Estimation of Ecosystem Services Provided by Street Trees in Kyoto, Japan

Round 1

Reviewer 1 Report

I found the study very interesting, overall methodology sounds convincing and this is a timely manuscript considering the necessity of the cost-benefit analysis of street trees. While saying so, usually a generic model such as i-Tree also comes with lot of assumptions and validating it for example, the underlying allometric relationships of trees are not that straight forward to use in different geographically distant places than in US. At the same time, for a bold statement on convincing planners to plant more trees should be taken better care while mentioning the values not as bold as it appears at the same time, give an overall impression of the overall importance of trees should be stressed. I believe a moderate revision will improve the manuscript much better. In particular, introduction section needs substantial modification while discussion require moderate modification.

Specific comments:

Line 17: I was wondering, how these two sentences are coherent? The mentioned species are the largest groups within the sampled trees and thus they provide US$58/tree of ecosystem services. – Rather, the readers should know what are methods of calculations and then the results. What are the temporal dimension of these values – energy savings only 1.7 dollar for the trees up to present state?

All the values at the present rates are not too convincing for highly valued urban landscapes for the planners or managers. The authors should try to convey more as an additional values.

Line 31-34: Please consider rephrasing it with two simple sentences rather such a big sentence with too many facts. Moreover, consider English editing such as: .. impact urban ecosystems … not impacts…

Overall, introduction is weak. The state of the art of knowledge is missing. Simply, stating that i-tree Eco needs to be validated in Kyoto is not enough. If the authors are trying to answer the objective three – you need to clarify some solid facts/figures regarding the major ES from the street trees. Please see some recent publications for example, for cooling benefits:

Rahman et al. (2020). Traits of trees for cooling urban heat islands: A meta-analysis. Building and Environment.

Rahman et al. (2020). Tree cooling effects and human thermal comfort under contrasting species and sites. Agricultural and Forest Meteorology.

Rahman et al. (2017). Microclimatic differences and their influence on transpirational cooling of Tilia cordata in two contrasting street canyons in Munich, Germany. Agricultural and Forest Meteorology.

For storm water management:

Xu et al. (2020). Surface runoff in urban areas: The role of residential cover and urban growth form. Journal of Cleaner Production.

Rahman et al. (2019). Comparing the infiltration potentials of soils beneath the canopies of two contrasting urban tree species. Urban Forestry & Urban Greening.

Urban tree models:

Rötzer et al. (2020). Modelling urban tree growth and ecosystem services – review and perspectives. Progress in Botany

How i-tree model code iterations can be used to calculate cooling and pollution depositions:

Pace et al. (2020). A single tree model to consistently simulate cooling, shading, and pollution uptake of urban trees. International Journal of Biometeorology.

 

How to read/interpret Table 1? Row wise or Row – column wise?

Line 280: Why local name is used instead of scientific name?

Line 293: Reference quote, by [58].

Table 8: Interesting, showing the tradeoffs with some negative values!

Line 372: Now I understood, the benefits are calculated on annual basis! However, does this mean the cost is higher than the benefits $90 vs $ 58? If so, the authors need to be very careful to illustrate it properly, as I have already mentioned in the beginning!

Line 388: This study in Kyoto is the first to use real street tree samples in the quantification of ES, … may be something like, This study in Kyoto is the first attempt to use the empirical data in quantifying the ES from street trees…..

Line 398: Many previous studies… but where are the references?

Line 403-412: Can you please related some studies where climate and the growth conditions have impact apart from the heavy pruning practice in Kyoto for the lower structural dimensions of specific tree species. Too much stress on some species also send a negative impression (in particular keeping the biodiversity agenda in mind). May be the authors can also try to mix the concepts of growth conditions, heavy pruning and mixtures of different tree species with bigger stature?

Line 441: This point also needs to be addressed while talking about the higher cost! Counting the cost at higher end (Japan) while using the gains at lower cost (US) might also cause the anomalies!

 

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript "Estimation of ecosystem services provided by street trees in 2 Kyoto, Japan" describes one of the first 12 applications of the i-Tree Eco international project. A tool developed by the USDA Forestry Service has been used to quantify the value of ecosystem services such as carbon storage, stormwater runoff reduction, adverse (physical) health mitigation and energy savings, starting with different street tree species which dominate the street scapes of Kyoto. In doing so, the authors can compare the specific annual benefits of these species and present a tool to support policy-makers in priority-setting.

This study for the first time adopted the i-tree model for street trees in Japan.

Detailed comments:

The abstract is informative but misses a description of the method itself which has been enourmously used all over the world in younger history.

In the introduction, the authors only refer to physical health improvements even though mental health improvements may even have a greater contribution (see e.g. Marselle et al. 2020). The increase of property values is problematic as a potential social disruptor and should not be considered as a service by itself. The objectives are decribed well.

In the methodology section the authors already account for the limited value of the assumptions in the model originally made for the US. Much information is given concerning the input data for the model in a very transparent way. Only for human health effects the assumptions seem to be crude (referring to most comparable cities and counties in the US) and concentrate on reduction of air pollution. In table 5, results are shown for each air pollutant and adverse health effect. These effects seem to be summarized even though this is incorrect in epidemiological and environmental burden of disease studies due to concurring effects.  

The discussion is very short and lacks a description of the uncertainties when considering health effects. Levels of uncertainty would have been very helpful to better represent the epidemiological studies which were implemented in the overall model.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Dear authors,

I am still a bit irritated that you did not take mental health improvements into account, but maybe this was done not to have to run new modelling.

But cosidering you new discussion chapter and the conclusions (especially the additions to the limitations sector I am fine now with the manuscript.

Go ahead, and thumbs up!