The Influence of Minimal Cultivation Techniques on Growth Rate of Robinia pseudacacia L. Seedlings

Round 1

Reviewer 1 Report

The authors have carried out a very interesting study linked to 2 pressing problems of our time. The first is climate change, which is altering habitats and threatening the existence of many plant and animal species. The second is the problem of the increasing number of disturbed areas that need to be restored. The research of the authors of the paper will be useful in solving these problems. Therefore, the topic of this paper is relevant.

The scientific novelty lies in the identification of the influence of different substrates and their humidification conditions on seed germination, seedling survival and young plant growth of Robinia pseudoacacia L.

The research results are theoretically important for understanding the adaptability of Robinia pseudoacacia L. A practical application of the results of the research can be found in the restoration of disturbed areas.

The title of the paper is too long. I suggest that the authors think about improving it.

The relevance of the study is well argued in the introduction. The state of the problem is described in detail. The research objectives are clearly stated.

Line 42-43. "The growth and development of black locust plants are influenced by physical and chemical properties of the soil [10–12]". This is a known fact. Formulate the unsolved problem more clearly.

The methodology approaches are described in detail. The authors described in detail Study site, seed source of provenance and plant materia, Humidity regimes, Substrate, Experimental design, Data and statistical analyses. The experiment is quite complicated, so I suggest illustrating it in the form of an experimental diagram. This will make the paper easier to understand. The authors used methods adequate to the tasks set. The experiment is quite well-designed. The study design is good. Data analyzed for seedlings height was statistically processed using one-way analysis of variance (ANOVA). The height and diameter of the seedlings was statistically processed by applying the Duncan test. To compare seedlings traits under the condition of different treatments the T-test was applied.

The research results are illustrated with figures and tables that are informative and do not duplicate each other. The paper contains 11 informative tables and 4 visual figures. The results are presented clearly. The visualization is acceptable.

The discussion needs to be improved. The Discussion section is an important part of the paper. It is here that the authors should determine the place of their research in world science, compare the results obtained with those of other studies, including those carried out in other countries and climatic zones, explain the strengths of the approaches used, the novelty, the practical and theoretical significance of the results.

Conclusions are drawn from the results. However, this section also needs to be improved. The conclusions should be formulated more clearly so that the theoretical and practical significance of the research results is clear. The paper will be of interest to a wide range of readers whose scientific interests are related to Robinia pseudoacacia. Despite the fact that English is not my native language, I read the paper with interest and had no difficulties in understanding. 

Author Response

Thank you for your comments and suggestions which have helped us to significantly improve the paper. We have prepared a reviewed version of the article, taking into account your suggestions. In our perspective, the new version of the paper is more fully developed. We sincerely hope that you will also share this view.

Thank you again for your comments, which have helped us to substantially improve the paper, as well as for all the time you have devoted to this article.

                                                                                    The authors!

Author Response File: Author Response.pdf

Reviewer 2 Report

The Robinia pseudoacacia now rivals hybrid poplars (Populus spp.) as the second most planted broadleaved tree species in the world after Eucalyptus spp. This wide-spreading planting is because black locust is an important multipurpose species, producing wood, fodder, and a source of honey as well as bio-oil and biomass. It is also important for carbon sequestration, soil stabilization and re-vegetation of landfills, mining areas and wastelands, in biotherapy and landscaping. 

In the manuscript presented by Cristina Draghici et al. the growth of black locust seedlings on different types of substrate with different texture and pH was analyzed, in three different regimes of available water content during five months. The experiment used seeds from three sources located in the south-east, southern and western Romania.

The manuscript is written in good style. It is written in simple language.

In this review, I offer a few suggestions as to where certain points can be elaborated upon or revised in the manuscript.

 Detailed comments:

1.      Lines 2-4: Please rephrase the title. The title should be short.

2.      Lines 30-236: Introduction needs to be improved. In the manuscript submitted for review, the authors critically reviewed the existing knowledge on the Robinia pseudoacacia. Some detailed descriptions may be omitted.

3.      Lines 227–236: Please complete with hypotheses.

4.      Figure 1. On a green background, the red font color is illegible.

5.      Tables 3 and 4: Formatting the unit (me/100 g)

6.      Figure 4. Improve the quality of Figure.

7.      Reference Lines 486-613: References  not prepared in accordance with the requirements journal Forests.

Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range.

8.      The authors did not provide the publication's DOI numbers or the Uniform Resource Locator (URL) in the reference list, consequently making it  difficult to find the quoted publication.

Author Response

Thank you for your comments and suggestions which have helped us to significantly improve the paper. We have prepared a reviewed version of the article, taking into account your suggestions. In our perspective, the new version of the paper is more fully developed. We sincerely hope that you will also share this view.

Thank you again for your comments, which have helped us to substantially improve the paper, as well as for all the time you have devoted to this article.

                                                                                    The authors!

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper entitled “Preliminary results regarding the influence of growing minimal technologies upon Robinia pseudoacacia L. seedlings used for afforestation or public green spaces development projects” covers the topic of seedling production. The document needs structuring and clarifications in the introduction, materials and methods, results, and discussion (see comments). Therefore, major changes are recommended.

Comments

1) Introduction – the information needs to be organised. It should be focused on the state of the art regarding the theme addressed in this study. The objectives of the study should be clear.

2) Lines 65-70 – text needs to be improved. How does it relate to the present study?

3) Lines 100-118 - text needs to be improved. How does it relate to the present study?

4) Line 118 – reference seems to be missing.

5) Lines 119-135 - text needs to be improved.

6) Lines 212-215, 221-222, 222-226 – references seem to be missing.

7) Line 216 – instead of “our country” use the name of the country.

8) Lines 231-236 – state the objectives clearly and the questions to be answered.

9) Materials and methods need structuring and standardisation. It is not easy to follow the materials and the methodology used.

10) Figure 1 – quality needs to be improved. The text in yellow and red is hard to read.

11) solarium or greenhouse?

12) Lines 262-281 – the text needs standardisation.

13) The authors used the acronym Bi (i=1, …,8) for the treatments. But different terms are used along the text for each treatment. Please standardise.

14) Lines 296-297 – further details are needed.

15) Line 302 – further details are needed.

16) Lines 307-308 – 70%, 50% and 30% of what?

17) Lines 327-329 – figure caption does not correspond to the images of Figure 2

18) Line 345 – The authors are referring to base diameter or diameter at breast height?

19) Lines 345-347 – the text is not clear. Please clarify.

20) Lines 349-353 – the statistical analysis is not complete, some of it is missing. In this section, the authors should describe in detail all the statistical tests used. Also, the software should be included.

21) Table 5 – consider changing this table to the results section.

22) Table 6 – include the information on the seedling emergence day after sowing (7^th, 14^th and 21^th) in the materials and methods section.

23) Tables 7, 8, 10, 11 – the meaning of the letters should be included in the figure caption.

24) Lines 375-378 – please check English.

25) Table 8 – growth or height? It is not clear whether the results are from all the sites or not. Please clarify also in the text.

26) Lines 380-390 – check for inconsistencies between the text and Table 9.

27) Lines 408-417 – please clarify the text.

28) The results section should be thoroughly checked and structured. Also, it seems that some results are poorly described, such as the diameter analysis and the field sowing.

29) Lines 456-459 – where is this data presented in the results?

30) Lines 462-472 – what is the justification for the higher heights in the field sowing?

31) Lines 473-479- justification missing

32) Lines 485-490 – discussion is missing

33) Line 508 – how were the physiological processes evaluated?

34) In the discussion section the results of this study should be separated from former published studies. The section lacks structuring as well as some justification.

35) The conclusions section needs to be improved. Summarise the results of this study.

Extensive editing of English language required

Author Response

Thank you for your comments and suggestions which have helped us to significantly improve the paper. We have prepared a reviewed version of the article, taking into account your suggestions. In our perspective, the new version of the paper is more fully developed. We sincerely hope that you will also share this view.

Thank you again for your comments, which have helped us to substantially improve the paper, as well as for all the time you have devoted to this article.

                                                                                    The authors!

Author Response File: Author Response.pdf

Reviewer 4 Report

Dear authors,

Although the Black locust is regarded as an invasive species in many ecosystems, it has a potential to be used in landscaping activities. Your work is interesting but the manuscript still needs some corrections to be made as follows:

1) Lines 57-60: Please, check again this sentence "Therefore, coarse, sandy, airy, permeable, neutral or slightly acidic soils are favorable for growing black locust seedlings, while clayey, compact, battered, carbonate-rich soils are not contraindicated for its culture." I am not sure to understand what wo you mean here - are or are not contraindicated?

2) Lines 67-70: Please, check again these sentences "Analysis of high-quality Robinia pseudoacacia L. containerized seedlings was conducted using seeds from two sources (Greek and Hungarian provenance) [18] and (seed source for Cupressus sempervirens L. seedlings [19]). The black locust seeds of Cyprus provenance had higher survival rates compared to seeds from Greece". If you have studied seeds from two sources (Greek and Hungarian), why do you compare with a third one (Cyprus)? Or there is something missing in the text of the first sentence?

3) Lines 264-266: Please, add the measurement units for NPK content in substrates used.

4) lines 342-343: I can not understand your experimental design. You have mentioned that "In solarium, the experiment was applied in 54 repeats according to the 3x8x3x54 model (3 seed source of provenance; 8 types of substrate; 3 humidity regimes)" - if you have 3 seed sources by 8 types of substrate this is equal to 24 pots. Afterthat, 24 multiplyed by 3 types of watering is equal to 72, not to 54. Furthermore, aren't they any replications of each experimental variant?

Generally, the Result, Discussion and Conclusion sections are well done, but the tables and figures should be reffered in the text before to be inserted in it.

Author Response

Thank you for your comments and suggestions which have helped us to significantly improve the paper. We have prepared a reviewed version of the article, taking into account your suggestions. In our perspective, the new version of the paper is more fully developed. We sincerely hope that you will also share this view.

Thank you again for your comments, which have helped us to substantially improve the paper, as well as for all the time you have devoted to this article.

                                                                                    The authors!

Author Response File: Author Response.pdf

Reviewer 5 Report

This paper explores local conditions (potting mixes, growing environment, seed sources for an introduced species) and watering on growth and survival of black locust seedlings. Although the paper uses terminology around drought, no physiological measurement to assess water deficit was undertaken. This limits the usefulness of the findings to nursery managers and researchers outside the area where the study was undertaken. The paper needs major revision. I have provided some of the matters needing attention in the following text.

The title can be simplified and reworded.

The Introduction is far too long and discursive. It should be rewritten, providing a brief introduction of containerized seedling production in forestry, and a more succinct appraisal of locust nursery production and the priority research gaps that would benefit from experimentation to provide practical outcomes. The research aims and objectives can be more strongly linked to the previous published accounts for this afforestation species. This species is produced in forest nurseries in many regions where afforestation projects have been in place for decades. No clear argument is given for wanting to test the watering regime in this study.

The results section must be restructured with clear and more complete information (see the following points). Please replace solarium with plastic tunnel house or greenhouse or similar term. Was it a production nursery – what is the standard practice in the region for raising tree seedlings? Data on the light quality (PAI) must be included. For providing details of the experiments, this is best done under subheadings: Nursery trial; Field trials. Combining the two is a little confusing to the reader. For the field sites, consider providing the minimum and maximum temperatures to complement the average. Table 2 can be moved into the supplementary material as there is no obvious difference between the seed lots used in the study. In Table 3 state how many replicate soil samples were used for the measurements. As most readers do not have access to “according with the protocol of soil science laboratory of the Faculty of Forestry from Brașov City”, the methods must be provided in Table 3 as a footnote. It is unclear whether the data in Table 4 is background to the field trials or solarium experiment. If the former, it should be included in Table 2. If the latter, it should be moved into the section regarding establishing the field trials. Lines 305-208 do not provide sufficient information on the watering regimes that were used. The percentages given are confusing – what do they refer to? How was the water applied – wicking from below or gravimetrically from above? By hand or automatic misting? What was the frequency of watering? Note that when containers are watered the content quickly comes to field capacity. If insufficient water is applied there may be areas within the container that are at field capacity and others that are below field capacity. Please rewrite this so that it can be repeated exactly by others. I recommend replacing the word humidity with more appropriate soil science terminology. Figure 2a – only 1 image is necessary here and it should be a close up of the trays with emergent seedlings – the word description can be deleted as the description lies within the earlier text. Figure 2b is a general picture and does not show the design. Figure 2b shows shade cloth suspended above the plants – mention this in the text and state when and why it was used. The quality of Figure 2c is rather poor – what is its purpose? What is all the foreign material on the surface of the soil? What is the age and height of the plants? The experiment design of the nursery and field trials have not been provided. Were they fully randomized block or RCB design? Line 342 mentions 54 repeats – is this referring to trays or individuals? How was the experiment laid out – how many blocks? Often there is a gradient of environmental conditions in greenhouses and tunnel houses – was this taken into account when laying out the design? The designs and layouts of the experiments should be given in separate subsection for the nursery and field trials, as mentioned earlier. When were the field trials undertaken? Under what conditions?

The results section needs revising. Note that it is standard practice to describe significant interaction effects before describing single factor effects. Therefore, restructure the results on plant growth. In general, figures and tables should stand alone and provide enough information to be fully understood. As an example, Table 7 caption should mention which experiment, state in a footnote that values within a column (n= ) with the same letter are not different by Duncans multiple range test (P = ). Please use the active voice when describing results. For example, in place of “The seedling heights from peat MKS 3 and O.S. Săcueni recorded increases by 5.06 cm lower than peat MKS 1” write “Seedlings in peat MKS 3 and O.S. Săcueni substrates were 5 cm shorter than in  “. The data on germination is not so interesting in this paper as the trials were done with equal number of seedlings using thinning. I can be moved into supplementary materials. What are the error bars in Figure 3 (SE or SD?) – consider adding statistical analysis into this figure. The terms “medium drought” and “severe drought” should be defined with regard to either plant water relations or soil water content. In Figure 4 it is evident that seedling mortality occurred, and it varied with treatment. The manuscript must explain whether dead seedlings were excluded or included in the ANOVA. Indeed, this section of the results should be presented first, before seedling growth.

Include in the discussion the criteria used in commercial nursery protocols regarding the desirable seedling dimensions for out-planting of this species (e.g. height, form, diameter). Did the plants grown in these trials meet expectations.

The English must be improved. Also, there are spelling errors in some figures.

Spelling, syntax and grammar require attention in parts.

Author Response

Thank you for your comments and suggestions which have helped us to significantly improve the paper. We have prepared a reviewed version of the article, taking into account your suggestions. In our perspective, the new version of the paper is more fully developed. We sincerely hope that you will also share this view.

Thank you again for your comments, which have helped us to substantially improve the paper, as well as for all the time you have devoted to this article.

                                                                                    The authors!

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors responded to all my comments and significantly improved the paper. I have no further comments.

Author Response

Thank you very much!

   The Authors!

Author Response File: Author Response.pdf

Reviewer 3 Report

Revision 2

The authors answered most of the reviewer’s questions. Yet, some minor issues should be addressed. So minor changes are recommended.

Comments

1) Software used should be included in the text.

2) Table 5 – consider changing this table to the results section.

Moderate editing of English language required

Author Response

Thank you very much!

   The Authors!

Author Response File: Author Response.pdf

Reviewer 5 Report

The authors have substantially improved the manuscript.

There are just a small number of edits to be made.

1. It is not obvious where the three field condition experiments were located - were they within existing forest nurseries, or another place? Add this to Line 227.

2. In the footnotes to tables, where relevant, state "Within a column, the means ..." so it is clear that the post hoc test have been done separately.

3. The Conclusions section should be redrafted. At present it reads like a summary. Try and focus on the big issues here (small details belong in the Discussion) including the contrast between the greenhouse and outdoors experiments (what approach do you recommend for growing these seedlings in your country in the future?). How about seed sources - what does your study conclude? I hope these pointers help you to have a shorter and more powerful conclusion section.

Please check the text carefully for obvious errors in syntax such as Line 35: .. suitable for what?

Author Response

Thank you very much!

   The Authors!

Author Response File: Author Response.pdf