A Method for Quantifying Understory Leaf Area Index in a Temperate Forest through Combining Small Footprint Full-Waveform and Point Cloud LiDAR Data
Round 1
Reviewer 1 Report
L46. Please delete the Figure 1.
L89. Remove the red line
L102-118. Please revise the paragraphs. Focus on the focal point of the paragraph rather than mentioning the case study. This would help the reader to understand what you are trying to say.
L143. Why you neglected?
Table 1. Please provide it in text format inside the paragraph.
L187. Why the text are in red color?
L223. Why the text are in red color?
L249. Why you chose Richardson-Lucy (RL) algorithm? Provide the supporting points?
L301. How do yo combine it? Please elaborate it for better readability.
L332. Add a reference
L342. Please do not start the sentence with Figure 5 shows. Add the Figure 5 within a parenthesis after the text.
L395. Replace such as with e.g.,
L399. Please avoid the use the adjective ("good")
L422. Please add also alternative way to overcome the study limitations.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The aim of this study was to develop a method for quantifying the understory LAI in a temperate forest through the combination of small-footprint discrete return and full waveform airborne LiDAR data. In principle, this is an interesting study and potentially may lead to a good science. Unfortunately, there is a serious flaw in the datasets and methods by which the researchers reached their results, and that makes all their discussions and conclusions meaningless.
The ground truth of the understory LAI in this study was measured at 1.5m above ground using a fisheye camera. This means that the authors only consider the plants that are less than 1.5 m tall as understory vegetation. Then it is meaningless to determine the height boundary between overstory and understory vegetation in this study anymore. Otherwise, how can the authors validate the LAI of the understory vegetation with a height greater than 1.5m? This issue also relates to the setting of a cutoff threshold of 2m high when there is no distinct boundary between the overstory and understory vegetation.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
This study explores the applicability of the combined use of LiDAR point cloud and full-waveform to retrieve LAI of understory vegetation which is an important parameter for understanding forest functions and ecosystem processes. The article is well written and can be accepted for possible publication in Remote Sensing after addressing the following comments.
Abstract: Well written, by too wordy. I wonder if it can indicate improvement in accuracy when using the two methods (point cloud and full-waveform) as compared to the one method.
Introduction: The introduction is very good, the authors demonstrate a thorough knowledge of the published literature and highlight the importance and background to carry out this investigation.
L 47-56: Authors could also add the utility of understory vegetation and/or LAI in enhancing the biomass estimations.
Line 89 – as possible edit of track change error.
Figure 1: Very Good.
Figure 2: Difficult to understand the index map in the left-most map window. Authors should also add labels in the maps to understand the spatial context and neighboring regions of the study area. It may also be good to assign sub-figures (a,b,c) to each map window.
Methods: Methods are technically strong and well explained
Eq 2 could be modified, authors may use variables to indicate 1 and 4,
Results: Results are well explained.
Figure 9: A confidence interval could have been added.
Discussion. It is good. However, the discussion concerning other published papers on the topic must be included.
Conclusion. No Comments.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors have clarified my previous concerns and I have no further comments.
