the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 04 Sep 2026
Holocene hydroclimatic reorganization and prehistoric settlement response in the East Asian summer monsoon transition zone
Abstract. Holocene hydroclimatic changes in the East Asian monsoon region were spatially heterogeneous, but their timing and driving mechanisms within the monsoon transition zone remain insufficiently constrained. Here, we present a multi-proxy biomarker record from Nansi Lake, eastern China, to reconstruct Holocene hydroclimatic variability in this sensitive monsoon transition belt. The record indicates relatively dry conditions during the early Holocene, a pronounced humid interval during the middle Holocene, and generally drier but more variable conditions during the late Holocene. This pattern is broadly consistent with the middle-Holocene moisture maximum recorded in northern China, but contrasts with central-sector records characterized by wetter early and late Holocene conditions and drier mid-Holocene. Beyond this latitudinal contrast, proxy records across the monsoon transition zone reveal a longitudinal hydroclimatic gradient, with peak Holocene humidity generally delayed from west to east. This eastward delay may have been modulated by changes in El Niño activity and regional topographic effects on monsoon moisture transport. Furthermore, comparison with archaeological site distributions suggests that this hydroclimatic reorganization was accompanied by an eastward shift in prehistoric settlement density within the transition zone. These findings highlight the spatial complexity of Holocene hydroclimatic change in monsoon transition regions and provide a long-term perspective on landscape–human interactions under changing moisture regimes.
- Preprint
(3663 KB) - Metadata XML
- BibTeX
- EndNote
Status: open (until 30 Oct 2026)
- CC1: 'Comment on egusphere-2026-4480', Giacomo Medici, 18 Sep 2026 reply
-
RC1: 'Comment on egusphere-2026-4480', Anonymous Referee #1, 20 Sep 2026
reply
This manuscript presents an n-alkane record from a 2.45m sediment core from Nansi Lake, Shandong, reconstructing Holocene hydroclimatic changes in the East Asian summer monsoon transition zone and linking them to spatiotemporal changes in archaeological site density. The topic is of clear scientific significance. The Holocene precipitation pattern in the monsoon transition zone has long been debated, and reliable quantitative or semi-quantitative reconstructions from southwestern Shandong have been lacking; the Nansi Lake record helps fill this spatial gap. The attempt to link hydroclimatic reorganization with the eastward shift in prehistoric settlement density is also novel. The analytical work is generally sound, and the paper is well structured. I therefore recommend minor revision, subject to the authors addressing the following points, particularly the influence of late Holocene human activity on the sedimentary record and a series of detailed issues in the text, figures, and references.
The influence of late Holocene human activity on the sedimentary record requires explicit treatment. This is my main substantive concern. Nansi Lake is located in a densely populated region with a long history of human occupation, and the late Holocene interval in particular is characterized by intensive anthropogenic disturbance. The paper uses n-alkane proxies (Paq, C23/C31, LPTP) to infer effective moisture and lake water depth, and interprets the late Holocene decline and increased variability in these proxies as reflecting drier and less stable hydrological conditions with enhanced terrestrial input. However, this interpretation does not adequately consider the possibility that human activities, rather than, or in addition to climate drove the observed proxy changes. An additional discussion should be added to claim it.
L31–34 (Abstract): The abstract should specify which proxies were used and what they indicate in terms of hydrological and wet-dry changes.
L53: “its”should be changed to “EASM”; “has” should be changed to “have”.
L55: “EASM” should be changed to “East Asia”.
L56: useful.
L62–64: Monsoon circulation indicates monsoon intensity; it would be better to use one consistent term throughout.
L120: Figure 1c is missing from the figure.
L147: “gentle N2” — please clarify or revise.
L148: Was the saponified treatment performed at room temperature? Please specify.
L149–150: “extracted”? “separated” may be more accurate.
L155: “for 60 min?” — please confirm and clarify.
L157: The full name of “LPTP” should be spelled out at first occurrence.
L143–160: Was an internal standard used? Please specify.
L149, 160, 173, 176, 177, 180, 185, etc.: The “n” in “n-alkane” should be italicized. This needs to be corrected throughout the manuscript.
L196–197, 206: Terms such as “early Holocene” and “late Holocene” should be defined chronologically.
Figure 1: Panels 1c and 1d are missing from the figure, although they are mentioned in the caption. The figure and caption are inconsistent.
Figures 4 and 5: The proxies and units need to be clearly labeled. For example, the y-axis for Nansi Lake is the Paq parameter, not lake water depth. For pollen-based precipitation reconstructions, the units are not indicated.
Figure 6: The caption indicates summer precipitation patterns, but the color bar on the right appears to show standardized relative precipitation anomalies. This should be clarified.
Figure 7: The text in the figure is too small to read. Please enlarge it.
Citation: https://doi.org/10.5194/egusphere-2026-4480-RC1
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 236 | 86 | 40 | 362 | 37 | 34 |
- HTML: 236
- PDF: 86
- XML: 40
- Total: 362
- BibTeX: 37
- EndNote: 34
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
General comments
Very good research on the past climate. Please, follow my specific comments to improve your manuscript.
Specific comments
Lines 52-107. Enlarge the views of this good papers beyond the Holocene climate and speleothems.
Lines 60-61. Measurements of oxygen-isotope records on speleothems. Please, insert recent literature on this topic:
- Dayem, K.E., Molnar, P., Battisti, D.S., Roe, G.H. 2010. Lessons learned from oxygen isotopes in modern precipitation applied to interpretation of speleothem records of paleoclimate from eastern Asia. Earth and Planetary Science Letters, 295(1-2), 219-230.
- Medici, G., Marianelli, D., Cornacchia, I., Gori, F., Brandano, M. 2026. Multi-disciplinary approach to paleokarst occurrence in the Eocene–Oligocene succession of the Apulia Carbonate Platform (Salento, Italy). Facies, 72(2), 17.
Line 101-107. Very good to specify general goal, and specific objectives at the end of the introduction.
Line 112. “hydrologically connected”. Please, provide more information on the flow in the sub-surface and the hydraulic connections between the lakes.
Line 112. Provide information on the lithology of the aquifer.
Lines 112-123. Provide information on the nature of the lake sediments.
Lines 120-123. What about evolution of Air Temperature and Precipitation over time?
Line 174-359. Large mixing between results and interpretation.
Line 359. What about inserting a separate discussion?
Figures and tables
Figure 1. Increase graphic resolution. Coordinates are difficult to read.
Figure 2. Graph Depth vs 210Pbx too small. I suggest to create a separate figure.
Figure 7. Increase the graphic resolution. The coordinates are difficult to read.