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To assess the mitigation effectiveness of farmers’ adaptation measures for seasonal drought, we focused on the 2013 seasonal drought disaster in Jiangxi Province, southern China, the major rice growing areas, a typical case from China. First, we surveyed 755 farm households in Jiangxi Province that were harmed by seasonal drought in 2013. Based on the data from this survey, we constructed econometric models and used an instrumental variable approach to evaluate the effects of adaptation measures on the rice yield reduction due to seasonal drought, and then examined the factors influencing the capacity of farmers to adopt effective adaptation measures. The results show that: 1) More adaptation measures adopted by farmers can be effective in reducing the negative impacts of seasonal droughts on rice production. 2) All three types of measures, structural adjustment adaptation measures (SAAM), irrigation adaptation measures (IAM) and engineering adaptation measures (EAM) can significantly mitigate rice yield reduction due to seasonal drought, and SAAM and IAM perform more effectively. 3) Farmers’ social communication, frequency of droughts and access to disaster prevention information can help to increase the capacity of farmers to adopt adaptation measures, while distance from roads has a negative effect. 4) In terms of the different supportive policies, policies with higher-level agents and human support are more effective in increasing the ability of farmers to adopt adaptation measures. Our findings provide the following policy insights. On the one hand, it is necessary to increase the capacity of farmers to adopt measures by improving their social communication, incentivizing them to access information on resilience, and providing more supportive policies, especially policies with higher-level agents and human support. On the other hand, farmers should be encouraged to actively adopt adaptation measures to reduce the hazards of seasonal drought, especially SAAM and IAM.

Heatwaves are among the deadliest weather-related disasters. They are not only seen in summer but also may appear in spring and autumn, especially under climate warming. Although the mechanisms of summertime heatwaves have been extensively studied, how they differ from spring and autumn seasons and possibly season-dependent mechanisms of heatwaves are poorly understood. Here we examine the specific processes associated with spring, summer, and autumn heatwaves in southern China during 1961–2020. We show that heatwaves in all three seasons are intensifying in frequency, duration, and intensity, and they exhibit distinctly season-dependent circulation changes. Summer heatwaves are characterized by a warm-core high-pressure structure, while spring and autumn heatwaves exhibit a warm low pattern. Summer heatwaves are mainly triggered by the westward (eastward) extension of the western North Pacific subtropical high (South Asian high), and are accompanied by anomalous lower-level anticyclone and positive pressure anomalies. In contrast, spring and autumn heatwaves coincide with lower-than-normal pressure and anomalous southwesterly over East Asia, indicative of a weakening of the East Asian winter monsoon circulation and the Siberian high. Their developments are linked to the eastward movement of an upper-tropospheric wave-like pattern over the mid-latitudes. It is also found that autumn heatwaves are largely contributed by local preceding soil moisture deficit, in comparison to spring and summer heatwaves. Our findings contribute to a better understanding of the heatwave characteristics in different seasons and provide insights into their mitigation strategies.

A model‐circulation increment‐based dynamic statistical technique (MIDST) is proposed in this paper to improve the prediction of summer rainfall over southern China (SC) where quite low prediction skills have been found in the Beijing Climate Center Climate System Model version 1.1 with a moderate resolution (BCC_CSM1.1m). The results show that BCC_CSM1.1m can hardly represent the variability of the summer rainfall anomaly and its year‐to‐year increment over SC, and the skillful predictions are mostly confined over the middle reaches of the Yangtze River. Using the dynamic model output and statistical method, the MIDST is established to capture the coupled modes between the year‐to‐year increments of the summer rainfall anomaly and the associated simultaneous three‐dimensional coupled air‐sea circulation predictors. The cross‐validation indicates that the prediction skills of the MIDST are evidently improved for both the summer rainfall increment prediction and summer rainfall anomaly prediction compared with the direct BCC_CSM1.1m prediction. The skillful prediction can persist for long forecast leads over most regions except southwestern China. As the major predictability source of seasonal prediction, the intense response to changes in the circulation related to the El Niño‐Southern Oscillation (ENSO) is well captured, and thus, the performance improvement of the MIDST is primarily due to its more realistic representation of the incremental circulation related to the ENSO. [ABSTRACT FROM AUTHOR]

This study addresses how site index may affect crown shape by developing a crown shape regression model for the planted L. kaempferi at high altitudes in the subtropical climate of China. A total of 9241 branches from 78 trees, including 39 dominant trees and 39 intermediate trees, were measured in Hubei Province, southern China. The branch characteristics, including branch length, branch angle, and branch chord length of all living branches, were measured by felling trees. The models that showed good performance in crown shape modeling were used and compared in the present study. The goodness of fit statistics and stability of parameter estimation of the modified Kozak equation were better than those of the segmented polynomial equation. A nonlinear mixed-effect crown shape model was developed based on the modified Kozak equation. In addition to the tree level variables of diameter at the breast height (DBH), crown ratio (CR), and tree height-to-DBH ratio, an attempt was made to incorporate the site index into the crown shape model for the planted L. kaempferi. However, the site index was not a significant variable in the crown shape model. The purpose of our study was to lay the foundation for further study of the growth of the trees and the effects of crown morphology on stem growth in the future. [ABSTRACT FROM AUTHOR]

To improve typhoon forecasting in southern China, which is one of the most susceptible regions in China by typhoons, it is essential to investigate the microphysical characteristics of various types of typhoon precipitation. In this study, the dual-frequency precipitation radar (DPR) data from the Global Precipitation Measurement (GPM) satellite is adopted to reveal the raindrop size distribution (RSD) characteristics of 18 typhoons that made landfall in southern China during 2014 - 2022. The RSD characteristics of precipitation in the horizontal and vertical directions of summer typhoons (STs) and autumn typhoons (ATs) are examined. There is no obvious difference between the parameters corresponding to STs andATs without considering the precipitation types. The mass-weighted mean diameter (Dm) both STs and ATs are primarily composed of small-sized (Dm <1.4 mm) and medium-sized (1.4 mm ≤ Dm <2.4 mm) precipitation particles, while STs contain a higher proportion of large-sized (Dm ≥2.4 mm) precipitation particles. Convective precipitation during STs contributes most to the large-sized precipitation particles. The STs and the ATs are both dominated by stratiform precipitation, the proportion of convective precipitation is higher in the STs than that in the ATs. While the strong precipitation centres of ATs are primarily made up of small-sized and medium-to-small-sized (1.4 mm ≤ Dm <1.7 mm) precipitation particles, the strong precipitation centres of STs are primarily made up of medium-to-large-sized (1.7 mm ≤ Dm <2.4 mm) precipitation particles at various vertical profiles. Compared to ATs, the storm height and freezing level height of STs are typically higher, and these variables may contribute to divert Dm to relatively larger droplet diameters. An examination of the RSD characteristics of STs and ATs in southern China may assist in advancing our comprehension of the microphysical characteristics of typhoon precipitation. [ABSTRACT FROM AUTHOR]

Streptomyces are filamentous bacteria that are extensively present in soil, play an important role in carbon cycling, and produce a large number of highly valuable secondary metabolites. In this study, total number of 411 isolates of Streptomyces were collected from ecologically similar habitats from 13 provinces in Southern China. They were clustered into 96 operational taxonomic units including eight potentially new species based on their 16S rDNA sequences. Phylogenetic analysis disclosed that the isolates with similar geographical distributions clustered together. Beta diversity of Streptomyces showed it manifests in a latitudinal diversity gradient (R2 = 0.3828, p = 0.0113). The beta diversity did not change significantly with geographic distance, and this could be due to the large longitudinal and relatively smaller latitudinal sampling range, as the phylogenetic clustering of regions with higher annual average temperature was analyzed with the nearest taxon index (R = −0.23, p = 0.045). Result of the Streptomyces biogeography evaluation shows the diversity of the genus is controlled by many of the same processes. Bioassay results disclosed that there were 27 isolates strongly antagonistic to plant pathogenic fungi and 71 isolates with strong nematocidal activity against pine wood nematode. Our results provide significant insights into the diversity and biocontrol potential of cultivatable Streptomyces in Southern China. [ABSTRACT FROM AUTHOR]

There is a continuous and relatively stable rainy period every spring in southern China (SC). This spring precipitation process is a unique weather and climate phenomenon in East Asia. Previously, the variation characteristics and associated mechanisms of this precipitation process have been mostly discussed from the perspective of seasonal mean. Based on the observed and reanalysis datasets from 1982 to 2021, this study investigates the diversity of the interannual variations of monthly precipitation in spring in SC, and focuses on the potential influence of the tropical sea surface temperature (SST) anomalies. The results show that the interannual variations of monthly precipitation in spring in SC have significant differences, and the correlations between each two months are very weak. All the interannual variations of precipitation in three months are related to a similar western North Pacific anomalous anticyclone (WNPAC), and the southwesterlies at the western flank of WNPAC bring abundant water vapor for the precipitation in SC. However, the WNPAC is influenced by tropical SST anomalies in different regions each month. The interannual variation of precipitation in March in SC is mainly influenced by the signal of El Niño-Southern Oscillation, and the associated SST anomalies in the equatorial central-eastern Pacific regulate the WNPAC through the Pacific-East Asia (PEA) teleconnection. In contrast, the WNPAC associated with the interannual variation of precipitation in April can be affected by the SST anomalies in the northwestern equatorial Pacific through a thermally induced Rossby wave response. The interannual variation of precipitation in May is regulated by the SST anomalies around the western Maritime Continent, which stimulates the development of low-level anomalous anticyclones over the South China Sea and east of the Philippine Sea by driving anomalous meridional vertical circulation. [ABSTRACT FROM AUTHOR]

Southern China is prone to floods during the wet season, and regional extreme precipitation is expected to become more frequent given the context of climate change. However, the prediction skills and predictability of the spatial distribution of extreme precipitation days (EPDs) over southern China remain unclear. To address this issue, through observational diagnosis and numerical experiment, the present study revealed the formation mechanisms of the two leading modes of pre-summer (May and June) EPDs in southern China, and established a physical-based empirical model (P-E model) to predict the distribution of EPDs in the region. The results revealed the following: (1) the first mode of pre-summer EPDs in southern China displayed a uniform pattern, while the second mode presented a meridional dipole pattern. The uniform pattern of the first mode is associated with the tropical western North Pacific anomalous anticyclone (TWPAC), whereas the meridional dipole pattern of the second mode is related to the subtropical western North Pacific anomalous anticyclone (SWPAC); (2) the spring North Atlantic tripole sea surface temperature (SST) pattern, the northern North America surface air temperature, and the snow cover depth over central Siberia contribute to the variation of the first mode and TWPAC, whereas the spring extratropical North Atlantic dipole SST pattern and the spring change of sea ice concentration over the Barents and Kara seas are physically linked with the variation of the second mode and SWPAC; (3) based on these predictors, the established P-E model demonstrated predictive skill with regard to the principal components of the first two modes, and the spatial distribution of EPDs in southern China was reconstructed. The areal mean temporal correlation coefficient skill for the independent prediction period (2011–2021) was 0.34, while for the pattern correlation coefficient skill averaged over the entire period was 0.28. In comparison with the maximum attainable skills, both metrics indicate potential for improvement. The findings of this study represent a reference for the prediction and predictability of the spatial distribution of pre-summer EPDs in southern China. [ABSTRACT FROM AUTHOR]

Abstract A model‐circulation increment‐based dynamic statistical technique (MIDST) is proposed in this paper to improve the prediction of summer rainfall over southern China (SC) where quite low prediction skills have been found in the Beijing Climate Center Climate System Model version 1.1 with a moderate resolution (BCC_CSM1.1m). The results show that BCC_CSM1.1m can hardly represent the variability of the summer rainfall anomaly and its year‐to‐year increment over SC, and the skillful predictions are mostly confined over the middle reaches of the Yangtze River. Using the dynamic model output and statistical method, the MIDST is established to capture the coupled modes between the year‐to‐year increments of the summer rainfall anomaly and the associated simultaneous three‐dimensional coupled air‐sea circulation predictors. The cross‐validation indicates that the prediction skills of the MIDST are evidently improved for both the summer rainfall increment prediction and summer rainfall anomaly prediction compared with the direct BCC_CSM1.1m prediction. The skillful prediction can persist for long forecast leads over most regions except southwestern China. As the major predictability source of seasonal prediction, the intense response to changes in the circulation related to the El Niño‐Southern Oscillation (ENSO) is well captured, and thus, the performance improvement of the MIDST is primarily due to its more realistic representation of the incremental circulation related to the ENSO.

Benggangs are a special type of severely eroded landform in southern China. They cause severe damage to soil resources, which has had a large negative impact on local ecological environments and people’s lives. Benggang erosion has received abundant attention in the past few decades, but few studies have systematically summarized and analyzed the progress, deficiencies and future directions of research of Benggang erosion. The purpose of this paper is therefore to analyze the progress of research on Benggang erosion, summarize the research deficiencies and propose future research directions and priorities. Benggangs gained attention in the 1960s, and studies of Benggang erosion have achieved rich results, including the characteristics of parental materials, spatial variation of soil properties in Benggang areas, mechanisms of the occurrence and process of Benggang erosion, dynamic monitoring of Benggang erosion, estimation of erosion volume, measures for controlling Benggang erosion and evaluation of their effectiveness. These studies have improved our knowledge and understanding of the basic attributes, occurrence, development, and factors influencing Benggang erosion and have provided a scientific basis for the optimal arrangement of measures for conserving soil and water and the rational development and effective management of Benggangs. We nevertheless believe that deficiencies remain in the aspects of the optimization of monitoring methods, mechanism of composite erosion, control of erosion and evaluation of the effectiveness of controlling Benggang erosion under the current level of development of research on soil erosion and the high standard of ecological protection. Further studies are necessary in the following areas: space-air-ground integrated technology for optimizing the monitoring of Benggang erosion; mechanism of hydraulic-gravitational composite erosion and the construction of models; research, development and application of new material for the prevention and control of Benggang erosion and development of a system for evaluating the effectiveness of erosion control. These research topics can supplement and enrich the content of traditional research on Benggang erosion and are very important for the restoration of ecological environments and improving ecological services and functions in areas with Benggang erosion.

In this study, a 140 kyr stack (MT2022) of 95 stalagmite δ18O records from Southern China was synthesized using the error weighted mean method and the linear weighted mean method. This stack record was derived from approximately 1100 U/Th dating and 40000 δ18O data points. On orbital scale, MT2022 agrees with the variation of the summer (21 July) insolation at 65°N and restores as much detail as possible of the actual variability of Asian Summer Monsoon (ASM) from stalagmite records. The age model of MT2022 was established according to the dating results of each sample record, and the start and end periods of each weak monsoon event were constrained by at least five stalagmite sample records, with average errors of less than 0.2 kyr. By comparison, we find that MT2022 was generally consistent with the Speleothem Interstadial Onset Compilation data set (SIOC19) and had more sample records from the ASM domain, which is more suitable to represent the ASM evolution. Furthermore, comparing MT2022 to three Greenland ice core timescales, we discovered that MT2022 was quite consistent with NGRIP (GICC05) over the last 60 kyr and differed from GRIP (ss09sea) and GISP2 (Meese-Sowers). The main discrepancy between MT2022 and GRIP occurs around Dansgaard-Oeschger (DO) events 14 and 20–23, whereas MT2022 and GISP2 start to deviate prominently beyond 40 kyr BP. The high degree of consistency between GICC05 and MT2022 allows their accuracy to be validated against each other, thus, MT2022 may provide a new chronological reference for climatic events in the last glacial-interglacial cycle as well as an age calibration standard for other palaeoclimate archives. [ABSTRACT FROM AUTHOR]

Introduction: Thalassemia is the most common monogenic disease in South and Southeast Asia. An accurate assessment of the relative frequency and composition of thalassemia mutations is important for the design of appropriate strategies to prevent the disease. In this study, we aimed to decode the molecular characterization of thalassemia mutations in Zhuhai region of southern China. Methods: A total of 8048 individuals who were potential thalassemia carriers were enrolled. Gap‐polymerase chain reaction (Gap‐PCR) and reverse dot‐blot (RDB) hybridization methods were employed to detect common deletional and non‐deletional thalassemia mutations. Multiplex ligation dependent probe amplification (MLPA) and Sanger sequencing were used to analyze and verify rare and complex mutations. Results: We diagnosed 3433 individuals as thalassemia carriers or patients. Of these, 2395 (69.76%) individuals with α‐thalassemia harbored 13 α‐globin gene mutations. The three most common α‐thalassemia mutations were ‐‐SEA (60.08%), ‐α3.7 (20.62%) and ‐α4.2 (9.25%). We diagnosed 903 (26.30%) individuals with β‐thalassemia and identified 20 β‐globin gene mutations, of which the three most frequent were CD41/42 (‐TCTT) (38.10%), IVS‐II‐654 (C>T) (23.69%) and TATAbox‐28 (A>G) (15.18%). In addition, we identified 15 rare thalassemia variants. We also summarized the association between the thalassemia genotype and hematological parameters, which demonstrated the broad phenotypic heterogeneity caused by globin gene mutations. Conclusion: This is the first survey of thalassemia molecular epidemiology and hematological phenotype in Zhuhai region. It uncovered a high prevalence and complex molecular spectrum of thalassemia. These findings can be used as a basis for thalassemia diagnosis, counseling and prevention management. [ABSTRACT FROM AUTHOR]

Background: Abdominal aortic aneurysm (AAA) is a severe cardiovascular disease. The mortality rate for an AAA rupture is very high. Understanding the risk factors for AAA rupture would help AAA management, but little is known about these risk factors in the Chinese population. Methods: This retrospective study included patients that were diagnosed with AAA during the last 5 years in a large national hospital in southern China. AAA patients were divided into a rupture and non-rupture group. Clinical data were extracted from the hospital medical record system. Clinical features were compared between the rupture and non-rupture groups. The associations between potential risk factors and rupture risk were evaluated using a multivariate logistic regression analysis. Results: A total of 337 AAA patients were included for analysis in the present study. AAA diameter was significantly larger, and high-sensitivity C-reactive protein (hs- CRP) and serum creatinine levels were both significantly higher in AAA rupture patients. High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) levels were significantly lower in AAA rupture patients. After adjustment, the multivariate logistic analysis found that AAA diameter and hs-CRP were independently positively associated with AAA rupture, and HDL-C level was adversely associated with AAA rupture. Conclusions: Our data suggests that larger AAA diameter and higher hs-CRP level are associated with a higher risk of AAA rupture, and higher HDL-C level is associated with a lower risk of AAA rupture. The results of this study may be helpful for the management of AAA patients in southern China. [ABSTRACT FROM AUTHOR]

Heritage buildings are a crucial aspect of a country's cultural heritage, serving as a means of preserving and passing down its history and traditions to future generations. The heritage buildings in southern China possess significant conservation, utilization, and research value. However, research is lacking on the spatial distribution characteristics and subdivision types of these buildings in the region. This study aimed to investigate the spatial agglomeration and distribution characteristics of heritage buildings in southern China, as well as the factors contributing to the formation of these spatial distribution patterns. This article focused on the protection of 981 heritage buildings in southern China since the founding of China. The study examined the buildings' spatial agglomeration and distribution characteristics from various dynasties and subdivided types. It utilized the average nearest neighbor analysis, unbalance index, and kernel density estimation to analyze this distribution. Additionally, this study also investigated the primary factors influencing the spatial distribution and differentiation of these buildings. The results demonstrated the following: (1) In general, the spatial distribution of heritage buildings in southern China is characterized by unevenness and clustering, with a concentration in the eastern coastal and Sichuan provinces. (2) In terms of temporal dimension, the spatial distribution of heritage buildings exhibits unique characteristics in various dynastic zones. (3) In the type dimension, the number of different types of heritage buildings varies greatly. (4) Further analysis of the distribution and types of heritage buildings indicates that quantitative differences are primarily influenced by natural, human, and socio-economic factors. This research was unique as it explored the geospatial distribution characteristics and determinants of heritage buildings. It offers a valuable perspective on the spatial distribution of heritage buildings and can serve as a reference for future studies on the preservation and protection of such buildings in China. Additionally, the findings can provide guidance for the management and rational use of heritage buildings in southern China. [ABSTRACT FROM AUTHOR]

The spider genus Sinoalaria Zhao & Li, 2014 is redefined and reviewed. A total of ten species are studied, including four new species: S. chi Yu & Lin, sp. nov. (♂♀), S. shenhei Yu & Lin, sp. nov. (♀), S. shuidi Yu & Lin, sp. nov. (♀), S. xiaotu Yu & Lin, sp. nov. (♂♀). Two new combinations are proposed: Sinoalaria nitida (Zhao & Li, 2012), comb. nov. and S. prolata (Zhao & Li, 2012), comb. nov., both transferred from Karstia Chen, 2010. The material of six known species were re-examined and photographed, including the type species, S. chengguanensis (Zhao & Li, 2012). A key is provided for all species of the genus, as well as diagnoses, illustrations, and a distribution map. [ABSTRACT FROM AUTHOR]

In order to investigate the species diversity of Herpothallon in China and further identify its distribution characteristics and species composition, one hundred and twenty-eight specimens of the lichen genus Herpothallon were collected from many provinces of tropical and subtropical regions of China as part of our field investigations. Identification was carried out using morphological, anatomical and chemical methods. The examined specimens are deposited in the Lichen Section of the Botanical Herbarium, Shandong Normal University (SDNU) and the Herbarium of Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China (KUN) . A total of 12 species of Herpothallon are reported, of which H. australasicum (Elix) Elix & G. Thor, H. granulosum Jagadeesh Ram & G. P. Sinha, H. himalayanum Jagadeesh & G. P. Sinha, H. isidiatum Jagadeesh Ram & G. P. Sinha and H. minutum Jagadeesh are new records for China. Hitherto known species of Herpothallon in China were comprehensively analyzed. The results are as follows: (1) There are two additional species of Herpothallon found in China making a total of 14 and accounting for 29.17% of the known Herpothallon species worldwide. (2) These species belong to five types of geographical elements: Pantropical distribution, Tropical Asia to Tropical Australia distribution, Topical Asia and tropical America disjunctive distribution, Tropical Asia distribution, and Endemic to China. (3) Herpothallon species in China grows mainly in the altitude ranging 300 m to 2 500 m. (4) Most of these species are mainly corticolous with a few being foliicolous, saxicolous and muscicolous in China. The results of initial filed work indicate that this group is distributed sporadically in some mountainous forests in tropical and subtropical regions of the world, and indicate that a higher biodiversity of Herpothallon in South China, changes in substrate and altitude also have important effects on the distribution of Herpothallon in China, which are important for the understanding of the genus composition and the protection of lichen diversity of Herpothallon in China. We plan to carry out further surveys and studies on this genus to provide more detailed and reliable data that can make species definition more objective and establish a more reliable classification. [ABSTRACT FROM AUTHOR]

March rainfall over southern China (SC) experiences a significant decrease of the intensity of interannual variation (IIV) around 1996/1997. During 1982–1996, the IIV of March rainfall over southern China (SCMR) are stronger than during 1997–2011, and the interannual variation of SCMR is closely related to sea surface temperature (SST) anomalies. The eastern Pacific El Niño (La Niña) would weaken (strengthen) the Walker circulation, accompanying convergence (divergence) anomalies over tropical eastern Pacific and divergence (convergence) anomalies over western Pacific in the lower level. The divergent wind anomalies blow from western Pacific (SC) to SC (western Pacific) and converge (diverge) over SC, which favors ascending (descending) motions over there. The water vapor convergence (divergence) anomalies and ascending (descending) motions over SC cause more (less) SCMR. Besides, positive (negative) tropical southeastern Indian Ocean SST anomalies are of benefit to the more (less) SCMR by affecting vertical circulation. However, the relation between SCMR and SST anomalies decreases after 1997. During 1997–2011, SCMR experiences the lower IIV period than before. The snow depth over the Eurasia continent has an important impact on the SCMR. The SCMR is negatively correlated with the snow depth from the Siberia to Northeast China, but positively correlated with the snow depth over the Tibetan Plateau (TP). The ground obtains more (less) heat flux with less (more) snow, accompanying positive (negative) outward long wave radiation anomalies and latent heat flux anomalies, which helps to maintain positive (negative) air temperature anomalies over the Siberia to Northeast China. Meanwhile, the ground over TP obtains less (more) heat flux with more (less) snow, favoring negative (positive) air temperature anomalies. The configuration of air temperature and geopotential height dipole anomalies conforms to static equilibrium over East Asia, and favors the cyclone-anticyclone (anticyclone-cyclone) dipole anomalies from the low latitudes to the mid-high latitudes in the upper level, which represents the southward (northward) subtropical upper-level westerly jet over TP, conducive to more (less) SCMR. The external forcings that have impacts on the interannual variation of SCMR experience an interdecadal change before and after 1996/1997. [ABSTRACT FROM AUTHOR]

The roles of rainfall with various intensities in hydraulic erosion processes are obviously different. In-depth knowledge about the spatiotemporal variation in extreme rainfall erosivity is critical for soil erosion risk assessment and formulation of response measures. In the period of 1961–2020, more than 390,000 erosive rainfall data from 212 meteorological stations were collected to explore the erosion characteristics of different intensities of rainfall erosivity across southern China. The asymmetric characteristic of extreme rainfall erosion was analyzed and expressed by an asymmetric change index (ACI) defined in this study. Correlation analysis was applied to study the impact of global extreme climate events on the ACI. The results showed that different patterns of precipitation had evident asymmetric characteristics in rainfall erosivity, and fewer high-intensity precipitation events contributed to much higher total rainfall erosivity, particularly for rainstorms (≥100 mm). The ACI of the rainfall erosivity exhibited evident spatial heterogeneity; insignificant increasing trends were found in the ACIs for heavy rainfall, torrential, and rainstorm erosivities over the past 60 years. The change rate of ACI varied greatly on both monthly and interdecadal scales, and the ACI of rainstorms showed the maximum linear increasing trend on the long-time scale. There were significantly high correlations between the ACI and erosive rainfall days and the ACI and erosive rainfall (p < 0.01), and the correlation coefficients were relatively higher from May to October, where the precipitation was concentrated. Additionally, the El Niño-Southern Oscillation and tropical cyclones clearly influenced the spatiotemporal distribution of the ACI and rainfall erosivity but were limited to specific periods and regions. These results could provide a reference for extreme soil erosion event monitoring and control in southern China. [ABSTRACT FROM AUTHOR]

A heavy nocturnal warm sector rainfall occurred over the western coastal region of South China in June 2020, of which the precipitation magnitude was seriously underestimated by the operational TRAMS (Tropical Regional Atmosphere Model System) model. In this study, by improving the configuration of initial conditions (ICs) and lateral boundary conditions (LBCs) in offline nesting, the simulation of the convection initiation (CI) process can be well improved. The CI simulation is found to be sensitive to the vertical resolution in ICs in this case. When the low‐level vertical resolution of ICs is increased, the nocturnal near‐surface cold layer caused by inland mountains can be resolved better, which is necessary to form the convergence line along the coastline. Another important impact of increasing the vertical resolution of ICs is the successful simulation of horizontal convective rolls (HCRs) over the northern South China Sea. The HCRs apparently increase the depth of the warm‐moist marine boundary layer jet (MBLJ), and finally lead to the CI along the coastline. The increased vertical resolutions of LBCs can reduce the discontinuity of simulated moist tongue across the southern lateral boundary of the TRAMS model, which provides more moisture for the warm sector rainfall through MBLJ. LBCs with Higher temporal frequency help to alleviate the western position bias of rain belt by reducing the temporal interpolation error. Our study highlights the importance of finer ICs and LBCs in offline nesting for regional operational NWP systems in the South China region. Plain Language Summary: Warm‐sector heavy rainfall in South China usually develops under weakly forced weather condition, numerical forecasting of its initiation and intensification process is a difficult problem. To investigate its sensitivity to the configuration of initial conditions (ICs) and lateral boundary conditions (LBCs), a simulation study is carried out for a nocturnal warm sector rainfall event happened in western Guangdong. When the low‐level vertical resolution of ICs is increased, the nocturnal near surface cold layer from inland mountains can be resolved better. Another important impact of increasing vertical resolution of ICs is the successful simulation of horizontal convective rolls (HCRs) over the northern South China Sea. The HCRs apparently increase the depth of warm‐moist marine boundary layer jet (MBLJ), and finally lead to the CI along coast line. Additionally, the vertical resolution and the updating frequency of the lateral boundary conditions also have important effects on the simulation of the rainstorm intensification process. This paper emphasizes the importance of accurate ICs and LBCs to improve the predictability of warm‐sector rainfall in South China, which can provide practical reference for the design of operational systems. Key Points: Increasing low‐level vertical resolution of initial conditions is critical to the convection initiation (CI) simulation of warm‐sector rainfall caseThe increased vertical resolutions of lateral boundary conditions (LBCs) can provide more moisture for the CI and upscale convective growth process through marine boundary layer jetHigher temporal frequency LBCs is help to alleviate the western position bias of rain belt by reducing the temporal interpolation error [ABSTRACT FROM AUTHOR]

Three new genera and eleven new species are reported from Hainan Island, China. The new genera are Logunattus gen. nov., including L. dufui sp. nov. (♂), and the generotype L. libaii sp. nov. (♂♀), Qiongattus yuanyeae gen. et sp. nov. (♂♀), and Spiralembolus gen. nov., including the generotype S. yinggeling sp. nov. (♂♀), and S. yui sp. nov. (♂♀). Another six new species are Carrhotus qingzhaoae sp. nov. (♂♀), Gedea liangweii sp. nov. (♂♀), Heliophanoides moi sp. nov. (♂), Indopadilla songi sp. nov. (♂♀), Myrmarachne mixiaoqii sp. nov. (♂♀), and Nandicius shihaitaoi sp. nov. (♂♀). The unknown female of the endemic species, Pancorius hainanensis Song & Chai, 1991 is also described for the first time. Diagnostic photos of these species are provided. [ABSTRACT FROM AUTHOR]

In this paper, the evolution of the microphysical characteristics in different regions (eyewall, inner core, and outer rainbands) and different quadrants [downshear left (DL), downshear right (DR), upshear left (UL), and upshear right (UR)] during the final landfall of Typhoon Ewiniar (2018) is analyzed using two-dimensional video disdrometer and S-band polarimetric radar data collected in Guangdong, China. Due to the different types of underlying surfaces, the periods before landfall (mainly dominated by underlying sea surface) and after landfall (mainly dominated by underlying land surface) are also analyzed. Both before landfall and after landfall, the downshear quadrants had the dominate typhoon precipitation. The outer rainbands had more graupel than the inner core, resulting in a larger radar reflectivity, differential reflectivity, specific differential phase shift, and mass-weighted mean diameter below the melting layer. Compared with other regions, the eyewall region had the smallest mean logarithmic normalized intercept parameter before landfall and the smallest mean mass-weighted mean diameter and the largest mean logarithmic normalized intercept parameter after landfall. The hydrometeor size sorting was obvious in the eyewall and inner core (especially in the eyewall) after landfall. A high concentration of large raindrops fell in the DL quadrant, and more small raindrops fell in the UR quadrant. Although the ice-phase process and warm rain process were both important in the formation of tropical cyclone precipitation, the warm rain process (ice-phase process) contributed more liquid water before landfall (after landfall). This investigation provides a reference for improving the microphysical parameterization scheme in numerical models. [ABSTRACT FROM AUTHOR]

Four new Viola species from southern China, i.e. Viola qingruii, V. heyuanensis, V. chaozhouensis, and V. longissima, are described and illustrated based on morphology and molecular phylogeny. Viola qingruii is widely distributed in the coastal mountains of southeastern China, while V. heyuanensis, V. chaozhouensis, and V. longissima, are all narrow endemics in Guangdong Province, China. These species are described and compared with the morphologically related species V. lucens, V. tenuis, V. guangzhouensis and V. huizhouensis. Phylogenetic analysis based on ITS confirmed that all of the four new species belong to Viola sect. Plagiostigma subsect. Diffusae. An identifcation key is provided to distinguish the four new species from other species of V. subsect. Diffusae in southern China. In addition, the origin and evolution of characters such as aerial stems, stolons, elaiosomes and tuberculate seeds in Viola are briefly discussed. [ABSTRACT FROM AUTHOR]

The efforts of the state and the literati, such as the implementation of beneficent politics(仁政) and the rectification of folk customs, led to the alteration of the medical environment throughout the Song period. Epidemics with a severe impact that occurred frequently were what started the transition. Urbanization, increased transit accessibility, and population growth have all contributed to the emergence of epidemics. In addition, a disease that was indigenous to southern China, where regional development and population expansion were focused, started to spread widely. When an epidemic spread, the local population occasionally received medical care, but most of the time they relied on spiritual care from the neighborhood shaman or spirit medium. Spiritual treatment is utilized to treat malignant infectious diseases, even though professional doctors primarily focus on treating patients with traditional medicine. By editing and releasing publications on medicine at the national level, the Song dynasty government and intellectuals encouraged the development and transmission of efficient treatment procedures to advance medical practices. Meanwhile, folk remedies or medical prescriptions discovered by renowned scholars like Su Shi(蘇軾) and Shen Kuo((沈括) were included in the medical book and made available to the general public. Although there was a difference of opinion between the Song government and intellectuals, they commonly rejected shamanistic treatment and pursued the spread of medicine treatment through the transmission of codified medical knowledge. In the end, the spread of the epidemic and the subsequent transmission and development of Song dynasty medicine had a significant impact on the emergence of codified medicine treatment, but this was not solely to advance medical knowledge; it also served to further their political and ideological objectives. As a result, the following Jin(金) and Yuan(元) dynasties’ physicians instantly criticized the Song dynasty’s medical advancements. It is indisputable, however, that the medical development of the Song dynasty had a considerable influence on later Chinese medical practice in that it established the ideological superiority of formal and orthodox therapy over traditional and heterodox spiritual care.

Studies about high temperatures in China rarely touched the period beyond summer. But in September–early October 2021, a record-breaking high temperature event occurred in southern China, and affected agriculture in many provinces. Both the daily maximum temperature and the number of high temperature days were the highest in September since 1951. To better understand the different features and possible causes of the extreme event in autumn from those in summer, the analysis of atmospheric circulation patterns was conducted. The western Pacific subtropical high (WPSH) was quite stronger and extended much more westward in most of the days in September 2021 than its climatology, which directly caused this unprecedented autumn high temperature event. Besides, the mid-latitude trough over the east of Japan may also play an essential role in this high temperature event. Due to the southward extension of the trough, a cyclonic circulation anomaly appeared at 850 hPa, and its northerly wind component prevailed in the west of the trough and blocked the eastward retreat of the WPSH. As a result, southern China was stably controlled by the WPSH, which led to the persistence of this high temperature event. The conclusion is further confirmed by the statistical results from the analysis of the multi-year data and analogue analysis. Compared to the previous studies, this study reveals the essential role of the mid-latitude trough and highlights the joint impacts of the WPSH and the trough in causing the unprecedented autumn high temperature event.

Abstract Background Rice (Oryza sativa L.) production, such as farmers’ livelihood and the soil quality, has been identified to be strong influenced by climate change in China. However, the benefits of low carbon technologies (LCTs) are still debatable in rice production for farmers, which have been identified to tackle agricultural challenges. The choice of potential LCTs relevant to the case study is based on a literature review of previous empirical studies. Thus, the objectives of the study were to (1) investigate the public perception and preferences of LCTs in rice production of China, and (2) analyze the influences of the factors on farmer’s decision in adopting LCTs in rice production. There were 555 farmer surveys from eight representative rice production counties in HP province of southern China, both the Poisson estimators and multivariate probit (MVP) approach were applied in the study. Results Our results show that water-saving irrigation, integrated pest management techniques and planting green manure crops in winter season were the three major LCTs adapted by farmers in rice production. The intensity and probability of LCTs adoptions were influenced by the main factors including farmers’ education level, climate change awareness, machinery ownership, technical support and subsidies. There is a significant correlation among the LCTs, and the adoption of the technologies is interdependent, depicting either complementarities or substitutabilities between the practices. Conclusions This study suggests that policies enhance the integration of LCTs would be central to farmers’ knowledge, environmental concerns, technical service and financial support in rice production systems in China.

Abstract Background With an increasing incidence of obesity, the relationship between obesity and body image has become a hot research topic worldwide. From high school to university, young people experience changes in their social environment. University students have a high incidence of eating disorders and insufficient physical activity. The purpose of this study was to explore the relationship between body dissatisfaction, insufficient physical activity, and disordered eating behaviors among university students in southern China. Methods In total, 1296 university students aged 18–23 years were recruited for this study. The participants completed anthropometric measurements, the Physical Activity Rating scale-3 (PARS-3), and the Chinese-Dutch Eating Behavior Questionnaire (C-DEBQ). The ideal weight and silhouette were reported by university students using a questionnaire. Results Compared with men, young women had a higher level of body dissatisfaction. For men, body mass index (BMI; β = 0.76, P

Abstract Background Human apolipoprotein E (APOE) polymorphisms are attributable to the presence of three common alleles, namely, ε2, ε3, and ε4, which generate six genotypes, viz, E2/E2, E2/E3, E3/E3, E3/E4, E4/E4, and E2/E4. APOE polymorphisms are associated with all types of tumors and cardiovascular diseases (CVD). However, the relationship between the type of APOE polymorphisms and tumorigenesis remains debatable. Therefore, we aimed to investigate the role of APOE polymorphisms on the tumor with or without CVD in southern China. Methods A total of 1438 participants were categorized into 4 groups: 409 patients with tumor, 369 patients with CVD, 338 patients with both tumor and CVD, and 322 controls. APOE polymorphisms were determined by genotyping assay. The factors influencing tumor patients with or without CVD were also analyzed by logistic regression analysis. Results The present study involved different types of solid tumors. Lung cancer was the most common cancer (20.2%, 151/747), followed by colorectal (17%, 127/747), esophageal (9.8%, 73/747), and liver (8.7%, 65/747) cancers. E3/E3 was the most frequent genotype, and ɛ3 was the greatest allele frequency in our study population. The frequencies of the E3/E3, E3/E4, E2/E3, E2/E4, E4/E4, and E2/E2 genotypes in tumor patients were 76.97% (575/747), 14.19% (106/747), 6.83% (51/747), 1.2% (9/747), 0.4% (3/747), and 0.4% (3/747), respectively. Tumor patients carrying ε3 with or without CVD showed higher levels of TG, TC, and LDL-C and lower levels of HDL-C compared to the controls carrying ε3. On the other hand, the tumor patients carrying ε4 with or without CVD showed higher levels of TG and LDL-C and lower levels of HDL-C (all P < 0.05). The frequency of APOE ε4 allele and the E3/E4 genotype was relatively greater in tumor or CVD patients (P < 0.001). In addition, ε4 allele acted as an independent risk factor for tumor patients group (P = 0.037, adjusted OR = 1.92, 95% CI 1.04–3.55) and tumor + CVD patients group (P = 0.012, adjusted OR = 2.53, 95% CI 1.22–5.23). Conclusions Individuals carrying ε4 are at a higher risk of tumor with or without CVD, and APOE polymorphisms affect the serum lipid profiles.

Accurate cropland information is crucial for the assessment of food security and the formulation of effective agricultural policies. Extracting cropland from remote sensing imagery is challenging due to spectral diversity and mixed pixels. Recent advances in remote sensing technology have facilitated the availability of very high-resolution (VHR) remote sensing images that provide detailed ground information. However, VHR cropland extraction in southern China is difficult because of the high heterogeneity and fragmentation of cropland and the insufficient observations of VHR sensors. To address these challenges, we proposed a deep learning-based method for automated high-resolution cropland extraction. The method used an improved HRRS-U-Net model to accurately identify the extent of cropland and explicitly locate field boundaries. The HRRS-U-Net maintained high-resolution details throughout the network to generate precise cropland boundaries. Additionally, the residual learning (RL) and the channel attention mechanism (CAM) were introduced to extract deeper discriminative representations. The proposed method was evaluated over four city-wide study areas (Qingyuan, Yangjiang, Guangzhou, and Shantou) with a diverse range of agricultural systems, using GaoFen-2 (GF-2) images. The cropland extraction results for the study areas had an overall accuracy (OA) ranging from 97.00% to 98.33%, with F1 scores (F1) of 0.830–0.940 and Kappa coefficients (Kappa) of 0.814–0.929. The OA was 97.85%, F1 was 0.915, and Kappa was 0.901 over all study areas. Moreover, our proposed method demonstrated advantages compared to machine learning methods (e.g., RF) and previous semantic segmentation models, such as U-Net, U-Net++, U-Net3+, and MPSPNet. The results demonstrated the generalization ability and reliability of the proposed method for cropland extraction in southern China using VHR remote images. [ABSTRACT FROM AUTHOR]

Eriocheir hepuensis Dai, 1991, the Hepu mitten crab, is here formally reported from Thanh Hoa and Quang Ninh Provinces, northern Vietnam. Previous reports of " E. sinensis " and " E. japonicus " from "Cua lông", Thai Binh Province, northern Vietnam, require clarification, are probably misidentifications of E. hepuensis , and highlight the problems of species identification within Eriocheir. The taxonomy of E. hepuensis is also discussed. [ABSTRACT FROM AUTHOR]

Southern China spring rainfall (SCSR) is significant for agricultural sowing and soil moisture accumulation before the rainy summer. A better prediction of the rainfall improves our ability to risk response to natural disasters. It is found that the SCSR can be promoted by multi‐year El Niño events through the high‐latitude pathway (HP) and low‐latitude pathway (LP). The long‐lasting El Niño warming heats the tropical troposphere persistently until the decaying spring, which strengthens the Arctic polar vortex and the mid‐latitude blockings. This HP is in favor of more southward transport of Rossby wave energy and cold air, resulting in strong ascending motions over southern China (SC) in spring. The multi‐year El Niño also induces an enhanced western North Pacific anticyclone and a secondary circulation transporting moisture to SC through the LP. The HP is more important in the early spring, while the LP dominates the heavy SCSR in the late spring. Plain Language Summary: Southern China (SC) experiences a period of rainy time in spring, with the rainband located from South China to the Yangtze River. The southern China spring rainfall (SCSR) is influential for agriculture and soil moisture accumulation before the flood season in summer. A better prediction of the SCSR improves our ability to risk response to natural disasters. El Niño‐Southern Oscillation (ENSO) is the dominant climate signal that exerts significant remote impacts, especially in East Asia. However, whether it can help to predict the SCSR is still unclear. In this study, we show that a particular type of ENSO event, the multi‐year El Niño, initiates remarkable impacts on the SCSR. The long‐lasting Pacific warming favors a HP that transports more cold air and wave energy southward to SC during the decaying spring. Moreover, it also strengthens the western North Pacific anticyclone and generates a meridional secondary circulation with low‐level moisture transport toward SC. The low‐latitude and HPs collaborate to generate strong ascending motions and water vapor convergence in SC, being responsible for the large SCSR. Thus, the remote climate impact of multi‐year ENSO events is distinctive from the other ENSO events. Key Points: Multi‐year El Niño enhances southern China (SC) spring rainfall through both the low‐latitude pathway (LP) and the high‐latitude pathway (HP)Long‐lasting tropical warming supports the HP which transports wave energy and cold air to SC and exerts ascending motionsThese ascending motions and moisture transportation by El Niño‐induced western Pacific anticyclone can be further intensified by the LP [ABSTRACT FROM AUTHOR]

Scolytinae beetles serve as important regulators of ecosystem integrity. However, some of these species have been identified as important pests. The Guangdong region of China exhibits unique geographic characteristics, but is also subject to substantial anthropogenic disturbances, making it an important region for ecological research. This study was designed to assess the biodiversity and abundance of these Scolytinae beetles in subtropical areas, to define indicators associated with environmental disturbances, and to thereby provide additional valuable information that can support the conservation of the ecosystem and the monitoring and controling of pest species. For these analyses, a two-season survey of Scolytinae communities was performed across three habitats to examine the patterns of variation within these communities. These analyses revealed that environmental disturbances were associated with a drop in Scolytinae beetle population diversity, with Hypothenemus sp.2, Xyleborinus andrewesi, and Xyleborinus artestriatus offering particular value as indicators associated with severe environmental disruptions. Plant diversity and composition also impacted Scolytinae beetle communities through a range of complex mechanisms. Scolytinae beetle diversity was also found to be higher during the rainy season relative to the dry season, with beetle abundance being responsive to average temperatures, but unrelated to average relative humidity levels. [ABSTRACT FROM AUTHOR]

As the northernmost locality yielding one of the most representative Early Pleistocene Gigantopithecus–Sinomastodon faunas in southern China, the Longgupo site has preserved valuable geological archives that have significantly improved our understanding of Pleistocene biostratigraphy and biogeography. A convincing chronological framework of this locality is therefore important to elaborate on the evolution of Quaternary faunas as well as paleoenvironment. To reconcile the existing geochronological results with new advances in geochronology and biochronology, we present here a revised magnetostratigraphic age model based on detailed rock magnetic and paleomagnetic data and strengthened by biochronology as well as recently published electron spin resonance and uranium series (ESR/U‐series) age data. Two geomagnetic polarities were identified from the Longgupo sequence: the upper one is thin and normal, corresponding to the Olduvai normal subchron; and the lower one is distinctly thick and reversed, corresponding to the pre‐Olduvai Matuyama Chron. The age of the Longgupo fauna constrained by this refined magnetochronological framework is therefore estimated to be about 2.5–2.0 Ma, consistent with the newly published ESR/U‐series age of 2.5–2.2 Ma. [ABSTRACT FROM AUTHOR]

Background: In recent years, depression in early adulthood has become an urgent global public health concern. The university years mark a transitional period from adolescence to adulthood. Young people are required to face academic and life pressures independently, which increases the risk of mental health problems in university. Purpose: The main goal of the current study was to explore the sex differences in depression, body dissatisfaction, sleep quality, and exercise intensity among university students in southern China and to analyze the factors affecting the level of depression among university students. Methods: In total, 1,258 university students aged 18-23 years were recruited for this study. All participants completed anthropometric measurements, the Selfrating Depression Scale, Physical Activity Rating Scale, and Pittsburgh Sleep Quality Index. Body dissatisfaction levels were measured using sex-appropriate silhouettes. Results: Compared with young women, young men had higher exercise intensity and sleep quality, whereas young women's body dissatisfaction and depression levels were significantly higher than those of young men. Sleep quality score (ß = 0.34, p < 0.01), sex (ß = 0.15, p < 0.01), physical activity score (ß = -0.14, p < 0.01), and body dissatisfaction (ß = 0.14, p < 0.01) were significant predictive factors of the Self-rating Depression Scale score. Conclusion: Low levels of physical dissatisfaction have a positive effect on depression, and high levels of physical activity and quality sleep can also improve depressive symptoms. At the same time, increasing body satisfaction has the effect of increasing physical activity and improving sleep quality. Therefore, there is great potential to prevent and ameliorate depression by reducing body dissatisfaction. [ABSTRACT FROM AUTHOR]

Background: Extensive knowledge of allergic multimorbidities is required to improve the management of allergic diseases with the industrialization of China. However, the demography and allergen distribution patterns of allergic multimorbidities in China remain unclear, despite the increasing prevalence of allergies. Methods: This was a real-world, cross-sectional study of 1273 outpatients diagnosed with one or more allergic diseases in Guangzhou, the most populated city of southern China, with leading industrial and commercial centers, between April 2021 and March 2022. Seven allergic diseases (allergic rhinitis (AR), asthma (AS)/cough variant asthma (CVA), atopic dermatitis (AD)/eczema, food allergy (FA), allergic conjunctivitis (AC), drug allergy (DA), and anaphylaxis) were assessed. Positive rates of sensitization to different allergens were measured using an allergen detection system of the UniCAP (Pharmacia Diagnostics, Sweden) instrument platform to compare the groups of allergic multimorbidities against a single entity. Results: There were 659 (51.8%) males and 614 (48.2%) females aged from 4 months to 74 years included in the analysis. The study participants who were diagnosed with allergic diseases had an average of 1.6 diagnoses. Overall, 46.5% (592 of 1273) of the patients had more than one allergic condition, and allergic rhinitis was the most common type of multimorbidity. Women were more likely to suffer from an allergic disease alone, whereas allergic multimorbidities were more likely to be diagnosed in men (p = 0.005). In addition, allergic multimorbidities were common in all age groups, with an incidence ranging from 37.1% to 57.4%, in which children and adolescents were more frequently diagnosed with allergic multimorbidities than adults (18–60 years old) (all p < 0.05). Allergic multimorbidity was observed throughout the year. A difference in the positive rate of allergens sensitization and total immunoglobulin E (tIgE) levels between different allergic multimorbidities was observed. Conclusions: Allergic multimorbidities were very commonly found in nearly half of all patients with allergies. The proportion of allergic multimorbidities varied with the type of disease, sex, age, and allergen distribution pattern. These findings may help clinicians to develop "One health" strategies for the clinical management of allergic diseases. [ABSTRACT FROM AUTHOR]

The decadal variability of the summer extreme precipitation over southern China (EPSC) is remarkable, especially for the significant decadal enhancement after the 1990s. The study documented that the summer sea surface temperature (SST) over the North Atlantic and spring sea ice concentration (SIC) over the East Siberian Sea can significantly affect the EPSC. The summer SST over the North Atlantic influences the low-pressure cyclone in the western Pacific by modulating the SST over the tropical Pacific, thus affecting EPSC. A decrease in the SIC of the East Siberian Sea induces a negative Arctic Oscillation, which induces the increased SST over northwest Pacific and the anomalous cyclone over there, in turn, affecting EPSC. Both predictors have a quasi-period of 10–14 years, which provides useful predictive signals for EPSC. The leading 7-year SST and the leading 5-year SIC are chosen to establish the prediction model based on the decadal increment method, which can well predict the EPSC, especially for the shift in the early 1990s. These results provide a clue to the limited predictability of decadal-scale extreme climate events. [ABSTRACT FROM AUTHOR]

Climate change has drastically affected rice production and imperiled food security. Adaptations are imperative in response to future climate change. Joint adaptations in cultivation and stress resistance were optimized under representative concentration pathways 4.5 (RCP4.5) and 8.5 (RCP8.5) scenarios, in a new perspective of minimizing heat stress and cold stress for double-season rice in southern China. In general, earlier sowing date and shorter duration were projected for early rice, while later sowing date and longer duration were expected for late rice in near term and long term of twenty-first century. Regional demonstrations signaled that south of the Yangtze River and South China would be exposed to a respective advancement of 16.6 and 8.9 days in sowing date, a decrement of 193.6 and 477.3 °C·day in duration for early rice in 2071–2100 under RCP8.5 relative to 2021–2050 under RCP4.5. Regarding late rice, a postponement of 4.7 and 12.7 days in sowing date, and an increment of 896.9 and 237.0 °C·day in duration were likely to be exhibited in south of the Yangtze River and South China, respectively. Cold stress could be reduced to a small intensity but heat stress for early rice would be getting severer, given optimal cultivations were considered. To maintain the intensity of heat stress in 1991–2020, the threshold for heat stress would be boosted to 37.3 °C and 36.6 °C in south of the Yangtze River and South China in 2071–2100 under RCP8.5, respectively. The results highlighted that south of the Yangtze River should adapt to much earlier planting, less shorter duration, and higher heat resistance for early rice, as well as less later planting and much longer duration for late rice, in contrast with South China. [ABSTRACT FROM AUTHOR]

Environmental factors have a regulatory effect on plant leaf functional traits, affecting ecosystems' functions and processes. Due to special adaptive strategies, Dicranopteris dichotoma can occupy an important ecological niche at different vegetational restoration stages related to changes in leaf functional characteristics. This study was conducted to explore the changes in leaf functional traits and their responses to environmental factors in four different vegetational restoration stages in the red soil erosion area at Changting, Fujian. We measured 11 leaf functional traits and 13 environmental factors. One-way analysis of variance (ANOVA) was used to compare the differences in environment, soil factors, and leaf functional traits at different vegetation restoration stages. Redundancy analysis and partial least squares model were used to analyze the main factors affecting leaf functional traits. The results depicted that with the succession of the vegetational restoration stage, environmental factors and the functional traits of leaves exhibited significant differences (P

The scientific revelation of the mechanism underlying land fragmentation’s influence on agricultural technical efficiency is extremely important. This study utilized survey data from 305 villages across 12 provinces in Southern China in 2020 to assess technical efficiency through the application of the stochastic frontier production function. Moreover, we investigated the direct impact of land fragmentation on technical efficiency and the indirect impact transmitted through crop diversification and part-time farming by employing Tobit and mediating effect models, respectively. The key findings are as follows: (1) The sampled farmers, on average, operated 0.614 hectares of land with 17.395 plots, and the mean of their technical efficiency was 0.630. (2) The overall effect of land fragmentation on technical efficiency demonstrated a “U”-shaped relationship. (3) Crop diversification and part-time farming were mediating factors in the impact of land fragmentation on technical efficiency. Specifically, an “inverted U”-shaped relationship existed between land fragmentation and crop diversification, whereas a negative linear relationship was observed between land fragmentation and part-time farming. Conversely, crop diversification presented a positive linear relationship with technical efficiency, and part-time farming had an “inverted U”-shaped relationship with technical efficiency. (4) The impact of land fragmentation on technical efficiency varied across altitude zones. It is recommended to control land fragmentation based on local conditions, encourage crop diversification, and strengthen employment guidance and skills training for farmers to ensure the orderly transfer of land.

A reconstruction of the tectonothermal evolution of the Laojunshan–Song Chai granite gneiss massif (North Vietnam, South China) was carried out, based on summaries of the latest isotopic and fission-track dating results. The recorded wide range (420–465 Ma) of the age of granite gneiss rocks testifies to the long-term existence of a partially molten layer at a depth of 20–30 km for several tens of Ma. By the Devonian–early Carboniferous, a section of the excessively thickened crust was denudated, the massif was exhumated to the level of the upper crust, and isotope systems were “frozen”. The rate of uplift of the rocks of the massif is estimated to be about 0.2–0.5 mm/year. In the further history of the granite gneiss massif, episodes of repeated burial to a depth of about 13 km are recorded, associated with the Indosinian collision. The rocks have experienced metamorphism of the amphibolite-green schist facies, accompanied by tectonic transport in the form of a thrust sheet. Over the next 200 Ma, the uplift of the massif and the erosion of the overlying strata occurred in discrete pulses, during a sequence of active tectonic events. Thus, the thermochronological and P-T history of the Laojunshan–Song Chai massif is a kind of chronicle of regional tectonic–thermal events. In the history of the massif, traces of two orogenic cycles associated with the collision of the Cathaysia and Yangtze blocks in the Lower Paleozoic and the Indosinian collision in the Triassic are recorded.

It is well known that tropical cyclones (TCs) making landfall in Southern China (SC) account for more than half of all TCs making landfall in China. Therefore, it is important to have an in-depth understanding of the activities of TCs in SC under climate warming. Our results show that there have been no significant changes in the frequency and duration of these TCs, but their intensities have unexpectedly decreased by ∼20% since 1980, which is inconsistent with the previous understanding that climate change increases TC intensity. The results consistently show a significant decrease in the different TC intensity percentiles, which is related to the intensity distribution that shows a significant decrease in the proportion of tropical storms and a significant increase in the proportion of tropical depressions, as well as a slight decrease in the proportion of category 1–2. Because of the locations of those TCs activity show a clear shoreward migration tendency, indicating that land friction can suppress TC intensification, so that TC intensity has weakened. In addition, results also suggest that TC development is strongly suppressed and is mainly related to the enhancement of atmospheric stability, vertical wind shear and subtropical high under global warming. These results are quite different from the previous understanding of the changes in TC intensity under global warming. Such knowledge can help us better understand the relationship between climate change and the impact of TC activity at the regional scale.

Forest fires in the southern region of China pose significant threats to ecological balance, human safety, and socio-economic stability. Forecast zoning the occurrence of these fires is crucial for timely and effective response measures. This study employs the random forest algorithm and geospatial analysis, including kernel density and standard deviation ellipse methods, to predict forest fire occurrences. Historical fire data analysis reveals noteworthy findings: (i) Decreasing Trend in Forest Fires: The annual forest fire count in the southern region exhibits a decreasing trend from 2001 to 2019, indicating a gradual reduction in fire incidence. Spatial autocorrelation in fire point distribution is notably observed. (ii) Excellent Performance of Prediction Model: The constructed forest fire prediction model demonstrates outstanding performance metrics, achieving high accuracy, precision, recall, F1-scores, and AUC on the testing dataset. (iii) Seasonal Variations in High-Risk Areas: The probability of high-risk areas for forest fires in the southern region shows seasonal variations across different months. Notably, March to May sees increased risk in Guangxi, Guangdong, Hunan, and Fujian. June to August concentrates risk in Hunan and Jiangxi. September to November and December to February have distinct risk zones. These findings offer detailed insights into the seasonal variations of fire risk, providing a scientific basis for the prevention and control of forest fires in the southern region of China.

Accurately tracking the changes in rice cropping intensity is a critical requirement for policymakers to formulate reasonable land-use policies. Southern China is a traditional region for rice multi-cropping, yet less is known about its spatial–temporal changes under the background of rapid urbanization in recent decades. Based on images from Landsat and MODIS and multiple land cover products, the gap-filling and Savitzky–Golay filter method (GF-SG), the enhanced pixel-based phenological features composite approach (Eppf-CM), random forest (RF), and the difference in NDVI approach (DNDVI) were combined to map the rice cropping pattern with a spatial resolution of 30 × 30 m over Southern China in 2000 and 2020 through Google Earth Engine (GEE). Subsequently, the spatial–temporal changes in rice cropping intensity and their driving factors were examined by Getis-Ord Gi* and geographical detector. The results showed that the produced rice cropping pattern maps exhibited high accuracy, with kappa coefficients and overall accuracies exceeding 0.81 and 90%, respectively. Over the past two decades, the planting areas of double-season rice in Southern China decreased by 54.49%, and a reduction was observed across eight provinces, while only half of the provinces exhibited an increase in the planting areas of single-season rice. Compared to the year 2000, the planting area of the conversion from double- to single-season rice cropping systems in 2020 was 2.71 times larger than that of the conversion from single- to double-season rice cropping systems. The hotspots of the change in rice cropping intensity were mainly located in the central part of Southern China (excluding the Poyang Lake Plain). The decline in the rural labor force, coupled with ≥10 °C accumulated temperature and topographical factors, plays a crucial role in the decreased intensity of rice cropping. Our findings can be beneficial for realizing regional agricultural sustainability and food security.

Abstract Southern China spring rainfall (SCSR) is significant for agricultural sowing and soil moisture accumulation before the rainy summer. A better prediction of the rainfall improves our ability to risk response to natural disasters. It is found that the SCSR can be promoted by multi‐year El Niño events through the high‐latitude pathway (HP) and low‐latitude pathway (LP). The long‐lasting El Niño warming heats the tropical troposphere persistently until the decaying spring, which strengthens the Arctic polar vortex and the mid‐latitude blockings. This HP is in favor of more southward transport of Rossby wave energy and cold air, resulting in strong ascending motions over southern China (SC) in spring. The multi‐year El Niño also induces an enhanced western North Pacific anticyclone and a secondary circulation transporting moisture to SC through the LP. The HP is more important in the early spring, while the LP dominates the heavy SCSR in the late spring.

IntroductionMastacembelus armatus is a commercially valuable fish, normally distributed in southern China and Southeast Asia. The natural population size of M. armatus is shrinking in recent years because of overfishing and habitat loss. In order to clarify the genetic diversity and differentiation of M. armatus populations, we collected 114 samples from eight populations in southern China and Vietnam and analyzed their population structure using nuclear ribosomal DNA sequences, the concatenated 18S and ITS2 regions.MethodsGenomic DNA from the fin clip was extracted and sequenced on an Illumina novaseq 6000 (Illumina, USA) high-throughput sequencing platform in accordance with the manufacturer’s instructions. After assembly and annotation, haplotype diversity, TCS network analysis, AMOVA analysis, population pairwise genetic distances, and UPGMA tree construction were conducted based on the concatenated sequences of 18S and ITS2.Results and discussionIn total, eleven nrDNA haplotypes were detected based on the concatenated sequences of 18S and ITS2. Amongst, three haplotypes were the main haplotypes, as representatives of three corresponding Clusters. There were two major Clusters in China, however, the Cluster in Vietnam was significantly divergent from the other two in China, likely due to the lack of river connection between China and Vietnam. Interestingly, based on low FST value, we found that gene flow occurred between the isolated island, Hainan Province, and the mainland China of Guangxi Province, probably as a result of exposed continental shelf connected them during glacial periods. In general, combing our data and literature data, genetic diversity and differentiation of M. armatus populations are relatively high regardless of spatial scale, although their natural population size is declining. This suggests that it is not too late to adopt measures to protect M. armatus, which benefits not only species itself but also the whole ecosystem.

A new millipede species, Paracortina kyrang sp. nov., is described from a cave in Cao Bang Province, northern Vietnam. The new species is diagnosed by having an extraordinarily long projection on the head of males, reduced eyes, a gonocoxite with two processes, a long and slender gonotelopodite with two long, clavate prefemoroidal processes densely covered with long macrosetae apically, and with a distal, reverse, short spine on mesal side, and a rather sinuous distal part of the telopodite. This is the third species of the genus that is known from Vietnam. A brief comparison of some secondary sexual characters is made. [ABSTRACT FROM AUTHOR]

Bacterial wilt is a destructive soilborne disease caused by Ralstonia solanacearum, posing a severe threat to plants in the Solanaceae family. It impacts on tobacco productivity worldwide. This study was conducted to analyze the changes in the soil's physical and chemical properties, the number of microbes, and the bacterial diversity of the rhizosphere soil before and after the wilt disease. The rhizosphere soil of healthy and diseased tobacco plants was collected from Pucheng, Nanping, Fujian Province, Southern China. The results revealed significant differences in the trends of physical and chemical properties of the soil of healthy and diseased plants. The soil pH, available potassium (K), available phosphorous (P), and organic matter contents (SOM) were lower in the rhizosphere soil for healthy plants than for pre-diseased plants (HW). Only the available P, among all physical and chemical properties in the rhizosphere of diseased plants (HS), was significantly lower than those for pre-diseased plants (HW), changing from 149.59 mg/kg to 59.19 mg/kg. The order of numbers of the three main microbes in the rhizosphere soil for healthy plants (HC) and pre-diseased plants was the following: bacteria > actinomycetes > fungi. The number of actinomycetes in the soil of the diseased tobacco plants increased significantly. A comparison of the rhizosphere soil of diseased and healthy tobacco plants showed that the relative abundance of the bacterial community in the rhizosphere soil of the pathogenic tobacco plants changed significantly. The community diversity was increased, and the Pseudomonadaceae, to which the bacterial pathogen of bacterial wilt belonged, rose to a certain extent. Both pre-diseased and healthy plants showed changes in the physical and chemical properties, microbial quantity, and microbial diversity, thus proving that tobacco disease was closely related to the soil's ecological environment. [ABSTRACT FROM AUTHOR]

Cropland abandonment is one of the most widespread types of land-use change in Southern China. Quickly and accurately monitoring spatial-temporal patterns of cropland abandonment is crucial for food security and a good ecological balance. There are still enormous challenges in the long-term monitoring of abandoned cropland in cloud and rain-prone and cropland-fragmented regions. In this study, we developed an approach to automatically obtain Landsat imagery for two key phenological periods, rather than as a time series, and mapped annual land cover from 1989 to 2021 based on the random forest classifier. We also proposed an algorithm for pixel-based, long-term annual land cover correction based on prior knowledge and natural laws, and generated cropland abandonment maps for Guangdong Province over the past 30 years. This work was implemented in Google Earth Engine. Accuracy assessment of the annual cropland abandonment maps for every five years during study period revealed an overall accuracy of 92–95%, producer (user) accuracy of 90–96% (73–87%), and Kappa coefficients of 0.81–0.88. In recent decades, the cropland abandonment area was relatively stable, at around 50 × 104 ha, while the abandonment rate gradually increased with a decrease in the cultivated area after 2000. The Landsat-based cropland abandonment monitoring method can be implemented in regions such as southern China, and will support food security and strategies for maintaining ecological balance. [ABSTRACT FROM AUTHOR]

Rice paddies are one of the main sources of anthropogenic terrestrial CH4. In recent decades, the substitution of single-cropping rice (SCR) for double-crop rice (DCR) has become more common in southern China. However, the concomitant impacts on CH4 emissions have not been quantified. We incorporated high-resolution rice cropping system maps into the CH4MOD model to calculate changes in CH4 emissions in southern China due to DCR conversion to SCR over the period 1990 to 2015. We find that a total planting area of 253.64 ×104 ha was converted from DCR to SCR. This conversion resulted in a 451.94 Gg reduction in CH4 emissions, accounting for 8.4% of CH4 emissions from paddies in China in 2015. The largest reduction was in the Middle–Lower Yangtze plain with high labor pressures. As urbanization continues, we project that the total CH4 emissions have the potential to decrease by between 17.1% and 9.2% under DCR conversion to SCR in southern China in the extreme and most likely scenarios, respectively. As farmers voluntarily move to SCR in response to labor scarcity, making full use of the land-use change trend of DCR to SCR may be an opportunity to reduce agricultural methane emissions, which is important for achieving Sustainable Development Goals (SDGs) and should be given more attention. [ABSTRACT FROM AUTHOR]

Introduction: Esophageal squamous cell carcinoma (ESCC) shows remarkable variation in incidence, survival, and risk factors. Although the genomic characteristics of ESCC have been extensively characterized, the genomic differences between different geographic regions remain unclear. Methods: In this study, we sequenced 111 patients with ESCC from northern (NC) and southern (SC) China, combined their data with those of 1081 cases fromprevious reports, and performed a comparative analysis among different regions. In total, 644 ESCC cases were collected from six geographic regions (NC, SC, Xinjiang, China [XJC], Japan [JP], Vietnam [VN], and Europe & America [EA]) as the discovery cohort. Validation cohort 1 included 437 patients with ESCC from the NC region. Validation cohort 2 included 54 and 57 patients from the NC and SC regions, respectively. Results: Patients with ESCC in different regions had different genomic characteristics, including DNA signatures, tumor mutation burdens, significantly mutated genes (SMGs), altered signaling pathways, and genes associated with clinical features. Based on both the DNA mutation signature and the mutation profile of the most common genes, the NC and SC groups were clustered close together, followed by the JP, XJC, EA, and VN groups. Compared to patients with ESCC from SC, SMGs, including KMT2D, FAT1, and NOTCH1 were more frequently identified in patients with ESCC from NC. Furthermore, some genes (TDG and DNAH8) correlated with overall survival in completely opposite ways in patients with ESCC from different geographical regions. Conclusions: Our study provides insights into genomic differences in ESCC among different regions. These differences may be related to differences in environmental carcinogens, incidence, and survival. [ABSTRACT FROM AUTHOR]

Sarcocheilichthys parvus (Cypriniformes: Gobionidae) is a stream fish which is endemic to sub-tropical coastal drainages in southern China, thus offering a valuable model for understanding how genetic divergence arises in streamadapting freshwater fishes in this region. Using the mitochondrial Cyt b gene, integrative analyses of phylogeny, population demography, and ancestral area and paleo-drainage reconstructions are carried out to explicitly explore the role of landscape evolution in genetic diversification of S. parvus. The time-calibrated phylogeny of S. parvus indicates the splitting of two major lineages (A and B) at ~3.66 Ma. Lineage A inhabits the Poyang Lake sub-drainage of the middle Yangtze River, Han River and Pearl River, and can be split into two sub-lineages (A-I and A-II), where sub-lineage A-II can be further sub-divided into three infra-sub-lineages (A-IIa, A-IIb and A-IIc). Except for the infra-sub-lineage A-IIc, which is restricted to the Han River and Pearl River, the other sub-lineages and infra-sub-lineages live exclusively in the Poyang Lake sub-drainage. Lineage B lives in the lower Yangtze River, Qiantang River, Jiaojiang River and Ou River, displaying close genetic relationships among the drainages. Rapid population expansion has occurred since the Late Pleistocene. Our findings indicate that the splitting of lineages A and B could be attributed to geographic isolation due to the Zhe-Min Uplift, acting as a biogeographic barrier before the late Early Pleistocene. Furthermore, the strong genetic divergence within Lineage A could be explained by the isolation role of the Nanling Mountains and Poyang Lake acting as an ecological barrier; while the lack of phylogenetic structure within Lineage B may have been the result of paleo-drainage connections or episodic freshwater connections during the eustatic low stand of sea level in the late Middle-Late Pleistocene. [ABSTRACT FROM AUTHOR]