PONE-D-19-17674

Early Impact of Agropastoral Activities and Climate on the Littoral Landscape of Corsica during Mid-Holocene

PLOS ONE

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Additional Editor Comments:

This is a very good paper but reviewers suggest to do a bit more work before we can accept this manuscript. I went through the paper and I think the reviewers highlighted some important points to be fixed. I therefore suggest moderate revisions

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: N/A

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

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Reviewer #1: Yes

Reviewer #2: No

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Overall comments:

This is an interesting paper that presents a well-argued palaeoenvironmental research in the Taravo Valley, a littoral plain of the southwest coast of Corsica rich in archaeological evidence beginning in the Chalcolithic Age. The multidisciplinary approach (sedimentology and geomorphology combined with palynology) is deeply developed to reconstruct the landscape transformations of this area and infer the interrelationships between humans, climate and vegetation during the middle and late Holocene. The multiproxy data (on sediments and pollen) are well integrated and discussed, and provide detailed information on landscape dynamics and past land-uses.

The manuscript is well designed and consistent, although I suggest few changes to facilitate its reading and comprehension before being published.

Main comments:

1) As the paper focuses on the early impact of human activities and climate on the landscape during the mid-Holocene, it would be useful to briefly describe the environmental setting/plant landscape shortly before the stable human occupation of the area during the Chalcolithic Age. For this purpose, the Authors could add/compare in the discussion the unpublished data of other (few) samples from CAN REILLE prior to 3000 BC (S1 Figure). The Authors may wish to consider this comparison in order to investigate the vegetation changes at the passage from wild to human environments (see for example: Mercuri et al. (2013) Quaternary International 303: 24-42).

2) Regarding the methodological section, I suggest the Authors specify the main plant taxa indicators of agropastoral activities; except for the well-known crop species, pasture plants are not so commonly known (in particular, for readers not familiar with botany, clarify the ‘pastoral’ meaning of the nitrophilous plants listed in the caption of Fig. 7). 3) Please, reconsider the timing of the most ancient testimonies of vine cultivation in Italy (L. 455-456): the results of the research by Ucchesu et al. (2015; Vegetation History and Archaeobotany 24: 587-600) provide evidence that cultivated grapevines were present in Sardinia during the Late Bronze Age, also suggesting that the selection and domestication processes of the wild grape may have started during the Middle BA.

Minor comments:

1) Chapter 2.2: please provide the author(s) for each plant name at the species level.

2) Chapter 2.5: the title should be modified as in this section (and throughout the whole text) there is any specific reference to the Mesolithic Age.

2) Chapter 5.1: the sub-heading titles ‘Four detritic phases…’ (L. 328), but below are presented five detritic events (L. 330); in addition, the list of these phases lacks the point 4 (I guess ‘4)’ should be before ‘D4’ at L. 339), and the point 5 refers to the opposite bank of the Taravo. The different steps of detritism should be clarified.

3) L. 407-408: The sentence is unclear: with ‘15 fires’ do you mean 15 big fire events? I could be wrong, but in the reference you quoted I didn’t see any information about ‘number of fires’; Carcaillet et al. deals with the role of fire in the past vegetation changes and confirm an increase of fire frequency since 2500 BP probably driven by the slash-and-burn agriculture. In addition, the period 2500-2000 BC is not 1000 years. Please rephrase.

4) Please, check for the accuracy of some words (e.g., L. 147-149: ‘maquis’, ‘pine forests’, ‘subsp.’ not in italics; L. 246-252: the abbreviations of the authors of plant names are not in italics, and ‘Sylvestris’ not capitalized; L. 436-437: ‘dicoccum’ instead of ‘dicoccun’, ‘Vicia ssp.’ instead of ‘Vivia ssp.’, and ‘fabaceae’ with the first letter capitalized), numbers/dates (e.g., L. 212: add the dash between 1400 and 700, and change ‘BC’ to ‘AD’; L. 631: ‘1350’ instead of ‘135000’) and graphic symbols (e.g., L. 332: comma instead of bracket after 3000 BC; L. 367 and L. 369: change ‘>’ to ‘<’ and vice-versa).

5) Table 2: the abbreviations of the authors of plant names are not in italics; dicoccum’ instead of ‘dicoccun’, and ‘Sylvestris’ not capitalized.

6) Table 5: in LPAZ 10, ‘Olea’ should be in italics.

7) Fig.1 caption: please specify that b. Bastani, c. Creno, etc… are reference sites.

Reviewer #2: General considerations.

The manuscript entitled “Early impacts of agropastoral activities and climate on the littoral landscape of Corsica during Mid-Holocene” aims to documents the Mid to Late Holocene landscape history of the lower Taravo valley in Corsica. It provides valuable new knowledge about alluvial geomorphological evolution and vegetation dynamics under climatic and human pressure, which enriched previous studies in the lowland and coastal areas of Corsica. The multidisciplinarity approach in sedimentology and palynology meet the standards of the disciplinary fields, together with a rich state of the art of local archaeological knowledge. Finally, this study offers the opportunity to publish a part of an original unpublished pollen analysis from 1998.

My main hesitations relate to the manuscript itself, which I feel needs considerable improvement to promote the results. Firstly, the title is unclear: it introduces “Early impact” and “Mid-Holocene period”, while the paper considers a period from 5000 BP (3000 BC) to present day, namely from the transition between Mid-Holocene and Late Holocene and during the whole Late Holocene. Then, much would be gained with a more clearly exposed aim of the paper. Many approximate sentences make the manuscript not as accurate as it might be. Here is an example: p. 8, l.349, the authors wrote “A detrital event D1 (around 3000 BC) is not recorded as major climatic events in the Western Mediterranean”. Wouldn’t it be more accurate to write “The detrital event D1 (around 3000 BC) in the Cannicia marshes does not correspond to any major climatic events recorded in the Western Mediterranean”? Other kind of imprecisions with suggestions are detailed below (Specific comments). Period names are not standardized. The term “Late Holocene” seems more commonly used than the “recent Holocene Epoch” the authors choose at the beginning of the text. Thereafter, “Upper Holocene” is found as well. In the first discussion paragraph (5.1), it would be clearer to describe the Detritism event (D) in the same way than the Phases of Morphosedimentary stability (T).

Obviously, paragraph 5.3 is in a much more completed form than the other part of the text, both for argumentation and English expression (I encourage the authors to have their manuscript proofread to improve the English expression). All the other parts of the manuscript should reach this quality to achieve the goal of the publication in PlosOne.

Specific comments (by page/line numbers):

p.2 l. 56 to 58: The references cited by the authors did not attest to the presence of RCC (identified and published by Mayewski et al. 2004 at the hemispheric scale), but they highlight or document the regional/local effect of these RCC.

l. 72-73: remove “recent Holocene” if the considered period is …” since the Last Glacial Maximum”

l. 84: Please explain why “archaeological research programs”… “required more paleoenvironemental analysis”.

l. 86: “(“ missed

p.3 l. 147 to 148: “maquis” and “pine forest” might be regular not italic.

p.4 l. 135: “… along with maquis such as…”, add species after maquis.

p. 4/5. The paragraph 2.4 would be more relevant and useful for the reader with a critical review of the available data: date of the analysis, location, chrono-stratigraphical control of the sequences… (ref. [55] Reille et al. 1997, is about Late Glacial). A chronological phases description would be more appropriate than the somewhat “oldfashion” chronozones.

p.5 l. 212: remove “1300-1400”

p.6 l. 292: Please precise which application of Blaauw you used (Clam, I think so?) and which version. Idem on Fig. 3

l. 292-295: This sentence is unclear for me. What are the dates between brackets, the earliest radiocarbon dating for each sequences?

p.7 and Tab. 5: it would be nice to provide here the chrono-stratigraphic boundaries of the LPZ, and to precise the way you called the LPAZ. It is strange to begin a sequence with a subzone 5c.

On table 5: remove “7:” and “10:”

p.7 l.323: You talk about “four cores” that “highlight four phases of intense detritism”. Didn’t you studied the sediments of only CAN 1 to 3?

l.326: Isn’t it Fig. 8 instead of Fig. 9?

l.332: What is: “. 2200 BC)”?

l.339: “4)” is missing

p. 8 l.351-352: more accurately, “An event that was coeval with D2 is also observed…..”

l.378: What is D5?...

p. 9 l.407-408: please be more precise, the fire history derives from the Creno sequence study.

l.409: “It attests to the intensity of Chalcolithic and Early Bronze Age agropastoral activities on vegetation”. This rather might be an argued assumption.

l.422/432: the references about Olea europaea in the Mediterranean are too old, and then the dating is not up to date. Please see for example: Carrion et al. QSR 29, 2010; Breton et al. C.R. Biologie332, 2009 or Newton et al. VHA, 2013.

l.438: A diversity of agricultural…

p.10 l.472: the decrease of arboreal pollen (instead of the frequencies)

l.488: beginning the sentence with “During Roman Times…” is not consistent with what you reminded just above about “the age model of the last 2000 years is weak…. the correlations that we propose with the cultural phases are hypothetical…”

p.12 l.567-572: the authors assume that, in the Lower Taravo Valley, “important landscape changes … may have precipitated significant sociocultural transformations”. What about the opposite? Isn’t it possible to also discuss the hypothesis that “significant sociocultural transformations have precipitate important landscape changes”. What is in good accordance with the last sentence of the paragraph “Agropastoral activities may have contributed to soil erosion…”

p. 13 l.601: Cerealia instead of cerealia

References

p. 22 l. 1047: 1961 (6 is missing)

Tables and Figures:

Tab.3 The bibliographical reference is wrong: [120] instead of [122].

Fig. 7 The “Nitrophilous plants” curve actually sums all the apophytes: nitrophilous and ruderals. I do not understand why some taxa that are in this “Nitrophilous plants” curve, such as Asteroideae sum of Rumex, are displayed alone as well. It makes the diagram unclear.

Fig. 10 Nice synthetic figure. Just two remarks: 1) samples without pollen have got values, despite the white background, 2) the first “Occupation phases” graph, just after “Nitrophilous plants” curve, does not have an header (Corsica ?).

Fig. 11 A and B: text in black on dark grey is unreadable

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Reviewer #1: No

Reviewer #2: No

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Early Impact of Agropastoral Activities and Climate on the Littoral Landscape of Corsica since Mid-Holocene

PONE-D-19-17674R1

Dear Dr. Vella,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

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Andrea Zerboni, Ph.D.

Academic Editor

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Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

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Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: (No Response)

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Reviewer #2: No