Aesthetic Quality Assessment of Landscapes as a Model for Urban Forest Areas: A Systematic Literature Review

Round 1

Reviewer 1 Report

Dear authors,

in your manuscript you address an important topic of current research on the visual aesthetics of the environment and its perception, assessment and influence by humans/society. The manuscript contains many important approaches and presents the methodological procedure of the review process in a largely comprehensible way. The manuscript as a whole has been carefully prepared. Nevertheless, there remain some substantive issues and important basic notes that can help improve the manuscript via structural revision and meaningful, concise additions. I would strongly encourage the authors to revise their manuscript in detail. It can be an enrichment for the thematic focus of the aesthetics of urban forests, if the repeatedly mentioned criteria and indicators, which are derived from the research, are then also named more concretely. Additional literature research will certainly be required in some parts.

The main problem of the manuscript lies in the mixing of spatial scales and objects of observation and in the high claim to infer from philosophical schools to practical methods of assessing urban aesthetics.

Content-related comments

In the title, the authors use and weight the terms "Aesthetic Quality Assessment" with reference to "Urban Forest Areas". The resulting expectations of the reader can only be fulfilled to a limited extent by the actual content of the manuscript.

Introduction:

-        First, it should be very clearly defined and detailed what the authors mean by "Urban Forest Areas", but also what can be defined as a result of the literature review. Unfortunately, some rather general explanations and references to the urban forest do not follow until Section 3.5. It should be clear to the reader from the outset what we mean by "urban forest areas." What are the special features compared to other forest areas? What are the demands of people/society on urban forest lands? Why are "urban forest areas" so important and continue to gain in importance? What does this mean for the consideration, recording and evaluation of aesthetics? Important aspects of Section 3.5 could be integrated here.

-        Throughout the manuscript, the emphasis is on the aesthetics of landscape, and interesting references are made to it. In fact, "Urban Forest Areas" are usually only a small part within a landscape, i.e., a landscape element. To achieve the goals of the manuscript, this relationship and the issue of spatial scale/unit of observation must be clearly presented. It might make sense to clarify the title, which already makes this connection, e.g.

"Aesthetic quality assessment of landscapes as a model for urban forest areas". This is just a basic suggestion. This would better describe what you are conveying and analyzing in your manuscript. What do we know about the qualitative assessment of aesthetic elements in the landscape and how can these approaches be applied to "Urban Forest Areas"? - if that is what you actually want to present.

 -        p. 2, line 70-77: The presentation of the objectives should be adapted to a new sequence of the manuscript structure and needs more concrete explanations. What is the objective of each thematic paragraph and how does it relate to the title/ to "Urban Forest Areas"? How do the individual items contribute to the clarification/analysis of the overall manuscript goal?

Materials and Methods:

The selection of the final keywords is understandable, but it seems necessary to add important keywords like "criteria" or "indicators". Also in this section it becomes clear that a strict focus on "Urban Forest Areas" regarding the aesthetic aspects will hardly be possible, as the authors already show that the keywords (e.g., Scenic beauty) are mostly related to the landscape context. It would be interesting to see what impact the landscape-related keywords have on the overall research and subsequent informative value. Graph 1 should show the number of publications on the keywords/keyword combinations for each selection level.

p. 2, line 96: Is it really appropriate to use the keyword "forest area" when focusing on "urban forests"?

p. 3, line 102: Why was the search window limited to the 2014-2020 period? Especially in the USA, Great Britain, Japan, Scandinavia and Central Europe, there were corresponding publications on this topic much earlier. This also applies to some books. Therefore, the question arises whether the exclusive use of publisher-related OA databases is really the optimal way to go. Here should be researched again.

Here are just a few examples:

·        Bruce, V.; Green, P.R.; Georgeson, M.A. Visual Perception: Physiology, Psychology and Ecology, 4th ed.; Psychology Press: New York, NY, USA, 2003.

·        Kaplan, R.; Kaplan, S. The Experience of Nature: A Psychological Perspective; Cambridge University Press: New York, NY, USA, 1989.

·        Konijnendijk, C.; Kjell Nilsson, Thomas Randrup, Jasper Schipperijn. Urban Forests and Trees:

A Reference Book; Springer: Berlin, Heidelberg, Germany, 2005. https://doi.org/10.1007/3-540-27684-X

·        FAO. 2016. Guidelines on urban and peri-urban forestry, by F. Salbitano, S. Borelli, M. Conigliaro and Y. Chen. FAO Forestry Paper No.­178. Rome, Food and Agriculture Organization of the United Nations.

·        Krott, M.; Nilsson, K. Urban forestry: multiple-use of town forests in international comparison. IUFRO Working Group S.6.14.001998, Wuppertal, Germany, 1998.

Figure 1: How did the reduction in publications from "identification" to "screening" come about? Is this mainly due to the time window chosen?

Please check the spelling: "The article mast be in English language".

p. 4, line 118-120: What exactly is behind the categories, z. B. "factors", "variable"? Please explain in more detail.

Results and Discussion:

p. 4, line 124-125:  For the entire manuscript, the equation of landscape and forest aesthetics is problematic (see comment above). It would be important to clarify what specific definitions and basic assumptions emerged from the review for aesthetics in urban forests.

p. 4, line 150-152: If the focus is to be on the aesthetics of urban forests, these very physical parameters and their perception are of extreme importance as they characterize the forests. Important aesthetic elements in forests have been shown to be: tree species mixtures, structural diversity, deadwood, flowering trees, sight lines, foliage color and so on. Without naming these elements, assessment, evaluating, and shaping forest aesthetics makes no sense.

Some examples of the direct combination of forest management and aesthetics:

 ·        Ribe, R.G. Aesthetic perceptions of green-tree retention harvests in vista views. The interaction of cut level, retention pattern and harvest shape. Landsc. Urban Plan. 2005, 73, 277–293.

·        Mao, B.; Gong, L.; Xu, C. Evaluating the Scenic Beauty of Individual Trees: A Case Study Using a Nonlinear Model for a Pinus Tabulaeformis Scenic Forest in Beijing, China. Forests 2015, 6, 1933–1948.

·        Hoffman, R.E.; Palmer, J.F. Silviculture and Forest Aesthetics within Stands; USDA Forest Service; Northeast Experiment Station; The New York Center for Forestry Research and Development: New York, NY, USA, 1996.

·        Palmer, S.E.; Schloss, K.B.; Sammartino, J. Visual Aesthetics and Human Preference. Annu. Rev. Psychol. 2013, 64, 77–107.

·        Ruddell, E.J.; Gramann, J.H.; Rudis, V.A.; Westphal, J.M. The Psychological Utility of Visual Penetration in near-view Forest Scenic-Beauty Models. Environ. Behav. 1989, 21, 393–412.

·        Price, C. Quantifying the aesthetic benefits of urban forestry. Urban Forestry & Urban Greening 1(3) 2003, 123-133. https://doi.org/10.1078/1618-8667-00013

·         p. 4, line 158: "Philosophy and Background of Aesthetics" - Here, an adjustment of the heading would be useful, since you are primarily contrasting the two paradigms.

p. 4-6: This is a very interesting section, but it should be better connected to the main focus and objective. What references does this make to the aesthetics of urban forests?

Table 1: The individual aspects need better explanation. Once again, "landscape quality assessment" is referred to rather than "urban forest aesthetics". This is irritating. For example, what physical or psychological criteria are meant? It is of great interest for implementation and transferability that these criteria are precisely named and listed. This is also the only way to identify commonalities between the two theoretical approaches.

Why is objective assessment cheap? This must be backed up with measurements or expertise. The strict comparison of the two theoretical approaches is very black and white, which does not correspond to the real implementation.

How is that meant? "Aims to understand the physical characteristics of the landscape, mostly for the purpose of management". In Central Europe, there are so-called forest function maps that identify areas of particular relevance to forest aesthetics, and these are then shaped in terms of aesthetic optimization using silvicultural methods. This knowledge of the aesthetic impact of forests is based on numerous surveys and interviews.

Figure 2 and 3: An attempt could be made here to combine the two graphs.

p. 7, line 249-274: "Expert approach" – In the manuscript, the statement has a negative connotation, as you imply that experts have no knowledge of the aesthetic demands of the population, but then they would not be experts in this field. The expert knowledge (so called Delphi studies/ Delphi method) is usually fed by the findings collected via surveys, studies and excursions. For decades, a pure focus on timber management concerns has not corresponded to reality, especially in urban forests worldwide. Further aesthetic improvements are of course possible through ever new findings.

Perhaps the term "expert approach" is a bit misleading, as it is the philosophical approach you outlined. This should be emphasized more.

p. 9, Table 2: Here again the term "landscape quality" is used. It would be advantageous if the table structure is divided into advantages and disadvantages and the first column contains the criteria.

"No variation of opinion because the expert is one person". – This is a contradiction to "Ease of application based on the specific rules or guidelines". These guidelines are of course not worked out by one person (see comment above).

à In conclusion, it remains to say about the 3 division of approaches that the representation in a flow chart would certainly be more purposeful, because the approaches always interlock and it depends on what the "converging approach" feeds its information from. The strict juxtaposition seems difficult.

The following sections are the real core of the manuscript, if you follow the title and objectives!

p. 9, section 3.4: This section should be immediately combined with subsequent sections A and B. Here the reference to the focus "Urban forests" has to be made. As mentioned earlier, landscape is only one overarching spatial scale.

p. 9-11: These sections contain the variables and criteria that are truly relevant to the recording and evaluation of (urban) forest aesthetics. The compilation in Table 3 is very good and needs to be more closely related to forest aesthetics. The synonyms listed here are also the parameters that can be recorded and evaluated using both theoretical approaches. They should be supplemented by other parameters and precisely defined in terms of forest aesthetics. For example, what does the term/characteristic "uniformity'" encompass and how is it to be evaluated with regard to urban forest aesthetics?

p. 11-12: "Benefits of Urban Forest Aesthetics" – This section should be integrated earlier in the manuscript, as it illuminates the relevance of the entire manuscript and the focus.

p. 12-13, Table 4: Descriptions must be specified and please be supported with references as in Table 3.

p. 13, line 446-449: The following sentences are symptomatic of the entire manuscript: "Due to the lack of a clear assessment of aesthetics, researchers used the preferences method to determine aesthetic values. However, values of preferences do not have to be purely individual; it can also be collectively expressed by experts and non-experts [7,56]". Unfortunately, the statements remain very general and they contradict each other somewhat in the statements. Also left open at the end of the manuscript is the question of what specific criteria have emerged from research as appropriate for evaluating urban forests or are suggested by the authors. It is not that there are no parameters or criteria for assessing aesthetic values in forests.

p. 14, line 481-483: The following statement seems very bold, since it is the design of urban forests that has the longest tradition in the world of focusing on aesthetic values and regularly evaluating them based on visitor preferences. à "However, there is a limited number of literatures relevant to management, assessment, and planning for urban forest aesthetics [82]. Besides, there are no clear urban forest policies designed to promote aesthetic measurement and values."

p. 14, line 511-513: This very connection is not clear to me, since the urban forest is only a sub-area in the overall landscape context. Critics might turn the argument around and claim that spatial levels of consideration are then irrelevant and urban forests, which are located in already attractive landscapes, do not need special consideration in their aesthetic design.

Comments for author File: Comments.pdf

Author Response

Response to reviewer 1 by using word file 

Author Response File: Author Response.docx

Reviewer 2 Report

This is an interesting paper and can significantly contribute to the field of urban forestry. I have given detailed inputs (see comments and notes related to highlighted sections) in the attached PDF file. Overall, I see the following three areas that require significant work -

1) In a systematic review paper, it is expected that authors document all the articles/documents, authors, disciplinary areas, locations, and years of publications in the method/material section or the early phase of the finding.

2) Authors should also work on their writing expressions in the result sections. It often reads literature reviews than findings extracted from the 81 documents. It is better to isolate the literature discussion from the result sections. Please also consider simplifying some of these terms - for example, what is the subjective/ objective paradigm? These are hard to follow.

3) There are many typos and grammatical errors from top to bottom. I started to pick those initially, but I just lost patience after some time. The paper should undergo thorough proofreading and English language editing by professionals.

Comments for author File: Comments.pdf

Author Response

Response to reviewer 2 by using word file 

Author Response File: Author Response.docx

Reviewer 3 Report

Thank you for the opportunity to referee this paper.

The link between urban area, forest and aesthetic value is very interesting.

However, the promise of this analysis, indicated in the title, is not maintained.

Probably there is a problem in the criteria used to select papers.

Only few papers (number 17,18,20,24,32) for example, are about this topic.

Great part of them are about forest OR Landscape OR Aesthetic value.

For this reason, the results are too general and not related to urban forests.

The authors describe methodology, criteria and indicators universal used to assessment of natural or rural landscape and not specifically linked to urban forests.

Author Response

Response to reviewer 3 by using word file 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear authors,

the careful revision has given the manuscript a very good quality. The hypotheses, structure and objectives of the manuscript are now very well understood. The manuscript is a real asset in the context of the visual aesthetics of urban forests and landscapes. I am pleased with the careful revision.

Reviewer 2 Report

I commend the authors for the comprehensive revision - it is now much improved. I still see unclear expressions and grammatical errors in places which require careful proofreading.

Comments for author File: Comments.pdf