A Predictive Model of Leaf Flammability Using Leaf Traits and Radiant Heat Flux for Plants of Fire-Prone Dry Sclerophyll Forest
Round 1
Reviewer 1 Report
The Authors presented a predictive model of leaf flammability based on two leaf traits: Leaf Mass per Area (LMA) and Leaf Area (LA), including also Leaf Water Content (LWC) and a calculated Radiant Heat Flux (RHF) based on 10 representative species of Blue Mountains (New South Wales Australia). The model and its performances were also tested using different and previous datasets of plant traits.
The article is well written and quite understandable even to non-experts in modeling.
It is very focused on validating the model with local (perhaps regional) datasets of plant species (excluding conifers but maybe they are not growing there) possibly reducing a bit the global scientific interest.
I am not sure if Figures 1-3 could be considered M&M or moved to Results in some way as they are describing results of flammability tests. I leave this suggestion to the Editor.
The LWC was not stressed enough maybe because the samples were collected on the same day/s (it is not described in M&M)? and the intra- and interspecific variation of LWC is not shown or considered when results are discussed.
In my opinion, the consideration of only two foliar traits reduces a little the overall transferability of the model.
However, the quality of the work is good so I think it can be considered for publication with few adjustments.
Line 32. Leaf represents an important part of the biomass of plant species to be considered during a fire, but they are not the only relevant element. Even twigs, stems, and all wood organs with a diameter of less than 5 mm are considered very important for the flammability in the major wildfire predictive models. Please slightly modify the sentence.
Lines 81-83. I suggest including more details in the sampling methodology. How extended was the area from which samples were collected? How plants were selected? And above all, did you maintain a rigorous and standardized sampling method of the branch from each individual? Position on the crown, orientation of the sampling and the degree of exposure or coverage of the individual from whom the sample was taken have a significant influence, at least, on its water and in volatile flammable compounds content, lignification rate, etc. reflected in flammability.
Line 100. Did you make a bulk of all leaves or how you selected the leaves to be used for the 4 different temperature tests?
Line 194. In the caption of Figure 3 you should specify which are the pink (included?) and which are the browns (not included?)
Line 270. Please change 'volatile oils' to 'Flammable BVOCs'. I suggest the following citation to be included here as the authors considered specifically the role of both flammable BVOCs and water content in terpenoids in flammability of storing and non-storing forest species: Della Rocca G, Madrigal Olmo J, Marchi E, Michelozzi M, Moya B, Danti R. Relevance of terpenoids on flammability of Mediterranean species An experimental approach at a low radiant heat flux. IForest. 2017;10(5):766-75.
This aspect could be also considered in the Introduction.
Author Response
We thank the reviewer for their helpful comments. We have added further detail on collection of leaf samples (second paragraph of Materials and Methods), and also on the ranges of LWC (data added to Figure 3). We believe that our approach of using the minimal number of leaf traits necessary to model the flaming response actually broadens the utility of the model and belies the predictive power of these two traits. If a larger number of traits, or traits not as commonly collected as LA and LMA were needed to give accurate results, time consuming collection of new leaf trait data might be required to apply the model.
Line 32. Leaf represents an important part of the biomass of plant species to be considered during a fire, but they are not the only relevant element. Even twigs, stems, and all wood organs with a diameter of less than 5 mm are considered very important for the flammability in the major wildfire predictive models. Please slightly modify the sentence.
>We have clarified the purpose of this sentence with additional text (lines 38-40). Our intention was to describe the importance of LMA and LA in determining the flammability of a leaf.
Lines 81-83. I suggest including more details in the sampling methodology. How extended was the area from which samples were collected? How plants were selected? And above all, did you maintain a rigorous and standardized sampling method of the branch from each individual? Position on the crown, orientation of the sampling and the degree of exposure or coverage of the individual from whom the sample was taken have a significant influence, at least, on its water and in volatile flammable compounds content, lignification rate, etc. reflected in flammability.
>We have expanded the section in the Methods and Materials with further details on sampling.
Line 100. Did you make a bulk of all leaves or how you selected the leaves to be used for the 4 different temperature tests?
>Leaves were selected haphazardly from the replicate branch sections. Detail added to line 107.
Line 194. In the caption of Figure 3 you should specify which are the pink (included?) and which are the browns (not included?)
>Details added to the figure legend.
Line 270. Please change 'volatile oils' to 'Flammable BVOCs'. I suggest the following citation to be included here as the authors considered specifically the role of both flammable BVOCs and water content in terpenoids in flammability of storing and non-storing forest species: Della Rocca G, Madrigal Olmo J, Marchi E, Michelozzi M, Moya B, Danti R. Relevance of terpenoids on flammability of Mediterranean species An experimental approach at a low radiant heat flux. IForest. 2017;10(5):766-75.
This aspect could be also considered in the Introduction.
>We have added this paper to the Discussion.
Reviewer 2 Report
The article explores research gaps in predictive models for leaf flammability. Its emphasis is experimental, on fire-prone dry sclerophyll species and focused on the relationship between plant flammability and leaf traits.
The article presents a consistent and detailed experimental design, making its reproducibility and verification easily possible.
However, its results are little explored, and the discussion is limited and almost focused on the analysis of accuracy. Likewise, there is no specific session regarding conclusions, with a few conclusive elements being presented along with the discussion. This is the aspect that needs to be improved in the presented text.
Author Response
We thank the reviewer for their comments. We have expanded the Discussion with further detail on the potential uses of the model.
Reviewer 3 Report
The authors present predictive model for leaf flaming based on plant traits that are commonly available. The model was shown to provide high accuracy in predicting leaves initiating flaming combustion.
I found this paper to be very clearly written and think the results are useful for the wildfire modeling community. I look forward to future results and contributions.
Author Response
We thank the reviewer for their comments.
Reviewer 4 Report
Este artículo presenta un interés para la comunidad con respecto a los incendios y cómo pueden afectar las hojas de los árboles o plantas estudiados. La introducción es corta, pero bastante clara a la hora de centrarse en el tema a exponer. Material y métodos es el que parece más largo y pesado a la hora de leer, pero veo que si alguien tuviera que reproducirlo según las pautas establecidas por los autores, sería difícil hacerlo y costaría mucho trabajo. Los gráficos explican con precisión lo que se hizo en el artículo. Los resultados después de tanta explicación en material y métodos de cómo hacer el modelo, me parecen escasos y la discusión es corta, pero detallada.
This article is of interest to the community regarding fires and how they may affect the leaves of the trees or plants studied. The introduction is short, but clear enough to focus on the subject. Material and methods seem the longest and heaviest when it comes to reading, but I see that if someone had to reproduce it according to the guidelines established by the authors, it would be difficult todo so and would costa lot of work. The graphics accurately explain what was done in the article. The results after so much explanation in material and methods of how to make the model, seem to me scarce and the discussion is short, but detailed.
Author Response
We thank the reviewer for their comments. We have expanded the Discussion with further detail on the potential uses of the model.
