Northeastern Region Of China Research Articles

Changes in diversity and importance of clonal plants during sand dune succession in northeastern China

AbstractMany major biomes throughout the world are dominated by plants with clonal growth forms. While many recent studies have examined the effects of clonality on the growth of individual plants, relatively few studies have tested the community level effects of clonality as a function of environmental characteristics. By investigating six sand dune sites that have undergone different numbers of years of natural restoration constituting a succession sere, we quantified if the abundance and importance of clonal plants was related to successional age in the stressful environment of a semi‐arid sand dune region in northeastern China. We expected that clonal plants would dominate at every stage of the succession sere. We also predicted that species diversity would decrease in later stages of the succession sere due to the extremely high proportion of clonal plants in the community. Our results showed that, through 45 years of succession, the total plant species richness and Shannon–Wiener diversity index continually increased. While the species number of clonal plants was consistently low during the succession, the importance of clonal plants increased gradually from none at 3 years to 49 % of the total, approximately equal to that of aclonal plants, at the 45‐year site. Clonal plants with phalanx strategies were more important than guerillas at all ages in sand dune succession. At the beginning and early stages of sand dune succession, aclonal plants were more important than clonal plants, perhaps due to greater seed propagation. The distribution or arrangement of aclonal and clonal plants in the whole process of sand dune complemented each other. The results presented give new perceptions on the function of biodiversity in maintaining ecosystems.

A comprehensive eco-efficiency model and dynamics of regional eco-efficiency in China

Abstract In order to have a comprehensive eco-efficiency measure which can incorporate productivity, resource efficiency, environmental efficiency, and inter-temporal comparability and circularity, the paper proposes an extended data envelopment analysis model, named GB-US-SBM model, which combines global benchmark technology, undesirable output, super efficiency and slacks-based measure. Using the GB-US-SBM model, this paper investigates the dynamics of regional eco-efficiency in China from 2000 to 2010. The empirical results show that the movement of average eco-efficiency of China presents a “V” shape from 2000 to 2010 with the trough occurred in 2005, but there are big differences of eco-efficiency among the regions. For the growth of eco-efficiency, technological progress contributes 56.87%, 58.21%, 18.27%, 62.19%; scale efficiency contributes 40.01%, 61.14%, 167.43%, 39.12%; efficiency change contributes 3.82%, −19.99%, −63.40%, −2.16% to the eastern, middle, western and northeastern regions of China respectively. These imply that there is a big space for western region to enhance its technological progress, and huge space for the whole country to promote its management ability.

Variations in tree-ring width indices over the past three centuries and their associations with sandy desertification cycles in East Asia

A database of 39 annually resolved, tree-ring width chronologies covering the Mongolian Plateau, northeastern China region, and the Yellow River drainage was established to identify variations in sandy desertification cycles over the past three centuries. Our results show that the arid, semiarid, and semi-humid East Asia experienced multiple sandy desertification cycles over the past 300 years. The Mongolian Plateau experienced sandy desertification from the 1730s to the 1750s and the 1810s to the 1910s. Northeastern China region was subject to sandy desertification from the 1700s to the 1720s, the 1770s to the 1820s, and the 1830s to the 1860s. In the Yellow River drainage, sandy desertification occurred from the 1700s to the 1730s, the 1750s to the 1780s, and the 1810s to the 1850s. The occurrence of sandy desertification was closely related to weakened summer monsoon and enhanced winter monsoon associated with decreases in precipitation and increases in aeolian activity during the Little Ice Age; reversals of sandy desertification resulted mainly from increases in precipitation and decreases in aeolian activity during the Current Warm Period. The sandy desertification cycles we reconstructed have been verified by monitoring results of modern sandy desertification trends and evidence from ancient archives and archaeological records.

Six New Species of Gomphonema Ehrenberg (Bacillariophyceae) Species from the Great Xing'an Mountains, Northeastern China

Six new species of the diatom genus Gomphonema Ehrenberg are described from lakes, swamps, bogs and streams from the Great Xing'an Mountains region of Northeastern China. Descriptions are based on light and scanning electron microscope observations of valve shape, size and ultrastructure. Of the six new species, four are known from the Great Xing'an Mountains only, while two others have been recognized in nearby Mongolia. All six species are known from habitats that are circumneutral to alkaline. Each species is described and compared with similar taxa. These new species descriptions, in addition to the recognition of other new species in the region, suggest aquatic habitats in the Great Xing'an Mountains may support an endemic diatom flora.

Seed dispersal and seedling recruitment of trees at different successional stages in a temperate forest in northeastern China

Aims Spatial distribution of adult trees in a forest community is deter mined by patterns of both seed dispersal and seedling recruitment. The objectives of our study were to understand the processes of seed dispersal and seedling recruitment of dominant tree species in a temperate forest of northeastern China and to identify the factors constraining seed dispersal and seedling establishment at different stages of forest succession. Methods During three summer and autumn sessions between 2006 and 2008, altogether 113 080 seeds from 22 different tree species were collected in three large field plots representing different for est types in the Changbai Mountain region of northeastern China. The spatial distribution of seed abundance was analyzed using a Syrjala test. Regeneration success of nine major tree species was assessed using variables defining ‘limitations’ in ‘seeds’ and ‘seedling establishment’. Important Findings We found that seed production fluctuated between years and varied greatly with forest types. Four tree species, Acer spp., Fraxinus mandshurica, Tilia amurensis and Betula spp., had the greatest seed production and the widest range of seed dispersal, whereas Quercus mongolica showed the most sustained seed production pattern. The spatial patterns of seed abundance differed significantly among for est types and years. The tree species investigated in this study differed in the degree of seed limitation, as well as in limitation of seedling establishment. There were both negative and positive cor relations between seed density and seedling density, depending on site and parental tree density. Seeds of 16 tree species were found in the Populus davidiana–Betula platyphylla forest (PBF) plot, 11 in the conifer and broad-leaved mixed forest (CBF) plot but only 8 in the broad-leaved-Korean pine mixed forest (BKF) plot. The number of seed-contributing species was not only greater in the secondary forests (CBF and PBF plots) than in the primary forest (BKF plot) but was also more variable during the 3 years of assessment. Results from the correlations between seed density and seedling occur

Climate change and the food production system: impacts and adaptation in China

China has received a lot of attention from both the scientific and policy community in its ability to maintain selfreliance in food supply (Verburg et al. 2000; Yang and Li 2000; Yu et al. 2012). Advances in technology and changing agronomic practices have been responsible for significant increases in food production in China over past several decades (Xiong et al. 2012). Yet, since the 1980s, the unprecedented growth of both the economy and the population has led to a decrease in the area of cropland (Deng et al. 2006; He et al. 2013). The growing competition for land, water, and energy, and the overexploitation of fisheries, seriously impairs the production of food. Global environmental change, particularly climate change, makes the situation more challenging. Changes in climate may have implications for climate-sensitive systems such as agriculture, forestry, and other natural resources (Wu et al. 2011; Verburg et al. 2013). China is among the most affected countries by climate change (Ye et al. 2012). Continuous measurements from meteorological stations show that there is a strong warming of China over the past five decades and the temperature has increased by 1.2 C since 1960, which is much higher than the overall rate of global surface temperature change (Piao et al. 2010). Although there is no observed significant longterm trend in country-average precipitation since 1960, there are significant regional precipitation trends. The drier regions of northeastern China (including North China and Northeast China) are receiving less and less precipitation in summer and autumn (a 12 % decline since 1960). By contrast, the wetter region of southern China is experiencing more rainfall during both summer and winter. As for future projections, climate models tell us unambiguously that the warming trend will continue, and China’s average temperature is estimated to increase further by 1–5 C by 2100. This acceleration in temperature warming and its associated changes in precipitation have affected agriculture and food production in China. One of the greatest challenges for China in the twenty-first century will be to ensure that the food supply sustainably meets the needs of the population despite the necessary adaptations to climate change. Meeting this task will require technical and institutional innovations that increase food production and facilitate adaptation to changing climatic conditions. Climate change affects agriculture and the food production system in many ways (Godfray et al. 2011). Changes in climatic variables drive changes in overall food production through interacting effects on crop yields and crop areas. Although there has been much research to investigate the impacts of climate change on crop/food production (Barry and Cai 1996; Chen et al. 2013; Li et al. 2011, 2005; Piao et al. 2010; Wang et al. 2009; Zhang and Huang 2012), these studies are generally either focused on a single aspect of the interactions between climate change and food production or are performed in specific small regions. This causes some inconsistency in assessment results of climate change impacts, and well-recognized conclusions are therefore unavailable (Yang et al. 2013). W. Wu H. Tang Key Laboratory of Agri-Informatics, Ministry of Agriculture of China, Beijing 100081, China e-mail: wuwenbin@caas.cn

BENEFITS IDENTIFICATION AND EVALUATION OF FLOODWATER UTILIZATION IN BAICHENG REGION, NORTH‐EASTERN CHINA

ABSTRACTThe utilization of small and medium magnitudes of floodwater has remarkable benefits when the supply of conventional water is scarce relative to demand. Conceptually correct and empirically accurate estimates of the benefits of floodwater utilization are essential for rational replenishment of scarce water in the fields of agriculture, industry, households, recreation and so on. This article raises several issues that should be considered in deriving sound evaluation of benefits of floodwater utilization. These include: (i) identifying and defining benefit categories according to flood loss analysis; (ii) establishing a universal benefits indices system and choosing the variable fuzzy pattern recognition model to evaluate the system; (iii) illustrating the benefits of floodwater utilization based on the floodwater utilization practices in the Baicheng Region of northeastern China. An integrated floodwater utilization benefits research framework suggests that a combination of direct economic benefit, eco‐environmental benefit and social benefit can provide complementary insights into sustainable water utilization. Evaluation of the comprehensive benefits of floodwater resources enables decision makers to make more informed choices on floodwater use safely and allocated soundly, in which the full extent of growing demands for these uses is seen in the face of increased scarcity. Copyright © 2013 John Wiley & Sons, Ltd.

Assessment of soil redistribution and spatial pattern for a small catchment in the black soil region, Northeastern China: Using fallout 210Pbex

Soil erosion greatly reduces soil fertility. Quantification of soil erosion is required to effectively implement soil conservation practices. This study used the 210Pbex measurements to assess long-term rates and spatial pattern of soil redistribution in an agricultural catchment in the black soil region, Northeastern China. A total of 61 sampling cores were collected from the catchment, where 137Cs has been previously used to study medium-term soil redistribution rates. The potential use of 210Pbex was validated through using 137Cs measurements in our previous study and other methods. 210Pbex-based soil redistribution rates ranged from −106.5 to 166.9tha−1yr−1 with a mean value of −3.9tha−1yr−1. The net erosion rate for the entire catchment was −8.3tha−1yr−1, which is much higher than the tolerable soil erosion rate. The spatial pattern of soil redistribution was investigated based on the 210Pbex measurements. The correlations between the rates of soil redistribution and slope gradient and curvature were not significant at the 0.05 risk level. Although the shelterbelts could greatly affect spatial pattern of soil redistribution, ca. 78% of the eroded soils were lost per year from the agricultural catchment and soil erosion has accelerated in the last few decades. Integrated soil conservation measures are urgently required to effectively control soil loss in the black region of Northeastern China.

An Application of Remote Sensing Data in Mapping Landscape-Level Forest Biomass for Monitoring the Effectiveness of Forest Policies in Northeastern China

Monitoring the dynamics of forest biomass at various spatial scales is important for better understanding the terrestrial carbon cycle as well as improving the effectiveness of forest policies and forest management activities. In this article, field data and Landsat image data acquired in 1999 and 2007 were utilized to quantify spatiotemporal changes of forest biomass for Dongsheng Forestry Farm in Changbai Mountain region of northeastern China. We found that Landsat TM band 4 and Difference Vegetation Index with a 3×3 window size were the best predictors associated with forest biomass estimations in the study area. The inverse regression model with Landsat TM band 4 predictor was found to be the best model. The total forest biomass in the study area decreased slightly from 2.77×10(6) Mg in 1999 to 2.73×10(6) Mg in 2007, which agreed closely with field-based model estimates. The area of forested land increased from 17.9×10(3) ha in 1999 to 18.1×10(3) ha in 2007. The stabilization of forest biomass and the slight increase of forested land occurred in the period following implementations of national forest policies in China in 1999. The pattern of changes in both forest biomass and biomass density was altered due to different management regimes adopted in light of those policies. This study reveals the usefulness of the remote sensing-based approach for detecting and monitoring quantitative changes in forest biomass at a landscape scale.

Division Scheme for Environmental Management Regionalization in China

Based on regional heterogeneity of environmental characteristics and factors influencing those characteristics, environmental units may be classified into homogeneous zones. Then, essential strategies and mitigation measures in each zone may be developed and environmental quality may be holistically improved using a system of environmental management regionalization (EMRZ). Here, an EMRZ scheme for China was devised by outlining regional management using integrated qualitative and quantitative methods. First, the land was subdivided into four environmental management domains using China's three physical geographic domains. Second, using a regionalization indicator system, the environmental characteristics of neighboring provinces in four domains was quantified using the one-dimensional Euclidean distance method; regions with high similarity were merged into one environmental management region (EMR) and the preliminary draft of EMRs was obtained. Based on the preliminary scheme, eight EMRs using prefecture-level administrative regions were obtained through boundary adjustment based on important natural geographical boundaries and existing regional plans. These include the Northeastern China Region, the North China Plain Region, the Loess Plateau Region, Southeast Coast Region, the Middle Reaches of the Yangtze River, the Southwestern China Region, the Northwestern China Region, and the Tibetan Plateau Region. Priority environmental problems of each EMR were discussed. The main contribution of this study is that it develops a novel methodological framework for EMRZ integrating qualitative and quantitative methodologies, and considers the spatial contiguity of each EMR and the spatial integrity of each administrative unit. Future research will focus on priority goals and establishment of suitable environmental management policies for each EMR based on known local environmental problems.

Aerosol optical properties over urban and industrial region of Northeast China by using ground-based sun-photometer measurement

The special and temporal characteristics of aerosol optical depth (AOD) and Angstrom exponent (Alpha) were analyzed by using the data from a CE318 sun-photometer at Shenyang, Anshan, Benxi and Fushun in urban and industrial region of northeastern China. The high AODs over Shenyang and Fushun occurred in the summer and winter with two peaks. In contrast, the monthly averaged AODs at Anshan and Benxi have a single peak distribution. The AOD frequency distribution at Shenyang and Benxi can be well fit by a bi-modal normal distribution with r2 = 0.94 and 0.91. The AOD frequency distribution at Anshan and Fushun have identical peak value at approximately 0.40. The seasonal AOD at Benxi is larger than the other three stations, and the seasonal Alpha at Shenyang is the largest of all stations followed by Anshan, Fushun and Benxi. An analysis of the AOD and Alpha scatterplots suggests that the aerosol size in Shenyang, Anshan, Benxi and Fushun can be affected by both fine and coarse particles.

Tentatively Research on Responsive Design of Architectural Spaces in Cold Region of Northeastern China

This paper takes the cold region as a background and stands on the point of architectural space, to analysis the problem of architecture space design with the use of responsive theory, aiming to explore an architectural space design method and theory to respond the specific climatic conditions.

Effect of Cultivation Pattern on the Light Radiation of Group Canopy and Yield of Spring Soybean (Glycine Max L. Merrill)

Heilongjiang Province is the main soybean-producing area in china. In this study, we analyzed the canopy structure, dynamic characteristics of light radiation and yield of Hefeng50 (the main variety of soybean in Heilongjiang Province) under six different cultivation patterns (ORP, TPCR, ORCP, BRHD, SRHD and FPHD). The results showed that SRHD and BRHD at different growth period (blossom period R1, podding R3 and grain filing period R5) produced an even distribution of the population leaf area, suitable mean foliage inclination angle (MFIA), low transparency coefficients for defuse penetration (TCDP) and transparency coefficients for radiation penetration (TCRP), high leaf area index (LAI), extinction light coefficient (K value), fraction of radiation intercepted (FRI) and light energy utilization rate. Grain number, dry matter weight per plant, and yield of SRHD and BRHD were significantly higher than those of other cultivation patterns. The yield of SRHD, BRHD, ORCP, FPHD and TPCR was increased by 136%, 112%, 79%, 50.1% and 14.7%, respectively, compared to that of ORP. These results suggest that SRHD and BRHD are the optimal cultivation pattern for the improvement of soybean yield in phaeozem region of northeastern China.

Causes for the Formation of Waterlogged Land in the Black Soil Region of Northeastern China

Waterlogged land characterized by low productivity impact the productivity of the adjacent land and increase soil erosion. Gangzhongwa, one type of waterlogged lands, is widely distributed in Jiusan cultivated lands in Heilongjiang province China. Observation of soil profiles and measurements of soil physical properties were carried to investigate the factors related to the waterlogged land formation. The results showed Gangzhongwa waterlogged land is formed due to three reasons: firstly, the water table of groundwater is shallow and the soil profile texture varies regularly from clay loam layer, and sandy loam layer to aquitard layer; secondly soil infiltration is significantly correlated with sand content and gravel content; and thirdly the subsurface runoff makes the soil profile saturated where the surface clay loam layer is thin but the sandy layer is thick with larger infiltration rates. This study presents some theoretical insights for the Gangzhongwa waterlogged land conservation plan.

Interannual variability in soil respiration from terrestrial ecosystems in China and its response to climate change

Soil respiration is an important process in terrestrial carbon cycle. Concerning terrestrial ecosystems in China, quantifying the spatiotemporal pattern of soil respiration at the regional scale is critical in providing a theoretical basis for evaluating carbon budget. In this study, we used an empirically based, semi-mechanistic model including climate and soil properties to estimate annual soil respiration from terrestrial ecosystems in China from 1970 to 2009. We further analyzed the relationship between interannual variability in soil respiration and climatic factors (air temperature and precipitation). Results indicated that the distribution of annual soil respiration showed clear spatial patterns. The highest and lowest annual soil respiration rates appeared in southeastern China and northwestern China, respectively, which was in accordance with the spatial patterns of mean annual air temperature and annual precipitation. Although the mean annual air temperature in northwestern China was higher than that in some regions of northeastern china, a greater topsoil organic carbon storage in northeastern China might result in the higher annual soil respiration in this region. By contrast, lower temperature, less precipitation and smaller topsoil organic carbon pool incurred the lowest annual soil respiration in northwestern China. Annual soil respiration from terrestrial ecosystems in China varied from 4.58 to 5.19 Pg C a−1 between 1970 and 2009. During this time period, on average, annual soil respiration was estimated to be 4.83 Pg C a−1. Annual soil respiration in China accounted for 4.93%–6.01% of the global annual soil CO2 emission. The interannual variability in soil respiration depended on the interannual variability in precipitation and mean air temperature. In order to reduce the uncertainty in estimating annual soil respiration at regional scale, more in situ measurements of soil respiration and relevant factors (e.g. climate, soil and vegetation) should be made simultaneously and historical soil property data sets should also be established.

Phylogeographic analyses of Phragmites australis in China: Native distribution and habitat preference of the haplotype that invaded North America

Abstract Phragmites australis is a cosmopolitan clonal species, but one haplotype from Eurasia has become highly invasive in North America. This article describes an investigation of the phylogeographic composition of 77 populations from China, based on the sequencing of two chloroplast non‐coding DNA regions. A total of 11 haplotypes were detected, based on the sequence alignments of two chloroplast DNA fragments from 421 sampled individuals. Six of these haplotypes were completely new, and did not correspond to any of this species’ 27 previously known haplotypes. The invasive haplotype M and haplotypes O and P were shown to occur frequently. Haplotype O is widely distributed across all regions and probably represents the primitive haplotype of this species. In contrast, P is mainly distributed in the humid eastern and northeastern regions of China, whereas M is more frequent in western and northwestern China—arid habitats with low precipitation. Between eastern and northeastern and western and northwestern regions, there was distinct genetic differentiation; the former region has a higher genetic diversity than the latter. The high occurrence of haplotype M in western China suggests that it prefers more arid habitats. These findings shed new light on the native distribution, adaptation, and habitat preference of haplotype M, which invaded North America.

S-wave velocity structure of northeastern China from joint inversion of Rayleigh wave phase and group velocities

SUMMARY We imaged the crust and uppermost mantle structure beneath northeastern (NE) China with fundamental mode Rayleigh waves recorded by 125 broad-band stations deployed in the region. Rayleigh wave phase and group velocities along more than 700 interstation paths were estimated using the wavelet transformation method and then these data were utilized to construct 2-D phase and group velocity maps in the period range of 15–60 s. Owing to the dense ray coverage and short ray path, our results provide better lateral resolution in the NE China region compared with previous phase and group velocity studies. The regularized Rayleigh wave phase and group velocity dispersions at each cell were jointly inverted to determine 1-D shear wave velocity structure using the linear inversion method and then assembled into a 3-D model. Our results show that obvious low velocities exist in the uppermost mantle beneath the Changbaishan volcanic region, which may be due to asthenospheric upwelling. The thin lithosphere with fast S-wave velocity in the lower crust of the Songliao Basin implies that the lithospheric mantle beneath NE China is partly removed.

Seasonal and Interannual Variations of Evapotranspiration and Energy Exchange over Different Land Surfaces in a Semiarid Area of China

AbstractSeasonal and interannual variations of evapotranspiration (ET) and energy exchange were estimated over degraded grassland and cropland land surfaces in a semiarid region of northeastern China using the eddy covariance technique from 2003 to 2008. The peak daily ET, which occurred in August, was 1.5–4.5 mm day−1for the degraded grassland and 1.5–5.5 mm day−1for the cropland land surface. Annual cumulative ET was roughly equal to annual precipitation at both sites. However, the annual cumulative ET at the cropland site was slightly larger (about 10–30 mm) than it was at the grassland at the end of each year. More water might come from irrigation at seedtime and from the soil. With the factor analysis technique, the results revealed that the atmospheric water demand was the most important factor in the ET process on a half-hour time scale in this semiarid area. On a seasonal time scale, ET was greatly constrained by surface conductance and precipitation; on an annual time scale, ET was greatly constrained by the total amount of precipitation at both sites. The accuracy of ET estimation using the Penman–Monteith formula in this semiarid area was also discussed.

Characterization of Full-Length Enterovirus 71 Strains from Severe and Mild Disease Patients in Northeastern China

Human enterovirus 71 (EV71)-associated hand, foot, and mouth disease (HFMD) has been a leading cause of childhood infection in China since 2008. Epidemic and molecular characteristics of HFMD have been examined in many areas of China, including the central and southern regions. However, clinical and genetic characterization of EV71 in the northeastern region of China is scarce. In this study, a series of analyses were performed on seven full-length EV71 sequences from HFMD patients who had either severe or mild disease. We have determined that these seven circulating EV71 viruses from Changchun, China are actually complex recombinant viruses involving multiple type A human enterovirus (HEV). Classified as EV71 subtype C4 (EV71 C4), these Changchun EV71 viruses contain genetic recombination events between the CA4, CA5, EV71B4 and EV71C1 strains. Most of the structural protein region (P1) of these viruses resembled that of the prototype EV71 C1 strains. The non-structural protein domains (P2 and P3) showed a high degree of similarity with CA4, CA5 and EV71 B4 in different regions. The 5′UTR had unclassified recombination,while partial 3D region of these viruses showed a high degree of similarity to CA16. Phylogenetic analysis of full-length or partial sequences of isolates from severe or mild disease patients in Changchun always formed a single cluster in various phylogenetic analyses of different genomic regions, suggesting that all seven strains originated from one single common ancestor. There was no correlation between viral genomic sequence and virulence. Thus, we found that circulating recombinant forms of EV71 are prevalent among HFMD patients in Northeastern China. The existence of a unique cluster of EV71 related viruses in Northeast China has important implications for vaccine development that would address the increasing prevalence of HFMD.

SEMA3A rs7804122 polymorphism is associated with Hirschsprung disease in the Northeastern region of China

Hirschsprung disease (HSCR) is a congenital disorder characterized by an absence of intrinsic ganglion cells in the nerve plexuses of the lower colon. Our previous results showed increased semaphorin 3A (SEMA3A) expression may be the risk factor for HSCR pathology in a subset of patients. Therefore, the association between polymorphisms in SEMA3A and the risk of HSCR was examined. The genotypes of two SNPs (rs7804122 and rs797821) in the SEMA3A gene in 119 patients with HSCR and 93 controls were examined using PCR-sequencing to determine the contribution of SEMA3A to the HSCR phenotype. PCR reaction with cDNA template was also used to find out whether a novel mutation (Chr7:83634610A→T) influences the SEMA3A pre-mRNA splicing. Genotypes comprising allele G of rs7804122 (GG or AG) were over-represented in patients (48.74 vs. 24.8%; p = 0.0013) which indicated that the risk of HSCR was significantly higher among subjects with the GG or AG genotype than among the subjects with the AA genotype. No statistically significant associations were found for SNP rs797821 at the allele or genotype levels. The differences in genotypes and allele distributions of rs7804122 and rs797821 between various clinical classifications were not statistically significant. The novel heterozygous mutation (Chr7:83634610A→T) 30bp away from an intron/exon boundary, had no detectable effect on splicing efficiency. Our results for rs7804122 provided preliminary evidence that the SEMA3A gene is involved in the susceptibility to HSCR in the Northeastern Chinese population.