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Determining subduction‐related processes is crucial for understanding lithological heterogeneity, as substantial quantities of slabs are recycled into the mantle. Molybdenum isotopes are valuable for distinguishing sources materials due to the significant isotope differences between the crust and the mantle. In this study, we systematically investigate Mo isotopes in a suite of well‐characterized continental basalts from Keluo and Halaha‐Chaoer, located in Northeast China. The δ98Mo values of Keluo range from −0.41 to −0.23‰, with an average of −0.34‰, while Halaha‐Chaoer samples ranged from −0.18 to −0.12‰, with an average of −0.15‰. The δ98Mo values of Keluo basalts are lighter than the mean value of fresh oceanic basalts (−0.21‰), whereas those of Halaha‐Chaoer basalts are similar to oceanic basalts. Combined with other geochemical indications (LOI, Ce/Pb, La/Yb and so on), the Mo isotopic variations cannot be attributed to chemical weathering, continental crust contamination or magmatic processes. Instead, the δ98Mo variations in this study are explained by the incorporation of different oceanic crustal materials into the magma sources. Correlations of δ98Mo with Ba/Th, Th/U, 143Nd/144Nd indicated that both sediment and altered oceanic crust have significantly influenced these variations. This study demonstrates the potential of Mo isotopes to distinguish different types of recycled oceanic crust materials. [ABSTRACT FROM AUTHOR]

The understanding of the spatial distribution of soil organic carbon (SOC) and its influencing factors is crucial for comprehending the global carbon cycle. However, the impact of soil geochemical and climatic conditions on SOC remains limited, particularly in dryland farming areas. In this study, we aimed to enhance the understanding of the factors influencing the distribution of SOC in the drylands of the Songliao Plain, Northeast China. A dataset comprising 35,188 measured soil samples was used to map the SOC distribution in the region. Multiple linear regression (MLR) and random forest models (RFM) were employed to assess the importance of driving indicators for SOC. We also carried out partial correlation and path analyses to further investigate the relationship between climate and geochemistry. The SOC content in dryland soils of the Songliao Plain ranged from 0.05% to 11.63%, with a mean value of 1.47% ± 0.90%. There was a notable increasing trend in SOC content from the southwest to the northeast regions. The results of MLR and RFM revealed that temperature was the most critical factor, demonstrating a significant negative correlation with SOC content. Additionally, iron oxide was the most important soil geochemical indicator affecting SOC variability. Our research further suggested that climate may exert an indirect influence on SOC concentrations through its effect on geochemical properties of soil. These insights highlight the importance of considering both the direct and indirect impact of climate in predicting the SOC under future climate change. [ABSTRACT FROM AUTHOR]

As the world's second-largest economy, China has experienced rapid industrialization and urbanization, resulting in high energy consumption and significant carbon emissions. This development has intensified conflicts between human-land relations and environmental conservation, contributing to global warming and urban air pollution, both of which pose serious health risks. This study uses nighttime light (NTL) data from 2005 to 2019, along with scaling techniques and statistical analysis, to estimate city-scale energy carbon emissions over a 15-year period. Focusing on Northeast China, a traditional industrial region comprising 36 cities across three provinces, we examine spatial patterns of energy carbon emissions and assess spatiotemporal evolution through spatial autocorrelation and dynamic changes. These changes are further evaluated using standard deviation ellipse (SDE) parameters and SLOPE values. Additionally, the Tapio decoupling index is applied to explore the relationship between city-scale emissions and economic growth. Our findings for the 36 cities over 15 years are: (1) Heilongjiang shows low, declining emissions; Jilin improves; Liaoning has high, steadily increasing emissions. (2) The global spatial autocorrelation of energy carbon emissions is significant, with a positive Moran's I, while significant local Moran's I clusters are concentrated in Heilongjiang and Liaoning. (3) The greatest emission changes occurred in 2015, followed by 2019, 2005, and 2010. (4) Emission growth is fastest in Heilongjiang, followed by Liaoning and Jilin. (5) Tapio analysis shows positive decoupling in Heilongjiang, declining decoupling in Jilin, and no change in Liaoning. This study provides a quantitative basis for dual carbon goals and offers emission reduction strategies for government, industry, and residents, supporting energy transition and sustainable urban planning. [ABSTRACT FROM AUTHOR]

Summer low-temperature in Northeast China (NEC) could cause local grain reduction. Recent studies have highlighted a notable increase in low-surface air temperature (SAT) events during June in NEC, which diverges significantly from the patterns observed in July, August, and the overall summer average. An analysis of June SAT over NEC from 1961 to 2020 reveals an interdecadal shift around 2003, characterized by decreased periodicity and increased interannual variability. This study investigates the influence of sea surface temperature anomalies (SSTAs) in the North Atlantic during the preceding February on this shift. It is found that the North Atlantic tripole SSTAs (NAT_SST) has a significant impact on June SAT in NEC post-2003. A proposed mechanism is that February NAT_SST can maintain the tripole anomalies into May-June, and inducing SSTAs over the tropical eastern Pacific (SST_EP) after 2003. Both observational and model simulation results support that NAT_SST influences June SAT in NEC through a wave train originating from the North Atlantic, while SST_EP affects SAT in NEC via the Circumglobal teleconnection and British-Baikal corridor-like patterns. The combined effects of May-June NAT_SST and SST_EP resonate to amplify June SAT anomalies over NEC, enhancing both the amplitude of SAT anomalies and interannual variability. Meanwhile, the periodicity of June SAT in NEC shifts to a 2–4 years cycle, aligning with the post-2003 alternation of NAT_SST. This contrasts with the period before 2002, where the relationship between February NAT_SST and May-June SST_EP was inverse, offsets the effects of the two SSTAs. [ABSTRACT FROM AUTHOR]

Speaking skills are critical in second language acquisition. This study investigates the most common speaking skills problems among non-native Arabic learners in universities in Northeast China and the differences between speaking skills problems based on gender and academic level. A quantitative research design was adopted. It used the questionnaire to collect data. The sample of this study included 104 Chinese students who learn Arabic from two universities in Northeast China. The results indicate that the most common problems with Arabic speaking skills are a lack of vocabulary, opportunities to meet native Arabic speakers, fear of mistakes, teacher-centered classes, and the teacher using too many students’ native languages in the classroom. Besides that, the results show no statistically significant difference in Arabic speaking skills problems based on gender. However, the findings show statistically significant differences in Arabic speaking skills problems based on the academic level. The learners of the second year have more Arabic speaking skills problems than the learners of the first year, and the learners of the third year also have more Arabic speaking skills problems than the learners of the first year. According to the findings, the study suggests recommendations for Arabic learners, instructors, and policymakers in universities in non-Muslim gathering areas in Northeast China. [ABSTRACT FROM AUTHOR]

To investigate the association between single nucleotide polymorphism (SNP) at the rs3918188, rs1799983 and rs1007311 loci of the endothelial nitric oxide synthase (eNOS) gene and genetic susceptibility to systemic lupus erythematosus (SLE) in northeastern China. The base distribution of eNOS gene rs3918188, rs1799983 and rs1007311 in 1712 human peripheral blood samples from Northeast China was detected by SNaPshot sequencing technology. The correlation between genotype, allele and gene model of these loci of the eNOS gene and the genetic susceptibility to SLE was investigated by logistic regression analysis. The results of the differences in the frequency distribution of their gene models were visualised using R 4.3.2 software. Finally, HaploView 4.2 software was used to analyse the relationship between the haplotypes of the three loci mentioned above and the genetic susceptibility to SLE. A multifactor dimensionality reduction (MDR) analysis was used to determine the best SNP-SNP interaction model. The CC genotype and C allele at the rs3918188 locus may be a risk factor for SLE (CC vs AA: OR = 1.827, P < 0.05; C vs A: OR = 1.558, P < 0.001), and this locus increased the risk of SLE in the dominant model and the recessive model (AC + CC vs AA: OR = 1.542, P < 0.05; CC vs AA + AC: OR = 1.707, P < 0.001), while the risk of SLE was reduced in the overdominant model (AC vs AA + CC: OR = 0.628, P < 0.001). The GT genotype and T allele at locus rs1799983 may be a protective factor for SLE (GT vs GG: OR = 0.328, P < 0.001; T vs G: OR = 0.438, P < 0.001) and this locus reduced the risk of SLE in the overdominant model (GT vs GG + TT: OR = 0.385, P < 0.001). There is a strong linkage disequilibrium between the rs1007311 and rs1799983 loci of the eNOS gene. Among them, the formed haplotype AG increased the risk of SLE compared to GG. AT and GT decreased the risk of SLE compared to GG. In this study, the eNOS gene rs3918188 and rs1799983 loci were found to be associated with susceptibility to SLE. This helps to deeply explore the mechanism of eNOS gene and genetic susceptibility to SLE. It provides a certain research basis for the subsequent exploration of the molecular mechanism of these loci and SLE, as well as the early diagnosis, treatment and prognosis of SLE. [ABSTRACT FROM AUTHOR]

Salt–alkaline stress is one of the most stressful occurrences, causing negative effects on plant development and agricultural yield. Identifying and utilizing genes that affect alkaline tolerance is an excellent approach to accelerate breeding processes and meet the needs for remediating saline–alkaline soil. Here, we employed a mapping population of 176 recombinant inbred lines (RILs) produced from a cross between alkali-tolerant Longdao5 and alkali-sensitive Zhongyouzao8 to identify the quantitative trait loci (QTLs) determining alkali tolerance at the seedling stage. For the evaluation of alkali tolerance, the recovered seedling's average alkali tolerance index (ATI), root number (RN), root length (RL), seedling dry weight (SW), root dry weight (RW), and seedling height (SH) were assessed, together with their relative alkaline damage rate. Under alkaline stress, the ATI was substantially negative connected with the root number, seedling height, seedling dry weight, and root dry weight; however, it was considerably positive correlated with the relative alkaline damage rate of the root number and root dry weight. A total of 13 QTLs for the root number, root length, seedling height, seedling dry weight, root dry weight, and alkali tolerance index under alkaline stress were identified, which were distributed across chromosomes 1, 2, 3, 4, 5, 7, and 8. All of these QTLs formed two QTL clusters for alkali tolerance on chromosome 5 and chromosome 7, designated AT5 and AT7, respectively. Nine QTLs were identified for the relative alkaline damage rate of the root number, root length, seedling height, seedling dry weight, and root dry weight under alkali stress. These QTLs were located on chromosome 2, 4, 6, 7, 8, 9, and 12. In conclusion, these findings further strengthen our knowledge about rice's genetic mechanisms for alkaline tolerance. This research offers clues to accelerate breeding programs for new alkaline-tolerance rice varieties. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: A prerequisite for the successful application of phytoliths in paleoenvironmental reconstruction is the correct interpretation of their environmental significance. In this context, key questions include: What magnitude of temperature/precipitation change is required to effect significant changes in surface soil phytolith percentages? When temperature/precipitation increases by a certain amount, what is the corresponding response of the percentages and assemblages of surface soil phytoliths? Additional detailed research is required to answer these questions. Materials and methods: We analyzed the phytoliths in 90 surface soil samples collected along the isohyets corresponding to the mean annual precipitation (MAP) of 400 mm (with the mean annual temperature (MAT) range of 3.24℃) and 600 mm (with the MAT range of 8.29℃) in Northeast China. Our objective was to determine the response of phytoliths to different temperature gradients. Soil phytoliths were extracted and identified using heavy liquid separation and microscope observations. Results: The DA of the phytolith percentages enabled the separation of samples collected along the two isohyets, with a total accuracy of 94.44%. MAT was the principal factor affecting the spatial distribution of phytoliths, with an explanation rate of 46.40%. In the surface soil samples collected along the two isohyets, the percentages of ELONGATE, ACUTE BULBOSUS, and PTERIDOPHYTE-TYPE morphotypes, were significantly negatively correlated with MAT, while the percentages of SQUARE were significantly positively correlated with MAT. However, the relationship between PAPILLATE percentages and MAT varied, showing both positive and negative correlations. A temperature gradient of ~ 3℃ was insufficient to significantly affect the percentages of SADDLE, BULLIFORM FLABELLATE, and BILOBATE. The phytolith index (C/W) can be effectively used to reconstruct the palaeoclimate in Northeast China. An MAP change of 200 mm resulted in significant changes in the percentages of ELONGATE, SADDLE, BULLIFORM FLABELLATE, and TRACHEARY (with the respective rates of 39.57%, 780.77%, 179.00% and 81.25%). However, the percentages of ACUTE BULBOSUS, SQUARE, RONDEL, BILOBATE, CRENATE, PTERIDOPHYTE-TYPE, SILICIFIED STOMATA, and PAPILLATE did not change significantly. Conclusions: Our results contribute to an improved understanding of the response of various phytolith morphotypes to temperature, and they provide a modern process basis for future phytolith-based paleoclimatic reconstruction in this region. [ABSTRACT FROM AUTHOR]

This study assessed the presence of potentially toxic elements (PTEs) in China's northeastern black soil belt, an area with limited prior research. We collected 304 soil samples (0–20 cm) from Gonghe Town, Hailun City, and analyzed the PTE contamination degree using the single-factor pollution index and Nemerow pollution index. The results demonstrated that the mean concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) were 11.16, 0.11, 65.29, 22.56, 0.03, 27.07, 26.09, and 66.01 mg/kg, respectively. Source apportionment was conducted via correlation analysis, principal component analysis, and positive matrix factorization, identifying four main sources: natural (33.2%), irrigation (29.5%), fuel (23.4%), and fertilizer (13.2%). The ecological risk index indicated a slight ecological risk, while the human health risk showed that non-carcinogenic risks were negligible and carcinogenic risks were acceptable. Our findings emphasize the need to prioritize controlling PTEs from fertilizer, particularly cadmium, and to a lesser extent, irrigation and fuel sources, focusing on As, Pband Hg. This research provides critical insights for policymakers aiming to manage PTE contamination in black soils. [ABSTRACT FROM AUTHOR]

Soil aggregates are important indicators of soil structure stability and quality. The black soil region of northeast China, known for its high agricultural productivity, faces significant challenges due to soil erosion. This study investigates the impact of terracing on the stability and erodibility characteristics of soil aggregates in sloped farmlands, which is crucial for this important agricultural area. Three research sites with the same basic management modes were selected along a latitudinal gradient, from the mid-temperate zone to the cold temperate zone, in the black soil region of northeast China. The Savinov method was used to analyze the differences in soil aggregate size distribution, stability characteristics, and soil erodibility between terraced and non-terraced slopes at each research site. The results showed that terracing increased the content of large soil aggregates (>0.25 mm) by 5.38–6.35%, with the increase becoming more pronounced from north to south. The improvement in soil structure varied by location and slope position, with the most significant improvement at the middle slope position. Terracing enhanced soil aggregate stability, reduced soil erodibility, and improved soil structure by increasing clay and soil organic matter (SOM) content and reducing soil bulk density (BD), promoting the conversion of small aggregates to large aggregates. Soil stability indicators such as water-stable aggregates (WSAs), mean weight diameter (MWD), and geometric mean diameter (GMD) were dominated by aggregates > 5 mm, while erodibility indicators such as fractal dimensions (Ds) and the soil erodibility factor (K values) were mainly influenced by aggregates < 0.25 mm. Terraces can improve the soil structure and stability of sloping farmland by increasing the content of large soil aggregates and enhancing overall soil quality. The benefits of these improvements increase with latitude. These findings provide critical insights for determining effective management practices for sloped farmlands in the black soil region under various site conditions. They offer scientific evidence for preventing soil erosion and improving soil quality, thus supporting the sustainable development strategy for protecting black soil and ensuring long-term agricultural productivity. [ABSTRACT FROM AUTHOR]

Understanding the spatiotemporal patterns and driving mechanisms of cropping patterns' evolution tailored to local conditions is crucial for the effective allocation of black soil in northeast China and the advancement of agricultural development. This study utilized the Google Earth Engine platform to extract the spatial distribution data of major grain crops in northeast China for the year 2022. Using crop classification data from 2000 to 2022, the spatial overlay analysis method identified cropping pattern types based on spatial and temporal changes. The primary cropping patterns identified were continuous maize cropping, maize–soybean rotation, mixed cropping, and continuous soybean cropping. Simultaneously, this research constructed three distinct crop periods: Period I (2000–2002), Period II (2010–2012), and Period III (2020–2022). Over three periods, these patterns covered 94.73%, 88.76%, and 86.39% of the area, respectively. The evolution of the dominant cropping pattern from Period I to Period II involved the transition from continuous soybean cropping to continuous maize cropping, while from Period II to Period III, the main shift was from continuous maize cropping to maize–soybean mixed cropping. From a spatial perspective, since Period I, maize has increasingly replaced soybean as the dominant crop, with continuous maize cropping expanding northward and continuous soybean cropping contracting. The maize–soybean rotation area also migrated northward, particularly in the core area of the Songnen Plain, evolving mostly into continuous maize cropping. Maize cropping areas exhibited significant regional characteristics, being densely distributed in the Sanjiang Plain and Liaohe Plain, and along major tributaries in northeast China. Consequently, the interplay of the natural environment, economic policies, and agricultural technologies drove these changes. The findings offer valuable insights for optimizing cropping patterns and developing rotation systems in northeast China. [ABSTRACT FROM AUTHOR]

Abstract To investigate the association between single nucleotide polymorphism (SNP) at the rs3918188, rs1799983 and rs1007311 loci of the endothelial nitric oxide synthase (eNOS) gene and genetic susceptibility to systemic lupus erythematosus (SLE) in northeastern China. The base distribution of eNOS gene rs3918188, rs1799983 and rs1007311 in 1712 human peripheral blood samples from Northeast China was detected by SNaPshot sequencing technology. The correlation between genotype, allele and gene model of these loci of the eNOS gene and the genetic susceptibility to SLE was investigated by logistic regression analysis. The results of the differences in the frequency distribution of their gene models were visualised using R 4.3.2 software. Finally, HaploView 4.2 software was used to analyse the relationship between the haplotypes of the three loci mentioned above and the genetic susceptibility to SLE. A multifactor dimensionality reduction (MDR) analysis was used to determine the best SNP-SNP interaction model. The CC genotype and C allele at the rs3918188 locus may be a risk factor for SLE (CC vs AA: OR = 1.827, P

Abstract Climate change and land use change caused by human activities have a profound impact on ecological security. Simulating the spatio-temporal changes in ecosystem service value and ecological security patterns under different carbon emission scenarios in the future is of great significance for formulating sustainable development policies. This study quantified the four major ecosystem services (habitat quality, water retention, soil erosion, and carbon storage) in Northeast China (NC), identified ecological source areas, and constructed a stable ecological security pattern. The results show that the spatial patterns of soil erosion, carbon storage, water retention, and habitat quality, the four major ecosystem services in NC, are relatively stable in the next 30 years, and there is no significant difference from the current spatial pattern distribution. The SSP1–2.6 carbon emission scenario is a priority model for the development of NC in the next 30 years. In this carbon emission scenario, the NC has the largest ecological resources (191,177 km2) and the least comprehensive resistance value (850.006 × 10−4). At the same time, the relative resistance of the corridor in this scenario is the smallest, and the area of the mandatory reserve pinch points is the least. The ecological corridors in the SSP1–2.6 scenario form a network distribution among the ecological sources, connecting several large ecological sources as a whole. This study fills the knowledge gap in building a stable ecological security pattern in NC under the background of global change, and provides a scientific basis for the decision-making of regional ecological security and land resource management.

Gully erosion is one of the most severe types of land degradation, hindering food production and sustainable agricultural development. However, the historical evolution process and the impact of land use change on gully erosion remain unclear. To address this issue, we conducted a field investigation on gully erosion in 2018 and interpreted land use and gullies using historical remote sensing images in 1968 and 1978 over an area of 84.48 km2. The study found that from 1968 to 1978 to 2018, all gully morphological parameters including gully length density and gully areal density increased significantly. The main origin of gully erosion found was from dry farmland. The annual soil loss rate induced by gully erosion was 1.46 mm during 1968–2018. Gully erosion rates were higher during 1968–1978 than during 1978–2018. Furthermore, the length, areal and volumetric erosion rates in gullies formed by multiple gullies merging was greater than that of newly formed gullies (NFG) and gullies developing continuously from a single pre-existing gully, while the widening rate of NFG was highest. The susceptibility of land use types to gully erosion was in the order of woodland

Rapid urbanization is universally acknowledged to degrade ecosystem services, posing significant threats to human well-being. However, the effects of urban shrinkage, a global phenomenon and a counterpart to urbanization, on ecosystem services (ESs) remain unclear. This study focuses on China's Rust Belt during the period from 2000 to 2020, constructing a comprehensive analytical framework based on long-term remote sensing data to reveal the temporal and spatial patterns of ESs and their associations with cities experiencing varying degrees of shrinkage. It employs a random forest (RF) model and a Shapley additive explanation (SHAP) model to measure and visualize the significance and thresholds of socioeconomic factors influencing changes in ESs. Our findings highlight the following: (1) Since 2010, the three provinces of Northeast China (TPNC) have begun to shrink comprehensively, with the degree of shrinkage intensifying over time. Resource-based cities have all experienced contraction. (2) Regional urban shrinkage has been found to enhance the overall provision capacity of ESs, with the most significant improvements in cities undergoing continuous shrinkage. (3) The impact of the same socioeconomic drivers varies across cities with different levels of shrinkage; increasing green-space ratios and investing more in public welfare have been identified as effective measures to enhance ESs. (4) Threshold analysis indicates that the stability of the tertiary sector's proportion is critically important for enhancing ESs in cities undergoing intermittent shrinkage. An increase of 10% to 15% in this sector can allow continuously shrinking cities to balance urban development with ecological improvements. This research highlights the positive aspects of urban shrinkage, demonstrating its ability to enhance the provision capacity of ESs. It offers new insights into the protection and management of regional ecosystems and the urban transformation of the three eastern provinces. [ABSTRACT FROM AUTHOR]

Gully erosion poses a significant global concern due to its role in land degradation and soil erosion, particularly pronounced in Northeast China's diverse agro-geomorphic regions. However, there is a lack of comprehensive studies on gully characteristics, development rates, and the topographic threshold of gully formation in these areas. To address this gap, we selected three different agro-geomorphic watersheds, named HL (Hailun), ML (Muling), and YKS (Yakeshi), with areas of 30.88 km2, 31.53 km2, and 21.98 km2, respectively. Utilizing high-resolution (2.1 m, 2 m) remote sensing imagery (ZY-3, GF-1), we analyzed morphological parameters (length, width, area, perimeter, etc.) and land use changes for all permanent gullies between 2013 and 2023. Approximately 30% of gullies were selected for detailed study of the upstream drainage area and gully head slopes to establish the topographic threshold for gully formation (S = a·A−b). In HL, ML, and YKS, average gully lengths were 526.22 m, 208.64 m, and 614.20 m, respectively, with corresponding widths of 13.28 m, 8.45 m, and 9.32 m. The gully number densities in the three areas were 3.14, 25.18, and 0.82/km2, respectively, with a gully density of 1.65, 5.25, and 0.50 km km−2, and 3%, 5%, and 1% of the land has disappeared due to gully erosion, respectively. YKS exhibited the highest gully head retreat rate at 17.50 m yr−1, significantly surpassing HL (12.24 m yr−1) and ML (7.11 m yr−1). Areal erosion rates were highest in HL (277.79 m2 yr−1) and lowest in YKS (105.22 m2 yr−1), with ML intermediate at 243.36 m2 yr−1. However, there was no significant difference in gully expansion rate (0.37–0.42 m yr−1) among the three areas (p > 0.05). Differences in gully development dynamics among the three regions were influenced by land use, slope, and topographic factors. The topographic threshold (S = a·A−b) for gully formation varied: HL emphasized drainage area (a = 0.052, b = 0.52), YKS highlighted soil resistance (a = 0.12, b = 0.36), and the parameters a and b of ML fell within the range between these of HL and YKS (a = 0.044, b = 0.27). This study has enriched the scope and database of global gully erosion research, providing a scientific basis for gully erosion prevention and control planning in Northeast China. [ABSTRACT FROM AUTHOR]

It is of great significance to carry out accurate identification of urban shrinkage and comparative analysis of its influencing factors in large national regions, to reduce the error based on administrative area identification. By constructing the VANUI index, calculating the one-dimensional linear regression coefficient of the DN value of night light and the WorldPop population grid data, and based on the overlay of the regression coefficient of the DN value of night light, and the regression coefficient of the WorldPop population grid data, the urban areas of East Germany and Northeast China in the two stages of 2000-2009 and 2010-2018 were divided into four types: absolute growth, smart shrinkage, negative growth and absolute shrinkage. This pa‐ per then studied and compared the spatio-temporal distribution and transformation path of the two stages of absolute shrinkage and smart shrinkage in the two regions, and constructed a panel regression model from population growth, scientific and technological development level, medical service level and other aspects to conduct a comparative analysis of the influencing factors of the two stages of urban shrinkage in the two regions. The results show that the absolute shrink‐ age areas in the two regions have a great similarity in spatiotemporal distribution and transformation path; the smart shrinkage areas are similar in spatiotemporal distribution, but different in transformation path; the absolute shrinkage areas in the two regions and two stages is relatively small; the mechanism of population growth in the two regions has both similarities and differences, and has different connotations due to differences in national conditions. This study shows that: (1)Urban shrinkage areas have the potential for short-term growth, and their development rights should be treated equally; (2)The absolute shrinking areas should be given special attention and governance, while the smart shrinking areas should be regarded as a reasonable development model for urban shrinking areas; (3)Continuously improving the level of medical, elderly care services and research investment, steadily promoting the transformation of living environment and infrastructure in existing areas, and reasonably controlling incremental development can help alleviate the phenomenon of urban shrinkage. [ABSTRACT FROM AUTHOR]

The spring atmospheric heat source (AHS) over the Tibetan Plateau (TP) has been suggested to affect the Asian summer monsoon and summer precipitation over South China. However, its influence on the summer precipitation in Northeast China (NEC) remains unknown. The connection between spring TP AHS and subsequent summer precipitation over NEC from 1961 to 2020 is analyzed in this study. Results illustrate that stronger spring TP AHS can enhance subsequent summer NEC precipitation, and higher soil moisture in the Yellow River Valley–North China region (YRVNC) acts as a bridge. During spring, the strong TP AHS could strengthen the transportation of water vapor to East China and lead to excessive rainfall in the YRVNC. Thus, soil moisture increases, which regulates local thermal conditions by decreasing local surface skin temperature and sensible heat. Owing to the memory of soil moisture, the lower spring sensible heat over the YRVNC can last until mid-summer, decrease the land–sea thermal contrast, and weaken the southerly winds over the East Asia–western Pacific region and convective activities over the South China Sea and tropical western Pacific. This modulates the East Asia–Pacific teleconnection pattern, which leads to a cyclonic anomaly and excessive summer precipitation over NEC. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shenyang Agricultural University is the property of Journal of Shenyang Agricultural University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The new round of prospecting breakthrough strategic action in Northeast China, aiming at the construction of large resource bases, focusing on strategic minerals in short supply, based on the four-level zones, i.e. fundamental survey zone, key survey zone, important exploration area and significant mine, has initially formed a new prospecting layout of national-local-enterprise pattern, which has supported the establishment of a new coordination mechanism guided by the government, with association of public welfare, industry and sci-tech breakthrough, and established a three-level(national, regional and provincial) technical support business system. Based on the characterization of Daxinganling metallogenic belt, eastern Liaoning-southern Jilin metallogenic belt, eastern Jilin-Heilongjiang metallogenic belt, eastern section of northern margin of North China craton, Songliao Basin and its peripheral metallogenic areas, the paper systematically analyzes the main minerals and prospecting potential of 12+1 large resource bases, defines the work deployment of the four-level zones, and points out key problems to be solved urgently in ore prospecting in Northeast China, so as to better support the national energy resources security and overall revitalization of Northeast China in the new era. [ABSTRACT FROM AUTHOR]

Northeast China, located at the convergence of North China plate, Siberian plate and Western Pacific plate, is an important area for studying the composite orogeny and mineralization of North China Craton, Paleo-Asian Ocean tectonic domain and Paleo-Pacific tectonic domain, and also one of the key regions of strategic mineral resources prospecting due to its superior metallogenic geological conditions. Since 2011, China has continuously strengthened the basic geological survey and research work in Northeast China, carrying out a series of 1:50 000 regional geological and mineral surveys, metallogenic background and comprehensive studies in the main metallogenic belt, basin-mountain junction belt and resources base in the area, to ensure the sustainable development of resources and energy and solve major basic geological problems. Lots of basic and original geological achievements have been made, which have successively filled the blank of large-scale geological surveys in Northeast China. Relying on the Regional Geology of Northeast China project, the study systematically sorts out the new data and results obtained from the basic geological survey projects since 2011, and summarizes the main basic geological research and achievements in Northeast China. On this basis, the tectonic units of North China Craton and Xing'an-Mongolian orogenic belt are further decomposed, which have restored the tectonic evolution history of the Paleo-Asian Ocean, Okhotsk Ocean and Paleo-Pacific Ocean, and completed the tectonic framework of Northeast China. With the discussion of the tectonic constraints on regional mineralization, the results will provide basic geological support for the new round of prospecting breakthrough strategic action. [ABSTRACT FROM AUTHOR]

Coastal aeolian deposits are product of the coupling between aerodynamics and coastal hydrodynamics, which is of great significance for reconstructing aeolian activities and the coastal environmental change. Here, we investigated the coastal aeolian deposits on Changxing Island, northeastern China, using geochemistry and microscopy of the minerals together with the published sedimentological data. The results showed that aeolian deposits are mainly derived from beach sands reworked by wind. Previously published Optically Stimulated Luminescence (OSL) dating results show that the deposition ages of the aeolian deposits are 41 ka, 49 ka, and 67 ka, respectively. The sedimentologic and geochemistry of aeolian deposits are sensitive to climate change. Notably, the micromorphology structure of the surface of quartz sand particles reveals the process of the coastal environment evolution. ∼41 ka, the surface of the grains is characterized by significant subaqueous environments, showing subangular with high relief, large conchoidal fracture, and V-shaped pits. These features correspond to the early sub-interstadial stage of MIS3, characterized by a warm and humid climate and sea level highstand. Under the relative sea level rise, the high rate of sand supply produced by coastal erosion contribute to aeolian deposit formation. In contrast, at 49 ka and 67 ka, the quartz grain exhibits typical aeolian environment features that exhibits subrounded with low relief, upturned plates, and dish-shaped pits, which respond to glacial periods of cold and windy conditions and sea level lowstand. The exposure of abundant sandy material, coupled with lower vegetation cover and strong East Asian winter monsoon (EAWM) contribute to higher sediment availability and sand accumulation. We therefore propose that sediment supply control by sea-level change is the primary reason for coastal aeolian sand deposition under different climatic backgrounds. [ABSTRACT FROM AUTHOR]

Promoting the green utilization of cultivated land in Northeast China is an important way to practice the concept of green development and promote the protection of black land. The super efficiency SBM model including non-expected output and the Tobit model were comprehensively used to quantitatively measure the spatial and temporal distribution pattern and influencing factors of green utilization efficiency of cultivated land in 40 prefecture-level cities, Northeast China from 2012 to 2021. The results show that ① from 2012 to 2021, the overall green utilization efficiency of cultivated land in Northeast China is relatively high, while the efficiency of each region in Northeast China begins to fluctuate and decline after 2018, and then rebounds after 2020; ② the spatial difference of green utilization efficiency of cultivated land in Northeast China is significant, and its distribution pattern gradually changes over time, showing the evolution characteristics of "high in the east and low in the west", "high around, low in the middle", and "high in the north and south, low around" during the study period; the proportion of grain crop rotation area and the total power of agricultural machinery per unit of crop sown area have a significant negative impact on the green utilization efficiency of cultivated land in Northeast China, and the level of scientific and technological development has a significant positive impact; however, the influence intensities of factors are different in different regions. The suggestions should be standardized and guided in policies and institutions, technical support and empowerment should also be provided, so as to improve the green utilization efficiency of cultivated land in Northeast China through practical measures and realize the sustainable use of black land. [ABSTRACT FROM AUTHOR]

Although black soil in northeast China undergoes severe erosion, the contribution of parent materials, mainly Quaternary loess and non-loess sediments, to soil erodibility remains unclear. Considering the inheritance of ferromagnetic materials by parent materials, changes in magnetic parameters can successfully determine soil erodibility on a regional scale with a close climatic background. Here, we analysed the magnetic indicators of 142 samples from the black soil horizon formed on loess and non-loess sediments, covering areas of severe and slight erosion in the region to determine the effects of parent materials on the erodibility of black soil in northeast China. Both low-frequency magnetic susceptibility and frequency magnetic susceptibility (χfd) were proportional to the decrease in erosion rate due to erosion-induced leaching of ferromagnetic materials, and the change in χfd was narrow for black soil with loess parent materials, corresponding to relatively low soil erodibility. Compared with loess, the addition of soil organic matter could stabilise soils against erosion, thereby inducing a decrease in the erodibility of black soil formed on loess. Additionally, sustainable soil management policies to protect black soil from further erosion are necessary and urgent under the pressure of maintaining high grain yields and preventing erosion in northeast China. [ABSTRACT FROM AUTHOR]

Gullies with lower altitudes compared to the surrounding environment are widely distributed in farmland of the watershed and their numbers are still expanding. However, it is still unclear how these gullies regulate the functional insects in farmland. In this study, land use types combined with the herbaceous plant, herbicide application, soil moisture, topography and climatic factors during crop growth were considered to understand how gullies influence the dynamics of functional insects in farmland from a watershed (240 ha) of Northeast China. The primary findings demonstrate that the richness and abundance of functional insects are generally greatest in gullies, particularly in stable gullies, and decrease in the following order: forest belts, grasslands, and farmlands within the watershed. Notably, the ratios of beneficial insects to pests (BI/Pest) in terms of richness and abundance were lower in gullies before July but reversed after July, in comparison to farmland. Stable gullies exhibited higher BI/Pest abundance and diversity ratios than developing gullies. The richness and abundance of functional insects were higher in the middle sections of gullies compared to their heads and tails. Furthermore, the ratios of BI/Pest were generally lower in farmlands than in any gully position. Functional insect dynamics were mainly determined by season, followed by plant abundance and biomass in the gullies, and rarely by soil moisture in the both watershed and single gullies scales. Generally, the richness and abundance of functional insects in farmland were mainly influenced by gullies, especially influenced by the gully middle position. Insect composition in farmland influenced by stable gullies was stronger than by developing gullies, and stable gullies were more beneficial in reducing the threat of pests to crops in the farmland of the watershed. [ABSTRACT FROM AUTHOR]

Assessing Sustainable Development Goal (SDG) indicator 15.3.1, which refers to the proportion of degraded land to total land area, and analysing its status and drivers is essential for the development of policies to promote the early achievement of SDG target 15.3 of Land Degradation Neutrality (LDN). In this study, Northeast China was selected as the study area, and the progress of indicator 15.3.1 was assessed based on the perspective of Net Primary Productivity (NPP) calculated by the CASA model. WorldPop population spatial distribution data were used as a proxy for human activities, combined with climate data to calculate the effects of changes in temperature, precipitation and population spatial distribution on vegetation NPP based on the partial correlation coefficient method and the Geodetector method. The results showed that 92.81% of the areas that passed the test of significance showed an increasing trend in vegetation NPP from 2000 to 2020. The vegetation NPP was affected by a combination of temperature, precipitation and population. The effects of temperature and precipitation on spatial differences in NPP for various vegetation types were significantly greater than those of population, but in high-density population zones, the effects of population on spatial differences in NPP were generally greater than those of temperature and precipitation. Precipitation was the main driver for spatial variation in NPP in deciduous broad-leaved forests, cultivated vegetation and thickets, while temperature was the main driver for spatial variation in NPP in evergreen coniferous forests. Generally, the warming and wetting trend in Northeast China contributed to the accumulation of NPP in cultivated vegetation, thickets, steppes and grasslands. The sensitivity of NPP to temperature and precipitation in deciduous broad-leaved and deciduous coniferous forests varied according to geographical location. [ABSTRACT FROM AUTHOR]

Flash drought is characterized by rapid onset and short-duration drought conditions caused by a combination of factors, including high evaporation, high temperature, and prolonged periods of little to no precipitation, leading to a sudden and severe decrease in soil moisture levels. In comparison to conventional drought, it is more susceptible to the effects of global warming and has the potential to become a common drought phenomenon in the coming years, necessitating further research. In this paper, we focused on flash drought events, specifically in forest parts of northeastern China that are included within the Greater Khingan Mountains (GKM), Lesser Khingan Mountains (LKM), and Changbai Mountains (CM), using daily soil moisture data as well as SPOT- VEGETATION NDVI satellite data from 2000 to 2020 and determined their impact on the forest NDVI. Our major findings are as follows. (1) The forest within GKM had the maximum area being affected by flash drought events. (2) The frequency ranged from 1 to 2 times, whereas the total duration varied between 20 and 55 days over the study area in a 21-year period. (3) Flash drought was most common in the plant-growing seasons. (4) The flash drought events had a negative influence on the forest NDVI. Our study contributes to a deeper understanding of the flash drought dynamics in forest areas of northeast China for flash drought monitoring, prediction, and management strategies in this region. [ABSTRACT FROM AUTHOR]

Frost is one of the most frequent, intense, and influential agrometeorological disasters that occurs frequently in Northeast China. The study of the spatiotemporal changes of ground frost is of great significance for farmers and policymakers in Northeast China, as it can inform decisions related to crop selection, planting schedules, and the development of regional climate adaptation plans. In this study, the spatiotemporal changes of frost indices (last spring frost (LSF), first fall frost (FFF), and frost-free period (FFP)) in Northeast China were analyzed from 1961 to 2020. Then, we investigated the mutation characteristics of the frost indices and their correlation with geographical factors. The results revealed that (1) the LSF, FFF, and FFP in Northeast China were concentrated at 120–140 DOY, 260–280 DOY, and 110–170 days, respectively. The spatial distribution of frost indices exhibited significant spatial heterogeneity. (2) The LSF, FFF, and FFP showed significant trends of advancement, delay, and extension, with trends of −1.94 days/10 a, 1.72 days/10 a, and 4.21 days/10 a, respectively. (3) More than 80% of the LSF, FFF, and FFP of the sites showed trends of advancement, delay, and extension, with greater variability in the central part of Heilongjiang Province. (4) The FFF and FFP experienced an abrupt change in the late 1990s. (5) The correlation between latitude and LSF, FFF, and FFP was the strongest, with correlation coefficients of 0.77, −0.79, and −0.78, respectively. This study provides a comprehensive understanding of the changing characteristics of ground frost indices that impact agricultural production in Northeast China against the backdrop of climate change. The findings hold significant scientific value in guiding the adaptation of agricultural production layouts in Northeast China to the evolving climatic conditions. [ABSTRACT FROM AUTHOR]

Copyright of New Architecture is the property of New Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil organic matter (SOM) in cultivated land is vital for land quality and food security. This study examines SOM distribution and influencing factors in northeastern China, providing insights for sustainable agriculture. Utilizing 10 m resolution SOM data, the analysis covers regions including the Greater and Lesser Khingan Mountains, Liaohe Plain, Sanjiang Plain, Songnen Plain, the northwest semi-arid region, and the low hilly areas of Paektu Mountain. The Geodetector method is employed to assess various influencing factors. The key findings are as follows: (1) The average SOM content in Northeast China (37.70 g/kg) surpasses the national average, is highest in the Greater and Lesser Khingan Mountains (49.32 g/kg), and lowest in the northwest semi-arid region (26.15 g/kg). (2) SOM content is maximized in regions with high altitudes, steep slopes, low temperatures, and moderate precipitation. (3) The annual average temperature is the primary factor influencing SOM distribution, with a combination of temperature and administrative divisions providing better explanatory power. (4) SOM trends vary across protected areas, with slope being critical in semi-humid plains, elevation in arid regions, and no dominant factors identified in the Sanjiang Plain. These findings underscore the need for tailored black soil protection policies to effectively leverage local resources and preserve ecosystem integrity. [ABSTRACT FROM AUTHOR]

Climate change and land use change caused by human activities have a profound impact on ecological security. Simulating the spatio-temporal changes in ecosystem service value and ecological security patterns under different carbon emission scenarios in the future is of great significance for formulating sustainable development policies. This study quantified the four major ecosystem services (habitat quality, water retention, soil erosion, and carbon storage) in Northeast China (NC), identified ecological source areas, and constructed a stable ecological security pattern. The results show that the spatial patterns of soil erosion, carbon storage, water retention, and habitat quality, the four major ecosystem services in NC, are relatively stable in the next 30 years, and there is no significant difference from the current spatial pattern distribution. The SSP1–2.6 carbon emission scenario is a priority model for the development of NC in the next 30 years. In this carbon emission scenario, the NC has the largest ecological resources (191,177 km2) and the least comprehensive resistance value (850.006 × 10−4). At the same time, the relative resistance of the corridor in this scenario is the smallest, and the area of the mandatory reserve pinch points is the least. The ecological corridors in the SSP1–2.6 scenario form a network distribution among the ecological sources, connecting several large ecological sources as a whole. This study fills the knowledge gap in building a stable ecological security pattern in NC under the background of global change, and provides a scientific basis for the decision-making of regional ecological security and land resource management. [ABSTRACT FROM AUTHOR]

Despite the significant impacts of biomass burning (BB) on global climate change and regional air pollution, there is a relative lack of research on the temporal trends and geographic patterns of BB in Northeast China (NEC). This study investigates the spatial–temporal distribution of BB and its impact on the atmospheric environment in the NEC region during 2004 to 2023 based on remote sensing satellite data and reanalyzed data, using the Siegel's Repeated Median Estimator and Mann–Kendall test for trend analysis, HDBSCAN to identify significant BB change regions, and Moran's Index to examine the spatial autocorrelation of BB. The obtained results indicate a fluctuating yet overall increasing BB trend, characterized by annual increases of 759 for fire point counts (FPC) and 12,000 MW for fire radiated power (FRP). BB predominantly occurs in the Songnen Plain (SNP), Sanjiang Plain (SJP), Liaohe Plain (LHP), and the transitional area between SNP and the adjacent Greater Khingan Mountains (GKM) and Lesser Khingan Mountains (LKM). Cropland and urban areas exhibit the highest growth in BB trends, each surpassing 60% (p < 0.05), with the most significant growth cluster spanning 68,634.9 km2. Seasonal analysis shows that BB peaks in spring and autumn, with spring experiencing the highest severity. The most critical periods for BB are March–April and October–November, during which FPC and FRP contribute to over 80% of the annual total. This trend correlates with spring planting and autumn harvesting, where cropland FPC constitutes 71% of all land-cover types involved in BB. Comparative analysis of the aerosol extinction coefficient (AEC) between areas with increasing and decreasing BB indicates higher AEC in BB increasing regions, especially in spring, with the vertical transport of BB reaching up to 1.5 km. County-level spatial autocorrelation analysis indicates high–high clustering in the SNP and SJP, with a notable resurgence of autocorrelation in the SNP, suggesting the need for coordinated provincial prevention and control efforts. Finally, our analysis of the impact of BB on atmospheric pollutants shows that there is a correlation between FRP and pollutants, with correlations for PM2.5, PM10, and CO of 0.4, 0.4, and 0.5, respectively. In addition, the impacts of BB vary by region and season, with the most significant impacts occurring in the spring, especially in the SNP, which requires more attention. In summary, considering the escalating BB trend in NEC and its significant effect on air quality, this study highlights the urgent necessity for improved monitoring and strategic interventions. [ABSTRACT FROM AUTHOR]

This fundamental investigation aimed to deliver a new theoretical perspective to address the brain drain problem from Northeast China. The amenity theory could provide a robust ideological foundation that enables cities to attract talent and drive urban innovation and development. This study explores the spatial–temporal pattern evolution of talent inflow to Northeast China based on data from the China Migrant Dynamic Survey (CMDS) from 2012 to 2018. It utilizes spatial analysis methods and geographic detectors to interpret the factors that influence the spatial heterogeneity of talent inflow from the perspective of urban amenities. The following results were obtained. First, the trend in the number of talent inflows displays an initial increase followed by fluctuations before inflow destinations are concentrated in four major cities and certain resource-based cities in Northeast China. Second, a high-quality labor force is engaged in varied industries. Talents with different academic qualifications could avail themselves of diverse employment choices, primarily in information transmission, software, and information technology services. Those with undergraduate and postgraduate degrees could find positions in the education industry. Third, the talent flow mode has gradually changed from interprovincial to intercity movements within a particular province. However, the mode of talent flow differs according to discrete academic qualifications. Most postgraduates choose the interprovincial flow, and undergraduates and junior college students predominantly select the intercity flow within a particular province. Fourth, the inflow of talent to destinations in Northeast China is based on artificial amenities and tends toward cities that offer efficient public services, abundant leisure facilities, and innovative soft and hard environments. The major factors that affect the spatial differentiation in talent inflow to a city include the number of hospital beds per 10,000 people, scientific research, creative practitioners, talent-related policies, exhibition halls and other leisure and entertainment venues, and average housing prices in the city. Most interactions between artificial environment amenity factors and other elements are better than their individual effects, especially the interactive configuration of affordable urban housing prices, high-quality public resources, such as education and health care, and abundant leisure and entertainment facilities. [ABSTRACT FROM AUTHOR]

The permafrost in Northeast China is experiencing rapid degradation due to the influence of climate change and human activities, profoundly impacting the local ecological environment and engineering construction. Understanding the spatiotemporal dynamics of long-term permafrost in this region is crucial; however, systematic research on this topic remains scarce. This study combines meteorological station data, MODIS land surface temperature (LST) datasets, and borehole locations to apply the surface frost number (SFn) model. This approach enables the simulation and estimation of the spatial distribution and changes in the area of the surface frost number without vegetation effects (SFnv) and permafrost temperature (PT) in Northeast China from 1971 to 2020. The area of the SFnv > 0.49 within the permafrost region decreased substantially from approximately 44.353 × 104 km2 to 19.909 × 104 km2 between 1971 and 2020, with a notable change in 1988. The area of permafrost calculated using PT < 0 was slightly smaller, declining from 39.388 × 104 km2 to 29.852 × 104 km2. There was also a significant increase in the area with PT ranging from −1 °C to 0 °C, indicating a decline in permafrost stability. Approximately 10.926 × 104 km2 of stable permafrost has been transformed into semi-stable and unstable permafrost. Moreover, from 1982 to 2020, the NDVI was negatively correlated with the area of stable permafrost and positively correlated with the area of transitional or unstable permafrost. Vegetation cover decreased as transitional or unstable permafrost degraded. These findings provide valuable information for permafrost research and engineering development in cold regions, as well as for future planning and adaptation strategies. [ABSTRACT FROM AUTHOR]

During the corn stockpiling system reform in Northeast China between 2008 and 2015, corn production expanded dramatically, and corn residue, which was mostly burned in‐situ, caused severe air pollution issues. Using a difference‐in‐differences approach, we assessed the effects of the corn stockpiling system reform in China and its associated environmental outcomes with a provincial‐level dataset. Our results suggest that the implementation of this policy significantly increased annual corn production in Northeast China by 15.1%. We also observed a substitution pattern between corn and soybean cultivation in the treatment area, with a percentage point increase in the net soybean‐to‐corn profit ratio leading to a decrease in corn production by 0.023 percentage points. Overall, based on changes in crop patterns during the system reform, increased straw resulted in increased burning and the resulting consequence to the environment is a net pollution increase equivalent to 16.03%, 0.33%, and 3.64% of the smoke and dust, SO2, and NOX, respectively, from the industrial sector in the treatment provinces. [ABSTRACT FROM AUTHOR]

Changes in extreme precipitation in Northeast China (NEC), a climate-sensitive region, remain unclear with respect to future warming due to regionally unique geographic factors. This study examines how regional extreme precipitation may adapt to future climate change. Using statistical downscaling and the CMIP6 multi-model ensemble, we investigate the possible changes in future extreme precipitation for NEC under different warming scenarios and the influencing factors. The results indicate that extreme precipitation events, under different definitions, exhibit a gradual enhancement trend and are more pronounced for the more extreme precipitation definitions. However, in projections of the late twenty-first century, under the Scenario Model Intercomparison Project (2015–2100) Shared Socioeconomic Path (SSP)2–4.5 scenario, the growth of extreme precipitation events plateaued as warming slowed. The response of extreme precipitation to temperature changes under SSP2-4.5 (SSP5-8.5) was approximately linear, with average response rates of 7.29%/°C (6.71%/°C) and 16.84%/°C (17.33%/°C) for number of days with daily precipitation exceeding 20 mm and annual total precipitation of days exceeding the 99th percentile threshold, respectively. The distribution of these indices was more concentrated under SSP5-8.5 scenario. Variations in the spatial distribution of extreme precipitation were significantly correlated with vertical velocity at 500 hPa and were influenced by moisture availability. The predicted increase in extreme precipitation was greater in humid and mountainous regions and precipitation changes were most pronounced at higher latitudes. Our results suggest that future temperatures may increase the risk of extreme precipitation in NEC, posing a challenge for adaptation to changes in precipitation extremes. [ABSTRACT FROM AUTHOR]

Copyright of Chengda Lishi Xuebao (Cheng Kung Journal of Historical Studies) is the property of Guoli Chenggong Daxue, Lishi Xuexi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ecosystems are undergoing continuous degradation due to the dual perturbation of global climate change and human activities, posing unprecedented threats and challenges to the ecosystem services they provide. To gain a deeper understanding of the spatio-temporal evolution of ecosystem service value (ESV), it is essential to accurately capture the characteristics of its spatial and temporal changes and its influencing factors. However, traditional spatio-temporal statistical methods are limited to analyzing the heterogeneity of ESV in a single temporal or spatial dimension, which fails to meet the comprehensive analysis needs for spatio-temporal heterogeneity over an extended continuum. Therefore, this paper constructs a Bayesian spatio-temporal hierarchical model to analyze the ESV heterogeneity in both temporal and spatial dimensions in Northeast China from 2000 to 2020 to accurately identify the regions with unstable fluctuations in ESV and analyze the influencing factors behind them. It aims to comprehensively and systematically reveal the intrinsic laws of spatio-temporal evolution of ESV, and provide a scientific basis for relevant decision-making. The study found a continuous fluctuating downward trend of ESV in Northeast China from 2000 to 2020, with significant spatial and temporal heterogeneity. Notably, the distribution of hot and cold spots is regularly concentrated, especially in the transition zone from low hills to plains, which forms an "unstable zone" of spatial and temporal fluctuations of ESV. Natural factors such as NDVI and NPP exhibit a significant positive correlation with ESV, while social factors like population density and GDP show a strong negative correlation. Compared to traditional statistical methods, the Bayesian spatio-temporal hierarchical model, with its outstanding flexibility and accuracy, provides a new perspective and way of thinking for analyzing classical spatio-temporal problems. Firstly, the model examines time and space as a whole and fully accounts for the influence of spatio-temporal interactions on ESV. Secondly, the Bayesian spatio-temporal hierarchical model meets the needs of long-term continuous ESV outcome detection, which provides us with solid support for a deeper understanding of the evolution of ESV. [ABSTRACT FROM AUTHOR]

Water resources are the premise of sustainable agricultural development in Northeast China (NEC), the country’s largest granary. Revealing the long-term evolution of water resources from multiple perspectives, such as surface water area (SWA) and groundwater storage (GWS), is crucial for understanding their current status and predicting future trends to formulate adaptive strategies to promote sustainable water management. Here, firstly, we annually mapped surface water in 1987–2023 using the Google Earth Engine (GEE) cloud service, all these historical 30-m Landsat records, and a mature surface water detection algorithm; then, we calculated annual GWS using Gravity Recovery and Climate Experiment (GRACE) satellite data and compared the trends of SWA and GWS to analyze the current status and evolution direction of water resources. We found continuous expansion of SWA (169.3 km2/yr) since 2002 after a 15-year consecutive decline, while GWS significantly declined (2.37 mm/yr). Quantitative attribution analyses identified the increasing artificial lakes and aquaculture ponds as the major drivers of surface water expansion, with a contribution of 85.0 %, suggesting that the expanding surface water bodies seen from space were just an illusion of increasingly abundant water resources. In addition, we revealed the increasing water evaporation (0.2 km3/yr) and the ratio (0.005–0.2 %/yr) of water evaporation to evapotranspiration (ET) with surface water expansion, indicating that the contribution of water evaporation to ET is more prominent and evaporative water loss has become a new threat to local water security and deserves much more attention. Our research can not only bring new insights into the current status of water security in China’s largest granary but also provide a typical case for reference in analyzing water resource changes in other similar regions.

Gully erosion poses greater threat to ecological and food security globally. The gully development rate and the contributions of primary influencing factors have not been thoroughly understood, primarily due to the complicated environmental conditions characterized by climate, soil, topography, and human activities. Therefore, this study was conducted to explore the gully development and contributions of its driving factors from 2013 to 2021 based on historical Google Earth images and field investigation in a typical rolling hilly watershed of northeast China. The climatic factors reflected by precipitation, topographical factors related to gully, and anthropological factors reflected by tillage ridge orientation and linear anthropological factors (LAF) including roads and shelterbelts were obtained. The tillage effect index (TEI), LAF effect index (LEI) and the distance from gully to LAF (DL) were calculated to analyze the influence of anthropological factors on gully development. The results showed that the linear, areal and volumetric gully development rates (RL, RA and RV) showed great variabilities in different periods with the average of 5.69 m year−1, 137.37 m2 year−1 and 428.54 m3 year−1, respectively. The accumulated RL, RA and RV increased exponentially or linearly with accumulated precipitation amount (P), erosive rainfall duration (RD), erosive rainfall (ER), maximum 30-min rainfall intensity (I30) and rainfall erosivity (RE) increased (P

Northeast China, recognized as a global flash drought hotspot and a region of nationally important commercial grains and ecological fragility, is highly susceptible to the profound impacts of droughts on both food security and ecological safety. However, the regional-scale characteristics, possible causes and impacts of flash droughts across Northeast China are rarely investigated. Soil moisture data from 2000 to 2022 were utilized to identify the onset, frequency and duration of flash droughts using the quantile method. The spatial trajectories of flash droughts were determined based on the patch-scale centroid transfers. Further, the possible drivings and ecological impacts of flash droughts were analyzed using datasets of climatic variables and gross primary productivity. We found that flash drought coverage with short onset (1- pentad onset) was generally larger than that with long onset (2-, 3- and 4-pentad onset). The affected area of flash droughts generally decreased, while the onset speed increased over the past two decades. Flash droughts frequently occurred the intersection of western Jilin Province, southern Inner Mongolia Autonomous Region, and northern Liaoning Province but with short duration. Compared with 2001–2011, the start, middle and end centroids of flash droughts in 2012–2021 showed more spatial dynamic changes, mainly shifting towards the northeast-southwest and southeast-northwest directions. The onset of flash drought due to potential evapotranspiration, temperature, precipitation deficit, and vapor pressure anomalies account for an average of 33%, 28%, 22%, and 16%, respectively. However, the contributions of dominant meteorological factors and their combinations varied remarkably in different sub-regions. Long onset flash droughts exhibited larger impact on GPP than short onset flash droughts. This study highlights that due to climate change, the affected area of flash droughts in hotspot regions decreased, but the onset speed and spatial dynamics increased, and followed by a more severe ecological impact of short-onset flash drought. Therefore, it is imperative to incorporate the increasing impacts of flash droughts, which is critical to ensuring regional food security and ecological safety in the Northeast China.

The ecological security of tourism provides an important guarantee of the sustainable development of regional tourism. In this study, the authors use the Driving Force-Pressure-State-Impact-Response model to construct a system to assess the ecological security of tourism in three provinces of Northeast China. We analyze the characteristics of the dynamic spatiotemporal evolution of the ecological security of tourism in 34 prefecture-level cities, one prefecture, and one region in three provinces of Northeast China from 2010 to 2019 and identify obstacles to this evolution. The results show the following: (1) The ecological security of tourism in Northeast China fluctuated and grew during the study period. Significant changes were observed in the rankings of the provinces in the ecological security of tourism. The pattern of spatial distribution has gradually shifted, from “high in the west and low in the middle” in 2010 to “slightly high in the middle-east and slightly low in the west” in 2019. (2) The ecological security of tourism exhibited prominent characteristics of spatial agglomeration on the whole, where the degree of agglomeration has gradually decreased over time. Economically developed cities in Central China exhibited strong local autocorrelation, and the majority had the characteristics of spatial agglomeration and dependence. (3) There were significant differences in obstacles to the ecological security of tourism among the cities (prefectures and regions) and provinces. Industrial sulfur dioxide emissions and urban population density are the main obstacles to the ecological security of tourism, while the pressure system has emerged as the main hindrance to improvements in it in the three provinces considered here. These results provide insights into the ecological security of tourism in the three provinces of Northeast China, as well as a theoretical reference for formulating and implementing the relevant measures of risk prevention and control. This study shows that increasing the protection of the tourism ecological environment and the construction of new energy sources, building complete tourism infrastructure, coordinating the relationship between tourists and the natural environment, adopting differentiated tourism development measures, and overcoming the obstacles will help to gradually improve the level of tourism ecological security in three provinces of Northeast China.

In the MODIS snow product collection 6.1 (C6.1), some snowy pixels are misclassified as cloud pixels due to an excessive cloud mask algorithm. This increases cloud contamination in normalized difference snow index (NDSI) and affects snow mapping accuracy. Northeast China is used as an example to develop excessive cloud mask removal and gap-filling algorithms, and generate a daily cloud-free NDSI dataset for each snow season from 2001 to 2020. To identify pseudo-cloud pixels, the green band and NDSI were used to distinguish forested snow and clouds, thin snow in plains and clouds, respectively. This decreased cloud from nearly 60% to below 30%. We developed a spatiotemporal cube cloud removal algorithm based on NDSI similarity (STNSI) for the remaining clouds in which the central cloudy pixel was filled with neighborhood pixels in the spatiotemporal cube. Meanwhile, bias correction was performed, and the average cloud decreased to below 1% after the first iteration. The produced STNSI NDSI has high precision under different underlying surfaces, with OA and FS values greater than 0.9. Compared with the existing STAR NDSI, STNSI NDSI snow mapping accuracy improved, especially in forested areas where OA improved by 37%. Moreover, removing many pseudo-cloud pixels greatly enhances gap-filling efficiency.