Anthropogenic Impact on the Terrestrial Environment in the Lake Dian Basin, Southwestern China during the Bronze Age and Ming–Qing period

Round 1

Reviewer 1 Report

Liu et al., have analyzed the geochemical proxies and sporepollen from a section of the Anjiangbei site (AJB), and discussed the impact factor of human activities from late Bronze age to Ming-Qing period around the Dian lake in the Yunnan Plateau. They suggested that the changes of hydrological environment have a vital impact on the human activities in the Bronze Age, while the geopolitical changes play an important role during Ming-Qing period. This study providing new evidence for understanding the human–environment interaction in the Yunnan Plateau. I suggest that it can be accepted for publication. However, I have also some major concerns as outlined below.

1.      The study section from the Anjianbei site. It is better to offer more information about the Anjianbei site. Have it been excavated? What about the culture types? How the charcoal samples for AMS14C dating were selected in the section?

2.      There are many types of heavy metals.Why the Cu, Cr, Pb and Zn were selected as an indicator for human activities?

3.      The sediment is green-gray clay below 150cm and reddish clay upper 100cm. The lithology changes indicate the changes of sedimentary environment. Cyperaceae and Typha pollen content also support the changes of sedimentary environment from wetland to dryland in the study site. The tree pollen increased around the depth 100cm. It seems that hydrological environment changes rather than human activities impacted on the vegetation during AD1348-AD1352 in the AJB section.

4.      If the changes of archaeology sites number could be added, it will be helpful to discuss the influencing factors of human activities since Brone age around Dian Lake.

Author Response

Reviewer 1

General comments: Liu et al., have analyzed the geochemical proxies and sporepollen from a section of the Anjiangbei site (AJB), and discussed the impact factor of human activities from late Bronze age to Ming-Qing period around the Dian lake in the Yunnan Plateau. They suggested that the changes of hydrological environment have a vital impact on the human activities in the Bronze Age, while the geopolitical changes play an important role during Ming-Qing period. This study providing new evidence for understanding the human–environment interaction in the Yunnan Plateau. I suggest that it can be accepted for publication. However, I have also some major concerns as outlined below.

Specific comments:

1.The study section from the Anjiangbei site. It is better to offer more information about the Anjianbei site. Have it been excavated? What about the culture types? How the charcoal samples for AMS14C dating were selected in the section?

Response: Many thanks for your suggestions, we have added the descriptions of the Anjiangbei site and the dating samples selected in the manuscript. Please see line 140-147, and 157-162.

2.There are many types of heavy metals.Why the Cu, Cr, Pb and Zn were selected as an indicator for human activities?

Response: Many thanks for your comments. The element of Cu, Cr, Pb and Zn was closely related to metallurgical activities both in the Bronze Age and historical periods. The soil pollution of the heavy metals Cu, Cr, Pb and Zn by the metallurgical activities has taken place in many regions of China such as the Hexi Corridor and Sanjiang Plain during the prehistoric and historical period (Gao et al., 2014; Zhang et al., 2017). Addition, these heavy metal elements (Cu, Cr, Pb and Zn) are also the main sources of water pollution in Lake Dian at present. Thus, we select these elements as the indicator for exploring the anthropogenic impact on the environment around Lake Dian basin.  

Reference:

Zhang S J, Yang Y S, Storozum M J, et al., 2017. Copper smelting and sediment pollution in Bronze Age China: A case study in the Hexi corridor, Northwest China. Catena, 156: 92-101.

Gao C Y, Bao K S, Lin Q X, et al., 2014. Characterizing trace and major elemental distribution in late Holocene in Sanjiang Plain, Northeast China: Paleoenvironmental implications. Quaternary International, 349: 376-383.

3.The sediment is green-gray clay below 150cm and reddish clay upper 100cm. The lithology changes indicate the changes of sedimentary environment. Cyperaceae and Typha pollen content also support the changes of sedimentary environment from wetland to dryland in the study site. The tree pollen increased around the depth 100cm. It seems that hydrological environment changes rather than human activities impacted on the vegetation during AD1348-AD1352 in the AJB section.

Response: Many thanks for your comments. We have revised the discussion, please see line 280-282. Our main point is that pollen assemblages are less affected by human activities in sediments below 100 cm. In the upper 100 cm of the AJB section, the increase in crop pollen and the decrease in pollen from woody vegetation is a reflection of the increasing anthropogenic influence during the Ming-Qing period.

4. If the changes of archaeology sites number could be added, it will be helpful to discuss the influencing factors of human activities since Bronze age around Dian Lake.

Response: Many thanks for your comments. We have added the number of archaeological sites around the Lake Dian basin during different stages of the historical period. Please see Figure 6.

Author Response File: Author Response.docx

Reviewer 2 Report

General comments: The authors analyze the sporepollen and geochemical samples in the Lake Dian in order to explain the historic anthropogenic events that determined the changes in vegetation and heavy metal pollution in the soil during Ming–Qing period. The paper is, in general, well written and structured. Although the length is kind of short, especially in the first sections, it is easy to read and adequately described both the goals and justifications. Howerver, my main concern is mainly focused on the lack of information in Introduction and Methodology sections. Furthermore, Discussion section contains some paragraphs which do not address the previous results shown but the findings of ofther authors, which should be moved to the Introduction section.

Specific comments:

Title: Indicate the period studied.

Abstract:

Line 18: delete "the period of"

Line 22: show briefly those differences

Line 25: "The increase of the intensity....." ---> Assess it 

1. Introduction

It would be reccommended to add a paragraph with methodologies and results in other regions around the world and the relevant findings according these methods. Therefore, some paragraphs of Discussion should be moved to this section.

2. Regional setting

Add a map of vegetation in the region studied and compare with past records in Discussion.

3. Materials and methods

Please, describe more in depth the methodologies and software used: acid–base–acid procedure, OxCal v4.2.4 software, Tilia 3.0.1, etc.

Line 156: and...... What??? It lacks something, isn´t it?

4. Results

Line 170: It would be very helpful if authors include a time bar with the different periods and the location of their study.

Line 174: Dont start the section with the table. Isn´t from previous section?  Add the meaning of each paremeter in the caption. 

Figure 3: X-axis --> indicate variable and units

5. Discussion

Lines 225-230: Consider moving to Introduction

Subsection 5.2: Same

Lines 315-329: consider move some parts to Introduction

Lines 330-343: same

Lines 370-387: Avoid conclusions with no relation with results

Author Response

Reviewer 2

General comments: The authors analyze the sporepollen and geochemical samples in the Lake Dian in order to explain the historic anthropogenic events that determined the changes in vegetation and heavy metal pollution in the soil during Ming–Qing period. The paper is, in general, well written and structured. Although the length is kind of short, especially in the first sections, it is easy to read and adequately described both the goals and justifications. Howerver, my main concern is mainly focused on the lack of information in Introduction and Methodology sections. Furthermore, Discussion section contains some paragraphs which do not address the previous results shown but the findings of ofther authors, which should be moved to the Introduction section.

Specific comments:

Title: Indicate the period studied.

Response: Many thanks for your suggestion, and we have revised the title.

Abstract:

Line 18: delete "the period of"

Response: Thanks to your careful review, we delete these words.

Line 22: show briefly those differences

Response: Many thanks for your suggestion. we have revised the abstract, please see Line 25-29.

Line 25: "The increase of the intensity....." ---> Assess it

Response: Many thanks for your commment, and it is a good suggestion. We have added the number of archaeological sites around the Lake Dian basin during different stages of the historical period in Figure 6, and revised the abstract. Please see line 28-29.

1. Introduction

It would be reccommended to add a paragraph with methodologies and results in other regions around the world and the relevant findings according these methods. Therefore, some paragraphs of Discussion should be moved to this section.

Response: Many thanks for your commment. we have added some case studies in the Introduction. Our aim in the “Introduction” is to raise the issue that it is unclear whether there are significant differences in the driving factors of anthropogenic impact on the environment in terms of spatial and temporal dimensions. In the Discussion, the parts you mentioned is to show the anthropogenic impact on the eco-environment has been widely around the world.

Anyway, many thanks for your commment, and we have revised the Introduction. Please see line 43-49.

2. Regional setting

Add a map of vegetation in the region studied and compare with past records in Discussion.

Response: Thanks for your suggestion. We have added a map of the regional vegetation at Figure 1. We also add some descriptive information for vegetation history around Lake Dian in Line xxx-xxx.

3. Materials and methods

Please, describe more in depth the methodologies and software used: acid–base–acid procedure, OxCal v4.2.4 software, Tilia 3.0.1, etc.

Response: Thanks for your suggestion. We have added the description in the “Material and Methods”. Please see line 104-114.

Line 156: and...... What??? It lacks something, isn´t it?

Response: We apologize for this mistake and delete this word.

4. Results

Line 170: It would be very helpful if authors include a time bar with the different periods and the location of their study.

Response: Thanks for your suggestion. We have revised the “Result”. Please see line 212-21232-233, 239-240.

Line 174: Dont start the section with the table. Isn´t from previous section? Add the meaning of each paremeter in the caption.

Response: We apologize profusely for the typographical error in this post; this table should appeared at the end of the previous section.

Figure 3: X-axis --> indicate variable and units

Response: Nice suggestion. We have revised the caption of the Figure 4 (Figure 3 original). Please see line 251.

5. Discussion

Lines 225-230: Consider moving to Introduction

Response: Many thanks for your commment. we have added some case studies in the Introduction. Our aim in the “Introduction” is to raise the issue that it is unclear whether there are significant differences in the driving factors of anthropogenic impact on the environment in terms of spatial and temporal dimensions. In the Discussion, the parts you mentioned is to show the anthropogenic impact on the eco-environment has been widely around the world.

Anyway, many thanks for your commment, and we have revised the Introduction. Please see line 43-49.

Subsection 5.2: Same

Response: Many thanks for your commment. we have added some case studies in the Introduction. Our aim in the “Introduction” is to raise the issue that it is unclear whether there are significant differences in the driving factors of anthropogenic impact on the environment in terms of spatial and temporal dimensions. In the Discussion, the parts you mentioned is to show the anthropogenic impact on the eco-environment has been widely around the world.

Anyway, many thanks for your commment, and we have revised the Introduction. Please see line 43-49.  

Lines 315-329: consider move some parts to Introduction

Response: Many thanks for your commment. we have added some case studies in the Introduction. Our aim in the “Introduction” is to raise the issue that it is unclear whether there are significant differences in the driving factors of anthropogenic impact on the environment in terms of spatial and temporal dimensions. In the Discussion, the parts you mentioned is to show the anthropogenic impact on the eco-environment has been widely around the world.

Anyway, many thanks for your commment, and we have revised the Introduction. Please see line 43-49.

Lines 330-343: same

Response: Many thanks for your commment. we have added some case studies in the Introduction. Our aim in the “Introduction” is to raise the issue that it is unclear whether there are significant differences in the driving factors of anthropogenic impact on the environment in terms of spatial and temporal dimensions. In the Discussion, the parts you mentioned is to show the anthropogenic impact on the eco-environment has been widely around the world.

Anyway, many thanks for your commment, and we have revised the Introduction. Please see line 43-49.

Lines 370-387: Avoid conclusions with no relation with results

Response: Many thanks for your suggestion, we have remove some conclusions with no relation with results

Author Response File: Author Response.docx

Reviewer 3 Report

While potentially interesting, at its current form the paper does not clarify several crucial points. 

(1) Why was it important to compare the societal and environmental patterns during the Bronze Age and the Ming-Qing era? Does this comparison reveal anything significant regarding the nexus of climate/environmental change and human settlements? And specifically, why were these two time units chosen for the comparison?

(2) Equally important: what is the significance of Lake Dian Basin? It might be a regionally important site, but what scientific significance it has for an international reader is not clear from the manuscript. 

In addition the paper is very descriptive and at times superficial when describing environmental change and societal aspects. For example: (1) it is quite obvious that metal mining will lead to metal pollutants being present in the environment--what new insight does this finding imply? (2) the authors assume that social resilience has increased over time without clearly showing why they reach this conclusion. 

Thus, at its current state, it is not quite clear to me what exactly the point of this paper is, beyond a simple descriptive account of the study area (that too done with two very disjointed time periods). The authors must clarify these aspects and the overall scientific issue the study aims to address. 

The English is quite good and easily readable. However some typos and expressions may be fine-tuned. 

Author Response

Reviewer 3

General comments: While potentially interesting, at its current form the paper does not clarify several crucial points.

Specific comments:

• Why was it important to compare the societal and environmental patterns during the Bronze Age and the Ming-Qing era? Does this comparison reveal anything significant regarding the nexus of climate/environmental change and human settlements? And specifically, why were these two time units chosen for the comparison?

Reponse: Many thanks for your comment. According to the historical documents and the cultural Relics Atlas in Yunnan province, the periods of the Bronze Age and Ming-Qing were the time when a peak could be seen both in the population and the number of the archaeological sites in the Lake Dian basin. Our study aims to reveal the anthropogenic impact on the terrestrial environment in the Lake Dian basin, and explore the influencing factors behind. We should take the time when the polulation and human activities was high as the research period.

Many thanks for your comment. We have revised the Figure 6 to show the peak of the population and human activites in the Lake Dian baisn during the Bronze Age and Ming-Qing period.

• Equally important: what is the significance of Lake Dian Basin? It might be a regionally important site, but what scientific significance it has for an international reader is not clear from the manuscript.

Reponse: Many thanks for your comment. First, Lake Dian basin is sensitive to climate change, and many hydrological changes in the lake basin during the Holocene have been confirmed from examining paleoclimate records. Regional hydrological changes have had significant impacts on human activity. Second, Lake Dian baisn since the Late Holocene was a significant channel for cultural exchanges along the north-south direction of the Silk Road. The expansion of crop cultivation (foxtail and broomcorn millet, wheat, and barley) has taken place since the Bornze Age. Human subsistence could have a profound impact on the social environment in the Yunnan Plateau and then the intensity of human activites. Based on the field work, the Ancient Dian Kingdom has been built in the Lake Dian basin during the late Bronze Age, and the Kunming city as the captial of Yunnan province could be traced back to Yuan Dynasty. Thus, Lake Dian baisn is an ideal area for revealing the significant differences in the patterns of anthropogenic impact on the environment in the spatial and temporal dimensions and its influencing factors.

Many thanks for your comment, we have revised the Introduction. Please see line 58-77.

In addition the paper is very descriptive and at times superficial when describing environmental change and societal aspects. For example: (1) it is quite obvious that metal mining will lead to metal pollutants being present in the environment--what new insight does this finding imply? (2) the authors assume that social resilience has increased over time without clearly showing why they reach this conclusion.

Thus, at its current state, it is not quite clear to me what exactly the point of this paper is, beyond a simple descriptive account of the study area (that too done with two very disjointed time periods). The authors must clarify these aspects and the overall scientific issue the study aims to address.

Reponse: Many thanks for your comment. We have revised the “Introduction”, and the Figure 6. Hope these revisions will meet your requirements. 

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

I think the paper has become much clearer now and it is an interesting case study. The only comment I have now is that the discussion and conclusion sections may be further strengthened by offering a few more observations about the scale and pace of change in the lake basin in the two periods and what lessons this case offers for landscape studies in general. 
Some minor language and spelling related issues are still there. I believe these can be sorted out by careful copy editing.

Some minor language and spelling related issues are still there. I believe these can be sorted out by careful copy editing.

Author Response

Response to Reviewer 3

I think the paper has become much clearer now and it is an interesting case study. The only comment I have now is that the discussion and conclusion sections may be further strengthened by offering a few more observations about the scale and pace of change in the lake basin in the two periods and what lessons this case offers for landscape studies in general. 
Some minor language and spelling related issues are still there. I believe these can be sorted out by careful copy editing.

Reponse: Many thanks for your suggestion. We have revised the “Discussion” and “Conclusion”. Please see line, 283-284, 291-292, and 439-443. Addition, we have polished the language of this Manuscript.

Author Response File: Author Response.docx