Climate Change and Its Potential Impact on the Conservation of Wooden Pole Dwellings in Lake Bolsena: Insights from Climate Proxy Data and High-Frequency Water Monitoring

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This work addresses the rarely discussed topic of the impact of environmental changes in water occurring in the context of climate change on the preservation of water structures valuable as cultural heritage.
The timeframe of the climate data, their selection, and correlation with the current chemical state of the environment near the structures allowed the authors to draw important conclusions and valuable suggestions for changes in the management of the lake's catchment area. The work highlighted sensitive factors (e.g. falling water levels) that influence changes in water and sediment conditions, and consequently, intensify the degradation of wooden structures.

Furthermore, we received information regarding the rate and direction of changes in the lake's trophic status, which is an additional quality of the work. This provides a basis for decisions regarding the lake's protection, which ensuring that it can maintain as a mesotrophic lake for as long as possible in a climate-change environment and its basin changes.

The data used is extensive and well-selected. Modern research techniques and methods were used, guaranteeing results that are close to reality and have a low potential for measurement error. Additionally, the conclusions are supported by well-chosen statistical descriptions. The tables and figures in the text and supplementary are clear and well-prepared.

The literature cited in the work is sufficient and well-selected.

My only comment is regarding Figure 5 – its title resembles a description of the results – I suggest rewording it so that, while retaining this information, it reads more like a title.

Author Response

My only comment is regarding Figure 5 – its title resembles a description of the results – I suggest rewording it so that, while retaining this information, it reads more like a title.

Dear reviewer, we thank you for your kind evaluation. We modified figure ex-5 (now it is figure 7) and its description. Please, we kindly ask you to check it. 

Reviewer 2 Report

Comments and Suggestions for Authors

Figure 5b (OSAVI index) may confuse readers without a remote sensing background—consider improving the legend clarity or adding a simplified explanation of the colour classes. - “The combined effects of extreme heat and prolonged drought are clearly evident in aerial imagery of the Aiola structure, captured by an Unmanned Aerial Vehicle (UAV).” Could be shortened or split for clarity. - Phrases like “maximum number of consecutive, maximum number of consecutive days” appear due to editing oversights. - Repetition of terms like "high temperatures" or "elevated temperatures" in consecutive sentences can be smoothed. - Article usage ("the", "a") could be polished in a few places. - Some typos or copy-paste artifacts (e.g., "number of says" instead of "number of days") are present in figure captions. Terms like “thermal inertia,” “bioavailability,” and “suboxic to anoxic” are accurate but may benefit from brief clarification if targeting a broader scientific audience.

Author Response

Figure 5b (OSAVI index) may confuse readers without a remote sensing background—consider improving the legend clarity or adding a simplified explanation of the colour classes.

We better explained this in the methods section And we modified Figure ex-5 (now it is figure 7). Please check it. Thank you.

“The combined effects of extreme heat and prolonged drought are clearly evident in aerial imagery of the Aiola structure, captured by an Unmanned Aerial Vehicle (UAV).” Could be shortened or split for clarity.

We rephrased, please check lines 986-988.

Phrases like “maximum number of consecutive, maximum number of consecutive days” appear due to editing oversights.

We corrected them (Figure 3). Thank you for the comment.

Repetition of terms like "high temperatures" or "elevated temperatures" in consecutive sentences can be smoothed.

Thank you, we believe it is better now.

Article usage ("the", "a") could be polished in a few places.

Thank you, we improved the usage, please check it.

Some typos or copy-paste artifacts (e.g., "number of says" instead of "number of days") are present in figure captions.

We corrected them (Figure 3 and 4). Thank you for the comment.

Terms like “thermal inertia,” “bioavailability,” and “suboxic to anoxic” are accurate but may benefit from brief clarification if targeting a broader scientific audience.

For the “thermal inertia” we added the following phrase: “In fact, thanks to the high specific heat capacity of water, the water absorbs and re-leases heat more slowly than the surrounding air.” (Line 1246).

For the “bioavailability” term we added a short definition in brackets “(nutrients availability for organisms)” (line 1135).

For the “suboxic to anoxic”definition we added the specification in brackets. (lines 1565-1566).

Reviewer 3 Report

Comments and Suggestions for Authors

The paper deals with the climate change impact on the wooden pile dwellings at the Lake Bolsena case study. The research is of interest to readers from both a scientific and a practical engineering perspective. The idea and research orientation are well defined, and the methodology has a strong background regarding the literature review. A literature review provides a strong foundation for defining methodology. Contribution to the preservation of the wooden pile dwellings is established, but there is a need for the improvement of this research/manuscript. 

After several detailed readings, I am proposing a major revision. Here are the reasons for my decision.

-Climate changes, i.e., particular parameters, like that one presented in Table 1, Figures 1-4, definitely have an impact on the wooden pile dwellings. Authors should analyze time series of these parameters. Potential fluctuations, small systematic and random changes, errors, and variability in the researched time series should be analyzed. Also, sub-periods and trends, sudden jumps and declines in value, periodicity, and other properties of the time series should be checked. I am proposing RAPS and ITA (IPTA) methods for it. 

-The authors didn't take into account the impact of the insolation. Such should be elaborated and calculated.  

Author Response

-Climate changes, i.e., particular parameters, like that one presented in Table 1, Figures 1-4, definitely have an impact on the wooden pile dwellings. Authors should analyze time series of these parameters. Potential fluctuations, small systematic and random changes, errors, and variability in the researched time series should be analyzed. Also, sub-periods and trends, sudden jumps and declines in value, periodicity, and other properties of the time series should be checked. I am proposing RAPS and ITA (IPTA) methods for it.

Dear reviewer, thank you for your comment. In response, we have applied the Mann–Kendall trend test and Sen’s Slope estimator to the climatic time series used in our analysis. These non-parametric methods are well established in climatology for detecting monotonic trends and estimating their magnitude, and are particularly suitable for datasets with missing values, non-normal distributions, and potential outliers.

The results of these analyses are now reported in Section 3.5 (“Correlation between climatic and water properties”) of the revised manuscript. Regarding the proposed RAPS and ITA methods, we acknowledge their potential to offer complementary insights, particularly for identifying abrupt changes and local trends. However, due to the limited availability of detailed sub-annual records, we selected the Mann–Kendall and Sen’s Slope methods as a statistically robust and widely accepted alternative for our dataset.

We have added a brief discussion on the RAPS and ITA approaches in Section 3.5 and recognize their value for future research. In particular, these techniques could enhance the detection of non-linear dynamics and abrupt shifts, thereby supporting a more detailed and comprehensive understanding of the temporal behavior of climate parameters.

-The authors didn't take into account the impact of the insolation. Such should be elaborated and calculated.

We apologize for the oversight; however, this parameter was not considered due to the lack of available data for the study area in question.

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript entitled “Climate Change and Its Potential Impact on the Conservation of Wooden Pile Dwellings in Lake Bolsena: Insights from Climate Proxy Data and High‑Frequency Water Monitoring” offers a comprehensive assessment of how evolving climatic conditions threaten the long‑term preservation of submerged archaeological wood. By synthesizing three decades of regional climate proxies—such as temperature extremes, drought indices, and precipitation patterns—with year‑round in situ monitoring of key limnological parameters (temperature, redox potential, dissolved oxygen, and conductivity) at the Gran Carro site, the authors establish clear links between air‑water interactions and biogeochemical processes that affect wood decay.

Leveraging remote sensing via multispectral UAV surveys alongside continuous sensor records, the study not only documents historical trends in water‑level fluctuations and shoreline exposure, but also captures real‑time responses of the aquatic environment during recent heatwave and drought episodes. The integration of statistical correlation analyses with sediment chemistry and microbial activity data allows the authors to identify critical thresholds beyond which preservation conditions deteriorate.

Overall, this work advances our understanding of the vulnerabilities of underwater cultural heritage under a changing climate, and it proposes targeted management strategies to mitigate ongoing and future threats to wooden pile structures in shallow lake settings.

 

Abstract:

The abstract should clearly convey the study’s objectives, scope, and its most striking results. While the aims and methodological approach are well presented, the abstract currently lacks any concrete outcome data. I recommend the following minor revision:

Include key quantitative results (e.g., extent of water‑temperature rise, magnitude of redox‑potential decline, changes in dissolved‑oxygen levels) to complete the abstract and highlight its most significant findings.

 

Introduction:

 

The Introduction is currently fragmented into too many short paragraphs, which hinders the establishment of a clear contextual narrative. I recommend restructuring the section into five or six well‑developed paragraphs that guide the reader logically from general background to specific research questions and objectives.

Moreover, the literature review is rather superficial and does not sufficiently engage with the climatic impacts of drought. In particular, key findings from recent studies (e.g., DOI: 10.1016/j.jhydrol.2025.133948; DOI: 10.3390/hydrology12070192) should be discussed in greater depth. The citations provided appear merely illustrative—these should be expanded to include additional relevant authors and case studies that have examined drought‑driven hydrochemical and preservation challenges.

Finally, the last paragraph of the Introduction should outline the structure of the manuscript (e.g., “Section 2 describes…; Section 3 presents…; Section 4 discusses…”), thereby directing the reader’s attention and clarifying the organization of the paper.

 

 

Materials and Methods:

 

The Site Description subsection is well organized and provides comprehensive contextual information about the study region. However, the absence of a study area map detracts from the reader’s ability to visualize the geographic setting and sampling locations. I strongly recommend incorporating a high‑resolution map of the study area—ideally annotated with key sampling points and relevant geographic features—to enhance clarity and facilitate a better understanding of the experimental design.

 

The Materials and Methods section, as currently presented, contains several critical shortcomings that must be addressed before the manuscript can be considered further:

Data Description

The manuscript does not provide sufficient detail on the datasets employed. The provenance, temporal and spatial resolution, and any preprocessing steps for the climatic and limnological data should be described explicitly.

Recommendation: Include a comprehensive overview of each dataset, its source, and its processing workflow.

Metadata Presentation

No metadata table is provided. Readers cannot readily assess the quality, coverage, or limitations of the data without a summary of key attributes.

Recommendation: Add a table listing each dataset’s metadata (e.g., parameter, temporal span, spatial resolution, instrument/platform, data provider, processing level).

Methodological Detail

The Methods subsection lacks any description of the analytical approach. There is no explanation of statistical tests, correlation analyses, or UAV image‐processing workflows.

Recommendation: Offer a step‐by‐step account of each analytical method, including software tools, parameter settings, and validation procedures.

Workflow Diagram

The absence of a schematic workflow impedes the reader’s ability to follow the sequence of data acquisition, processing, analysis, and interpretation.

Recommendation: Provide a clear workflow diagram illustrating all major steps from raw data through to the final results.

In its current form, the Materials and Methods section falls short of the journal’s standards and could warrant rejection. However, I believe that with the incorporation of the above revisions, the authors can substantially improve clarity, reproducibility, and overall rigor.

Results:

 

While the individual subsections under the combined Results and Discussion heading are well organized and the findings are presented clearly, I have the following concerns:

Section Separation

Issue: Merging Results and Discussion under a single heading conflates descriptive findings with interpretative commentary.

Recommendation: Split this into two distinct sections—Results, which should present data and observations without interpretation, and Discussion, which should critically analyze those results in the context of existing literature and study objectives.

Depth of Discussion

Issue: The current text offers minimal interpretative insight and does not engage deeply with the implications or limitations of the findings.

Recommendation: Expand the Discussion to compare your results with previous studies, explore potential mechanisms, and address any uncertainties or alternative explanations.

Figure Quality and Cartographic Elements

Issue: Many figures suffer from low resolution, reducing readability. In map figures, key cartographic elements—namely a north arrow, scale bar, and legend—are absent.

Recommendation:

Provide high‑resolution versions of all figures.

For each map, include a clear north arrow, an appropriate scale bar, and a legend explaining all symbols and color scales.

Addressing these points will greatly improve the manuscript’s clarity, rigor, and professional presentation.

 

Conclusion

 

Once the above revisions have been implemented, the Conclusion will require a full rewrite. In its revised form, please ensure that it:

• Reflects the Challenges Encountered:Summarize any methodological or data‑related difficulties the authors faced (e.g., limited metadata, map generation, sensor calibration issues).
• Emphasizes Study Significance:Reiterate the key contributions of the work to heritage conservation and limnological monitoring under climate change.
• Acknowledges Limitations:Clearly state the study’s constraints (e.g., temporal coverage, spatial resolution, proxy assumptions) to temper interpretation.
• Offers Future Recommendations:Provide concrete suggestions for subsequent research or management actions, such as improved monitoring networks, expanded proxy datasets, or adaptive conservation protocols.

Incorporating these elements will produce a robust, focused Conclusion that ties together the manuscript’s findings and their broader implications.

 

Author Response

Dear reviewer, you will find the poit-by-point answer attached.

Thank you for your suggestions.

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

This study presents an original and interdisciplinary investigation into the potential impact of climate change on the preservation of submerged wooden structures in Lake Bolsena. The integration of long-term climate data (1990–2023), mid-term water quality records (2014–2019), recent high-frequency in situ monitoring (2022–2023), UAV-based imagery, and sediment chemical analyses is a major strength of the work. This multifaceted approach provides a comprehensive view of the environmental dynamics surrounding the archaeological site.

However, several limitations affect the overall robustness and explanatory power of the findings. The high-frequency data collected near the Gran Carro site only span approximately 15 months, which is insufficient for identifying long-term climatic or ecological trends. Furthermore, although microbial degradation is a central theme of the manuscript, no direct biological or microbiological evidence is presented to support the interpretations. The absence of microbial DNA analysis or culture-based assessments weakens the causal link between environmental parameters and degradation processes. The manuscript should clearly acknowledge these limitations and emphasize that the conclusions are exploratory and site-specific. Future studies incorporating longer time series and direct biological indicators would help strengthen the framework considerably.

The manuscript notes that water quality data from ARPA Lazio were collected on the western shore of the lake, whereas the Gran Carro archaeological site is located offshore on the eastern side. Given the estimated 10–12 km distance between these sites and the stratified nature of the lake, there is legitimate concern regarding the spatial representativeness of the ARPA data. The authors should either justify the relevance of these data as environmental proxies for the archaeological zone or acknowledge their limitations more explicitly. To enhance transparency and spatial interpretation, I strongly recommend including a location map identifying the archaeological site, ARPA station, climate station, and UAV monitoring areas.

Several methodological aspects also require clarification. The sediment sampling design lacks key information, such as the number of sampling points, replication strategy, depths, and frequency. Although the distinction between sediments in contact with wooden remains ("Wsed") and control sediments ("Sed") is conceptually relevant, the practical implementation of this comparison is not adequately described. The statistical methodology would also benefit from clearer justification: both Kendall and Spearman correlation tests are used without explanation of their respective purposes, and no trend analysis (e.g., Mann–Kendall or Sen's slope) is performed on the time series, despite repeated references to long-term trends. In addition, the UAV and OSAVI-based analyses are underdeveloped. The claim that no significant differences were observed between July and August 2023 is not supported by sufficient visual or quantitative analysis, and the image processing workflow is not detailed (e.g., orthorectification, index calibration, handling of reflectance artifacts). These components should be expanded to ensure reproducibility and analytical rigor.

The results section is comprehensive and logically structured, moving from climate trends to limnological changes, sediment chemistry, and potential microbial degradation. However, the manuscript often blends empirical observations with interpretative commentary, which sometimes obscures the boundary between results and discussion. In several instances, correlation results are interpreted in a way that implies causation, especially regarding microbial activity. Such interpretations should be presented with more caution, using probabilistic language (e.g., "may suggest", "is consistent with") rather than definitive statements.

The conclusion adequately summarizes the main findings but would benefit from a more critical reflection on the study’s methodological constraints, particularly the short observation period, the lack of biological validation, and the spatial disconnect between monitoring stations and the site of interest. Including these caveats, along with suggestions for future research such as expanded monitoring, microbial DNA assessment, and degradation modeling, would provide a more balanced and forward-looking closure.

In summary, while this study offers valuable insights into the vulnerability of submerged heritage under changing climatic conditions, several methodological and interpretive issues limit its current impact. I recommend that the authors revise the manuscript substantially by clarifying methodological details, justifying statistical approaches, tempering causal interpretations, and improving the spatial contextualization of the study. These changes would significantly enhance the scientific value and clarity of the work.

Author Response

Dear reviewer, you will find the point-by-point response attached.

Thank you for your suggestions.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

This time, the authors partially took into account my comments from the last time. 

They didn't apply the proposed RAPS and IPTA methods, which are crucial for identifying irregularities or fluctuations in the analyzed time series and for gaining insight into the homogeneity and isotropy of the data. It is not such a complicated task to handle. 

The comment about the unavailability of isolation data is not valid. By application of the PV-GIS, it could be obtained easily. I am insisting on this, and also for the application of the RAPS and IPTA methods.

Author Response

Comment 1: They didn't apply the proposed RAPS and ITA methods, which are crucial for identifying irregularities or fluctuations in the analyzed time series and for gaining insight into the homogeneity and isotropy of the data. It is not such a complicated task to handle.

Response 1: We sincerely appreciate Reviewer's insightful comment and fully recognize the importance of addressing their suggestion. We agree that adopting the RAPS and ITA methods—or at least acknowledging their relevance—is essential to strengthen the scientific rigor and completeness of our work.

We apologize for not having included this point in the previous version. We have now revised the manuscript accordingly, incorporating the RAPS and ITA methods as part of the analysis and discussion (lines 672-707 in the pdf file).

Comment 2: The comment about the unavailability of isolation data is not valid. By application of the PV-GIS, it could be obtained easily. I am insisting on this, and also for the application of the RAPS and IPTA methods.

Response 2: Dear reviewer, we added the insolation analysis in both “Methods” and “Results and discussion” (lines 405-436 in the pdf file) sections. Please, check them. Thank you for your comment.

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript entitled “Climate Change and Its Potential Impact on the Conservation of Wooden Pile Dwellings in Lake Bolsena: Insights from Climate Proxy Data and High Frequency Water Monitoring” offers a comprehensive assessment of how evolving climatic conditions threaten the long-term preservation of submerged archaeological wood. By synthesizing three decades of regional climate proxies—such as temperature extremes, drought indices, and precipitation patterns—with year-round in situ monitoring of key limnological parameters (temperature, redox potential, dissolved oxygen, and conductivity) at the Gran Carro site, the authors establish clear links between air–water interactions and biogeochemical processes that affect wood decay.

Leveraging remote sensing via multispectral UAV surveys alongside continuous sensor records, the study not only documents historical trends in water level fluctuations and shoreline exposure, but also captures real-time responses of the aquatic environment during recent heatwave and drought episodes. The integration of statistical correlation analyses with sediment chemistry and microbial activity data allows the authors to identify critical thresholds beyond which preservation conditions deteriorate.

The authors have generally taken my previous revision suggestions into account and have significantly improved the manuscript. However, some important improvements are still required in a few areas. For example, as I pointed out in the previous revision, conducting a thorough literature review and emphasizing the novelty of the current study remain essential. The Introduction section still consists of paragraphs that are not clearly connected to each other and does not analyze recent studies in the literature. With a brief search, relevant studies for this manuscript can be found (https://doi.org/10.1016/j.mambio.2019.08.002, https://doi.org/10.3390/w17071098, https://doi.org/10.1080/11263504.2013.814604, https://doi.org/10.3390/f12020143, https://doi.org/10.1007/978-3-031-52780-7_13). These are only examples. The relevant literature should be carefully analyzed to identify its shortcomings and strengths.

Updating the study area map, adding the workflow diagram, and including the “data presentation” section have substantially improved the manuscript.

Your defense for presenting the Results and Discussion in this manner is satisfactory and convincing.

The Conclusion section has been significantly improved.

Author Response

Comment 1: The authors have generally taken my previous revision suggestions into account and have significantly improved the manuscript. However, some important improvements are still required in a few areas. For example, as I pointed out in the previous revision, conducting a thorough literature review and emphasizing the novelty of the current study remain essential. The Introduction section still consists of paragraphs that are not clearly connected to each other and does not analyze recent studies in the literature. With a brief search, relevant studies for this manuscript can be found (https://doi.org/10.1016/j.mambio.2019.08.002, https://doi.org/10.3390/w17071098, https://doi.org/10.1080/11263504.2013.814604, https://doi.org/10.3390/f12020143, https://doi.org/10.1007/978-3-031-52780-7_13). These are only examples. The relevant literature should be carefully analyzed to identify its shortcomings and strengths.

Response 1: Dear reviewer, thank you for the comment. We improved the Introduction section as suggested. Please check the section.

Comment 2: Updating the study area map, adding the workflow diagram, and including the “data presentation” section have substantially improved the manuscript.

Your defense for presenting the Results and Discussion in this manner is satisfactory and convincing.

The Conclusion section has been significantly improved.

Response 2: Thank you for acknowledging the manuscript improvement and thank you for tour support.

Reviewer 5 Report

Comments and Suggestions for Authors

The authors have adressed all my suggestions, and the manuscript has been significantly improved.

Author Response

The authors have adressed all my suggestions, and the manuscript has been significantly improved.

Dear reviewer, thank you a lot for your valuable comments and support.