FIELD: A Software Tool That Integrates Harvester Data and Allometric Equations for a Dynamic Estimation of Forest Harvesting Residues

Round 1

Reviewer 1 Report

If I well understood, although it is not very clear, the purpose of the research presented by the authors in the manuscript is to show the usefulness of a new tool (called FIELD) for real-time estimation of wood harvesting residues. Not pre-harvest or post-harvest, but simultaneously with the timber harvesting operations. Is this estimation used by the respective harvesting company, or is it useful for an inventory of potentially subsequently recoverable logging residues? If the logging company collects and capitalizes on the logging residues, the resulting quantity will be accurately quantified according to the capacity of the used equipment and the FIELD tool can't really "contribute to supporting decisions during forest operations".

But the major problem is that mentioned right from the beginning (lines 20-22 in the abstract): FIELD uses StanForD pri files and geo-location data…in combination with locally developed species-specific allometric equations”. Well, those used are not so local.

It is well known in statistics that the coefficients of a regression equation (allometric or not) resulted for a certain set of data obtained through a statistical survey in a population (or in an area) homogeneous in terms of all the factors that influence the values of the studied characteristic. These coefficients must be recalculated whenever the conditions for applying the equation change (between these conditions, DBH is only one of the parameters, as the authors agree in lines 235-238). Obviously, through another statistical survey (as even the authors conclude in lines 302-305). A method with a very accurate component (using data from the harvester head) and a very imprecise one (using an inappropriate allometric equation) is on the whole an imprecise method.

Curiously, the authors observed that the attempt to take regression equations from other works mentioned in the bibliography generates very different values of harvesting residues (Figure 10, lines 241-243). However, they insist on considering in the methodology that "in this context, Forrest [29] and Feller [30] equations were considered suitable for the age of stands and general environmental conditions present in the study area (Table 2)".

In order to determine the parameters of the equation for the studied area, a method similar to the one given in detail in ”Biomass and nutrient distribution in two eucalypt forest ecosystems” (Feller, 1980) should have been applied (or another one, but this is used in one of the cited works).

There are also some aspects related to the writing of the manuscript, but I will not insist on them. For example, the content of Table 2 is fully repeated in Tables 3 and Table 4 (with an incorrect coefficient in the third equation of Table 3). Not to mention some inappropriate expressions like the one in the line 205 (“Mean DBH and average of the stands was 29cm and 37 years, respectively”).

Author Response

June 15th, 2021

 

Dear Editor,

 

Thanks for your review and suggestions for this manuscript. My co-authors and I have addressed and responded to the Reviewers’ comments and suggestions. Please find enclosed a revised copy of our manuscript.

The attached pages summarize how we have addressed the reviewers’ suggestions and comments. The comments and suggestions provided by the reviewers helped us improve the technical presentation of our study results and the readability of the manuscript, so we are immensely grateful for that. We believe that the current version of our manuscript is now much clear and informative than the previous version.

 

Thank you,

 

 

Heesung Woo

 

Research Professor

School of Forest and Environmental Sciences

Kangwon National University

Chuncheon, 24341

South Korea

Phone: +82 10 4354 1608 

 

Author Response File: Author Response.docx

Reviewer 2 Report

The question is important, the method is clearly described and evaluated. For my mind this is an article very near to practical use more than for a scientific discussion. Herewith I suggest to be accepted in the present form.

Author Response

Dear Editor,

Thanks for your review and suggestions for this manuscript. The comments and suggestions provided by the reviewers helped us improve the technical presentation of our study results and the readability of the manuscript, so we are immensely grateful for that. We believe that the current version of our manuscript is now much clear and informative than the previous version. 

Thank you,

Heesung Woo

Author Response File: Author Response.docx

Reviewer 3 Report

Journal: Forests (ISSN 1999-4907)

Manuscript ID: forests-1239175

Title: FIELD: A software tool that integrates harvester data and allometric equations for a dynamic estimation of forest harvesting residues

 

Overall  Comments and Suggestions for Authors

With respect to simulators that integrates harvester data and allometric equations especially for forest harvesting residues, this manuscript is interesting to the relevant researchers who deals with similar issues such as forest harvesting, forest carbon issues, and administrative.

Overall, authors describes the manuscript so clearly that there is no question on any parts of Introduction, Methods and Materials. I strongly agree with the concept and objectives in this study, so I appreciate the authors’ effort on it. I enjoyed a lot.

However, there are some issues about Result section. I don’t think that the results are the real results from this research. Those are nothing more than computational algorithm combined with the previously developed models from Forrest and Feller. Thus, I provided my ideas to revise it. Note that my comments here were mainly based on the view from a forest modeler. Feel free to argue those based on the authors’ perspective, but there are some unconvincing issues from my point of view.

I hope that this manuscript can be improved based on peer-review’s comments. My specific comments were provided in detail as follows.

 

Point 1.

Line 118: were 277mm and 298mm in the top and middle portions of the processed stems? Is mean diameter of 277mm at the bottom of top portion? Or in the middle of top portion? Or randomly selected? Is mean diameter of 298mm at the tip of top portion? Or middle? Or bottom? Can authors describe this part more clearly?

 

Table 1. What is the difference between 203 and 207? Also between 204 and 208?

 

Figure 3. Can authors add some comments to explain the points shown as outliers in Figure 3? What are the characteristics of outliers? Doesn’t it have a negative effect on output? Is the effect still meaningful?

 

 

Point 2.

Table 2. please standardize the upper and lower case of units and abbreviation such as kG, kg, ln, LN. Also, the parenthesis in the equation should be unified. Decided to put a uniform decimal point for R2, e.g. 0.xx, 0.xxx, or 0.xxxx. Standardize decimal points of parameters, e.g. 0.xxx.

All abbreviations must be defined in every table according to the author guideline of Forests. What is M, lnM, DBH? Bimass, logarithmic value of biomass, and diameter at breast height? Add a notation in caption or at the bottom of the Table.

 

 

Point 3.

The parameters and R-squared in Table 3 and 4 are not the results of this study. The total estimation with one of two units should be enough to include in Result section. Therefore, here is my suggestion. To clearly describe the result and simulation, how about the alternative Table as below? Or try alternatives with this concept.

Input		Biomass type	Biomass output with Forrest (1969)		Output with Feller (1984)
DBH	Height		tree-level (kg)	stand-level (kg/unit area)	tree-level (kg)	stand-level (kg/unit area)
Mean ± SD (Min–Max)	Mean ± SD (Min–Max)	Aboveground	Mean ± SD (Min–Max)	227,964	-	-
		Leaves	Mean ± SD (Min–Max)	75,874	Mean ± SD (Min–Max)	90,374
		Branches	Mean ± SD (Min–Max)	303,838	Mean ± SD (Min–Max)	503,488
		Stem	-	-	Mean ± SD (Min–Max)	585,013
		Total		607,676		1,178,875

           

 

Point 4.

Figure 8. Boxplot can be a better option to present distribution including central location and dispersion in a similar way to Figure 3. In addition, what about comparing both sources of Forrest and Feller together using color legend although Aboveground and Stem cannot be compared?

 

 

Point 5.

FIELD algorithm combined with Forrest or Feller mechanically provides the result, so the models used in FIELD are not original. In this circumstance, it is not so convincing to argue the FIELD accuracy without real observations, or biomass in this case. In other words, the independent dataset is required to develop the optimal models instead of just using Forrest and Feller. That is, many portions of accuracy relies on the model itself and it goes beyond the scope of the purpose in this study.

 

 

Point 6.

In Results and Discussion, therefore, it would be desirable to explain the advantages of implementation with FIELD and to highlight the main features rather than to focus on the equations’ output and comparison. For example, what do we get as outputs, e.g. volume and biomass at log-, tree-, stand-level. How fast and easy can we get those? What are the other positive (or negative) impacts with FIELD? How are key features, which authors want to highlight, superior to the traditional method in the forestry field? I fully understood the merits of FIELD and strongly agree with authors’ idea and its application. However, I felt like authors didn’t express the structure, composition, or potential of FIELD. Probably, some of my list cannot be dealt with in this manuscript, but I still believe this kind of perspective is necessary for originality of this paper.

 

Point 7.

If this manuscript is not proceeded further for publication in Forests, I recommend authors to resubmit it in this journal after revising. Alternatively, I also recommend authors to consider other journals as below which deal with this kind of manuscript, e.g. software or simulator: ELSEVIER Computers and Electronics in Agriculture or MDPI Mathematical and Computational Applications.

 

Comments for author File: Comments.pdf

Author Response

Comments and Suggestions for Authors

June 12th, 2021

 

Dear Editor,

 

Thanks for your review and suggestions for this manuscript. My co-authors and I have addressed and responded to the Reviewers’ comments and suggestions. Please find enclosed a revised copy of our manuscript. The attached pages summarize how we have addressed the reviewers’ suggestions and comments. The comments and suggestions provided by the reviewers helped us improve the technical presentation of our study results and the readability of the manuscript, so we are immensely grateful for that. We believe that the current version of our manuscript is now much clear and informative than the previous version. 

 

Thank you,

 

 

Heesung Woo

 

Research Professor

School of Forest and Environmental Sciences

Kangwon National University

Chuncheon, 24341

South Korea

Phone: +82 10 4354 1608 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Although the authors did not take into account all observations (especially those related to establishing the coefficients of the regression equation specific to the analyzed location), it appeared a more improved manuscript.

Author Response

June 19th, 2021

 

Dear reviewer,

 

Thanks for your review and suggestions for this manuscript. The comments and suggestions provided by the reviewers helped us improve the technical presentation of our study results and the readability of the manuscript, so we are immensely grateful for that. We believe that the current version of our manuscript is now much clear and informative than the previous version.

Thank you,

Heesung Woo

Research Professor

School of Forest and Environmental Sciences

Kangwon National University

Chuncheon, 24341

South Korea

Reviewer 3 Report

See the attachment or comments as below.

 

Journal: Forests (ISSN 1999-4907)

Manuscript ID: forests-1239175-v2

Title: FIELD: A software tool that integrates harvester data and allometric equations for a dynamic estimation of forest harvesting residues

 

Overall Comments and Suggestions for Authors

Dear authors,

This revised manuscript has been edited properly and I am pleased with that. Here are some of my supplementary comments for better publication. In the second rounding of peer-review, my comments are BLUE.

I appreciated the authors’ work on this study.

Kind regards,

Reviewer

 

Point 1.

Line 118: were 277mm and 298mm in the top and middle portions of the processed stems? Is mean diameter of 277mm at the bottom of top portion? Or in the middle of top portion? Or randomly selected? Is mean diameter of 298mm at the tip of top portion? Or middle? Or bottom? Can authors describe this part more clearly?

Response 1:

 “Accepted comments”. The ambiguity of description sentences were rewrite. The revised contents were described as below;

In this research tree diameters were automatically collected from the top and middle portions of processed stems (Figure 2). The mean diameter was 277mm and 298mm in the top and middle portions of the processed stems, respectively (Figure 3).

Reviewer’s comment:

It’s clearer. No more comment on this issue.

 

Table 1. What is the difference between 203 and 207? Also between 204 and 208?

Response 2:

 “Accepted comments”. The contents of table 1 was replaced with correct information. The revised table 1 is presented as below.

 

Variable number	Definition
201	Diameter over bark of the top section (mm)
202	Diameter under bark of the top section (mm)
203	Diameter over bark of the middle section (mm)
204	Diameter under bark of the middle section (mm)
301	Physical stem length, (cm)
401	Solid volume over bark (m3)
402	Solid volume under bark (m3)
403	Volume over bark of the top section (m3)
404	Volume under bark of the top section (m3)
500	Stem number. Unique stem id used for all types of stems
501	Log number in stem (eg., 1st log =1, 2nd = 2, and 3rd = 3)

Table 1. Description of the forest inventory data in pri-file (identification number of variables and definition)

Reviewer’s comment:

Okay.

 

Figure 3. Can authors add some comments to explain the points shown as outliers in Figure 3? What are the characteristics of outliers? Doesn’t it have a negative effect on output? Is the effect still meaningful?

Response 3:

Accept comments.

The figure 3 is simply presented mean diameter of the tree portion using StanForD data. As we described in study site, the harvesting operation was conducted on Australian Radiata pine plantation region. In general, the differences of DBH and tree height of plantation tree were expected very small. However, the figure 3 revealed that there is some outstanding individual tree in plantation area. To accept reviewer’s comment, we described above information in conclusion section to highlight FIELD application(Line no. 297 to 302).

The inserted contents were presented as below;

As we described in study site, the case study was conducted on Australian Radiata pine plantation region. In general, the differences of DBH and tree height of plantation tree were expected very small. However, the figure 3 revealed that there is some outstanding individual tree in plantation area. The generated spatial map of FIELD tool is expected to provide efficient information on forest managers and owners' future management plans.

 

Reviewer’s comment:

This is better.

 

Point 2.

Table 2. please standardize the upper and lower case of units and abbreviation such as kG, kg, ln, LN. Also, the parenthesis in the equation should be unified. Decided to put a uniform decimal point for R2, e.g. 0.xx, 0.xxx, or 0.xxxx. Standardize decimal points of parameters, e.g. 0.xxx. All abbreviations must be defined in every table according to the author guideline of Forests. What is M, lnM, DBH? Bimass, logarithmic value of biomass, and diameter at breast height? Add a notation in caption or at the bottom of the Table.

Response 4:

Accept comments. The overall manuscript abbreviations were inserted and revised. Additionally, the in consistency of decimal points were uniformly used. Lastly, the revised table 2 presented as below;

Table 2. Allometric equations employed and estimated total harvesting residue in the case study (Equations were developed by Forrest 1969 and Feller 1984)

	Forrest (1969)
Biomass type	Equations	R2
aboveground	lna(kg)=(-2.1+2.3*lnDBH(cm))	0.98
leaves	ln(kg)=(-7.5+3.3*ln(DBH(cm))	0.97
branches	ln(kg)=(-0.8+3.3*ln(DBH(cm))	0.94
	Feller (1984)
stem	(kg)=5.0+171.3*DBH2(m)*Height(m)	0.96
leaves	(kg)=-1.2+3.2*DBH2(m)*Height(m)	0.99
branches	(kg)=-2.4+9.3*DBH2(m)*Height(m)	0.98
Lna: The natural logarithm of a number

 

Reviewer’s comment:

Authors must be careful to write the unit. DBH unit between Forrest (1969) and Feller (1984) is different as those are cm and m. Is it true? Check this and correct it.

There are too many parentheses and unnecessary units in each equation to interpret.

Overall, I recommend the equations as follows to make it concise and readable. Change any symbols if it’s needed.

	Forrest (1969)
Biomass type	Equations	R2
aboveground	lnM=-2.1+2.3×lnDBH	0.98
leaves	lnM=-7.5+3.3×lnDBH	0.97
branches	lnM=-0.8+3.3×lnDBH	0.94
	Feller (1984)
stem	M=5.0+171.3×DBH2×H	0.96
leaves	M=-1.2+3.2×DBH2×H	0.99
branches	M=-2.4+9.3×DBH2×H	0.98
M is tree biomass by type (kg). DBH is diameter at breast height (cm). H is tree height (m). ln is natural logarithm.

 

 

 

Point 3.

The parameters and R-squared in Table 3 and 4 are not the results of this study. The total estimation with one of two units should be enough to include in Result section. Therefore, here is my suggestion. To clearly describe the result and simulation, how about the alternative Table as below? Or try alternatives with this concept.

Input		Biomass type	Biomass output with Forrest (1969)		Output with Feller (1984)
DBH	Height		tree-level (kg)	stand-level (kg/unit area)	tree-level (kg)	stand-level (kg/unit area)
Mean ± SD (Min–Max)	Mean ± SD (Min–Max)	Aboveground	Mean ± SD (Min–Max)	227,964	-	-
		Leaves	Mean ± SD (Min–Max)	75,874	Mean ± SD (Min–Max)	90,374
		Branches	Mean ± SD (Min–Max)	303,838	Mean ± SD (Min–Max)	503,488
		Stem	-	-	Mean ± SD (Min–Max)	585,013
		Total		607,676		1,178,875

Response 5:

Accept comments. The table 3 and 4 were combined into table 3 based on suggested table format. The revised table 3 presented as below;

 

Input Mean ± SD (Min-Max)		Biomass type	Estimated biomass with Forrest (1969)		Estimated biomass with Feller (1984)
DBH(cm)	Height(m)		Individual tree-level (kg) Mean ± SD (Min-Max)	Stand-level (kg/unit area)	Individual tree-level (kg) Mean ± SD (Min-Max)	Stand-level (kg/unit area)
37.34 ± 8.42 (10.40 - 61.10)	18.23 ± 4.13 (12.31- 20.18)	Aboveground	415.24 ± 240.47 (26.85 - 1627.50)	227,964	-	-
		Leaves	69.12 ± 56.72 (1.28 - 440.13)	75,874	84.32 ± 43.35 (1.45 - 456.72)	90,374
		Branches	159.12±156. 72 (2.50 - 887.12)	303,838	695.31 ± 208.17 (24.26 - 1836.53)	503,488
		Stem	-	-	625.24 ± 213.18 (17.15 - 1943.37)	585,013
		Total	-	607,676	-	1,178,875

Reviewer’s comment:

Thanks for author’s agreement. This should be clearer. Note that, when I mentioned ‘unit area’, it does not have to be literally ‘unit area’. It can be ‘ha’ or something as it should be, so I guessed it’s ha.

 

Point 4.

Figure 8. Boxplot can be a better option to present distribution including central location and dispersion in a similar way to Figure 3. In addition, what about comparing both sources of Forrest and Feller together using color legend although Aboveground and Stem cannot be compared?

Response 6:

Accept comments. The figure 8 was replaced with boxplot graph. The revised figure presented as below.

Reviewer’s comment:

When I made my previous comments, it meant that the comparison of two model types. For examples, Biomass of leaves and branches should be presented with separate boxplots by model type. It will help readers to easily compare the model application. Thus, I expected to see the comparison of four biomass type (aboveground, leaves, branches, and stem) with two legend type (Forrest and Feller). This still seems possible. Authors can re-consider about this.

 

 

Point 5.

FIELD algorithm combined with Forrest or Feller mechanically provides the result, so the models used in FIELD are not original. In this circumstance, it is not so convincing to argue the FIELD accuracy without real observations, or biomass in this case. In other words, the independent dataset is required to develop the optimal models instead of just using Forrest and Feller. That is, many portions of accuracy relies on the model itself and it goes beyond the scope of the purpose in this study.

Response 7:

We strongly agree with reviewer’s opinion. As we described in the manuscript, FIELD application has limitations in validation process. In this regard, there is required further study to a valid FIELD software application with under controlled experiment for actual measurement of harvesting residue and developing allometric equation simultaneously. Despite the limitations of FIELD application, this paper contributed a number of aspects using ICT techniques in practical forest management planning. We can  highlight the FIELD tool application as follows:

• Improving the accuracy of forest harvesting residue estimation
• Using StanForD harvester head data to improve harvest management
• Generate and up to date biomass availability map
• The real-time biomass monitoring system

 

Reviewer’s comment:

Authors mainly described the results section by comparing the output of model application although those were essentially originated from the previous studies and could not be verified for this study site. Authors are already aware of this issue. Models seems to be beyond the scope of this study. This manuscript should have been more dealt with the highlighted points as mentioned above. However, it wasn’t. Thus, I pointed out this is main disadvantages of this manuscript. I wish these features can be spotlighted more.

 

Point 6.

In Results and Discussion, therefore, it would be desirable to explain the advantages of implementation with FIELD and to highlight the main features rather than to focus on the equations’ output and comparison. For example, what do we get as outputs, e.g. volume and biomass at log-, tree-, stand-level. How fast and easy can we get those? What are the other positive (or negative) impacts with FIELD? How are key features, which authors want to highlight, superior to the traditional method in the forestry field? I fully understood the merits of FIELD and strongly agree with authors’ idea and its application. However, I felt like authors didn’t express the structure, composition, or potential of FIELD. Probably, some of my list cannot be dealt with in this manuscript, but I still believe this kind of perspective is necessary for originality of this paper.

Response 8:

Thanks for your comment. We accepted your suggestions and revised the manuscript. The manuscript results and discussion section was revised to provide the advantages of implementation with FIELD and to highlight the main features rather than to focus on the equations’ output and comparison. The revised contents were presented in line 281 to 314. Also, for your convenience, the revised contents presented as below:

This research investigated the digital role of improving the accuracy of forest harvesting residue estimation using ICT techniques and StanForD. However, the lack of harvester head data access and limited software validation process, the accuracy of FIELD estimation is not guaranteed. For these reasons, FIELD estimation needs additional validation process such as controlled harvesting residue field measurement or developing allometric equation in harvesting operation site, which is occurred StanForD. More importantly, FIELD tool has generated forest value map which including valuable information for improving forest management and silviculture planning. The value map has consisted of individual tree DBH with geo-location information. The use of combined value map and other environmental data such as soil composition, nutrients, and climate, are being expected to present how different parameter affects tree growing, predict the best management plan to plant the trees or help to increase future timber productivity.

In summary, combining the results from the FIELD tool and allometric equations have shown to be a promising approach to estimate biomass availability, and with a greater potential than those obtained from conventional residue estimation methods. Results from this case study have shown that the FIELD software has the potential to be successfully used as a management or monitoring tool in practical forest planning. Also, the use of StanForD files allows the costs effective collection and reading of large samples during harvesting operations [39]. This could be a good starting point to expand forest research into big data analytics aiming at discovering unknown or unrevealed patterns from data provided by silviculture, forest management, and forest inventory systems. In the case of biomass, this will require further research to validate the use new methodological approaches that improve the accuracy of availability estimates.

 

Reviewer’s comment:

Okay. This is better explanation.

 

Point 7.

If this manuscript is not proceeded further for publication in Forests, I recommend authors to resubmit it in this journal after revising. Alternatively, I also recommend authors to consider other journals as below which deal with this kind of manuscript, e.g. software or simulator: ELSEVIER Computers and Electronics in Agriculture or MDPI Mathematical and Computational Applications.

Response 9:

Thanks for your suggestions. The comments and suggestions provided by the reviewers helped improve the technical presentation of our study results and the readability of the manuscript, and we are grateful for that. We believe that our paper becomes much more clear and informational, compared to the previous version of the manuscript.

Reviewer’s comment:

I was pleased to review this manuscript again. I thank authors putting your effort to revise this manuscript. Hope that my comments can be helpful.

 

Comments for author File: Comments.pdf

Author Response

June 19th, 2021

 

Dear Editor,

 

Thanks for your review and suggestions for this manuscript. My co-authors and I have addressed and responded to the Reviewers’ comments and suggestions. Please find enclosed a revised copy of our manuscript. The attached pages summarize how we have addressed the reviewers’ suggestions and comments. The comments and suggestions provided by the reviewers helped us improve the technical presentation of our study results and the readability of the manuscript, so we are immensely grateful for that. We believe that the current version of our manuscript is now much clear and informative than the previous version. 

 

Thank you,

 

 

Heesung Woo

 

Research Professor

School of Forest and Environmental Sciences

Kangwon National University

Chuncheon, 24341

South Korea

Phone: +82 10 4354 1608 

Author Response File: Author Response.docx