Identification of the Forest Cover Growth on Landscape Level from Aerial Laser Scanning Data
and Ján Tuček 1,*Round 1
Reviewer 1 Report
Major comments:
_ The paper requires extensive English editing by a native specialist. The structure of the methodology and the result sections needs to be revised.
- The introduction needs to be developed in terms of explaining the methodologies used in other research and the novelty that the current research brings to us.
- Please add explanation on the effect of forest type on accuracy? You have chosen your study area in three different forest types with clearly different crown shapes, especially in coniferous and broadleaved forests. It is expected to see the result and discuss the challenges or advantages of each forest type.
Minor comments:
Line 22: The ALS data are not freely available on a large scale all over the world, so this method won't be widely applicable.
Line 31: Mention full name of UAV at the first place in the main text
Line 42: It is necessary to write down the abbreviations in the parenthesis next to the full name at the first place in the main text (inertial measurement unit(IMU))
Line 46: rephrase the sentence "Forest management is based on ..."
Line 55: Restate the paragraph ("Remote sensing technologies,..."). Refer to previous studies to provide useful information about what has been done, not just a list of references.
Line 61: [10-16]
Line 61: write down full name of DSM at the first place and put abbreviation in the parenthesis.
Line 62: ALS is not a method. Unless, when describing the method of a study, you contractually refer to it as an ALS method.
Line 66: "A similar method ..." . The method used by previous stusies has not been described, so the usage of "a similar method" is not appropriate.
Line 75: " The normalized DSM is ...". The normalized DSM itself is just a parameter, please state its use or in other words its interpretation.
Line 79: Three references (three kinds of definition) was mentioned in this paragraph in order to give a definition of forest. But no definition was given, we only see reference. Please write a definition (the one that was used in this study) and then state that there are some other definition, etc.
Line 102: "utilization" of what?
Line 102: "It is the ...stage of succession" The sentence is incomplete (grammatical problem).
Line 104: "Estimates of the extent of the changes vary." changes in what?
Line 105: "[31] presented an area of ...", area of what?
Line 119: "The secondary objective", This could not be an objective. I believe that accuracy assessment is an important phase of the main objective.
Line 124: purposively instead of "by purposive selection"
Line 129: Use the same phrase all over the study: experimental area, experimental plot.
Line 133: Please provide a map with coordinates for Figure 1
Line 153: "Digital Relief Model", The full phrase comes before abbreviation and abbreviation in the parenthesis.
Line 156: "Their metadata and 156 fundamental characteristics are also listed here.", This sentence can be deleted.
Line 157: According to the metadata
Line 157,158,159: "According to ...", need to be re-phrase
Line 161: unclear. what are area 20 and 26?
Line 162-166: The sentence is too long and incomprehensible
Line 167: "the last returns ...", Do you mean the last return density is 30 per meter square? please re-phrase the sentence.
Line 169: Areas 20 and 26 refer to the dataset you have used, but it makes no sense to refer to them without giving the reader any prior knowledge.
Line 172: While this is a good introduction to the software, I do not think it is appropriate to devote a page of a research article to describing the software used.
Line 196: "ODBC", what does it stand for?
Line 218: Abbreviations should be written in the parenthesis.
Line 231: Figure 2:
- Increase the font size of the text in the boxes. - please move the box 'compare with cadastre ..." under the box "minimum vidth via PIA"
Line 236-240: - how did you check the correctness? what was the reference?
- How did you improve the classification?
Line 248: "By reclassifying ...", Eliminating height values lower than a threshold can't be called reclassification.
Line 319: do you mean gaps by "clearings?
Line 377: Methodology as such:
The first two paragraphs of this section are a repetition of methodology and should be removed.
The third and fourth paragraphs of this section are more like a discussion and should be moved to the appropriate section.
Line 388: Do you mean the holes were filled by "are removed"?
Line 450: Figure 6: Improve the quality of image. The legend is not clear.
Line 458-461: The producer and user accuracy definitions are inappropriate.
Line 466: The Kappa coefficient equals to .... instead of "The value t\of the index..."
Line 485:
- The table 3 is not well-organized.
- What is the purpose of this table? It does not fit into the results section, nor is it relevant to the purpose of this article. However, such information can be discussed in the discussion or even in the conclusion.
Line 512: Please add a column indicating the methodology used for each study in table 4.
Extensive editing of English language by a native specialist is highly recommended.
Author Response
Please see the attachment
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript presents a semi-automatic procedure to forest grow monitoring. It identifies homogeneous areas of forest stands and forest patches. The flow chart of the procedure is based on several modules of open-source software, more specifically QGIS. The procedure is tested on three ALS point clouds. Reference data was produced photogrammetrically. The boundary of the forest stands and forest patches were vectorized by means of the stereo model using aerial images of 25cm resolution.
The author presents an exhaustive and well-organized state of the art. Used data are thoroughly described. Their data are freely distributed by Slovak cadastral and references are provided. The results are methodically presented and illustrated with figures and tables.
The method is not innovative, but the explanation of the procedure based on all open-source software may be of interest to the researcher. For this reason, I feel that the presentation of the research needs to be further developed by providing more detail on the processing step.
More specifically, the paragraph on ‘Methodology’ requires improving the explanation of the several modules/plugins (Tree Density Calculator/Voronoi polygons/r.slope.aspect/convex-hull/erase Holes /Zonal Statistic/PIA ) used. For example, a discussion on what parameters were used in the different plugins, and the corresponding results and also every consideration that can help other researcher. More images relative to intermediate results are welcome.
Tree Density Calculator/Voronoi polygons/r.slope.aspect/convex-hull/erase Holes /Zonal Statistic/PIA
More in detail:
1- Figure 2: it is confusing. Try to clarify…it could help add the corresponding plugin used. Imporve the quality of the images…
2- raw 241-243: I think you need also the ground layer to create the DSM….
3- 249: what height have you used to filter out …what is the height criterion
4- Figure 3. It misses a scale of the height
5- Images with curvature (results of r.slope.aspect)
6- raw 288-290. How was (automatically) vectorized the perimeter?
7- “it was necessary to create a tree crown mask raster from which 316 the area covered by vegetation (tree crowns) can be calculated” explain that
Author Response
Please see the attachment
Author Response File: Author Response.docx
