An Optimization Approach to Assess the Impact of Drying and Dry Matter Losses of Eucalyptus globulus Roundwood and Biomass on Supply Chains Costs and GHG Emissions
Round 1
Reviewer 1 Report
Drying wood in the forest reduces its weight, reducing the costs of the supply chain by reducing the load on transport trucks. However, dry wood requires more energy during size reduction, e.g. chipping. The authors could mention it in the introduction. I wonder what is the balance of energy growth from chipping and transport for wet and dry wood. E.g. variation of the cutting force of the wood depending on the humidity:
Gao, Y., et al. (2021). Analysis and experiment of cutting mechanical parameters for Caragana korshinskii (CK) branches. Forests, 12(10), 1359.
Warguła, Ł., et al. (2020). Symmetric nature of stress distribution in the elastic-plastic range of Pinus L. pine wood samples determined experimentally and using the finite element method (FEM). Symmetry, 13(1), 39.
3.5.Fuel consumption and GHG emissions
Authors should relate their results to those of other researchers.
Lijewski, P., et al. (2013). Research of exhaust emissions from a harvester diesel engine with the use of portable emission measurement system. Croatian Journal of Forest Engineering: Journal for Theory and Application of Forestry Engineering, 34(1), 113-122.
Warguła, Ł., et al. (2020). Influence of the use of Liquefied Petroleum Gas (LPG) systems in woodchippers powered by small engines on exhaust emissions and operating costs. Energies, 13(21), 5773.
Lijewski, P., et al. (2017). Fuel consumption and exhaust emissions in the process of mechanized timber extraction and transport. European Journal of Forest Research, 136(1), 153-160.
Manzone, M. (2015). Energy consumption and CO2 analysis of different types of chippers used in wood biomass plantations. Applied energy, 156, 686-692.
3.6. Supply chain costs
Authors should relate their results to those of other researchers.
Warguła, Ł., et al. (2020). Reduction in Operating Costs and Environmental Impact Consisting in the Modernization of the Low-Power Cylindrical Wood Chipper Power Unit by Using Alternative Fuel. Energies, 13(11), 2995.
To make a very interesting article, however, requires an update of the literature. It also requires comparing your own results with the results of other authors' research.
Author Response
We appreciate the reviewer’s positive comments and suggestions.
We have reviewed the manuscript to include some of the references he/she suggests and that we think are relevant to our paper. Specifically, we have added a few paragraphs and four references in the Introduction (lines 83-86, and line 102 in the updated version of the manuscript) and Discussion (lines 688-694 in the updated version) to include the impact of drying on chipping costs, energy consumption and CO2. Although most of the impacts are related to savings in transport, we agree that the impact on chipping costs should be addressed in this section.
Reviewer 2 Report
This paper investigates the impact of roundwood and residues in-forest drying and DML on supply chain costs and GHG emissions on fourteen supply points and two demand points one demanding roundwood, and another demanding wood residues by comparing four scenarios with different combinations of drying and DML from in-forest drying. The main contribution of this paper is the novelty of studying the combined impact of in-forest drying and DML on the economics and GHG emissions of Eucalyptus globulus wood and biomass supply chains using an optimization approach.
The manuscript is clear, well-written and structured. Nevertheless, a slight better description of how MC values are collected/supposed from each study area per scenario and are treated for the analysis in MCPLAN would be desirable for a better understanding of the results presented. Most of the figures are referred to roundwood. It would be good to present some of them also for wood residues. Specific comments are added in the enclosed document.
Comments for author File: 
Comments.pdf
Author Response
We appreciate the reviewer’s positive comments and suggestions. In lines 258-269 of the revised version of the manuscript, we added a sentence to explain how the drying curves are derived. As we have indicated in the text, the same set of drying curves was used for roundwood and residues. Thus, the results presented, such as monthly MC and drying time, are the same as for roundwood and residues. Regarding truckloads in Figure 8, this includes the total for roundwood and residues combined.
We also thank the Reviewer for providing good and detailed comments. All of them have been addressed and responded to in the attached pdf file.
Author Response File: Author Response.pdf
Reviewer 3 Report
Good job authors. The study is of interest to international readers and is quite well presented. In the intro, you review literature extensively, and the discussion is well balanced and relevant. However, some minor revisions are needed before publishing including the following:
-is it possible/feasible to provide a 4-in-1 figure showing the four hypothetical scenarios pictorily? Perhaps showing symbols for infield drying and DML? It would be good for the reader.
-much more important though is to provide an acronym for the four scenarios. SC1, SC2, etc. is not good for the reader. Much better is renaming the scenarios e.g. DryNoLoss, DryLittleLoss, DryBigLoss, NoDryNoLoss. These acronyms help the reader understand eg. Fig 4-7. The authors should do this; Editor: the change should be obligatory.
-change to unique/different symbols in Fig 5, 6 and 11. Eg. (x, +, square, o). Also obligatory, different coloured dots are not clear enough;
-use pattern fill in Fig 8 and 10. E.g. dots, diagonal lines, horizontal lines, etc. Also obligatory, different coloured bars are not clear enough;
-good use of different lines in Fig 7. However, expalin in the figure-caption what the solid line is.
-provide a clear objective statement at the end of the present intro's second last paragraph. There should be a clear objectives statement where second last paragraph's last sentence is. It should start: "The objective of our study was..."
-the intro's last paragraph should be moved to the start of M+M;
-Line 68: bind, not "bid".
-Figure 1: the resolution is too poor. Cannot read the distances, etc. in the legend. Provide also a better caption, explain e.g. where in the world we are, etc.
-In Table 2, give the frame size dimensions in cm or m, not mm. Four rows in total.
-Line 617: component, not "complement"??
-Line 657: heavily, not "the most".
-The manuscripts last sentence: does it not lack a verb? E.g. "to predict". Eg. "The actual supply chain impacts will also be possible to predict by developing MC and DML models that are better adjusted to local conditions."
Author Response
We really appreciate the Reviewer's positive comments and suggestions.
Responses to detailed comments are in the document attached.
Author Response File: 
Author Response.docx
