Relationship between Canopy Structure and Community Structure of the Understory Trees in a Beech Forest in Japan

Round 1

Reviewer 1 Report

Your manuscript is interesting and reports a nice study of understory tree productivity.  I think that this is an important topic that has received inadequate attention.  I have no major concerns, but I do have a number of points which could use clarification or modification of the wording.  Overall, the paper is well written and the tables/figures are all useful.  I list my points below by section and line number. 

 

Abstract: This is good overall, but I think it would be helpful to give a definition of understory trees (perhaps on line 13).  This is on line 57, but it would be good to also have <5 m tall in the Abstract.

 

Introduction:

 

Line 31.  Not only is survival important but also the ability of trees in the understory to grow into the canopy.  In addition, it would be useful to distinguish between small species that remain in the understory and small individuals in the understory that can grow into the canopy.

 

Lines 35-36.  The last part of the sentence is a little awkward and could be changed to something like “a plant that receives increased light can use the light effectively.”  

 

Lines 40-41.  It might be useful to add that shade-tolerant species in the understory were often present prior to canopy opening (in a seedling bank), whereas less shade-tolerant species are more apt to have established in gaps.  The source of individuals is important and may relate to niche partitioning.    

 

Line 59.  “community” at the end of the line does not seem necessary and could be deleted.     

 

Materials and Methods:

 

Line 76.  To clarify you could add “species are listed” to the beginning of the part in parentheses.

 

Line 97.  What is the source of equation 1?  There needs to be some justification given for using the same equation for all species. 

 

Lines 117-118.  This sentence is confusing.  By “stands” do you mean “stems”.  I assume this is stems that reached a height where GBH could be measured, but this is not clear.  What was the size cutoff for including stems?  Also, “recruitment” may not be the best term as I think of this as establishment from seed whereas I assume that you mean a stem has reached a specific size.

 

Line 119.  How did you separate shrubs from small trees or were species that could be considered shrubs included as trees?    

 

Lines 125-126.  Did any stems die during the sampling interval?  If so, how were these treated when calculating productivity? 

 

Results:

 

Line 160.  Do these counts include all stems or only the largest stem for an individual?  Some plants could have multiple stems from the base or forks below GBH height.  I assume that these counts include all stems, but this needs to be clear; the Methods would probably be the best place to describe how stems were counted.          

 

Lines 169-170.  Do you mean that this is the range in values among the subplots?    

 

Lines 173-174.  Does tree density refer to all trees >5 m tall?  In essence all trees that are not understory trees.  Is this number of stems or individuals from the same root system?

 

Figures 6 and 7.  I assume n (number of subplots) is 80 for each figure.  This could be in the figure captions.  Also in Figure 7, does tree density refer to understory trees only?  This is not clear. 

 

Discussion:

 

Line 197.  Delete “that”.    

 

Lines 210-211.  It might be useful to add something about size and relative growth rate.  Because understory trees are smaller than canopy trees they have less wood that has accumulated over many years (and is mostly dead) as in canopy trees, which results in higher relative growth rate of small than large trees when based on all wood.  The relative growth rate of understory trees may not be as much higher if based on live wood or leaf area (or mass).    

 

Lines 220-221.  The last part of the sentence is unclear and needs to be reworded.

    

Line 230.  Change “grow” to “growing”.  Also there needs to be some clarification of not growing.  Do you mean in height?  Many shrubs have multiple stems with new ones growing that replace old stems that die.  However the height of the plant may not change.    

 

Line 231.  Remove either “did” or “could”.      

 

Line 270.  I am not sure what “until regeneration” refers to.  Clarification is needed.

      

Line 278.  Do you mean snow breakage of stems?  It seems that snow cover alone would not cause stem mortality.    

 

Author Response

Dear Reviewer 1

Thank you for your review, pertinent suggestions, and constructive comments. We have revised our manuscript, and hope our comments and corrections are a proper response to your careful peer review.

Please see the attachment.

Sincerely

Author Response File: Author Response.docx

Reviewer 2 Report

see the attached document

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 2

Thank you for your review, pertinent suggestions, and constructive comments. We have revised our manuscript, and hope our comments and corrections are a proper response to your careful peer review.

Please see the attachment.

Sincerely

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Thanks authors for considering the comments that I raised. Sufficient revisions have been made and manuscript appears improved.