Future Scenarios for Viticultural Suitability under Conditions of Global Climate Change in Extremadura, Southwestern Spain

Round 1

Reviewer 1 Report

There is need to revise abstract, please add numeric potential outcomes of the research work in this part.

Conclusion also needs some minor revisions with adding some conclusive recommendations for laymen.

See references are cross checked in text and reference section.

Author Response

Please, see the attached file

Author Response File: Author Response.docx

Reviewer 2 Report

The study showed information about the future scenarios of climatic conditions in the region of Extremadura, Spain and the suitability of viticultural in a context of climate change. The aims of the work are well defined, and the methodology used in the assay responds in good form to the objectives. The study has a major importance for the suitability of the viticulture in the world. Congratulations for the author that offer a very good investigation.

There are some minor issues that need revision. Congratulation

 

Material and methods section

 

Table 1. Maybe is it necessary the explanation of every acronym used in the lower part of the table.

 

Results and Discussion section

 

Table 3. Maybe a separation line between the historical period and the two scenarios RCP 4.5 and RCP 8.5 helps the reader to discriminate every data.

 

Lines 368-369. In my opinion the authors could expand the effect of rising temperature in other parameters, not only in the accumulation of primary metabolites such as sugars and organic acids. Other compounds such as aromatic compounds and especially phenolic compounds, for example in anthocyanins, a key component of color in red wines could be cited in this work. Literature for consulting are the following:  Mori et al. 2007 J. Exp. Bot 58, 1935-1945; Gouot et al, 2019. J. Exp. Bot. 70, 397-423; Pons et al., 2017. Oeno One 51, 141-146.

Author Response

Please, see the attached file.

Author Response File: Author Response.docx

Reviewer 3 Report

MDPI Agriculture Manuscript 1973234

 Title: Future scenarios for viticultural suitability under conditions of global climate change in Extremadura, Southwestern Spain

 The manuscript describes projections of bioclimatic index for viticultural suitability in the Extremadura region of Spain. The study uses data obtained from 10 dynamically downscaled RCM simulations based on 10 CMIP5 GCM projections for IPCC’s RCP4.5 and RCP8.5 GHG emissions scenarios, which were generated and made available by Coordinated Regional Downscaling Experiment (CORDEX) project. The bioclimatic indices used in the analysis are the growing season temperature (GST), the growing season degree-day (GDD), heliothermal index (HI), and the biologically effective degree-day index (BEDD)

 According to the authors, throughout the 21st century, all these indices should gradually increase, which will have a significant impact on future viticulture in the region. Since the bioclimatic index projections are based on the same variable, air temperature, which are known to increase over the next decades, the study results are somewhat expected. Nevertheless, the spatial distribution of these indices show that the impact of global warming will be differentiated throughout the regions, with some sections of Extremaudura region becoming too warm for viticulture before others.

 The authors indicate that they also downloaded and utilized precipitation from the CORDEX database (Daily minimum temperatures, maximum temperatures, and precipitation data were obtained from CORDEX). However, I was able to see anywhere in the manuscript where precipitation was actually utilized.  One particularly noticeable shortcoming of the study is the lack of detailed mitigation and/or adaptation strategies for winegrape growers and policy makers in the region. The authors briefly mentioned about the need for technological developments, such as the use of new winegrape varieties more resistant to drought stress and heat or the application of shading nets. However, no further comments or specific recommendations are listed or discussed. The inclusion of a mitigation or adaptation recommendations for Extremadura would make the paper more comprehensive, innovative, and fitting for an Agriculture-themed journal.

 Overall, the manuscript is written in a clear and intelligible format. Its objectives, methodology, and results are well organized and satisfactory described. The conclusions obtained are supported by the discussion, tables, and figures presented.

 Therefore, I find that the manuscript should be accepted for publication only after the minor comments and questions listed below are answered.

 Comments and questions (Minor revisions):

 Line 62: include feedbacks processes to the sentence “The combined effect of this increase with the expected increase of other GHG reinforced by natural feedback processes will cause a 1-4C”.

 Line 62:  The current CO2 concentration is 414.72 ppm

 Line 66: CORDEX used dynamic downscaling techniques to increase the resolution of GCM simulations.  Update sentence

Through the Coordinated Regional Downscaling Experiment (CORDEX) project, a 65 set of climate projections are generated by dynamically downscaling CMIP6 GCM output using regional climate models (RCM)

 Line 68:  GHG are not radioactive substances.  Remove the statement.

 Line 84:  Add a reference for the HI index.

Monteverde, C and F. De Sales (2020) Impacts of global warming on southern California's winegrape climate suitability. https://doi.org/10.1016/j.accre.2020.08.002

 Line 104: Methods. Climate projections generated by numerical models (GCM and RCM) suffer from large drifts, which can distort both the natural variability and the climate response to changes in radiative forcing. Did the authors apply any type of bias-correction to the CORDEX data before calculating the bioclimatic indices?

 Line 137: Delete “and precipitation” from the statement, if precipitation was not used in this study.

 Line 141:  remove “for the past”

 Table 3: move (°C units) from table header to caption

 Line 375-276: I would recommend the authors to elaborate more on the mitigation and adaptation strategies and recommendations that wine growers can use to help them face the effects of global warming in the future. Since this is an Agriculture-themed journal, expanding on this topic would make the article more innovative and farther-reaching impacts to the Extremadura community. For instance, the authors could elaborate more about, which of the two techniques listed in the paper (grape variety change and shading nets), would be more cost-effective for growers in the area. Alternatively, they could also include in the text which method has already been successfully implemented in the area and what benefit has it brought.

Author Response

Please, see the attached file.

Author Response File: Author Response.docx