.
• Lines 296-297 (previously lines 359-361) were underlined, but with no comment on why. I have therefore left them as they were.
• Lines 515-516 (previously 625-626) regarding the comment “This is not consistent with your revison. You said that after the seedling reach 10-12 mm in basal diameter the attack decrease. See line 64-66”. In the referred lines (now line 57-58) it says “…the threat of lethal pine weevil damage is highest before the seedling reaches a stem basal diameter of 10-12 mm”. So, the referred lines do not say that attack decrease with size, it says that the risk of the damage to be lethal decreases as the seedling grows bigger. One bite of a pine weevil is a higher percentage of a thin stem circumference then a thicker stem, the risk of being girdled therefore decrease with seedling size. Hence, a larger seedling can withstand more bites, it does not mean that it does not attract more weevils.
• Lines (previously lines 788-789) were underlined, but with no comment on why. I reformulated the sentence and added a sentence before to clarify that the capped mound has been considered the optimal planting position. Then it becomes clearer to the reader why I talk about this position as being perceived as optimal.

Reviewer 2 Report

Reforestation, especially on uneven terrain, is quite a difficult task, when planning, it is necessary to take into account the technical limitations imposed by natural production conditions, as well as the environmental consequences of previously carried out work on them works, etc. The article discusses promising technologies for carrying out reforestation work, which is undoubtedly a relevant and important research issue.

However, there are some remarks that need to be noted1. Lines 107-108 - point 3 is missing.

2. In the caption to Fig. 2, the words on the left and right should be replaced with separate numbering in Fig. 2a and Fig. 2b. Photo 2, namely its second part on the right, is very difficult to understand; even with a description, it is difficult to understand what is shown on it. It might be worth adding arrows to indicate objects or parts in the photo.

3. Photos and drawings 1 and 2 are of very low quality.

4. In the materials and methods section, table No. 1 is presented, which presents the values of some of the estimated plant parameters; the triple value for each indicator raises questions, is this some kind of sampling? Or average? If these are comparative characteristics within one parameter, then I would like to see statistical processing of the data. This table also shows the sizes of the cells; what units of measurement are indicated? If these are micrometers, then why is the generally accepted designation μm not used?

5. It seems to me that the materials and methods section needs to be reworked and made more accessible to understanding, perhaps some of the material should be visualized. The same phrases, options and indicators are often repeated, which greatly hinders the perception of this section. It would also be nice to take photographs of the pipes in which the plants were planted and into which fertilizer was added, the plants and the variants of the mounds that are mentioned.

6. Also in the text there is an excessively large number of tables with options that are difficult to understand; perhaps some of them could be visualized differently?

In general, the entire article is difficult to read and understand; there are constantly repeated phrases that are confusing. There is not enough visual material. The discussion is very vague and not specific. It seems to me that the article needs to be reworked and presented in a more accessible version.

Author Response

Thank you for considering this work for publishing, and for the remarks that improved the quality of the manuscript.

Below my replies follow each remark:

1. Lines 107-108 - point 3 is missing.

Reply: This is now adjusted (now lines 108-109). I reformulated the hypotheses and unfortuately forgot to adjust the numbering.

2. In the caption to Fig. 2, the words on the left and right should be replaced with separate numbering in Fig. 2a and Fig. 2b. Photo 2, namely its second part on the right, is very difficult to understand; even with a description, it is difficult to understand what is shown on it. It might be worth adding arrows to indicate objects or parts in the photo.

Reply: The words left and right are now replaced with separate numbering. Dashed lines in now marks out the top surface (in red) and the organic layer (in yellow) and dotted blue line marks out the seedling root substrate.

3. Photos and drawings 1 and 2 are of very low quality.

Reply: The photos and drawings in figures 1 and 2 are now replaced. The drawing in figure 2 is replaced by another illustration.

4. In the materials and methods section, table No. 1 is presented, which presents the values of some of the estimated plant parameters; the triple value for each indicator raises questions, is this some kind of sampling? Or average? If these are comparative characteristics within one parameter, then I would like to see statistical processing of the data. This table also shows the sizes of the cells; what units of measurement are indicated? If these are micrometers, then why is the generally accepted designation μm not used?

Reply: The triple value is the three different seedling sizes, this is now specified in the caption: “Seedling sizes are defined by the volume of the container cells they were grown in, measured in cubic centimeters.” It is also clarified in the table, replacing “Cell size” with “Container cell volume (cm³)”. Cubic centimers are sometimes in popular Swedish texts shortened “cc” instead of “cm³”, why “cc” is used in the definitions of the different seedling sizes. I have now also photos in figure 2 to show the different seedling sizes used in the experiment.

5. It seems to me that the materials and methods section needs to be reworked and made more accessible to understanding, perhaps some of the material should be visualized. The same phrases, options and indicators are often repeated, which greatly hinders the perception of this section. It would also be nice to take photographs of the pipes in which the plants were planted and into which fertilizer was added, the plants and the variants of the mounds that are mentioned.

Reply: I have now re-worked the part of the material and methods section regadring the quality assessment (lines 188-206), by decsribing the grouping of planting positions in high and low quality in a simpler way. I removed the description of the 1-9 classification that was initially used since this descripition was overly detailed and not necessary to include in such detail. This was also removed from captions and discussion. I also reworked the part regarding statistsics to make it shorter and simpler, excluding the exploratory part that helped define which was low quality positions (lines 239-265). I included photograph of the planting pipe with dispenser in figure 2 as well as an example of how the planting positions could look in the field as a compelemt to the schematic illustration.

6. Also in the text there is an excessively large number of tables with options that are difficult to understand; perhaps some of them could be visualized differently?

Reply: In tables describing the ANOVA results on growth, the total dry weight analysis is now removed which makes those tables less busy. The table of relative growth of the seedlings is removed from the results, since this was not a statistical result, only a comparison that I realized is not necessary. The table with the 1-9 assessment is also removed. The table and figures for multiple shoots are also removed (formerly table 10, fig. 14), as well as table and figure for total dryweight (formerly figures 9 and 12) due to suggestion of reviewer 1 to focus on the main results. Unfortunately, without getting examples of which options that are difficult to understand, I cannot improve them. However, at least there are less tables now.

In general, the entire article is difficult to read and understand; there are constantly repeated phrases that are confusing. There is not enough visual material. The discussion is very vague and not specific. It seems to me that the article needs to be reworked and presented in a more accessible version.

Reply: It is hard to improve the article from a general remark that it is difficult to read, when no examples of which phrases are confusing, and with no examples of what parts are difficult to understand. However, I have added more visual material as asked for, with example of seedling sizes, an example how a group of seedlings in mineral soil, hinge and capped mound look in real life and a photo of the planting tube with argrow dispenser, in figure 2. It is also hard to know how to make the discussion less vague, without some examples of what is perceived as vague. However, I have now reworked parts of the discussion to make it shorter, hopefully this work will make it easier to understand. The discussion part regarding multiple top shoots on pine may have been a big part of making the discussion vague, since that part strayed away from the original hypotheses, and this part is now removed.

Round 2

Reviewer 1 Report

I found this version of the manuscript interesting to be published. The authors tested different planting positions that are common to identify in a soil preparation practice. They included two species and seedlings grew in different size containers. Fertilization treatments were also considered. The review issues of the first round were attended. One novelty of the work is the fact of evaluating the damage by pine weevil (Hylobius abietis L.). Apparently, there is no connection between the attack by insects and the micro-environment of the plantation site, but this work shows interesting results.

The English of the document is understandable. Although the style could be more direct to shorten the manuscript.

Reviewer 2 Report

I thank the authors for their attentive attitude to my comments and the corrections made.

Now the article looks more structured, Fig. 2 became clearer.

I have no more comments.

I wish you good luck in your future work.