Neoglacial trends in diatom dynamics from a small alpine lake in the Qinling Mountains of central China

Abstract. During the latter stages of the Holocene, and prior to anthropogenic global warming, the Earth underwent a period of cooling called the neoglacial. The neoglacial was associated with declining summer insolation and changes to Earth surface albedo. Although impacts varied globally, in China the neoglacial was generally associated with cooler, more arid climate, which led to renewed permafrost formation, and shifts in vegetation composition. Few studies in central China, however, have explored the impact of neoglacial cooling on freshwater diversity, especially in remote alpine regions. Here we take a palaeolimnological approach to characterise multidecadal variability in diatom community composition, beta-diversity, and flux-inferred productivity over the past 3,500 years in the Qinling Mountains, biodiversity hotspot. We investigate the impact of long-term cooling on primary producers in an alpine lake, which are fundamental to overall aquatic ecosystem function. We show that trends in beta-diversity and shifts in ecological guilds likely reflect changing lake-catchment resource availability, linked to both long-term attenuation of the Asian summer monsoon, and abrupt cool events, linked to a strengthened Siberian High. Important diatom community and productivity responses to the Medieval Climatic Optimum and the Little Ice Age are all apparent in our record, although impact from previous centennial-scale, cool-events are less evident.

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Neoglacial trends in diatom dynamics from a small alpine lake in the Qinling mountains of central China

Climate of the Past ◽

10.5194/cp-16-543-2020 ◽

2020 ◽

Vol 16 (2) ◽

pp. 543-554

Author(s):

Bo Cheng ◽

Jennifer Adams ◽

Jianhui Chen ◽

Aifeng Zhou ◽

Qing Zhang ◽

...

Keyword(s):

Decadal Variability ◽

Asian Summer Monsoon ◽

Central China ◽

Ice Age ◽

Qinling Mountains ◽

Alpine Regions ◽

Low Profile ◽

Community Restructuring ◽

Asian Summer ◽

The Impact

Abstract. During the latter stages of the Holocene, and prior to anthropogenic global warming, the Earth underwent a period of cooling called the neoglacial. The neoglacial is associated with declining summer insolation and changes to Earth's surface albedo. Although impacts varied globally, in China the neoglacial was generally associated with a cooler climate and an attenuated Asian summer monsoon. Few studies in central China, however, have explored the impact of neoglacial cooling on freshwater diversity, especially in alpine regions. Here we take a palaeolimnological approach to characterise multi-decadal variability in diatom community composition, ecological guilds, and compositional turnover over the past 3500 years from the alpine Yuhuang Chi lake on Mount Taibai in the Qinling mountains. Diatoms in the high-profile guild dominate much of the record from 3500 to 615 cal BP, which suggests that few nutrients in the lake were limiting overall, and disturbance and herbivory were likely low. After 615 cal BP, low-profile and planktic guild diatoms increase, suggesting greater turbulence in the lake, alongside a decline in available nutrients. Diatom turnover highlights periods in the lake history when deterministic processes structured diatom communities. For example, an abrupt decline in turnover is coincident with the shift from high- to low-profile diatoms at 615 cal BP, and this is likely due to the onset of the Little Ice Age in the region. We suggest that Yuhuang Chi lake became more shallow during peak regional aridity, which led to the short-lived community restructuring observed in the record.

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Impact of Climate Change on Potential Distribution of Chinese White Pine Beetle Dendroctonus armandi in China

Forests ◽

10.3390/f12050544 ◽

2021 ◽

Vol 12 (5) ◽

pp. 544

Author(s):

Hang Ning ◽

Ming Tang ◽

Hui Chen

Keyword(s):

Climate Change ◽

Potential Distribution ◽

Greenhouse Gas Emission ◽

Central China ◽

Qinling Mountains ◽

Climate Scenarios ◽

Impact Of Climate Change ◽

Precipitation Seasonality ◽

Suitable Area ◽

The Impact

Dendroctonus armandi (Coleoptera: Curculionidae: Scolytidae) is a bark beetle native to China and is the most destructive forest pest in the Pinus armandii woodlands of central China. Due to ongoing climate warming, D. armandi outbreaks have become more frequent and severe. Here, we used Maxent to model its current and future potential distribution in China. Minimum temperature of the coldest month and precipitation seasonality are the two major factors constraining the current distribution of D. armandi. Currently, the suitable area of D. armandi falls within the Qinling Mountains and Daba Mountains. The total suitable area is 15.83 × 104 km2. Under future climate scenarios, the total suitable area is projected to increase slightly, while remaining within the Qinling Mountains and Daba Mountains. Among the climate scenarios, the distribution expanded the most under the maximum greenhouse gas emission scenario (representative concentration pathway (RCP) 8.5). Under all assumptions, the highly suitable area is expected to increase over time; the increase will occur in southern Shaanxi, northwest Hubei, and northeast Sichuan Provinces. By the 2050s, the highly suitable area is projected to increase by 0.82 × 104 km2. By the 2050s, the suitable climatic niche for D. armandi will increase along the Qinling Mountains and Daba Mountains, posing a major challenge for forest managers. Our findings provide information that can be used to monitor D. armandi populations, host health, and the impact of climate change, shedding light on the effectiveness of management responses.

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Altitudinal Biodiversity Gradient and Ecological Drivers for Different Lifeforms in the Baotianman Nature Reserve of the Eastern Qinling Mountains

Forests ◽

10.3390/f10040332 ◽

2019 ◽

Vol 10 (4) ◽

pp. 332

Author(s):

Zhao ◽

Wang ◽

Yu ◽

Zhang ◽

Yao ◽

...

Keyword(s):

Nature Reserve ◽

Dispersal Limitation ◽

Central China ◽

Qinling Mountains ◽

Dissimilarity Index ◽

Β Diversity ◽

Species Overlap ◽

Predominant Process ◽

Community Clustering ◽

The Impact

Variation in species composition between two communities is so-called β diversity, or dissimilarity, and can be separated into two components: turnover and nestedness. However, the mechanisms underlying these two components remain ambiguous, particularly for different lifeforms. In this study, we examined the altitudinal gradient of biodiversity in the Baotianman Nature Reserve of the eastern Qinling Mountains in central China and found that turnover is the predominant process accounting for β diversity, that dispersal limitation is the main factor influencing species diversity, and that its effect on trees is greater than on shrubs, with herbs least affected. Nestedness, in contrast, is less prominent and generally affected by the richness deviation between communities, and the impact of richness deviation is stronger on shrubs than on trees, and in turn, stronger than on herbs. We zoned the altitudinal vegetation communities by pairwise dissimilarity index, and found that the peak value of turnover rather than β diversity indicates the existence of transitional zones; the higher the turnover index, the greater the diversity between communities. Comparatively, nestedness indicates species overlap between communities. The highest nestedness index usually occurs in the interior of vegetation zones. The result of community clustering by pairwise dissimilarity shows that understory species could have been mostly replaced upwards, while the dominant tree species may keep stable, indicating that dispersal limitation works differently for different lifeforms.

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Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry

The Cryosphere ◽

10.5194/tc-12-2249-2018 ◽

2018 ◽

Vol 12 (7) ◽

pp. 2249-2266 ◽

Cited By ~ 9

Author(s):

Nadine Steiger ◽

Kerim H. Nisancioglu ◽

Henning Åkesson ◽

Basile de Fleurian ◽

Faezeh M. Nick

Keyword(s):

Little Ice Age ◽

Ice Age ◽

Climate Forcing ◽

Relative Role ◽

Regional Warming ◽

History Of ◽

The Impact ◽

Term Response

Abstract. Rapid retreat of Greenland's marine-terminating glaciers coincides with regional warming trends, which have broadly been used to explain these rapid changes. However, outlet glaciers within similar climate regimes experience widely contrasting retreat patterns, suggesting that the local fjord geometry could be an important additional factor. To assess the relative role of climate and fjord geometry, we use the retreat history of Jakobshavn Isbræ, West Greenland, since the Little Ice Age (LIA) maximum in 1850 as a baseline for the parameterization of a depth- and width-integrated ice flow model. The impact of fjord geometry is isolated by using a linearly increasing climate forcing since the LIA and testing a range of simplified geometries. We find that the total length of retreat is determined by external factors – such as hydrofracturing, submarine melt and buttressing by sea ice – whereas the retreat pattern is governed by the fjord geometry. Narrow and shallow areas provide pinning points and cause delayed but rapid retreat without additional climate warming, after decades of grounding line stability. We suggest that these geometric pinning points may be used to locate potential sites for moraine formation and to predict the long-term response of the glacier. As a consequence, to assess the impact of climate on the retreat history of a glacier, each system has to be analyzed with knowledge of its historic retreat and the local fjord geometry.

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Warm-season hydroclimate variability in Central China since 1866 AD and its relations with the East Asian Summer Monsoon: evidence from tree-ring earlywood width

10.5194/cp-2018-141 ◽

2018 ◽

Author(s):

Yesi Zhao ◽

Jiangfeng Shi ◽

Shiyuan Shi ◽

Xiaoqi Ma ◽

Weijie Zhang ◽

...

Keyword(s):

Tree Ring ◽

Summer Monsoon ◽

East Asian Summer Monsoon ◽

Asian Summer Monsoon ◽

East Asian ◽

Central China ◽

Qinling Mountains ◽

Hydroclimate Variability ◽

Asian Summer ◽

Earlywood Width

Abstract. Historical hydroclimate records derived from tree-ring parameters are scarce in the core region of East Asian Summer Monsoon (EASM) in China, limiting our understanding of the inter-decadal hydroclimate variability of this region and its possible connections with the EASM. In this study, standard chronologies of total tree-ring width (TRW), earlywood width (EWW), and latewood width (LWW) were created using tree-ring samples of Pinus tabulaeformis in the eastern Qinling Mountains, Central China. The strongest growth-climate relationship was found between EWW and May–July self-calibrated Palmer Drought Severity Index (MJJ scPDSI). Therefore, a linear regression model, which explained 50.3 % of the variance in MJJ scPDSI (1951–2005), was developed to estimate the past MJJ scPDSI variations using EWW. The time series of MJJ scPDSI was extended back to the year 1866, and validated by independent hydroclimate series from nearby regions. Before the mid-1950s, the variations of MJJ scPDSI were in-phase with those of EASM intensity on decadal and longer timescales, suggesting that wet conditions would occur in the eastern Qinling Mountains when EASM was strengthened. Since the mid-1950s, however, the relationship has been out-of-phase. This phase change may be associated with an intensified dipole pattern of EASM precipitation.

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Variations in the East Asian summer monsoon over the past millennium and their links to the Tropic Pacific and North Atlantic oceans

10.5194/cp-2019-93 ◽

2019 ◽

Author(s):

Fucai Duan ◽

Zhenqiu Zhang ◽

Yi Wang ◽

Jianshun Chen ◽

Zebo Liao ◽

...

Keyword(s):

Summer Monsoon ◽

North Atlantic ◽

East Asian Summer Monsoon ◽

Asian Summer Monsoon ◽

East Asian ◽

Meridional Overturning Circulation ◽

Central China ◽

Ice Age ◽

Future Global Warming ◽

Asian Summer

Abstract. Variations of East Asian summer monsoon (EASM) during the last millennium could help enlighten the monsoonal response to future global warming. Here we present a precisely dated and highly resolved stalagmite δ18O record from the Yongxing Cave, central China. Our new record, combined with a previously published one from the same cave, indicates that the EASM has changed dramatically in association with the global temperature rising. In particular, our record shows that the EASM has intensified during the Medieval Climate Anomaly (MCA) and the Current Warm Period (CWP) but weakened during the Little Ice Age (LIA). We find that the EASM intensity is similar during the MCA and CWP periods in both northern and central China, but relatively stronger during the CWP in southern China. This discrepancy indicates a complicated regional response of the EASM to the anthropogenic forcing. The intensified and weakened EASM during the MCA and LIA matches well with the warm and cold phases of Northern Hemisphere surface air temperature, respectively. This EASM pattern also corresponds well with the rainfall over the tropical Indo-Pacific warm pool. Surprisingly, our record shows a strong association with the North Atlantic climate as well. The intensified (weakened) EASM correlates well with positive (negative) phases of North Atlantic Oscillation. In addition, our record links well with the strong (weak) Atlantic meridional overturning circulation during the MCA (LIA) period. All above-mentioned correlations indicate that the EASM tightly couples with oceanic processes in the tropical Pacific and North Atlantic oceans during the MCA and LIA.

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Impact of Critical Illness Insurance on the Burden of High-Cost Rural Residents in Central China: An Interrupted Time Series Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16193528 ◽

2019 ◽

Vol 16 (19) ◽

pp. 3528 ◽

Cited By ~ 1

Author(s):

Lu Li ◽

Junnan Jiang ◽

Li Xiang ◽

Xuefeng Wang ◽

Li Zeng ◽

...

Keyword(s):

Time Series ◽

Critical Illness ◽

Interrupted Time Series ◽

Term Effect ◽

Central China ◽

Mutual Aid ◽

Interrupted Time Series Analysis ◽

Long Term Effects ◽

The Impact

Critical illness insurance (CII) in China was introduced to protect high-cost groups from health expenditure shocks for the purpose of mutual aid. This study aimed to evaluate the impact of CII on the burden of high-cost groups in central rural China. Data were extracted from the basic medical insurance (BMI) hospitalization database of Xiantao City from January 2010 to December 2016. A total of 77,757 hospitalization records were included in our analysis. The out-of-pocket (OOP) expenses and reimbursement ratio (RR) were the two main outcome variables. Interrupted time series analysis with a segmented regression approach was adopted. Level and slope changes were reported to reflect short- and long-term effects, respectively. Results indicated that the number of high-cost inpatient visits, the average monthly hospitalization expenses, and OOP expenses per high-cost inpatient visit were increased after CII introduction. By contrast, the RR from BMI and non-reimbursable expenses ratio were decreased. The OOP expenses and RR covered by CII were higher than those uncovered. We estimated a significant level decrease in OOP expenses (p < 0.01) and rise in RR (p < 0.01), whereas the slope decreases of OOP expenses (p = 0.19) and rise of RR (p = 0.11) after the CII were non-significant. We concluded that the short-term effect of the CII policy is significant and contributes to decreasing OOP expenses and raising RR for high-cost groups, whereas the long-term effect is non-significant. These findings can be explained by increasing hospitalization expenses, many non-reimbursable expenses, low coverage for high-cost groups, and the unsustainability of the financing methods.

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Errata

Psychological Reports ◽

10.2466/pr0.109.5.701 ◽

2011 ◽

Vol 109 (2) ◽

pp. 701-701

Keyword(s):

Sexual Orientation ◽

Exploratory Study ◽

Mate Preference ◽

Work Demands ◽

Short Term ◽

Waist To Hip Ratio ◽

Saliva Cortisol ◽

And Shifts ◽

The Impact

Lucas, M., Koff, E., Grossmith, S., & Migliorini, R. (2011) Sexual orientation and shifts in preferences for a partner's body attributes in short-term versus long-term mating contexts. Psychological Reports, 108, 699–710. Table 1, p. 705: the correct mean rating of Long-term mate preference for Waist-to-hip ratio is 0.73. The correct mean ratings and standard deviations of Muscularity is 2.83 and 1.10 for Long-term mate preference and 3.33 and 1.16 for Short-term mate preference. Submitted August 29, 2011. Devereux, J., Rydstedt, L. W., & Cropley, M. (2011) An exploratory study to assess the impact of work demands and the anticipation of work on awakening saliva cortisol. Psychological Reports, 108, 274–280. Georgia Michalianou should have been listed as the first author of this article. Submitted September 20, 2011.

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Variation in the Asian monsoon intensity and dry-wet condition since the Little Ice Age in central China revealed by an aragonite stalagmite

Climate of the Past Discussions ◽

10.5194/cpd-10-1305-2014 ◽

2014 ◽

Vol 10 (2) ◽

pp. 1305-1335

Author(s):

J.-J. Yin ◽

D.-X. Yuan ◽

H.-C. Li ◽

H. Cheng ◽

T.-Y. Li ◽

...

Keyword(s):

Summer Monsoon ◽

Asian Summer Monsoon ◽

Eastern China ◽

Central China ◽

Ice Age ◽

Solar Irradiation ◽

Mountain Area ◽

Monsoon Intensity ◽

Wet Condition ◽

Asian Summer

Abstract. Highlight: this paper focuses on the climate variability in central China since 1300 AD, involving: 1. A well-dated, 1.5 year resolution stalagmite δ18O record from Lianhua Cave, central China; 2. Links of the δ18O record with regional dry-wet condition, monsoon intensity, and temperature over eastern China; 3. Correlations among drought events in the Lianhua record, solar irradiation, and ENSO index. We present a highly precisely 230Th/U dated, 1.5 year resolution δ18O record of an aragonite stalagmite (LHD1) collected from Lianhua Cave in Wuling mountain area of central China. The comparison of the δ18O record with the local instrumental record and historical documents exhibits at least 15 drought events in the Wuling mountain and adjacent areas during the Little Ice Age, in which some of them were corresponding to megadrought events in the broad Asian monsoonal region of China. Thus, the stalagmite δ18O record reveals variations in the summer monsoon precipitation and dry-wet condition in Wuling mountain area. The eastern China temperature varied with the solar activity, showing higher temperature under stronger solar irradiation which produces stronger summer monsoon. During Maunder, Dalton and 1900 sunspot minima, more severe drought events occurred, indicating weakening of the summer monsoon when solar activity decreased on decadal time scales. On interannual time scale, dry conditions in the studying area were prevailing under El Niño condition, which is also supported by the spectrum analysis. Hence, our record illustrates the linkage of Asian summer monsoon precipitation to solar irradiation and ENSO: wetter condition under stronger summer monsoon during warm periods and vice versa; During cold periods, the Walker circulation will shift toward central Pacific under El Niño condition, resulting further weakening of Asian summer monsoon. However, the δ18O of LHD1 record is positively correlated with temperature after ~1940 AD which is opposite to the δ18O – temperature relationship in earlier time. This anomaly relationship might be caused by the greenhouse-gas forcing.

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