Data-Driven Approach for Optimising Plant Species Selection and Planting Design on Outdoor Modular Green Wall with Aesthetic, Maintenance, and Water-Saving Goals

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper is highly relevant to urban development in CBDs.  In general, the descriptions of the different algorithms are clearly explained.  There are however some problems with the descriptions of the ‘Experimental Setup’, particularly the presentation of the data in the Figure and Tables.

Table 1’s List of plant forms raises a number of questions; in particular the inclusion of trees as a category.  A tree form would not be possible on a vertical green wall.  On enquiring about Green Walls in SE Asia, apparently Ficus spp are used as climbers and require constant pruning.  I suggest that the category ‘Trees’ should be replaced by ‘Climbers’.  This would also require that Philodendron sp be reclassified as a Climber.

2.3.3 Preparation and Set Up.  Whether the plant seedlings are all the same age needs to be clarified; not just that they were in a glasshouse for 30days.

2.4 Measurements & Data Collection.  The Health Rating 5-1 is inconsistent in that only Rating 4 mentions the condition of the plant form.  Also under 2.5.1 lines 287-290, root development is not accounted for, when it is a key factor in 2.4.1 rankings 5-1?

The presentation of the data in the tables and figures needs to be redone as it is quite difficult to interpret.  All figures and Tables need adequate legends, especially Figures 3, 5, & 6.  Figure 5 is particularly difficult to interpret.  Why is there only one colour bar when there are 2 different criteria being assessed?

Table 4 is also confusing.  Why are the top and marginal performers included together?  Suggest doing three different tables so species can be included, hen use current Table 4 as an overview.

Figure 1 needs a spell-check.

4. Discussion. Under 4.3, why only use increase in height as a criterion? – What about branching, variation on leaf morphology such as filamentous etc?

4.4 Limitations.  Suggest using separate variables lists; one to cover morphological attributes and how they relate to the objectives currently stated. Two – the current list retitled Environmental Objectives.  

Author Response

Comments 1: This paper is highly relevant to urban development in CBDs. In general, the descriptions of the different algorithms are clearly explained. However, there are some problems with the descriptions of the ‘Experimental Setup’, particularly the presentation of the data in the Figures and Tables.

Table 1’s List of plant forms raises a number of questions; in particular, the inclusion of trees as a category. A tree form would not be possible on a vertical green wall. On enquiring about Green Walls in SE Asia, apparently Ficus spp are used as climbers and require constant pruning. I suggest that the category ‘Trees’ should be replaced by ‘Climbers’. This would also require that Philodendron sp be reclassified as a Climber.

Response 1: Both species Ficus elastica and Ficus elastica ‘Melany’ are NOT climbers species, they are indeed tree species, these species are supposed to be pruned regularly on green wall. Although both Philodendron ‘Lemon Lime’ and Philodendron tatei ‘Congo’ tends to be hemi-epiphytic, they are still under Herbaceous category, and this plant habit should reflect their plant performance related to their physiology and its climbing trait is less relevant to our research focus. We wish to minimize the number of categories to enable us to draw meaningful conclusions. Thus, the plant form of these 4 species remained unchanged.

Comments 2: 2.3.3 Preparation and Set Up. Whether the plant seedlings are all the same age needs to be clarified; not just that they were in a glasshouse for 30 days.

Response 2: Thank you for pointing this out. The age of the plant seedlings cannot be determined, and standardized, but the sizes of replicates in each species are almost the same. To ensure this, plants were checked during preparation and installation. The sentence “Plants individuals in each species were similar in size to minimise discrepancy.” had clarified the status of plant materials in 2.3.2. Plant species.

 

Comments 3: 2.4 Measurements & Data Collection. The Health Rating 5-1 is inconsistent in that only Rating 4 mentions the condition of the plant form. Also, under 2.5.1 lines 287-290, root development is not accounted for, when it is a key factor in 2.4.1 rankings 5-1.

Response 3: Thank you for your observation. We revised the Health Rating criteria for consistency and ensure that root development is properly accounted for in the analysis.

Comments 4: The presentation of the data in the tables and figures needs to be redone as it is quite difficult to interpret. All figures and tables need adequate legends, especially Figures 3, 5, & 6. Figure 5 is particularly difficult to interpret. Why is there only one colour bar when there are 2 different criteria being assessed?

Response 4: Thank you for your feedback. We revised the tables and figures for clarity and ensure that all figures have comprehensive legends, particularly addressing the issues in Figure 5 by 2 legends representing water demand and difference in health rating. Legends was also added for Figure 3 and 6.

Comments 5: Table 4 is also confusing. Why are the top and marginal performers included together? Suggest doing three different tables so species can be included, then use current Table 4 as an overview.

Response 5: Thank you for this suggestion. The Plant codes were added in Table 4 to state clearly top and marginal performing species. Readers can refer to Table 1 for their species name. Both top and marginal performers were included to provide a holistic view by diversifying the plant selection when marginal performers are included.

Comments 6: Figure 1 needs a spell-check.

Response 6: Thank you for bringing this to our attention. A spell-check was done on Figure 1.

Comments 7: Discussion. Under 4.3, why only use increase in height as a criterion? – What about branching, variation in leaf morphology such as filamentous, etc.?

Response 7: Thank you for this valuable suggestion. It is observed that branching and variations in leaf morphology was not discernible within the 21 days of experiment period, despite the shoot and leaves elongated and grew. These measurements were recorded in longer study experiment.

Comments 8: 4.4 Limitations. Suggest using separate variables lists; one to cover morphological attributes and how they relate to the objectives currently stated. Two – the current list retitled Environmental Objectives.

Response 8: Thank you for your input. We revised Section 4.4 (now Section 4.5) to include separate variable lists as suggested, clarified the morphological attributes and environmental objectives.

Reviewer 2 Report

Comments and Suggestions for Authors

Section 2.1. Research framework presents a Data-driven approach for optimising plant species selection and planting design on LW. It is necessary to give a more detailed description of the proposed approach, in which software package it is implemented, what are the technical limitations.
All monitoring and measurements were carried out in the three-week study period from January 24 to February 14, 2022. Why was this period chosen, is it sufficient for the plant growth period? Is it sufficient to verify the data obtained according to the proposed data-driven approach for optimising plant species selection and planting design.
It is not entirely clear from the text of the article whether a comparison was made with other similar approaches described in the Introduction? Also, how will the obtained data change at other times of the year? To what extent are the recommendations given by the authors applicable if they were obtained during the study period of less than a month? How will the specified parameters change at higher temperatures, solar radiation, etc.

Author Response

Comments 1: Section 2.1. Research framework presents a Data-driven approach for optimising plant species selection and planting design on LW. It is necessary to give a more detailed description of the proposed approach, including which software package it is implemented in and what the technical limitations are.

Response 1: Thank you for your feedback. We revised and provided a more detailed description of the data-driven approach, including the software. As this is a common software with straight-forward function setting, no technical limitations were anticipated.

Comments 2: All monitoring and measurements were carried out in the three-week study period from January 24 to February 14, 2022. Why was this period chosen? Is it sufficient for the plant growth period? Is it sufficient to verify the data obtained according to the proposed data-driven approach for optimising plant species selection and planting design?

Response 2: We clarified the rationale behind the chosen study period and discuss its adequacy for plant growth and data verification. Although this study originally had planned for a 8-weeks monitoring period, the experiment was terminated due to the mandatory closure of campus with the onset of fifth wave of COVID-19 pandemic in Hong Kong. We acknowledged that the 3-weeks data is not ideal, but it is adequate to fulfil the objectives of the proposed data-driven approach for optimising plant species selection and planting design. This can be justified by instant morphological changes visible (e.g. plant health performance, plant height) under water constraints and could be measured and observed within weeks. For these chosen parameters, this monitoring period can definitely serve its purpose, but for other environmental parameters, the monitoring period should be reviewed and adjusted accordingly.

Comments 3: It is not entirely clear from the text of the article whether a comparison was made with other similar approaches described in the Introduction. Also, how will the obtained data change at other times of the year? To what extent are the recommendations given by the authors applicable if they were obtained during the study period of less than a month? How will the specified parameters change at higher temperatures, solar radiation, etc.?

Response 3: We appreciate the reviewer’s insightful comments and would like to address the points raised as follows:

Comparison with Similar Approaches: We compared two data-driven approaches deployed in our study: (1) the health rating threshold approach and (2) the random forest and hierarchical clustering approach for LW plant selection groupings. This comparison is detailed in Sections 3.8 and 3.9 of the manuscript. Currently, we have not identified any other similar approaches in the literature for comparison. There was a remark in Section 1.1. Introduction stating that “No previous research had tackled the interface of deploying empirical plant growth data and the formulation of a plant selection tool to support multiple project objectives for LW” , it clarified the absence of comparable studies.

Acknowledgment of Limitations: We have included a discussion of the limitations of our study in Section 4.5, noting that it does not account for seasonal variations and the corresponding plant responses during summer, particularly under conditions of high temperature and intense solar radiation. This limitation arose due to the unexpected closure of the campus and constraints on available resources.

Focus and Future Directions: It is important to clarify that the primary aim of this paper is not to investigate seasonal variations in plant responses, but rather to develop a data-driven model that facilitates plant selection and design. We anticipate that additional empirical data will be incorporated in future research to enhance the comprehensiveness of the model, making it more robust and applicable across various environmental conditions.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is very well written,but some improvements are required:

1.a better organisation of the abstract

2.the originality of the approach developed by the authors and a comparison with similar published articles.

3 the Figure 6-a better resolution.

4.suggestion for industrial implementation of the authors method presented in the article

Comments on the Quality of English Language

To be improved

Author Response

Comments 1: The manuscript is very well written, but some improvements are required: a better organisation of the abstract.

Response 1: Thank you for your feedback. We will reorganize the abstract for improved clarity and coherence.

Comments 2: The originality of the approach developed by the authors and a comparison with similar published articles.

Response 2: Currently, we have not identified any other similar approaches in the literature for comparison. There was a remark in Section 1.1. Introduction stating that “No previous research had tackled the interface of deploying empirical plant growth data and the formulation of a plant selection tool to support multiple project objectives for LW” , it clarified the absence of comparable studies.

 

Comments 3: Figure 6 needs a better resolution.

Response 3: We provided a higher resolution version of Figure 6 in the revised manuscript.

Comments 4: Suggestion for industrial implementation of the authors' method presented in the article.

Response 4: Thank you for your suggestion. We added paragraphs discussing potential industrial implementations of our method in the revised manuscript in Section 4.2.  To realize this data-driven approach to industrial implementation, it requires ex-pertise on frontend and backend development of application’s architecture. The process of application development is out of scope of this paper.

Reviewer 4 Report

Comments and Suggestions for Authors

Living wall design is a new direction in landscape design and, unlike
landscape design, has been little studied. The features of living wall
design depend on the location. And although the manuscript was written
by researchers passionate about the problem, it is necessary to shorten
the manuscript, not go into significant details and focus only on the
main problems: plant species, humidity, temperature and lighting.

In the abstract section, it is necessary to remove all growing
conditions, watering, etc., leaving only the important results and
conclusions

122- incorrect phrase

In the Materials and Methods section, only the methodology itself should
be clearly indicated, the description and discussion of the method is
indicated only in the Discussion section

The goals of the project have already been indicated above, moreover,
this section does not describe the goals and objectives.

367 - incorrect phrase

In the Results section, only the obtained results are also indicated,
their discussion should be moved to the Discussion section

Figure 6 - no description of what the pink and blue bands are

609- VG or VGS?

 

Author Response

Comments 1: Living wall design is a new direction in landscape design and, unlike landscape design, has been little studied. The features of living wall design depend on the location. And although the manuscript was written by researchers passionate about the problem, it is necessary to shorten the manuscript, not go into significant details and focus only on the main problems: plant species, humidity, temperature, and lighting.

Response 1: We shortened the manuscript and focus on the main issues as suggested.

Comments 2: In the abstract section, it is necessary to remove all growing conditions, watering, etc., leaving only the important results and conclusions.

Response 2: We revised the abstract to focus solely on the key results and conclusions.

Comments 3: Line 122 - incorrect phrase.

Response 3: Thank you for pointing this out. We corrected the phrase and sentence in line 122.

Comments 4: In the Materials and Methods section, only the methodology itself should be clearly indicated; the description and discussion of the method should be included only in the Discussion section.

Response 4: We revised the Materials and Methods section to focus solely on the methodology.

Comments 5: The goals of the project have already been indicated above; moreover, this section does not describe the goals and objectives.

Response 5: We clarified the goals and objectives in the appropriate section. Please note that the Project objective(s) or goals of VGS project mentioned in Section 2.5.3  are NOT objectives and goal of this study.

Comments 6: Line 367 - incorrect phrase.

Response 6: We corrected the phrase in line 367.

Comments 7: In the Results section, only the obtained results should be indicated; their discussion should be moved to the Discussion section.

Response 7: We revised the manuscript content to ensure that the Results section contains only the obtained results, with discussions moved to the Discussion section.

Comments 8: Figure 6 - no description of what the pink and blue bands are.

Response 8: We added the legend and descriptions for the pink and blue bands in Figure 6.

Comments 9: Line 609 - VG or VGS?

Response 9: We revised the wording used in line 609.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The revised paper addresses all the issues