the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 21 Mar 2024
Reconstruction of drought and long-rain chronologies since the 17th century in Central Japan using intra-annual tree-ring oxygen isotope ratios and documentary records
Abstract. Oxygen isotope ratios (δ18O) of tree-ring cellulose and historical documentary records are widely used to explore the hydroclimatic conditions of the past. In this study, we attempted to reconstruct chronologies of local climate disasters spanning four centuries in Central Japan using these proxy data. For tree-ring δ18O measurements, we prepared cellulose samples from a long-living cedar tree with continuously broad ring widths. To enhance the temporal resolution, we divided each annual ring into several (mainly six) segments. Analysis of correlations with observed relative humidity and precipitation data revealed that the intra-ring δ18O variations of the sample tree reflected the hydroclimatic conditions from April to July in each year. Subsequently, we chronologically listed the occurrence of eight types of disasters in the 17th to 19th centuries in the area adjacent to the sample tree according to 20 titles of “Town/City history,” compilation of historical documentary records from the local municipality. By comparison with the intra-ring δ18O data, we found that most of the major droughts and long rains recorded in the historical documents occurred in the Baiu rainy season (typically June–July) or pre-Baiu season that correspond to the growing season of the sample tree. Based on analysis of intra-ring δ18O variation for documentary-based drought and long-rain years, we set thresholds of intra-ring δ18O values to identify and extract drought and long-rain years. Drought and long-rain chronologies obtained by applying these thresholds were temporally continuous, complementing those based on documentary records. They depicted the relationships between the frequency of these climate disasters and the occurrence of major famines and the long-term tendency of length and magnitude of the Baiu rainy season in historical times.
- Preprint
(1625 KB) - Metadata XML
-
Supplement
(307 KB) - BibTeX
- EndNote
Status: final response (author comments only)
-
RC1: 'Comment on egusphere-2024-627', Anonymous Referee #1, 10 Apr 2024
This manuscript aimed to establish a chronology of local climate disasters over the past 400 years in central Japan based on Oxygen isotope ratios (δ18O) of tree-ring cellulose together with historical documentary records. The δ18O record is derived from a long-living cedar tree with wide rings. The authors separated each ring to six segments to present sub-seasonal δ18O variations. Correlation with climate factors showed that he intra-ring δ18O variations of the sample tree reflected the hydroclimatic conditions from April to July of each year. Together with historical documentary records of drought and long-rain years, they complement those climate disaster record and provide a more detailed chronology of drought and long-rain chronologies since the 17th century in Central Japan. This manuscript is well structured and written. This manuscript could be accepted after considering some points where I have some doubts about what has been done.
Specific comments:
My major concern is that the authors conducted this research based on only one tree sample. It is fortunate their intra-annual tree-ring oxygen isotope ratios shows similar variability with a chronology built by Nakatsuka et al. (2020).
The authors wrote: Nakatsuka et al. (2020) conducted a study on the long-term variation of the climatological component of tree-ring δ18O in Central Japan. Their resultant chronology was compared with the annual-averaged δ 18O chronology of this study (red line in Fig. 4b). These two chronologies showed similar long-term variations for almost the entire measurement period of this study. A significant positive correlation was also observed, r = 0.53 (n = 396, p < 0.01).
It would be much better that the authors add a figure showing the comparison between the two chronologies.
Lines 149-150: the authors wrote: the 4th to 6th segments in drought and 1st and 5th segments in long rain were significant (p<0.05), and so was the 4th segment in long rain (p<0.10). It is hard to understand.
Lines 204-205: It is not very clear how the mean precipitation for drought and long-rain years extracted by the intra-ring δ 18O data in 1701–1900 are reconstructed.
From Figure 4a, it is clear that during 1700-1900 AD the annual ring is divided into 6 segments for each year. So, I would suggest the authors clarify the variation of number of segments clearer in the text and figure captions.
Lines 220-224: it should be moved to Section 3.4?
Figure 6: How is the deviation calculated?
The authors wrote: The mean value and standard deviation of δ18O for each segment for each of the years of long rain, drought, flood, and famine are shown in Fig. S1. However, I did not find any content with regard to standard deviation.
Citation: https://doi.org/10.5194/egusphere-2024-627-RC1 - AC1: 'Reply on RC1', Kenjiro Sho, 28 Apr 2024
-
RC2: 'Comment on egusphere-2024-627', Anonymous Referee #2, 14 Apr 2024
This article is academically sound. It compared tree ring chronologies with historical documentary records. The idea is unique and very interesting. Both tree ring and documentary records are major sources of historical climate studies, but few studies carefully compared these two sources.
The analysis is reliable and the results are persuasive. I believe that it should merit publication in EGUsphere after a few modifications.
My suggestions are as following,
1. Apart from the records about precipitation, the documentary records about temperature could also have affected δ18O of tree ring, e.g., abnormally hot or cool growing seasons (including summer, spring and autumn), cold waves in growing seasons (unseasonal frosts and snow).
2. Insect damage is another type of factor; it would be better to analyse it separately.
3. Sometimes, local environmental change and incidents in the vicinity of the sampling sites could affect the tree rings. It would be better to exclude these effects.Citation: https://doi.org/10.5194/egusphere-2024-627-RC2 -
AC2: 'Reply on RC2', Kenjiro Sho, 02 May 2024
Thank you very much for providing valuable important comments. We are thankful for the time and efforts you expended. Our responses to the RC2 comments are as follows:
1. Apart from the records about precipitation, the documentary records about temperature could also have affected δ18O of tree ring, e.g., abnormally hot or cool growing seasons (including summer, spring and autumn), cold waves in growing seasons (unseasonal frosts and snow).
Reply: In the Town/City history documents used in this study, the number of records on cold summer is limited, 5 years (1703, 1736, 1787, 1836, and 1854) in 1701–1900 period. Significant cold summer years recorded in more than three titles of the Town/City histories are only two (1836 and 1854). Also, most of these cold summers coincided with long rain or flood. There are more than three titles of the Town/City histories recording long rain in 1836 and flood in 1854. Therefore, we decided that it was more reasonable to reflect cold summers in our research using long-rain and flood records that are more common than cold-summer records in the Town/City history documents. Records on abnormally hot spring/summer/autumn or cold waves are even fewer in documentary records used in this study.
Also, when the correlation between tree-ring δ18O of our sample tree and 10-day average temperature was calculated, we found lower correlation than relative humidity or precipitation in the growing season of the sample tree. In the central part of Japan, δ18O of precipitation is strongly influenced by altitude (altitude effect) and rainfall intensity (rainfall effect), and the temperature effect is marginal (e.g., Yabusaki & Tase, 2005). Therefore, it is generally difficult to read the signal of temperature variation in tree-ring δ18O in Central Japan.
References:
Yabusaki, S., and Tase, N.: Characteristics of the δ18O and δD of Monthly and Event Precipitation in Tsukuba from 2000 to 2002, J. Jpn Soc. Hydrol. Water Resour., https://doi.org/10.3178/jjshwr.18.592, 2005.
2. Insect damage is another type of factor; it would be better to analyze it separately.
Reply: There are only two years (1825 and 1836) when the insect damage was described in more than three titles of the Town/City histories in the 1701–1900 period (Table S2). It is an insufficient number of sample years to examine the relationship with tree-ring δ18O. We conducted the analysis described in 3.3 excluding these two years, but the result was nearly the same as the original result. Although it is known that large outbreaks of caterpillar or sawfly affect the tree-ring width and δ18O (e.g., Huang et al., 2008; Yuri et al., 2014), it has not been reported that these outbreaks occurred in the past in Central Japan. In Japan, most of all insect damage recorded in historical documents occurred by plant hoppers or grasshoppers. These insects damage seriously on agricultural crops such as rice plants, but they do not eat cedar reefs, so they do not affect the growth of the sample tree. Therefore, we could not consider insect damage in this study.
References:
Huang, J.-G., Tardif, J., Denneler, B., Bergeron, Y., Berninger, F.: Tree-ring evidence extends the historic northern range limit of severe defoliation by insects in the aspen stands of western Quebec, Canada, Canadian Journal of Forest Research, 38(9), 2535-2544, https://doi.org/10.1139/X08-080, 2008.
Yuri, G., Federica, C., Nicola La P., Marco, C., Andrea, B.: Tree rings and stable isotopes reveal the tree-history prior to insect defoliation on Norway spruce (Picea abies (L.) Karst.), Forest Ecology and Management, 319, 99-106, https://doi.org/10.1016/j.foreco.2014.02.009, 2014.
3. Sometimes, local environmental change and incidents in the vicinity of the sampling sites could affect the tree rings. It would be better to exclude these effects.
Reply: We did not find any record (document or other evidence) suggesting significant local environmental change or incident that can affect tree-ring δ18O of the sample tree within the analyzed period. The sampling site has been managed as a shrine from the beginning of the analyzed period (1600s) to the present. The sample tree always occupied the tree canopy because it was known as a prominent giant tree since the Edo era (17th-19th centuries). Since the sampling site is far from the urban area, it is also free from the effect of localized temperature increases such as the heat-island effect. These facts indicate that the local environment vicinity of the sample tree is relatively constant during the growth period.
Citation: https://doi.org/10.5194/egusphere-2024-627-AC2
-
AC2: 'Reply on RC2', Kenjiro Sho, 02 May 2024
-
RC3: 'Comment on egusphere-2024-627', Anonymous Referee #3, 14 Apr 2024
I concur with the recommendation and comments made by the first referee. In addition, I would like the authors to also address the following comments or questions:
1. Please provide the necessary details of the historical documents. For example, where the 20 cities/towns are actually located? How is a disaster defined and recorded (by examples)? What is the difference and connection between long rain and flood? Are there descriptions of connection between drought/long rain with famine in the original record?
2. The quality and reliability of the historical documents needs brief validation, including its comparison to documents from other regions, and application in previous investigation.
3. Please provide the scientific rationale of dividing the annual tree-ring sample into six subsamples. The same applies to the association between the delta O18 results in the subsamples and the 10-day relative humidity and precipitation.
4. The scientific significance of this study needs to be made clearer. For sample, the authors mention in the conclusion that
"The range of δ18O variation within an annual ring was generally larger than that of inter-annual variation (Fig. 4b), which indicates that substantial information originally contained in tree-ring δ18O variation is obscured in annually-measured tree ring δ18O data."
Then what contribution does this study offer if its drought/long rain chronologies also only have annual resolution?
5. The conclusion would benefit significantly from including a paragraph discussion the implication of its results, for example, the drought/long rain chronologies in the broad field of climate research.
Citation: https://doi.org/10.5194/egusphere-2024-627-RC3 - AC3: 'Reply on RC3', Kenjiro Sho, 15 May 2024
Viewed
| HTML | XML | Total | Supplement | BibTeX | EndNote | |
|---|---|---|---|---|---|---|
| 392 | 80 | 29 | 501 | 31 | 12 | 17 |
- HTML: 392
- PDF: 80
- XML: 29
- Total: 501
- Supplement: 31
- BibTeX: 12
- EndNote: 17
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1