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This paper presents new research on a lacustrine anoxic event (LAE). These data include stable carbon isotope (δ13Corg), pyrite sulfur isotope (δ34Spy), trace element and biomarker ratios from the Hongmiaozi Basin (North China) and unravel the response of continental lakes under the influence of early Aptian extreme climate conditions. According to the stratigraphic chronology (122–118 Ma) and carbon isotope correlations, terrestrial sediment was influenced by the early Aptian Oceanic Anoxic Event (OAE1a). The results show that the Xiahuapidianzi Group experienced a significant warming process under negative excursions in carbon isotopes due to the influence of increased carbon dioxide partial pressure (pCO2). The climate varied from warm and humid to hot and arid (high Sr/Cu, low Rb/Sr, calcareous mudstone), the evaporation and salinity increased (high Sr/Ba and B/Ga), and land input sources decreased (low Zr, Ti and Th). Moreover, high total organic carbon (TOC) content was source from bacteria, algae (n-alkanes), and euxinic depositional environments (Pr/Ph, Cu/Zn and U V Mo). In the stage of continuous carbon isotopes positive excursion, organic matter accumulated rapidly. A paleolake environment model has provided a better understanding of current global climate issues under global warming caused by increased carbon dioxide concentrations. [ABSTRACT FROM AUTHOR]

In this paper, hindcast experiments were carried out on the snowfall that occurred on 12-13 April 2010 in Northeast China using the WRF model. Three land surface parameterization schemes (Noah, Noah-MP, and SSiB) and three microphysics schemes (WSM5, Lin, and CAM5.1) were chosen for nine ensemble members. The results indicate that spatial distribution of snowfall is sensitive to the choice of land surface schemes. The Noah-MP land surface scheme yields the smallest spatial distribution among the three land surface schemes. The simulations with the Noah and Noah-MP land surface schemes are better than those with the SSiB land surface scheme in terms of spatial correlation coefficient. Microphysics schemes have an influence on snowfall amount in the nine simulation experiments. The Lin and CAM5.1 microphysics schemes lead to much less snowfall than the WSM5 microphysics scheme. Overall, the ensemble means of simulations with three different land surface schemes can capture the features of snowfall distribution, especially when combined with the CAM5.1 microphysics scheme. [ABSTRACT FROM AUTHOR]

Following a description of the climatology of the boreal summer persistent low temperature (LT) events of the Northeast (NE) China, this paper explores the synoptic characteristics of these events by decomposing atmospheric variables into three components: the daily climate, the zonal-averaged anomaly and the synoptic-scale anomaly. The synoptic-scale anomaly is used to construct the anomalous synoptic charts which tend to perform better compared to traditionally defined synoptic charts in terms of revealing synoptic characteristics of these LT events. Based on the analysis of 21 persistent LT events occurring during summers of 1961-2008 in NE China, we show that temperature anomaly at 850 hPa and geopotential height anomaly at 300 hPa were two critical early signals prior to the occurrences of these persistent LT events. [ABSTRACT FROM AUTHOR]

In this paper, we report new whole-rock geochemical and zircon U-Pb data for monzogranites in the NE Xing’an block. These data constrained the petrogenesis of C type (high Sr/Y) adakitic rocks and showed the spatial extent of the influence of the Mongol-Okhostsk ocean tectonic regime and the collision between the Jiamusi Massif and Songliao Terrane. New zircon laser-ablation inductivity coupled plasma mass spectrometry (LA-ICP-MS) U-Pb data indicated that the monzogranites in the studied area were emplaced in the Early Jurassic (~180 Ma). These rocks were characterized by unusally high SiO2 (≥67.49), and Sr (461-759 ppm), but strikingly low Y (4.63-8.06 ppm) and HREE (∑HREE = 3.83-6.49 ppm, Yb = 0.5-0.77 ppm) contents, with therefore high Sr/Y (67.2-119) and (La/Yb)N (29.7-41.5) ratios, showing the geochemical characteristics of C type adakitic granite. The data displayed negligible Eu anomalies (Eu/Eu* = 0.77-1.08), LREE-enriched and pronounced negative Nb and Ta anomalies. The C-type adakites in the studied area were most likely derived from the partial melting of a thickened lower continental curst. The magma source is most likely dominated by amphibolites and garnet amphibolites. In combination with previously-reported data from igneous rocks from the Mesozoic in NE China, we conclude that the Xing’an block was influenced by the Mongol-Okhotsk subduction tectonic system, and experiences compressive settings from the amalgamation of the Jiamusi block in the east of the CAOB. [ABSTRACT FROM AUTHOR]

Long-term dynamics of population decline can improve the conservation perspectives and strategies for endanger species. In China, new gazetteers having systematic compilation and wide geographical coverage can be considered as an important complementary for reconstruction historical distribution. For historical and cultural reasons, an endangered species-lynx ( Lynx lynx) was recorded regularly in new gazetteers. Therefore, the aim of this paper was to evaluate the population distribution in Northeast China from the 1950s to 2014. The data show that Felis lynx was widely distributed in Northeast China in the 1950s, but the number of the occurrence records have been significantly reduced by 85.6% in the last 60 years. This research also enlightens us that the new gazetteers can contribute to data shortage and it would be helpful to conservation biology. [ABSTRACT FROM AUTHOR]

The cut-off lows (COLs) during the period from June to August 1998 leading to the record flood in Northeast Asia, especially in Northeast China, has been investigated in this paper. The results are as follows: the blocking highs benefited significantly the formation and maintenance of COLs over Northeast China; an obvious frontogenesis zone existed in Northeast China and it implies that baroclinity played an important role in the initiation of COLs, especially in middle and upper troposphere; the maxima of the potential vorticity anomaly were located in the upper troposphere, then extended downwards to the middle and the lower troposphere. The pronounced interaction between systems in upper-middle and low troposphere can be revealed; the moisture supply was from South China, and even from East China Sea and South China Sea. The strong southerly current transported very rich moisture to Northeast China. The maximum of the convergence of moisture flux was below 850 hPa. Obvious interaction between the middle and lower latitude systems was found in the study. Also, the summer monsoon showed significant impacts on the sustained heavy rainfalls related with the COLs over Northeast China; the upward motion could be caused by the lifting of the large scale dynamic forcing and there was no obvious releasing of latent heating in the upper-middle troposphere. The cold dome in the COLs was quite different both from the warm core in tropical cyclone and from the weaker warm core in Meiyu (Baiu) front low. The calculation of vorticity budget shows that both the horizontal advection term and horizontal divergence term contributed importantly to the maintenance and the strengthening of positive relative vorticity. Finally, the complex dynamical characteristics regarding the COLs are discussed and further investigation is proposed. [ABSTRACT FROM AUTHOR]

Nowadays, environment problem has become the international hot issue. Experts and scholars pay more and more attention to the energy efficiency. Unlike most studies, which analyze the changes of TFEE in inter-provincial or regional cities, TFEE is calculated with the ratio of target energy value and actual energy input based on data in cities of prefecture levels, which would be more accurate. Many researches regard TFP as TFEE to do analysis from the provincial perspective. This paper is intended to calculate more reliably by super efficiency DEA, observe the changes of TFEE, and analyze its relation with TFP, and it proves that TFP is not equal to TFEE. Additionally, the internal influences of the TFEE are obtained via the Malmquist index decomposition. The external influences of the TFFE are analyzed afterward based on the Tobit models. Analysis results demonstrate that Heilongjiang has the highest TFEE followed by Jilin, and Liaoning has the lowest TFEE. Eventually, some policy suggestions are proposed for the influences of energy efficiency and study results. [ABSTRACT FROM AUTHOR]

Introduction: The transport of full containers and repositioning of empty containers are essential for the operation of a container logistic enterprise. In a large inland region, railway and road transportation take their own advantages for container transportation in terms of transport efficiency and costs. The combination of the two modes creates larger possibility for logistic enterprise to provide efficient service and reduce operation costs. Thus, this paper aims to optimize the inland intermodal transportation of full and empty containers.Methods: Different from cost minimum model, an integer programming model is proposed based on revenue management, making the model more reasonable in practice where logistic enterprises have the right to reject transportation demands from customers considering transport profits and capacity limitations. The real cases of transportation networks of Northeast China and parts of the southern Europe are applied to evaluate and describe the model and performance.Results: The results indicate that the proposed intermodal transportation optimization for both full and empty containers is feasible and profitable for logistic enterprises. The efficiency of container usage increases since we take the conversion of containers during transportation into account. Results also imply an inappropriate pricing strategy at certain inland depots in the case.Conclusions: This paper provides an optimization method for the intermodal transportation of full and empty containers in harbor-inland regions / hinterlands. Different from cost minimization in the literature, this paper models the transportation problem based on revenue management. That is, the model aims to maximize profits of logistic enterprise with the specific constraints in container transportation, as well as demand rejection. The model is proofed to be feasible in the real transportation networks and can create more profits for transportation enterprises. The analysis of real cases show that the total profits can be enlarged by considering the conversion of containers during transportation. In addition, it is verified that the optimization of inland transportation of empty and full containers reduces the operating costs of logistic enterprises. Moreover, results uncover the fact that a governed pricing policy at Suifenhe is not reasonable and may deteriorate the future export environment there. For the case based on part of southern Europe, it seems that the port, customer, inland transport operator and possibly container shipping company in Europe may benefit by establishing appropriate inland depots. [ABSTRACT FROM AUTHOR]

The evaluation of conservation effectiveness for wetland protected areas (WPAs) is essential to underpin knowledge-based conservation policies and funding decisions by government and managers. In this paper, the conservation effectiveness for 28 WPAs in Northeast China from 2000 to 2012 was quantitatively evaluated using landsat thematic mapper image data and a maximum entropy model (Maxent). The spatial distribution of conservation effectiveness and the influence of human activities on conservation effectiveness were determined by combining a landscape development intensity (LDI) index and spatial analysis in a geographical information system. The results showed that the natural wetland area of all WPAs in Northeast China declined by 11.5 % and the conservation effectiveness of most of these WPAs decreased between 2000 and 2012. A significant negative correlation between the LDI index and conservation effectiveness ( r = −0.824, p < 0.01) suggested that human activities were responsible for the low conservation effectiveness of WPAs. The WPAs with the high conservation effectiveness were mainly located in the Da-Xing'an and Xiao-Xing'an Mountains, where anthropogenic activities were limited. The reduction in the conservation effectiveness of WPAs in the Songnen and Sanjiang Plains, which showed the most degradation, was due to conversion of wetlands to croplands. This research offers an efficient and effective method to evaluate the conservation effectiveness of WPAs. The results of this study will inform future ecological conservation and management of WPAs in China. [ABSTRACT FROM AUTHOR]

Zircon U-Pb ages, Hf isotope data and whole-rock major and trace element data for the Middle to Late Ordovician gabbros and granites in the Erguna Massif, NE China were presented in this paper. The petrogenesis of these rocks and the Early Paleozoic tectonic evolution of the massif were discussed. Zircons from the granites and gabbros are of magmatic origin based on their cathodoluminescence (CL) images. The Pb/U ages obtained from 20 spots on zircons from the granites range from 446±9 to 464±10 Ma, yielding a weighted mean age of 455±10 Ma; and 16 spots on zircons from the gabbros range from 465±10 to 466±7 Ma, yielding a weighted mean age of 465±2 Ma. Chemically, the Late Ordovician granites in the Erguna Massif are weakly peraluminous and similar to A-type granites. The granites and gabbros are all enriched in light rare earth elements and large ion lithophile elements (e.g., Rb, K), and depleted in heavy rare earth elements and high field strength elements (e.g., Nb, Ta, and Ti); they all exhibit marked negative Eu anomalies. Their zircon ɛ( t) values range mainly from +1.86 to +6.21 (for the granites) and +1.39 to +3.89 (for the gabbros), except for one spot with a value of −0.27 (for a gabbro). The T ages for the gabbros and T ages for the granites vary from 928 to 1 091 Ma and from 1 287 to 1 675 Ma, respectively. It is concluded that the primary magma of the granites could have been derived by partial melting of Mesoproterozoic newly accreted crustal material, whereas the primary magma of the gabbros originated by partial melting of a depleted mantle wedge that had been metasomatized by fluids derived from a subducted slab. These Middle-Late Ordovician granites and gabbros constitute a typical bimodal igneous rock association, implying an extensional environment that was probably related to the post-collisional development of the Erguna and Xing'an massifs in the early Early Paleozoic. [ABSTRACT FROM AUTHOR]

This paper reports the analysis on cores and rock slices, data on seismic and logging activities, characteristics of core samples, and the paleogeographic background of the Yingcheng Formation of the Xujiaweizi faulted depression in the Songliao Basin. The results show that some of the volcanic rocks were formed during subaquatic eruptions. These subaqueous volcanic rocks are further characterized by the interbedded black mudstone and tuffite, the presence of double-layer perlite enclosing aphyric or sparsely phyric rhyolite, the presence of a bentonite layer, and the coefficient of oxidation (FeO/FeO). The types of rocks are volcanic breccia, lava breccias, perlite, rhyolite, tuff and sedimentary tuff. The subaquatic eruptions are distributed mainly in Wangjiatun, Shengping, Xuxi, Xuzhong, and Xudong. The XS-1 area is the most typical. The organic abundance of overburden mud rocks within the volcanic rocks of the Yingcheng Formation indicates that these rocks represent high-quality source rocks. The analysis also shows that continental subaquatic volcanic eruptions provide a rich supply of minerals and energies for the lake basin and increase the organic matter content in the water. Moreover, the water differentiation provides a good reducing environment for the conservation of organic matter, and is beneficial for the formation of high-quality source rocks. Finally, we propose a hypothesis to describe the mode of subaquatic eruptions and the formation of high-quality source rocks. [ABSTRACT FROM AUTHOR]

By using crater impact morphological theory and mathematics modeling, the paper studies the cratering process and morphological features of the Xiuyan Crater in Northeast China based on remote sensing imagery, digital elevation model (DEM) and drilling and measuring data. The results show that: 1) Simulated calculation indicates the diameter of the transient crater was 1406±12 m and the depth was 497±4 m. The diameter of the final crater was 1758±15 m and the depth was 374.5±3.5 m; the thickness of the breccia lens was 188.5±0.5 m. The data is basically the same as previous drilling data. 2) Preliminary determination of the size of Xiuyan impactor: The diameter at about 55 m for an iron meteorite, and about 115 m for a stony meteorite. 3) The depth-to-diameter ratio is 0.143, similar to the typical simple crater. The circularity index of the Xiuyan Crater is 0.884, indicating erosion and degradation. 4) The distribution pattern of radial fractures has priority in NW-SE and WNW-ESE and these fractures control the development and evolution of drainage inside the crater. [ABSTRACT FROM AUTHOR]

This paper investigates monthly and seasonal precipitation-temperature relationships (PTRs) over Northeast China using a method proposed in this study. The PTRs are influenced by clouds, latent and sensible heat conversion, precipitation type, etc. In summer, the influences of these factors on temperature decrease are different for various altitudes, latitudes, longitudes, and climate types. Stronger negative PTRs ranging from −0.049 to −0.075 °C/mm mostly occur in the semi-arid region, where the cold frontal-type precipitation dominates. In contrast, weaker negative PTRs ranging from −0.004 to −0.014 °C/mm mainly distribute in Liaoning Province, where rain is mainly orographic rain controlled by the warm and humid air of East Asian summer monsoon. In winter, surface temperature increases owing to the release of latent heat and sensible heat when precipitation occurs. The stronger positive PTRs ranging from 0.963 to 3.786 °C/mm mostly occur at high altitudes and latitudes due to more release of sensible heat. The enhanced atmospheric counter radiation by clouds is the major factor affecting increases of surface temperature in winter and decreases of surface temperature in summer when precipitation occurs. [ABSTRACT FROM AUTHOR]

In Northeast China during the winter, severe snowstorms can occur resulting in both societal and economic damage. In this paper, we explore an effective technique for the seasonal prediction of heavy snow activity, where previous synoptic studies have failed. We employ a year-to-year increment approach and ultimately identify four predictors, x to x. x is the area-averaged soil moisture over the northern part of Northeast China in the preceding month of September and represents the role of land processes. x represents the role of sea-air interactions in winter, x the preceding summer Mascarene High related to the winter SST over the tropical western Pacific, and x is the low-level the thermal condition over Northeast China from the previous year that oppose current year. Cross-validation tests for both 1963-2011 and independent hindcasts between 1983-2010 are performed to validate the prediction ability of our technique. The cross validation test results for 1963-2011 reveal a high correlation coefficient of 0.86 (0.77) between the predicted and observed year-to-year increment of the number of snow days. The model also predicts well the independent hindcast for the years 1983-2011. Therefore, this study provides an effective climate prediction model for Northeast China's heavy snow activities and thus requires preliminary application in operational settings. [ABSTRACT FROM AUTHOR]

This paper reviews the current evidence for settlement patterns and ceremonial activity amongst Hongshan Neolithic groups in northeastern China, with particular attention to the well-known ceremonial site at Niuheliang. We consider the location of Hongshan ceremonial sites in their wider landscape settings, arguing that such sites are a chronologically late stage of Hongshan ceremonial investment and that, within these broad complexes, the most impressive architecture and portable goods come from an especially late phase of activity. These more impressive localities were also particularly privileged places in terms of their access to major routes, specific kinds of local geology and integrated patterns of visibility. In contrast to more loosely organized Hongshan residential sites of similar size, ceremonial centres such as Niuheliang (and, within these, certain important sub-localities) clearly functioned as key mechanisms for social, political and regional stratification around roughly the mid 6th millennium BP. [ABSTRACT FROM AUTHOR]

This paper analyzes the large-scale atmospheric circulation characteristics of anomalous cases of January temperatures that occurred in Northeast China during 1960-2008 and precursory oceanic conditions. The January monthly mean surface air temperature (SAT) anomalies and the duration of low temperature are used to define temperature anomaly cases. The anomalous cyclonic circulation over northeast Asia strengthens the northerly flow in cold Januarys, while the anomalous anticyclonic circulation weakens the northerly flow in the warm Januarys. The negative (positive) North Pacific sea surface temperature anomaly (SSTA) and increased (decreased) sea ice concentration in the Barents-Kara seas in the preceding month are probably linked to the cyclonic (anticyclonic) circulation pattern over northeast Asia in the cold (warm) cases. Further analyses indicate that the preceding oceanic conditions play distinct roles in the SAT anomalies over Northeast China on different time scales. Strong relationships exist between North Pacific SSTA and the SAT in Northeast China on the interannual time scale. On the other hand, the sea ice concentration is more closely associated with the interdecadal variations of SAT in Northeast China. [ABSTRACT FROM AUTHOR]

The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni) in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China, for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis (PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability, while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals. [ABSTRACT FROM AUTHOR]

In the study, we analyze and assess quantitatively the spatial pattern of vegetation and its ecological degradation information in the Honghe National Nature Reserve (HNNR), a Ramsar-designated site in Northeast China. Statistics from historical survey data are used to measure the degradation of marshes over time and changes in the hydrological regime. Long-term statistical data are also employed to analyze both natural and human impacts on these changes. Both the wetland degradation model and its mechanisms are discussed in this paper. The research finds that the loss of water and other types of degradation in the vegetation habitat caused by the rapid deterioration of the hydrological regime has threatened the status of HNNR as a “storage area of natural genes.” Scientifically constructed strategies are urgently required to ensure sustainable economic benefits that do not adversely affect this nature reserve. [ABSTRACT FROM AUTHOR]

The Songhua Lake in the Northeast China is chosen as a study case in this paper. Monitoring of samples and analysis 18 indexes related to the eutrophication in the Songhua Lake had been conducted in 2002–2004. Ecological risk assessment methods are employed here. The study results showed that total phosphorus and total nitrogen were main risk factors to impact on the eutrophication of the Songhua Lake, and influence of the phosphorus on the lake eutrophication was larger than that of nitrogen. Algal growth potential test was also conducted to validate the results. High phosphorus and high nitrogen concentrations were mostly distributed in Huifahekou and Jiaohe sites of the Songhua Lake. Threshold values of total phosphorus, total nitrogen and Chl-a concentrations from dose-effective examination were 0.065 mg/L, 0.843 mg/L, and 11.90 μg/L, respectively. The probability of the eutrophication appeared in the Songhua Lake was 0.69, of them, risk-free type area was 19.21% of total lake area, slight risk type area was 30.10%, middle risk type area was 16.50%, heavy risk type area was 25.8%, hyper risk type area was 8.39%. In order to control the eutrophication in the Songhua Lake, maximum permission discharges of total phosphorus and total nitrogen to the lake would be 2,123.78, 7,018.82 t/a, respectively. [ABSTRACT FROM AUTHOR]

Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932-1954 and 1954-1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976-2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters. [ABSTRACT FROM AUTHOR]

This paper develops a conceptual model and an indicator system for measuring economic resilience of resource-based cities based on the theory of evolutionary resilience and the related concepts of persistence, adaptation, and transformation. Nineteen resource- based cities in Northeast China were analyzed using the indicator system. The results showed that Liaoning and Jilin provinces had higher economic resilience than Heilongjiang Province. Panjin, Benxi, and Anshan in Liaoning Province were the top three cities, while Shuangyashan and other coal-based cities in Heilongjiang Province ranked last. Metals- and petroleum-based cities had significantly higher resilience than coal-based cities. The differences in persistence, adaptability, transformation, and resilience among resource-based cities decreased since the introduction of the Northeast Revitalization Strategy in 2003. Forestry-based cities improved the most in terms of resilience, followed by metals-based and multiple-resource cities; however, resilience dropped for coal-based cities, and petroleum-based cities falling the most. The findings illustrate the importance and the way to develop a differentiated approach to improve resilience among resource-based cities. [ABSTRACT FROM AUTHOR]

A 3-year fixed site experiment was carried out on a Planosol in Northeast China to study the effects of biochar and controlled-release nitrogen fertilizer on rice yield, nitrogen-use efficiency, residual nitrogen, and nitrogen balance in soil-crop system. Five treatments were established: control (CK), bare urea (BU), controlled-release urea (CRU), 50% BU + 50% CRU (MBC), and 50% BU + 50% CRU + biochar (MBCB) treatments. The results showed that, compared with the BU treatment, the yield, N-use efficiency (NUE) and N agronomic efficiency (NAE) of the CRU treatment increased by 12.2%, 33.9% and 4.3 kg kg−1, respectively; while the soil residual N and N surplus at harvest decreased by 11.6% and 10.7%, respectively. Compared with the MBC treatment, the yield, NUE and NAE of the MBCB treatment increased by 10.2%, 16.5% and 4.0 kg kg−1, respectively; while the soil residual N and N surplus at harvest decreased by 10.8% and 12.3%, respectively. Therefore, mixed application of bare urea, controlled-release urea and biochar was effective for obtaining high rice yield, and high fertilization efficiency as well as for sustainable agricultural development in Northeast China. [ABSTRACT FROM AUTHOR]

Historical thematic maps and remote sensing data were applied to address spatiotemporal dynamics of land use/land cover (LULC) changes and its impact on wetlands sustainability based on eight LULC datasets from 1954 to 2015 in Baoqing County, Northeast China. This study demonstrated that LULC drastically changed in the past six decades due to conversion of wetlands, woodland, and grassland into cropland. The cropland was 578.8 km2 in 1954, accounting for 5.8% of the area in Baoqing County, and it increased to 54.3% in 2015, which was nearly equivalent to 9.4 times of that in 1954. Cropland increased 4843.6 km2 from 1954 to 2015 with average increased area of 79.4 km2/yr. The conversion of wetlands was the main reason for cropland increase (49.7%), and woodland (18%) and grassland (16.3%) conversion were other reasons. Results also revealed that 78% of wetlands were lost during the past six decades, of which 91.2% were converted cropland. Population increasing (population across Baoqing in 2015 was 7.8 times of that in 1949), agricultural technology development was the main reason for cropland increase, institutional and economic policies also played important roles for cropland dynamics, particularly paddy field influenced by market price. Agricultural development has caused severe wetlands degradation both in area and functionality, and still being the major threads for wetlands sustainable development. Several suggestions concerning the future land use policy formulation and wetlands sustainability were proposed. They are adjusting the 'food first' agricultural policy, reinforce management for wetlands nature reserves, creating infrastructure for the rational use of surface and groundwater, harnessing the degraded cultivated land. [ABSTRACT FROM AUTHOR]

To study the land surface and atmospheric meteorological characteristics of non-uniform underlying surfaces in the semi-arid area of Northeast China, we use a “High-Resolution Assimilation Dataset of the water-energy cycle in China (HRADC)”. The grid points of three different underlying surfaces were selected, and their meteorological elements were averaged for each type (i.e., mixed forest, grassland, and cropland). For 2009, we compared and analyzed the different components of leaf area index (LAI), soil temperature and moisture, surface albedo, precipitation, and surface energy for various underlying surfaces in Northeast China. The results indicated that the LAI of mixed forest and cropland during the summer is greater than 5 m2 m−2 and below 2.5 m2 m−2 for grassland; in the winter and spring seasons, the Green Vegetation Fraction (GVF) is below 30%. The soil temperature and moisture both vary greatly. Throughout the year, the mixed forest is dominated by latent heat evaporation; in grasslands and croplands, the sensible heat flux and the latent heat flux are approximately equal, and the GVF contributed more to latent heat flux than sensible heat flux in the summer. This study compares meteorological characteristics between three different underlying surfaces of the semi-arid area of Northeast China and makes up for the insufficiency of purely using observations for the study. This research is important for understanding the water-energy cycle and transport in the semi-arid area. [ABSTRACT FROM AUTHOR]

A new species of Microterys Howard (Hymenoptera: Encyrtidae), M. angustus Zu, Li & Wang sp. nov., is described from China as a parasitoid of Parthenolecanium corni (Bouché) (Hemiptera: Coccidae) on Acer saccharum Marsh. and Sophora japonica Linn.. [ABSTRACT FROM AUTHOR]

Global warming has caused unevenly distributed changes in precipitation and evapotranspiration, which has and will certainly impact on the wet-dry variations. Based on daily meteorological data collected at 91 weather stations in Northeast China (NEC), the spatiotemporal characteristics of dry and wet climatic variables (precipitation, crop reference evapotranspiration (ET0), and humid index (HI)) are analyzed, and the probable reasons causing the changes in these variables are discussed during the period of 1961-2014. Precipitation showed non-significant trend over the period of 1961-2014, while ET0 showed a significant decreasing trend, which led to climate wetting in NEC. The period of 2001-2012 exhibited smaller semiarid area and larger humid area compared to the period of 1961-1980, indicating NEC has experienced wetting process at decadal scale. ET0 was most sensitive to relative humidity, and wind speed was the second most sensitive variable. Sunshine hours and temperature were found to be less influential to ET0 in the study area. The changes in wind speed in the recent 54 years have caused the greatest influence on ET0, followed by temperature. For each month, wind speed was the most significant variable causing ET0 reduction in all months except July. Temperature, as a dominant factor, made a positive contribution to ET0 in February and March, as well as sunshine hours in June and July, and relative humidity in August and September. In summary, NEC has experienced noticeable climate wetting due to the significantly decreasing ET0, and the decrease in wind speed was the biggest contributor for the ET0 reduction. Although agricultural drought crisis is expected to be partly alleviated, regional water resources management and planning in Northeast China should consider the potential water shortage and water conflict in the future because of spatiotemporal dry-wet variations in NEC. [ABSTRACT FROM AUTHOR]

Sprites are brief optical emissions occurring above thunderstorms. Features of sprites and their parent thunderstorms and lightning activities have been studied by many researchers. Here, we report a single sprite recorded over a mesoscale convective system during its life cycle in Northeast China. The results show that the sprite might have been a dancing one, with a 20 km horizontal displacement from its parent cloud-to-ground flash (CG) and a 38 ms time delay; all the sprite elements occurred during the continuing current process of the parent flash. The peak current of the parent CG was the largest during the almost one-hour time window containing the sprite, and the absolute values of all the negative flashes were smaller than 100 kA during the same time period and did not produce sprite. The sprite did not occur during the time period in which the maximum area of the thunderstorm reached. The occurrence of sprite corresponded well with the decay of the thunderstorm convection, and no significant relationship between the occurrence of sprite and the increase in the 30-35 dBZ and 35-40 dBZ interval was found. The large wind gradient in the 8-12 km region of the thunderstorm may have played an important role in the sprite production. [ABSTRACT FROM AUTHOR]

Due to high intensity agricultural exploitation since the middle of the 20th century, farmland gullies have become a pervasive form of water erosion in Northeast China. Yet few researches are concentrated on how topography and land use affect long-term gully development in this region. In this study, gully distribution in a village with an area of 24.2 km in the central Mollisols area of Northeast China in different times were compared by Aerial photography (1968), Quickbird image (2009) and field survey, and factors affecting gully development including land use and topography were analyzed. The results showed that the total gully number decreased from 104 to 69, while occupying area rose from 34.8 ha to 78.4 ha from 1968 to 2009. Fundamental gully distribution had been formed by 1968 as most of 2009′s gullies were evolved from 1968′s gullies′ merge and width expansion process, and new gullies those initiated after 1968 occupied only 7% of total gully area in 2009. Gully area increasing ratio in grassland was the highest and that in forestland was the lowest. The threshold catchment area between simple and complex gully development was around 15 ha to 25 ha. This threshold value sets apart catchment areas that will develop simple or complex gullies in areas with similar environmental conditions. Gully control measurements were urgent because if appropriate gully control implements would not be applied, present gully erosion crisis could be doubled within 50 years. [ABSTRACT FROM AUTHOR]

Background: In a continuous spring maize system in Northeast China, the accumulation and succession characteristics of nitrate in Mollisol with four fertilization treatments, including no fertilization (CK), farmers' conventional fertilization (FC), recommendation fertilization (RF), and controlled release fertilizer application (CRF), were compared over a 6-year field plot trial. Results: On average, the RF and CRF treatments decreased nitrate nitrogen by 16.6 and 39.5 % in the 0-90 cm soil layer, respectively, and maintained a relatively high maize grain yield, as compared to the FC treatment. The accumulation of nitrate nitrogen was more obvious in the CRF treatment compared with the other fertilizer treatments under the arid climate. However, the high precipitation resulted in the leaching of nitrate nitrogen into the deeper soil layer in all the fertilizer treatments. The maximum of nitrate nitrogen in the 0-90 cm soil layer was 81.4 kg N/ha at a nitrogen fertilizer rate of 250 kg N/ha in the long-term trial, which was within the rational and safe level for groundwater. Conclusions: The best fertilization strategy to decrease nitrate accumulation in soil should consider both soil characteristics and precipitation. [ABSTRACT FROM AUTHOR]

The overall goal of this study was to understand carbon (C) stock dynamics in four different-aged Japanese larch ( Larix kaempferi) plantations in Northeast China that were established after clear-cutting old-growth Korean pine deciduous forests. Four Japanese larch plantations which were at 10, 15, 21, and 35 years old and an old-growth Korean pine deciduous forest which was 300 years old in Northeast China were selected and sampled. We compared the C pools of biomass (tree, shrub and herb), litterfall (LF), and soil organic carbon (SOC) among them. The biomass C stock of larch plantation at 10, 15, 21, and 35 years old was 26.8, 37.9, 63.6, and 83.2 Mg/ha, respectively, while the biomass C stock of the old-growth Korean pine deciduous forest was 175.1 Mg/ha. The SOC stock of these larch plantations was 172.1, 169.7, 140.3, and 136.2 Mg/ha respectively, and SOC stock of 170.4 Mg/ha in the control of old-growth forest. The biomass C stock increased with stand age of larch plantations, whereas SOC stock decreased with age, and C stock of LF did not change significantly ( P > 0.05). The increase of biomass C offset the decline of SOC stock with age, making total carbon stock (TCS) of larch plantations stable from stand ages of 10-35 years. The TCS in larch plantations was much smaller than that in the old-growth forest, suggesting that the conversion of old-growth forests to young larch plantations releases substantial C into the atmosphere. [ABSTRACT FROM AUTHOR]

Purpose: Conservation tillage can significantly affect the biological, chemical, and physical properties of soil. This study aimed to determine the effect of conservation tillage on the soil microbial community and respiration and on soil CO emissions. Materials and methods: In this study, the effects of 10 years of conservation tillage (no-till: NT and ridge tillage: RT) on soil CO fluxes and soil microbial communities were assessed in a black soil in Northeast China. Results and discussion: The annual soil CO emissions were higher under moldboard plow (MP) than under NT by 7.8 % ( P < 0.05). The average soil microbial respiration rate from RT was higher than that from MP by 11 % ( P < 0.05). Soil microbial respiration under NT (65 %) and RT (64 %) contributed more to soil CO emissions than MP (54 %). Total soil bacterial and fungal phospholipid fatty acids (PLFAs) were 1.6 times and 2.6 times greater under NT and RT, respectively, than under MP in the 0-5 cm layer, whereas they decreased by 21-47 % under NT and 26-41 % under RT in the 5-10, 10-20, and 20-30 cm layers. The F:B (the ratio of soil fungal PLFAs to bacterial PLFAs) varied with soil depth (0-10 cm) between conservation tillage (NT and RT) and MP. Conservation tillage induced the stratification of the soil microbial community on the vertical profile. Conclusions: RT increased soil microbial respiration, soil organic carbon (SOC) concentration, and soil microbial PLFAs at the 0-5 cm depth, whereas it did not influence the annual soil CO emissions compared to MP with a similar carbon input. These results suggested that RT might be an appropriate tillage practice for providing a better habitat for soil microbes and SOC sequestration in Northeast China. [ABSTRACT FROM AUTHOR]

Soil erosion in the Mollisol region of Northeast China is increasingly severe and directly affects national food security and sustainable development. However, few attempts have been made to create a clear distinction between the effects of rainfall and inflow on hillslope soil erosion. A laboratory study was conducted to discuss the roles and contributions of rainfall intensity and inflow rate to hillslope soil erosion and to fit equations based on variations of rainfall intensity and inflow rate (RI + IR) for soil erosion. A soil pan (8 m long, 1.5 m wide and 0.6 m deep and with an adjustable slope gradient of 0°-35°) was subjected to designed rainfall intensities (0, 50 and 100 mm h) and inflow rates (0, 50 and 100 mm h). The results showed that the effects of RI + IR treatments on hillslope soil loss were significantly greater than those on runoff. Furthermore, the effect of rainfall intensity on hillslope soil loss was significantly greater than the effect of inflow rate. Under the same total water supply, an increase in rainfall intensity resulted in greater average soil loss rates and stronger fluctuations in soil loss than an increase in the inflow rate. The occurrence of rill erosion significantly increased sediment transport capacity on the hillslope, which resulted in an increase in soil loss. Utilizing rainfall intensity and inflow rate, runoff and soil loss equations were generated and validated, and the performances of the two equations were satisfactory. Furthermore, it was determined that both equations are most applicable to the prediction of hillslope soil erosion under long rolling hillslope conditions. For the Mollisol region of Northeast China, the key factor affecting soil erosion on hillslopes is soil particle dispersion caused by rainfall. Therefore, taking measures to cover the soil, such as corn straw mulching, would effectively reduce rainfall erosivity and have significant positive effects on soil erosion prevention and control. [ABSTRACT FROM AUTHOR]

The estimation of annual maximum snow load is important for designing light-weight structures experiencing severe winter climate. The specified (basic) snow load in the Chinese design code is based on statistics of the return period values of ground snow load. The code tabulates the values for a few locations in a region. For example, values are only available at 31 sites for Heilongjiang Province with an area of more than 470,000 km, China. The snow load needs to be spatially interpolated for sites far away from the tabulated locations. However, the statistical justification of the selected probability distribution to model snow depth or load hazard is unclear and the preferred spatial interpolation technique is unknown. This study focuses on the extreme value analysis and spatial interpolation of the annual maximum snow depth and ground snow load using the records at 83 stations in Heilongjiang Province from 1981 to 2010. The statistical analysis results show that the use of the lognormal distribution rather than the Gumbel distribution for the annual maximum snow depth suggested in the code is preferred for most sites, and the application of the ordinary co-kriging is adequate for spatial interpolation of extreme snow depth. The results also show that the uncertainty in snowpack bulk density should not be neglected in estimating the extreme (ground) snow load for updating the snow load in Chinese design code. [ABSTRACT FROM AUTHOR]

A detailed analysis of the major ion chemistry, chemical weathering and CO consumption was conducted in the Songhua River basin, which is the largest basin with a draining area of 557 thousand km in Northeast China. The dataset used in this study included major ion concentrations came from 56 hydrological stations from the year of 1962 to 1984. The median of the total dissolved solid concentration of the Songhua River was 104.8 mg/L, about two times higher than the global average (65.0 mg/L), but lower than that of other Chinese Rivers. Prevalent ions were Na, Ca and HCO, and the average Ca/Na and Mg/Na molar ratios were 0.70 and 0.42, which were close to silicate weathering end-member. Long-term trend analysis by seasonal MK test showed that from 1962 to 1984, Ca, Na + K and HCO were significantly increasing, and the increasing rates calculated by linear fit slopes for Ca, Na + K and HCO ions were 0.22, 0.63 and 2.35 mg/year, respectively. An inverse model showed that the dissolved loads primarily came from rock weathering (91.5 %), including silicate weathering (66.4 %) and a small portion from carbonates (16.1 %) and evaporites (9.0 %). Other origins consisted of anthropogenic inputs (5.3 %) and atmospheric inputs (3.2 %). Average silicate and carbonate weathering rates were estimated as 4.03 and 1.76 t km year, and CO consumption rates of silicates and carbonates were 17.1 × 104 and 1.85 × 104 mol km year, respectively. These results are consistent with the lithologies of the study area, which mainly consisted of silicate rocks. [ABSTRACT FROM AUTHOR]

The aerosol optical depth (AOD), Angstrom exponent (Alpha), single scattering albedo (SSA), and volumes of aerosol size distributions were all retrieved from measurements made by a CE318 sunphotometer at four urban and industrial sites (Shenyang, Anshan, Benxi and Fushun) in Northeast China from 2009 to 2013. Values for direct radiative forcing (DRF) were then estimated using these measurements. For all four sites, the mean AOD appeared higher in the spring and summer, with the minimum occurring in the autumn. Conversely, the Alpha was lower in the spring but higher in the autumn and winter. The mean 440 nm SSA at the four sites varied from 0.81 to 0.87, indicating the highly spatial variability of aerosol optical properties. Frequent dust events resulted in a dominant contribution by coarse particles in spring, while fine particles were predominant during the summer. Mixtures of fine and coarse particles influenced aerosol optical properties in the autumn and winter. Results from this study provide useful information for the further understanding of retrieved aerosol optical properties and DRF in Northeast China. [ABSTRACT FROM AUTHOR]

To study the prediction of the anomalous precipitation and general circulation for the summer (June-July-August) of 1998, the Community Climate System Model Version 4.0 (CCSM4.0) integrations were used to drive version 3.2 of the Weather Research and Forecasting (WRF3.2) regional climate model to produce hindcasts at 60 km resolution. The results showed that the WRF model produced improved summer precipitation simulations. The systematic errors in the east of the Tibetan Plateau were removed, while in North China and Northeast China the systematic errors still existed. The improvements in summer precipitation interannual increment prediction also had regional characteristics. There was a marked improvement over the south of the Yangtze River basin and South China, but no obvious improvement over North China and Northeast China. Further analysis showed that the improvement was present not only for the seasonal mean precipitation, but also on a sub-seasonal timescale. The two occurrences of the Mei-yu rainfall agreed better with the observations in the WRF model, but were not resolved in CCSM. These improvements resulted from both the higher resolution and better topography of the WRF model. [ABSTRACT FROM AUTHOR]

The residents health risk of Pb, Cd and Cu exposure to street dust with different particle sizes (<100 and <63 μm) near Huludao Zinc Plant (HZP) was investigated in this study. The average concentrations of Pb, Cd and Cu in the <100-μm and <63-μm dust were 1,559, 178.5, 917.9 and 2,099, 198.4, 1,038 mg kg, respectively. It showed that smaller particles tended to contain higher element concentrations. Metals in dust around HZP decreased gradually from the zinc smelter to west and east directions. There was significantly positive correlation among Pb, Cd and Cu in street dust with different particle sizes. The contents of Pb, Cd and Cu in dust increased with decreasing pH or increasing organic matter. Non-carcinogenic health risk assessment showed that the health index (HI) for children and adult exposed to <63-μm particles were higher than exposed to <100-μm particles, which indicated that smaller particles tend to have higher non-carcinogenic health risk. Non-carcinogenic risk of Pb was the highest in both particle sizes, followed by Cd and Cu. HI for Pb and Cd in both particle sizes for children had exceeded the acceptable value, indicated that children living around HZP were experiencing the non-carcinogenic health risk from Pb and Cd exposure to street dust. [ABSTRACT FROM AUTHOR]

A set of numerical experiments designed to analyze the oceanic forcing in spring show that the combined forcing of cold (warm) El Niño (La Niña) phases in the Niño4 region and sea surface temperature anomalies (SSTA) in the westerly drifts region would result in abnormally enhanced NorthEast Cold Vortex (NECV) activities in early summer. In spring, the central equatorial Pacific El Niño phase and westerly drift SSTA forcing would lead to the retreat of non-adiabatic waves, inducing elliptic low-frequency anomalies of tropical air flows. This would enhance the anomalous cyclone-anticyclone-cyclone-anticyclone low-frequency wave train that propagates from the tropics to the extratropics and further to the mid-high latitudes, constituting a major physical mechanism that contributes to the early summer circulation anomalies in the subtropics and in the North Pacific mid-high latitudes. The central equatorial Pacific La Niña forcing in the spring would, on the one hand, induce teleconnection anomalies of high pressure from the Sea of Okhotsk to the Sea of Japan in early summer, and on the other hand indirectly trigger a positive low-frequency East Asia-Pacific teleconnection (EAP) wave train in the lower troposphere. [ABSTRACT FROM AUTHOR]

Assessments of the impacts of land use and land cover changes (LUCC) on the terrestrial carbon budget, atmospheric CO concentration, and CO-related climatic change are important to understand the environmental effects of LUCC and provide information about the effects of historical carbon emissions. Using regional land cover reconstructions from historical records, with a bookkeeping model, we estimated the carbon sink changes caused by historical cropland expansion in Northeast China during the past 300 years. The conclusions are as follows: (1) There was a dramatic land reclamation of cropland during the past 300 years in Northeast China. Approximately 26% of the natural land was cultivated, and 38% of the grassland and 20% of the forest and shrubland were converted to cropland. (2) The carbon emission induced by cropland expansion between 1683 and 1980 was 1.06-2.55 Pg C, and the estimation from the moderate scenario was 1.45 Pg C. The carbon emissions of the soil carbon pool was larger than that from the vegetation carbon pool and comprised more than 2/3 of the total carbon emissions. (3) The carbon emissions of the three provinces in Northeast China were different. Heilongjiang Province had the largest carbon emissions, and Jilin Province had the second largest emissions. (4) The primary source of carbon emissions was forest reclamation (taking 60% of the total emissions in the moderate scenario), the secondary source was grassland cultivation (taking 27%), and the tertiary sources were shrubland and wetland reclamation (taking 13%). Examination on the data accuracy revealed that the high-resolution regional land cover data allowed the carbon budget to be evaluated at the county level and improved the precision of the results. The carbon emission estimation in this study was lower than those in previous studies because of the improved land use data quality and various types of land use change considered. [ABSTRACT FROM AUTHOR]

Local actual evapotranspiration can be estimated with routinely measured meteorological variables using the Penman-Monteith model with surface resistance parameterized via the Katerji and Perrier approach (Agronomie 3(6):513-521, ; PM-KP model), or the nonlinear complementary relationship (CR) model proposed by Han et al. (Hydrol Process 26:3973-3981, ). A comparative study was carried out to evaluate the consistencies and differences of two models, as well as the performances of them for a cropland and grassland in northeast China. The departure of the actual evapotranspiration from the potential evaporation is described as a function of the ratio of the surface resistance to the aerodynamic resistance in the Penman-Monteith model, but the ratio of the aerodynamic term to the radiation term in the CR models. The two ratios are connected using a semi-empirical linear function by the Katerji and Perrier approach. The nonlinear CR model can be regarded as replacing the linear function by a power function after mathematical processing. On the other hand, the PM-KP model can be also considered as a CR-type model. On the daily basis at a maize cropland and degraded grassland in semiarid Northeast China, the nonlinear CR model with locally calibrated parameters performed better with data occupying all the growth stages, but the performances of the two models are similar during the early-, mid-, and late-season stages, respectively. On the half-hourly basis, the PM-KP model and the nonlinear CR model both performed well. It is deduced that on the daily basis the nonlinear CR model is more suitable for the cropland and grassland, but further comparisons are needed on the hourly basis. [ABSTRACT FROM AUTHOR]

In this work, authors examine the variabilities of precipitation and surface air temperature (T2m) in Northeast China during 1948-2012, and their global connection, as well as the predictability. It is noted that both the precipitation and T2m variations in Northeast China are dominated by interannual and higher frequency variations. However, on interdecadal time scales, T2m is shifted significantly from below normal to above normal around 1987/1988. Statistically, the seasonal mean precipitation and T2m are largely driven by local internal atmospheric variability rather than remote forcing. For the precipitation variation, circulation anomalies in the low latitudes play a more important role in spring and summer than in autumn and winter. For T2m variations, the associated sea surface pressure (SLP) and 850-hPa wind (uv850) anomalies are similar for all seasons in high latitudes with significantly negative correlations for SLP and westerly wind anomaly for uv850, suggesting that a strong zonal circulation in the high latitudes favors warming in Northeast China. The predictability of precipitation and T2m in Northeast China is assessed by using the Atmospheric Model Inter-comparison Project type experiments which are forced by observed sea surface temperature (SST) and time-evolving greenhouse gas (GHG) concentrations. Results suggest that T2m has slightly higher predictability than precipitation in Northeast China. To some extent, the model simulates the interdecadal shift of T2m around 1987/1988, implying a possible connection between SST (and/or GHG forcing) and surface air temperature variation in Northeast China on interdecadal time scales. Nevertheless, the precipitation and T2m variations are mainly determined by the unpredictable components which are caused by the atmospheric internal dynamic processes, suggesting low predictability for the climate variation in Northeast China. [ABSTRACT FROM AUTHOR]

The spatial heterogeneity of soil nutrients influences crop yield and the environment. Previous research has focused mainly on the surface layer, with little research being carried out on the deep soil layers, where high root density is highly related to crop growth. In the study, 610 soil samples were collected from 122 soil profiles (0-60 cm) in a random-sample method. Both geostatistics and traditional statistics were used to describe the spatial variability of soil organic matter (SOM) and total nitrogen (TN) deeper in the soil profile (0-60 cm) with high root density from a typical Mollisol watershed of Northeast China. Also, the SOM and TN in farmland and forest (field returned to forest over 10 years) areas was compared. The spatial autocorrelations of SOM at 0-50 cm depth and TN at 30-60 cm depth were strong, and were mainly influenced by structural factors. Compared to farmland, SOM and TN were typically lower in the 0-30 cm depth of the forest areas, while they were higher in the 30-60 cm depth. As well, both SOM and TN decreased from the 0-20 cm layer to the 30-40 cm layer, and then discontinues, while they continuously decreased with increasing soil depth in the farmland. SOM and TN were typically higher at the gently sloped summit of the watershed and part of the bottom of the slope than at mid-slope positions at the 0-30 cm depth. SOM and TN were lower on the back slope at the 30-60 cm depth, but were higher at the bottom of the slope. Also, the spatial distribution of the carbon storage and nitrogen storage were all highest at the bottom of the slope and part of the summit, while they were lowest in most of back slope in depth of 0-60 cm, and mainly caused by soil loss and deposition. SOM at 0-60 cm and TN at 0-40 cm greater than the sufficiency level for crop growth (3.7-79.2 and 0.09-3.09 g kg, respectively) covered 99 % of the total area, yet for TN, over 35 % of the total area was less than the insufficiency level at the 40-60 cm depth. Generally, accurately predicting SOM and TN is nearly impossible when based only on soil loss by water, although the fact that variability is influenced by elevation, soil loss, deposition and steepness, was shown in this research. Nitrogen fertilizer and manure application were needed, especially in conjunction with conservation tillage in special conditions and specific areas such as the back slope, where soil loss was severe and the deep soil that lacked TN was exposed at the surface. [ABSTRACT FROM AUTHOR]

Avian leukosis virus subgroup J (ALV-J), first isolated in 1989, preferentially infects meat-type birds. Chinese layer flocks have experienced outbreaks of this virus since 2008. To analyze the status of ALV-J infection in wild birds in China, 585 wild birds collected from three provinces of Northeast China from 2010 to 2012 were tested, and six ALV-J strains were isolated for the first time. Furthermore, the gp85 genes of the six strains were amplified, cloned, and sequenced. The results indicated that two different ALV-J strains coexisted in Chinese wild birds from 2010 to 2012. These results not only expand the epidemiological data available for ALV-J and provide necessary information for the further understanding of the evolution of ALV-J, but they also highlight the potential role of wild-bird migration in the spread of ALV-J. [ABSTRACT FROM AUTHOR]

The interannual variations of summer surface air temperature over Northeast China (NEC) were investigated through a month-to-month analysis from May to August. The results suggested that the warmer temperature over NEC is related to a local positive 500-hPa geopotential height anomaly for all four months. However, the teleconnection patterns of atmospheric circulation anomalies associated with the monthly surface air temperature over NEC behave as a distinguished subseasonal variation, although the local positive height anomaly is common from month to month. In May and June, the teleconnection pattern is characterized by a wave train in the upper and middle troposphere from the Indian Peninsula to NEC. This wave train is stronger in June than in May, possibly due to the positive feedback between the wave train and the South Asian rainfall anomaly in June, when the South Asian summer monsoon has been established. In July and August, however, the teleconnection pattern associated with the NEC temperature anomalies is characterized by an East Asia/Pacific (EAP) or Pacific/Japan (PJ) pattern, with the existence of precipitation anomalies over the Philippine Sea and the South China Sea. This pattern is much clearer in July corresponding to the stronger convection over the Philippine Sea compared to that in August. [ABSTRACT FROM AUTHOR]

A spring-composite index (s-CI) is proposed in this study that involves slightly altering the use of the accumulated precipitation from the composite index (CI) comparing the value with other three commonly used indices (standardized precipitation index, SPI; self-calibrated Palmer drought severity index, sc-PDSI; and CI). In addition, the spatial-temporal variation of the s-CI in the Songnen Plain (SNP) was investigated using the Mann-Kendall test and empirical orthogonal function (EOF) methods. The results indicated that the proposed s-CI could identify most drought events in 1990s and 2000s and performed relatively better than SPI, sc-PDSI, and CI in this region. Compared with the other three indices, the s-CI had a higher correlation with relative soil moisture in April and May. The recent spring droughts (2000s) were the most severe in April or May. The weather was drier in May compared with April in the 1980s, whereas the weather was wetter in May than in April in the 1960s and 1970s. Moreover, the spatial patterns of the first EOFs for both April and May indicated an obviously east-west gradient in the SNP, whereas the second EOFs displayed north-south drought patterns. The proposed index is particularly suitable for detecting, monitoring, and exploring spring droughts in the Songnen Plain under global warming. [ABSTRACT FROM AUTHOR]

A new species of structurally preserved fern rhizome, Ashicaulis plumites (Osmundaceae, Filicales), is described from the Middle Jurassic Tiaojishan Formation in western Liaoning Province, NE China. The new species is characterized by a peculiar sclerenchyma mass in the petiolar vascular bundle concavity. This sclerenchyma mass varies from a linear-shape to a mushroom-like shape with a remarkable outward protuberance, which distinguishes the present new species from other Ashicaulis species. Such a protuberance is very rare among osmundaceous ferns, and should represent a unique type for sclerenchymatous tissue in the osmundaceous vascular bundle concavity. Recognition of the peculiar structure of this new fossil species enriches anatomical diversity of permineralized osmundaceous ferns, indicating that the family Osmundaceae might have experienced a remarkable diversification during the Middle Jurassic in NE China. The new species show anatomical similarities to Osmunda pluma Miller from the Palaeocene of North America. The occurrence of A. plumites in the Middle Jurassic of China provides a new clue for understanding the evolution of some members of the living subgenus Osmunda. [ABSTRACT FROM AUTHOR]

Northeast China as an important agricultural zone for commercial and economic crop in China suffered from increased drought risk that seriously threatened agricultural production and food security in recent decades. Based on precipitation datasets from 71 stations from 1960 to 2009 and on the reliable statistical methods of the Mann-Kendall test, Sen's slope and the Standardized Precipitation Index, we analyzed the temporal and spatial variation of drought occurrence during the crop-growing season (from May to September) and summer (from June to August). The results showed that regional mean precipitation during the crop-growing season and summer over the last 40 years has decreased at the rate of −1.72 and −1.12 mm/year, respectively. According to timescale analysis of abrupt changes, there were two distinct time series (1965-1983 and 1996-2009) with decreasing precipitation trends at a 95 % confidence level. A comparison between the two time series of these two periods demonstrated that more frequent and more severe drought occurred during 1996-2009. Furthermore, drought risk in recent decades has become even more serious both in severity and in extent. Especially in the crop-growing season of 2001 and summer of 2007, over 25 % (2.0 × 10 km) of study area experienced severe drought (serious and extreme droughts). Our results highlight the urgent need for the development of effective drought adaptations for cropland over northeast China. [ABSTRACT FROM AUTHOR]

The Sanjiang Plain has the most representative and largest concentration of inland freshwater wetlands in China, most of which have been degraded or have disappeared as a result of agricultural development and climatic change since the 1950s. To better understand the spatial and temporal variation and driving forces of marsh reduction, this study investigated variations of marsh reduction in the Honghe region of the Sanjiang Plain, Northeast China over a 30-year period, and analyzed the role of the different driving forces separately and their combined effect on marsh reduction and identified what driving forces have played key roles on the reduction in different periods. Nine natural and anthropogenic variables from remote sensing, GIS data and field surveys, such as precipitation, temperature, precipitation anomaly, population density, agricultural population density, per capita GDP, distance to road, distance to canal and distance to settlement, were evaluated on their impact on observed variations of marsh reduction between 1975 and 2006. The results show that all of these driving forces have significant influences on the decline of the marsh area, and the combination of driving forces that has crucial impacts on marsh reduction varied largely from 1975 to 2006. During 1975-1989, it was the construction of canal and road networks in farms and changes in average annual precipitation that led to marsh reduction. After 1989, the reduction was mainly related to increases in agricultural population, per capita GDP and settlements. These findings may help understand the declines or degradation of marsh areas and provide an empirical and theoretical base for managers, who design and implement wetland management and planning. [ABSTRACT FROM AUTHOR]

Indications of earlier onset of spring have been observed in behavior of diverse animal and plant species in the Northern Hemisphere in response to recent climate warming. Knowledge of changes in the spring onset is a critical requirement for understanding ecosystem adaption to climate change, especially for agricultural regions. In this study, we present a climatological approach for detecting the temporal and spatial variability in onset of spring with particular emphasis on how they vary along geographical parameters. Yearly dates for spring onset were computed for 71 climate stations in Northeast China based on daily surface air temperature records. These analyses were conducted for the two study periods (1960–2004 and 1979–2004). We also examined the boundary shifts of spring onset for three selected dates between the periods of 1960–1978 and 1979–2004. The results showed that advancement of spring onset was more pronounced for the period of 1979–2004 than for the period of 1960–2004 (4.0 vs. 2.2 days/decade). For the 22 stations where the spring advancement was statistically significant in the two periods, the mean rate of advancement was −0.6 days/decade during the period of 1960 to 1978. The trends of advancement of spring onset decreased with both increasing latitude and altitude up to 300 m above sea level, and these geographical effects were clearer during 1979–2004. Analysis of boundary shifts of three specific dates revealed that the spring onset has moved to higher latitudes for each date with an average shift of about 1° of latitude (about 110 km). Our results suggest that attempts to address how ecosystems will adapt to spring advancement associated with climate warming should consider the differences in response rates and geographical effects across the study area. [ABSTRACT FROM AUTHOR]

Gully erosion has caused soil degradation and even reduced soil productivity. However, only few studies on the effects of gully erosion and artificial controlling measures on soil degradation in the Black Soil Region of Northeast China are available. Thus, this study explores the relationships between gully erosion, gully filling and soil parameters. Two sets of soil samples were collected in the field at: (1) 72 sample points in the gully erosion study area, 60 sample points in the ephemeral and classical gully erosion area (3,518 m), 12 sample points in the deposition zone (443 m), (2)10 reference points along a slope unaffected by gully erosion representing the original situation before the gully was formed. All soil samples were analyzed for gravel content (GC), soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), available phosphorus (AP), and available potassium (AK). The soil property values on unaffected slope were fitted by the polynomial curves as the reference values in no gully erosion area. The interpolated soil property values in gully eroded study area were compared with these polynomial curves, respectively, and then, changes of soil property values were analyzed. Gully erosion caused an increase in GC and a decrease in SOM, TN, AN, AP and AK. The change of GC, SOM, TN, AN, AP, AK was 8.8%, −9.04 g kg, −0.92 g kg, −62.28 mg kg, −29.61 mg kg, −79.68 mg kg. The soil property values in the study area were below optimal values. Thus, we concluded that gully erosion and gully filling caused both on-site and off-site soil degradation. Soil degradation area was 0.65 % of the cultivated land. In addition, it was proved that gully filling were an improper soil and water conservation measure, which seems to exacerbate the problem. Thus, it is suggested that soil where soil is deep is moved to fill the gully, and then the area around the filled gullies should be covered by grass for preventing the formation and development of the gully. [ABSTRACT FROM AUTHOR]