New Technologies for Expedited Forest Inventory Using Smartphone Applications
, Maria Emilia Silva 3, Jorge Cunha 2, Susana Morais 4, Alexandra Marques 2, André Ferreira 5, José Luis Lousada 6 and Teresa Fonseca 7,8
Round 1
Reviewer 1 Report
General remarks of the reviewer
Title: The title of the article is accurate and directly relates to the purpose of the research.
Abstract: Gives a good overview of the work.
Keywords: The keywords are specific to the topic under study, write in lower case.
Introduction: At the end of the introduction, please clearly articulate the research goal and working hypotheses.
Materials and Methods:
2.1. Study Area
In Figure 1, add GIS coordinates.
Results: Good statistical analysis of the results.
Discussions: The results have been commented extensively, but unfortunately confronted with the research of other authors much more modestly.
Conclusions: The conclusions are constructive.
Technical Notes
Make the Figures clearer if possible.
The description of the literature item needs to be corrected as required by the publisher: articles, books and other sources - italics of journal titles, year in bold, correct pages of journals and the access link and date of access in English. According to MDPI standard.
Details in the attached manuscript.
Comments for author File: 
Comments.pdf
Minor editing of English language required.
Author Response
Reviewer 1
Response to Comments
The Reviewer made comments and suggested improvements. All the comments and questions are answered point by point. The authors thank the Reviewer for their comments which will contribute to improve this manuscript.
The authors’ answers are in blue. In the text the modifications are highlighted in yellow.
Comments and Suggestions for Authors
General remarks of the reviewer
Title: The title of the article is accurate and directly relates to the purpose of the research.
Answer: Thank you.
Abstract: Gives a good overview of the work.
Answer: Thank you.
Keywords: The keywords are specific to the topic under study, write in lower case.
Answer: The authors made the suggested amendments.
Introduction: At the end of the introduction, please clearly articulate the research goal and working hypotheses.
Answer: The authors followed the suggestion. The paragraph was revised. Two new sentences were added: “The working hypotheses are: (i) there will be no significant difference in the precision of DBH measurements between the three smartphone applications.; (ii) the measurements obtained from the smartphone applications will show a high level of consistency with the results derived from traditional forest inventory methods. These hypotheses will guide the study and help evaluate the effectiveness of the smartphone applications in assessing the DBH, considering their accuracy, consistency with traditional methods, and potential differences among the available applications.”
Materials and Methods:
2.1. Study Area
In Figure 1, add GIS coordinates.
Answer: The authors are grateful for the observation and followed the suggestion. The image was replaced. The new image shows the GIS coordinates, as suggested.
Results: Good statistical analysis of the results.
Answer: Thank you for your comment.
Discussions: The results have been commented extensively, but unfortunately confronted with the research of other authors much more modestly.
Answer: The authors acknowledge the comment. The authors tried to use relevant research but there are few studies in the field that could be used to support the discussion section. The authors appreciate if the reviewer might eventually know further studies which may be included in this study.
Conclusions: The conclusions are constructive.
Answer: Thank you for your comment.
Technical Notes
Make the Figures clearer if possible.
Answer: The figures have been improved
The description of the literature item needs to be corrected as required by the publisher: articles, books and other sources - italics of journal titles, year in bold, correct pages of journals and the access link and date of access in English. According to MDPI standard.
Answer: The amendments were made.
Details in the attached manuscript.
Answer: The amendments were made.
*
We would like to express our gratitude to the Reviewer 1 for the time spent reviewing our manuscript and for providing us with valuable feedback. Their comments were greatly appreciated, and we believe they have significantly contributed to improving the quality and effectiveness of our work.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The study described in the article seems to be interesting in the meaning of professional outlook, and can appear valuable for forest inventory practitioners. The study logic is clear in general, formalized conclusion on studied objects is provided. The language style and quality are appropriate.
Main drawback of the article text presented for reviewing is the absolute absence of editing work provided before text sending. Despite the remark in rows 825 and 829-830 (“writing—review and editing…” and “All authors have read and agreed to the published version of the manuscript”), the text is full of numerous misprints, mistakes and style violations of different types. Such a presenting quality can be detected as a disrespect to the reader. Due to this, the text cannot be recommended for publishing till the detailed and accurate technical editing will be made:
- email addresses in rows 7-14 – different styles (active/nonactive);
- lost whitespaces in many places – rows 61, 63, 70, …, 776;
- excess whitespaces – rows 331, 817, …, 722
- excess dots – rows 372, 526, …, 817
- differences in applied quotation marks’ style – pages 2, 7, etc;
- color of text highlighting in rows 144-153;
- misprints in rows 155, 221 (decimal separator), 392, 432, 526, 756;
- table title indents of tables 1, 3, 4 – are not match the template;
- table title styles – are not match the template;
- table styles – are not match the template;
- figure title indents in section 3 – are not match the template;
- figure title styles in section 3 – are not match the template;
- paragraph indents in subsection 3.3.2 and after section 5 – are not match the template;
- subsection header indents in sections 2, 3 – are not match the template;
- subsection header styles in section 2 – are not match the template;
- section header indents in sections 4 and 5 – are not match the template;
- equation numbering style – is not match the template;
- References section style – is not match the template (name initials, Web site titles, excess dots and commas, “et al.” abbreviation using).
Additionally, some critical remarks to the article content can be proposed:
- row 87 – “Trestima Hi” – did you mean “Trestima Oy” (?);
- rows 102-108 – the use of “shown good results”, “not differ significantly” and “significant difference” phrases is a bad practice, as these phrases are too subjective and not “measurable” – try please to provide some formalized quantitative estimations, of redesign the text fregment;
- rows 114-115 – “Haute école des sciences agronomiques, forestières et alimentaires HAFL” – is better to restyle into “Haute école des sciences agronomiques, forestières et alimentaires (HAFL)”;
- table 1 – “Operational system” is not conventional term – “Operating system” have to be used;
- table 1 – content of last two columns is better to be presented in the form of lists (inside the table cells);
- row 175 (“covered eight counties”) – then Figure 1 (“northern region of Portugal”) – then rows 185-189 (“…Vila Real) and community lands in Montalegre…”) – most of the readers are not familiar with the administrative divisions of Portugal, it is better to write directly that the municipalities(?) are meant (for instance – Braga is the Braga municipality or Braga district here(?));
- Figure 1 – scale bar and graticule have to be added; titles in the map have to be scaled (too small and unreadable now); title positions have to be corrected (it is not clear now, are these titles refer to municipalities or to parcels); study region highlighting in the map inset (in upper right angle) have to be corrected and highlighted according to main map extent;
- rows 202-203 the “month” word in both rows is better to be excluded, in both places month name is enough;
- rows 290-291 – the sentence is confusing and better to be rephrased;
- row 306 – JMP software have to be commented – what is this, what for it is used, how it is available(?);
- row 328 and bellow – the “i” in “di” have to be switched into subscript character;
- figure captions in section 3 – is the “XX axis” designation correct(?), probably it is better to use “X axis”(?);
- table 2 – RMSE and BIAS presented up to 3rd sign after decimal separator have to be rounded or commented (is the 0.001 cm represent real accuracy of tree diameter measurement in the study?);
- rows 539-543 – “T1P2” and similar designation appear first time and have to be commented;
- Tables 3 and 4 – “a”, “b” and etc. marks have to be commented; also, using of apostrophes in the Table 3 has to be commented;
- Figure 13 – interval labels on horizontal axis have to be moved from interval centers close to interval separators.
.
Author Response
Reviewer 2
Response to Comments
The Reviewer made several comments and suggested improvements. All the comments and answered point by point and addressed. The authors thank the Reviewer for their comments which will contribute to improve this manuscript.
The authors’ answers are in blue.
Comments and Suggestions for Authors
The study described in the article seems to be interesting in the meaning of professional outlook, and can appear valuable for forest inventory practitioners. The study logic is clear in general, formalized conclusion on studied objects is provided. The language style and quality are appropriate.
Answer: The authors thank the Reviewer for their comment.
Main drawback of the article text presented for reviewing is the absolute absence of editing work provided before text sending. Despite the remark in rows 825 and 829-830 (“writing—review and editing…” and “All authors have read and agreed to the published version of the manuscript”), the text is full of numerous misprints, mistakes and style violations of different types. Such a presenting quality can be detected as a disrespect to the reader. Due to this, the text cannot be recommended for publishing till the detailed and accurate technical editing will be made:
Answer: We apologize for the numerous misprints, mistakes, and style violations that you have identified. The authors appreciate the Reviewer’s valuable feedback on our manuscript and effort in thoroughly reviewing our work. We have carefully considered the comments and addressed these issues. The reviewer's remarks were carefully considered during the revision process, and the necessary amendments were made accordingly. To keep the answer concise, the authors will indicate that a remark has been addressed by using the word "Done" before it.
Done - email addresses in rows 7-14 – different styles (active/nonactive);
Done - lost whitespaces in many places – rows 61, 63, 70, …, 776;
Done - excess whitespaces – rows 331, 817, …, 722
Done - excess dots – rows 372, 526, …, 817
Done - differences in applied quotation marks’ style – pages 2, 7, etc;
Done - color of text highlighting in rows 144-153;
Done - misprints in rows 155, 221 (decimal separator), 392, 432, 526, 756;
Done - table title indents of tables 1, 3, 4 – are not match the template;
Done - table title styles – are not match the template;
Done - table styles – are not match the template;
Done - figure title indents in section 3 – are not match the template;
Done - figure title styles in section 3 – are not match the template;
Done - paragraph indents in subsection 3.3.2 and after section 5 – are not match the template;
Done - subsection header indents in sections 2, 3 – are not match the template;
Done - subsection header styles in section 2 – are not match the template;
Done - section header indents in sections 4 and 5 – are not match the template;
Done - equation numbering style – is not match the template;
Done - References section style – is not match the template (name initials, Web site titles, excess dots and commas, “et al.” abbreviation using).
Additionally, some critical remarks to the article content can be proposed:
Done - row 87 – “Trestima Hi” – did you mean “Trestima Oy” (?);
Done - rows 102-108 – the use of “shown good results”, “not differ significantly” and “significant difference” phrases is a bad practice, as these phrases are too subjective and not “measurable” – try please to provide some formalized quantitative estimations, of redesign the text fregment; The amendments were made.
Done - rows 114-115 – “Haute école des sciences agronomiques, forestières et alimentaires HAFL” – is better to restyle into “Haute école des sciences agronomiques, forestières et alimentaires (HAFL)”;
Done - table 1 – “Operational system” is not conventional term – “Operating system” have to be used;
Done - table 1 – content of last two columns is better to be presented in the form of lists (inside the table cells);
Done. The term "county" was included for the sake of clarity in reading whenever it was deemed appropriate. - row 175 (“covered eight counties”) – then Figure 1 (“northern region of Portugal”) – then rows 185-189 (“…Vila Real) and community lands in Montalegre…”) – most of the readers are not familiar with the administrative divisions of Portugal, it is better to write directly that the municipalities(?) are meant (for instance – Braga is the Braga municipality or Braga district here(?));
Done. Figure 1 has been revised and enhanced. - Figure 1 – scale bar and graticule have to be added; titles in the map have to be scaled (too small and unreadable now); title positions have to be corrected (it is not clear now, are these titles refer to municipalities or to parcels); study region highlighting in the map inset (in upper right angle) have to be corrected and highlighted according to main map extent;
Done - rows 202-203 the “month” word in both rows is better to be excluded, in both places month name is enough;
Done. The sentence was revised. - rows 290-291 – the sentence is confusing and better to be rephrased;
Done. Information was provided about JMP being a registered mark of a statistical package - row 306 – JMP software have to be commented – what is this, what for it is used, how it is available(?);
Done - row 328 and bellow – the “i” in “di” have to be switched into subscript character;
Done - figure captions in section 3 – is the “XX axis” designation correct(?), probably it is better to use “X axis”(?);
Done. Values have been adjusted to two decimal places according to the accuracy of the measurements. - table 2 – RMSE and BIAS presented up to 3rd sign after decimal separator have to be rounded or commented (is the 0.001 cm represent real accuracy of tree diameter measurement in the study?);
Done - rows 539-543 – “T1P2” and similar designation appear first time and have to be commented;
Done - Tables 3 and 4 – “a”, “b” and etc. marks have to be commented; also, using of apostrophes in the Table 3 has to be commented;
- Figure 13 – interval labels on horizontal axis have to be moved from interval centers close to interval separators.In the opinion of the authors, the proposed change would not benefit the interpretation of the image so the suggestion was not followed.”
*
We would like to express our gratitude to the Reviewer 2 for the time spent reviewing our manuscript and for providing us with valuable feedback. Their comments were greatly appreciated, and we believe they have significantly contributed to improving the quality and effectiveness of our work.
Author Response File: Author Response.docx
Reviewer 3 Report
The development of new forest inventory methods is an important direction in the development of research in the field of forest resource management. Their goal is, among others, the use of modern technologies to obtain reliable information needed for forest production planning. The use of this type of application can significantly reduce traditional and labor-intensive measurements in the forest, but if used incorrectly, it can lead to an incorrect description of the forest, and thus to incorrect decisions in the field of forest management. Therefore, the article submitted for review should be considered valid in this respect.
Comparing the effectiveness of Katam, Arboreal and Trestima with traditional data collection methods has been fairly well documented. The paper identifies the most important factors affecting the accuracy of collecting data on trees and determines their usefulness in stands with different dendrometric characteristics.
However, some methodological assumptions raise doubts, in particular the small number of sample plots. The essence of inventory methods, based on measurements on representative plots, is to draw conclusions about the forest on the basis of a sufficiently large number of sample plots. The number of sample plots must therefore be large enough for statistical inference to make sense. On this basis, the variability of features is assessed and the average error of the sample is calculated. Therefore, drawing conclusions about the characteristics of the entire stand based on data from only 2-3 sample plots is insufficient. In addition, it should be clarified:
• Why were data from one sample plot per 1 ha recalculated, if all sample plots were of the same size??
• From what thickness were DBH measured?
• Why were data from traditional tree measurements chosen as the reference point for comparing different ways of collecting data? Each of the methods used in the research to measure trees on the sample plots is burdened with an average error of the sample, even those based on traditional measurement.
• It is inappropriate to combine different typological positions (figure 12, table 4). The indicators obtained in this way have no diagnostic value
• There is no table with the standard deviation of the number of trees and basal area according to typological stands
In addition, it should be emphasized in the work that these are preliminary research results, which, due to the small number of sample plots, do not give grounds for drawing general conclusions. Only observations based on more sample plots yield reliable results.
Detailed notes on text excerpts:
Figure 7-11, 13-17 - the scales in the graphs should be the same on the X and Y axes, at least in the same typologies
Comments for author File: Comments.pdf
Author Response
Reviewer 3
Response to Comments
The Reviewer made comments and suggested improvements. All the comments and questions are answered point by point and were addressed during the revision. The authors thank the Reviewer for their comments which will contribute to improve this manuscript.
The authors’ answers are in blue. In the text the modifications are highlighted.
Comments and Suggestions for Authors
The development of new forest inventory methods is an important direction in the development of research in the field of forest resource management. Their goal is, among others, the use of modern technologies to obtain reliable information needed for forest production planning. The use of this type of application can significantly reduce traditional and labor-intensive measurements in the forest, but if used incorrectly, it can lead to an incorrect description of the forest, and thus to incorrect decisions in the field of forest management. Therefore, the article submitted for review should be considered valid in this respect.
Comparing the effectiveness of Katam, Arboreal and Trestima with traditional data collection methods has been fairly well documented. The paper identifies the most important factors affecting the accuracy of collecting data on trees and determines their usefulness in stands with different dendrometric characteristics.
Answer: The authors thank the Reviewer for their comments.
However, some methodological assumptions raise doubts, in particular the small number of sample plots. The essence of inventory methods, based on measurements on representative plots, is to draw conclusions about the forest on the basis of a sufficiently large number of sample plots. The number of sample plots must therefore be large enough for statistical inference to make sense. On this basis, the variability of features is assessed, and the average error of the sample is calculated. Therefore, drawing conclusions about the characteristics of the entire stand based on data from only 2-3 sample plots is insufficient. In addition, it should be clarified:
Answer: The authors acknowledge the comment, but consider that the number of samples does not undermine the interest and merit of this study. Although there are only a few plots, each plot contains many trees which serve as sample points. This results in a large number of comparison points, even in situations where the number of plots is limited. For instance, Typology T10 consists of only 2 plots, but has a total of 64 trees. This allows for the analysis of a large number of cases for variables such as diameter at breast height and number of trees per hectare. In terms of the basal area variable, which aggregates the cross-sectional area projected on the ground, there are valid criticisms. However, since this is a preliminary study, we believe that combining the basal area with other variables provide good indicators of the apps’ efficiency, even if less precise. It is important to note that the purpose of this study was to conduct a broad preliminary analysis of several situations throughout the national territory, which required significant effort to locate diverse planned situations.
- Why were data from one sample plot per 1 ha recalculated, if all sample plots were of the same size??
Answer: The data was recalculated to 1 hectare to establish a consistent scale. The traditional method and the Arboreal application used a defined area of 400 m2 for the plots, but the Trestima and Katam applications lacked the option to set a specific plot size value.
- From what thickness were DBH measured?
Answer: In the traditional method, all trees with DBH above 2 cm were measured. In the applications, the minimum DBH varies according to the recognition capacity of the algorithm of each application, but is never less than 2 cm.
- Why were data from traditional tree measurements chosen as the reference point for comparing different ways of collecting data? Each of the methods used in the research to measure trees on the sample plots is burdened with an average error of the sample, even those based on traditional measurement.
Answer: The authors acknowledge the remark. Nevertheless, based on similar researches, the traditional method is always referred to as a reference for comparison. We consider that the traditional method is widely used and accepted by forest producers and if the results of the applications were similar, we would already have a good indicator of its effectiveness. Some tests were carried out with the cubing of the trees in the plot, but the operational cost of such a task proved to be too high and unfeasible for a study with the proposed dimension.
- It is inappropriate to combine different typological positions (figure 12, table 4). The indicators obtained in this way have no diagnostic value
Answer: We accepted the suggestion and modified table 4, dividing it into tables 4 and 5. We decided to retain figure 12 as an empirical reference for comparing the traditional method with each application across all the plots. To provide clarity, we added the following statement: "The information provided by Figure 12 is indicative of the proportion between the traditional method and each application that is statistically similar. The results may help users decide which technology to adopt, in combination with other analyses, but on their own do not conclusively determine the outcome of this study."
- There is no table with the standard deviation of the number of trees and basal area according to typological stands
Answer: Standard deviations were included in the mean test tables for N and G. The table with the mean values of the diameters was also updated and the statistical analysis was revised.
In addition, it should be emphasized in the work that these are preliminary research results, which, due to the small number of sample plots, do not give grounds for drawing general conclusions. Only observations based on more sample plots yield reliable results.
Answer: The authors agree with the remark. A new sentence was added in the conclusion section: “The present results should be interpreted as preliminary and the evolution of this study, guided by what has been exposed here with a greater sample amplitude, may generate more concrete and definitive conclusions.”
Detailed notes on text excerpts:
Figure 7-11, 13-17 - the scales in the graphs should be the same on the X and Y axes, at least in the same typologies.
Answer: The authors thank the reviewer for the suggestion. Figures 7 to 11 now have corrected scales. Figures 13-17 remain unchanged as they do not require comparison between the graphs. The purpose is to compare the observed traditional frequencies with the applications within the same graph. As the amplitude of the frequencies is very large, the standardization of the scale would make it impossible to perceive a difference between the classes with lower frequencies.
We would like to express our gratitude to the Reviewer 3 for the time spent reviewing our manuscript and for providing us with valuable feedback. Their comments were greatly appreciated, and we believe they have significantly contributed to improving the quality and effectiveness of our work.
Author Response File: Author Response.docx
