Northeastern Part Of China Research Articles

The unusual summer of 1994 in East Asia: IOD teleconnections

An extremely hot and dry summer of 1994 was reported in East Asian countries. Using observational data, we have demonstrated that the Indian Ocean Dipole (IOD) is at least one possible cause of the abnormal East Asian summer climate. An anomalous cyclonic circulation over the western Pacific and the southern China weakened the monsoonal northward flow in the lower troposphere. An anomalous anticyclonic circulation with the equivalent barotropic structure around Japan, Korea and the northeastern part of China caused the hot and dry summer of 1994. This accumulation of the lower potential vorticity in the Far East is related to the wave activity from the Mediterranean/Sahara region. The monsoon‐desert mechanism connects a Rossby wave source with the IOD‐induced diabatic heating around the Bay of Bengal. Another Rossby wave‐train pattern was generated in the upper troposphere and propagates northeastward from the southern China. Both the Rossby wave patterns influenced the circulation changes over East Asia.

Short Note: Magnitude-intensity Relation for Earthquakes in the Sino-Korean Craton

The Korean peninsula lies in the Eurasian Plate. Its seismicity shows an irregular strain release typical of intraplate seismicity. Historical earthquake records of Korea from the first to the 19th centuries greatly outnumber instrumental ones during the 20th century. Analyses of these historical data are of paramount importance for seismicity and seismic hazard studies of the peninsula. In order to quantify sizes of historical Korean earthquakes better, a linear regression relationship between Richter magnitude, ML , and epicentral Modified Mercalli intensity, I , of the earthquakes in the Sino-Korean craton was obtained in this study. The northeastern part of China is connected with the Korean peninsula geologically, and the patterns of strain release in these two regions are similar. Sixty-four earthquakes with surface-wave magnitude M s ≥ 4.7 in the Sino-Korean craton were used in this study. The data were drawn from the Chinese and Korean earthquake catalogs. Since ML is generally used in magnitude-intensity relationships at regional distances, M s of the earthquakes in this study were converted into ML. Least-square fitting of magnitude and intensity data of earthquakes in the Sino-Korean craton gives ML = 1.75 + 0.58 I . A comparison of this relationship with those for highly seismic southern California and rather stable Australia was made. The magnitude-intensity relationship in the Sino-Korean craton will lead to more reliable seismicity and seismic hazard studies of Korea.

Simulation of hydrologic changes associated with global warming

Using the results obtained from a coupled ocean‐atmosphere‐land model with medium computational resolution, we investigated how the hydrology of the continents changes in response to the combined increases of greenhouse gases and sulfate aerosols in the atmosphere, which are determined based upon the IS92a scenario. In order to extract the forced response from natural, internal variability, the difference between the mean of an eight‐member ensemble of numerical experiments and a control experiment are used for the present analysis. The global mean surface air temperature of the coupled model increases by about 2.3°C above the preindustrial level by the middle of the 21st century. Accompanying the warming, the global mean rates of both precipitation and evaporation increase by 5.2%, yielding the average increase in the rate of runoff by approximately 7.3%. The increase in the rate of runoff simulated by the model is particularly large in high northern latitudes, where the runoff from some rivers such as the Mackenzie and Ob′ may increase by as much as 20%. Runoff from many European rivers increases by more than 20%. Runoff also increases substantially in some tropical rivers such as the Amazon and Ganges. However, the percentage changes in simulated runoff from many other tropical rivers and middle latitude rivers are smaller with both positive and negative signs. In middle and high latitudes in the Northern Hemisphere, soil moisture tends to decrease in summer, whereas it increases in winter. However, in many semi‐arid regions in subtropical and middle latitudes, soil moisture is reduced during most of a year. These semi‐arid regions include the southwestern part of North America, the northeastern part of China in the Northern Hemisphere, and the region in the vicinity of the Kalahari Desert and southern part of Australia in the Southern Hemisphere. Since a semi‐arid region usually surrounds a desert, the reduction of soil moisture in such a region often results in the expansion of the desert. Soil moisture is also reduced during the dry season in many semi‐arid regions. For example, it is reduced in the savannahs of Africa and South America during winter and early spring in the Southern Hemisphere. In the Northern Hemisphere, it is reduced at the Mediterranean coast of Europe in summer.

Micrometeorological changes following establishment of artificially established artemisia vegetation on desertified sandy land in the Horqin sandy land, China and their implication on regional environmental change

Human-induced desertification in the Horqin sandy land in the north-eastern part of China has been reversed since the mid-1970s through re-vegetation. This land cover change affects surface energy and water transfer processes. We employed the Bowen ratio energy balance technique to examine micrometeorological changes following the establishment of artificially established artemisia vegetation on the severely desertified sandy land in Naiman, a county located in the Horqin. Re-vegetation on the desertified sandy land decreased the surface albedo and increased the surface roughness length, thereby resulting in considerable changes in both surface water and heat budget, and wind regimes. As compared with that (34%) before re-vegetation, albedo decreased by 15% as the sandy land was semi-fixed and decreased by 47% as the sandy land is entirely fixed. With change in albedo, partitioning of the available energy exhibited distinct patterns depending on vegetation cover, especially large increase in evapotranspiration, which may result in soil desiccation and thus further affecting temperature regime. Establishment of artificially established vegetation also affected wind regimes by altering surface roughness; consequently, erosion was avoided in the vegetated surfaces. These changes, if occurring in large spatial scale, may affect the local and regional climate according to the Charney theory.

Micrometeorological changes following establishment of artificially established artemisia vegetation on desertified sandy land in the Horqin sandy land, China and their implication on regional environmental change

Human-induced desertification in the Horqin sandy land in the north-eastern part of China has been reversed since the mid-1970s through re-vegetation. This land cover change affects surface energy and water transfer processes. We employed the Bowen ratio energy balance technique to examine micrometeorological changes following the establishment of artificially established artemisia vegetation on the severely desertified sandy land in Naiman, a county located in the Horqin. Re-vegetation on the desertified sandy land decreased the surface albedo and increased the surface roughness length, thereby resulting in considerable changes in both surface water and heat budget, and wind regimes. As compared with that (34%) before re-vegetation, albedo decreased by 15% as the sandy land was semi-fixed and decreased by 47% as the sandy land is entirely fixed. With change in albedo, partitioning of the available energy exhibited distinct patterns depending on vegetation cover, especially large increase in evapotranspiration, which may result in soil desiccation and thus further affecting temperature regime. Establishment of artificially established vegetation also affected wind regimes by altering surface roughness; consequently, erosion was avoided in the vegetated surfaces. These changes, if occurring in large spatial scale, may affect the local and regional climate according to the Charney theory.

Modelling and assessment ofwaterquality indicators in a semi-enclosed shallow bay

Bohai Bay is a large, semi-enclosed shallow water basin located along the western region of the Bohai Sea in the north-eastern part of China. As a result of rapid economic development in the surrounding coastal hinterland, the water quality characteristics within Bohai Bay have been of growing concern in recent years. Details are given herein of an aquatic environmental assessment study undertaken to investigate the hydrodynamic and transport processes within the Bay using an integrated numerical modelling approach and tield measurements. 3-D numerical model was used to simulate the tide flow and 2 D model was deployed with moving boundary to simulate the water quality. In order to improve on the water quality characteristics in the near-shore coastal zone, an ocean disposal plan was also considered, with various scenarios being simulated using the 2-D model. From an analysis of data collected from the held measurements, it was found that both chemical and phytoplankton indicators were important in the assessment of the overall water quality of the Bay. The occurrence of red tides was also found to be closely linked to the composition of phytoplankton community.

STUDY ON XORIDES (MOEROPHORA) (HYMENOPTERA: ICHNEU‐MONIDAE) FROM NORTHEASTERN CHINA

Abstract Two species of Xorides (Moerophora) collected in the northeastern part of China, in which one is new to science, namely Xorides (Moerophora)tuqiangensis Sheng sp. nov., and one, X. (M.) jakovlevi (Kokujev) 1903, is a Chinese new record, are reported. A key is provided to distinguish the Chinese species of this subgenus.

The degradation of soil fertility in pure larch plantations in the northeastern part of China

Soil degradation was found in first generation of Dahurian larch ( Larix gmelinii (Rupr) Rupr.) plantations in northern China and also in plantations of other larch species such as Larix olgensis and Larix leptolepis in the same area. Soil degradation in pure larch plantations may be exacerbated in the second rotation under continuous cropping and was accompanied by obvious concomitant decrease in tree growth. A study on nutrient cycling revealed that poor quality of larch litter, which decomposed very slowly, was a key factor leading to soil degradation and decline in tree growth in pure larch plantations. The accumulation of forest floor litter in ∼20-year-old pure larch stands was 23–28 ton ha −1 and this was higher than 9–16 ton ha −1 in virgin mixed Korean pine/ broad-leaf forests. Larch litter took 4.4 years to mineralise, whereas angiosperm litter (ash, birch and poplar) in a pure larch stand took only 0.9–2.4 years. The progressive accumulation of litter on the forest floor acted as a heat-isolating layer which inhibited thermal conduction and decreased soil temperature and limited soil microbial activities. Consequently, degradation of soil fertility occurred and this was exacerbated after two or more rotations under continuous cropping. The role of the understorey vegetation was significant in nutrient recycling and maintaining sustainable soil fertility in larch plantations. A low-cost, effective way to prevent soil degradation in pure larch plantations is to develop mixed stands formed either by creating a mixture with broad-leaved trees or by introducing understorey vegetation (herbs and shrubs). Large areas of man-made, pure larch stands should be replaced by many small patches of different, uneven-age stands and crop rotation with different tree species should be adopted instead of continuous larch cropping.

Effect of Application of Compost on the Stable Production of Paddy Rice in a Cool-Summer Damage-Prone Area, Northeastern Part of China

Effect of Application of Compost on the Stable Production of Paddy Rice in a Cool-Summer Damage-Prone Area, Northeastern Part of China

Composition and distribution of vegetation in cold temperate region of northeastern part of China

Cold-temperate region of China is an independent and the most northern one of the 8 vegetation regions of China. The specific composition of the vegetation in this region, besides the polytopic species, East-Siberia floral element is dominant (51.5%), but mixed with Mandshurica (38.7%) and Mongolia (2.3%) in horizontal vegetation zone. The floral elements vary greatly with altitude, in higher and the highest parts, they are mixed with Kantcaja-Erhock and Arctic alpine floral elements. The vertical distribution include 3 zones: subalpine dwarf forest zone, mountainous coniferous wood land zone and mountainous coniferous forest zone, and the last one include 3 subzones.

Saponin and Sapogenol. XLVII. On the Constituents of the Roots of Glycyrrhiza uralensis Fischer from Northeastern China. 1. Licorice-Saponins A3, B2, and C2.

From the air-dried root of Glycyrrhiza uralensis, collected in the northeastern part of China, ten new oleanane-type triterpene oligoglycosides were isolated together with glycyrrhizin (1) and several known flavonoids. Among the newly isolated triterpene oligoglycosides, the chemical structures of licorice-saponin A3 (2), licorice-saponin B2 (3), and licorice-saponin C2 (4) have been determined, on the basis of chemical and physicochemical evidence, to be expressed as 30-O-beta-D-glucopyranosylglycyrrhizin, 11-deoxo-glycyrrhizin, and 3-O-[beta-D-glucuronpyranosyl(1-->2)-beta-D-glucuronpyranosyl++ +]oleana- 11,13(18)-dien-30-oic acid, respectively. During the course of these studies, facile conversions from glycyrrhizin (1) to licorice-saponins A3 (2), B2 (3), and C2 (4) have been accomplished.

Saponin and sapogenol. XLVIII. On the constituents of the roots of Glycyrrhiza uralensis Fischer from northeastern China. (2). Licorice-saponins D3, E2, F3, G2, H2, J2, and K2.

Following the characterization of licorice-saponins A3 (2), B2 (3), and C2 (4), the chemical structures of licorice-saponins D3 (5), E2 (6), F3 (7), G2 (8), H2 (9), J2 (10), and K2 (11), seven of the ten oleanane-type triterpene oligoglycosides isolated from the air-dried roots of Glycyrrhiza uralensis Fischer collected in the northeastern part of China, were investigated. On the basis of chemical and physicochemical evidence, the structures of licorice-saponins D3, E2, F3, G2, H2, J2, and K2 have been determined to be expressed as 3 beta-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucuronopyranosyl(1-- >2)-beta-D-glucuronopyranosyloxy]-22 beta-acetoxyolean-12-en-30-oic acid (5), 3-O-[beta-D-glucuronopyranosyl(1-->2)-beta-D- glucuronopyranosyl]glabrolide (6), 3-O-[alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucuronopyranosyl(1--> 2)-beta-D-glucuronopyranosyl]-11-deoxoglabrolide (7), 24-hydroxyglycyrrhizin (8), 3-O-[beta-D-glucuronopyranosyl(1-->2)-beta- D-glucuronopyranosyl]liquiritic acid (9), 24-hydroxy-11-deoxoglycyrrhizin (10), and 3 beta-[beta-D- glucuronopyranosyl(1-->2)-beta-D-glucuronopyranosyloxy]-24-+ ++hydroxyoleana- 11,13(18)-dien-30-oic acid (11), respectively.

Varietal Variation in Plant Regeneration Capacity from Immature Embryo among Common Wheat Cultivars

Varietal difference in culture response of 14 days old immature embryos was examined by culturing on 2, 4-D medium, using 102 local wheat cultivars collected from varlous parts of the world. Callus induction ancl green spot formation occurred in all of the cultivars tested, indicating that culture method of immature embryo could be applicable to most of wheat cultivars. However, culture response showed wide varietal variation, being ranged from 25% to 100% in callus induction rate, from 18% to 94% in regeneration capacity of callus and from 10% to 85% in culture efficiency. The estimated correlation coefficient between the former two characters was r=0.09, indicating that callus induction rate and regeneration capacity of callus were controlled by independent systems. Though varietal variation in culture response was observed within each cultivated area, statistically significant difference existed also among the cultivated areas. Callus induction rate showed wide varietal variation and was lower in the Central region of wheat evolution. The negative correlation observed between callus induction rate and the first inoculation date suggested that low rate of callus induction in this region might be partly ascribable to the existence of late heading cultivars. On the other hand, regeneration capacity of callus was lower in the northern part of Japan and the northeastern part of China than in the other parts of both countries, and such difference seemed to be caused by genetic factors. In this case, culture method should be improved to increase the culture efficiency of these cultivars. For further improvement of tissue and cell culture systems of wheat, the suitable cultivars detected in this study would be useful as novel genetic materials.

Japanese barnyard millet (Echinochloa utilis, poaceae) in Japan

Two species are included in barnyard millet:Echinochloa utilis andE. frumentacea. These differ from each other in their genomic constitution and phylogeny. The former species originated fromE. crus-galli probably in eastern Asia, and is grown in Japan, Korea, and the northeastern part of China; the latter originated fromE. colona probably in tropical Asia, and is grown in Pakistan, India, and Nepal. “Japanese barnyard millet” is suggested as a suitable English common name forE. utilis; “Indian barnyard millet,” forE. frumentacea. In the past, Japanese barnyard millet was important in Japan as the staple food crop in districts where soil, weather conditions and irrigation systems were not suitable for paddy rice cultivation. When the rice crop suffered serious cool weather damage, the millet relieved people from starvation, especially in northeastern Japan. But the acreage devoted to the millet gradually decreased during and after the 1880s. Only the northern part of Iwate Prefecture is an exclusive Japanese barnyard millet cropping region at present. The breeding of cool- weather- resistant rice varieties and improvements in rice- growing techniques are mainly responsible for the decrease in acreage of the millet.

Climatic changes in the Qinghai-Xizang (Tibetan) region of China during the Holocene

Climatic changes in the Qinghai-Xizang Plateau of China were studied by analyzing the composition of peat and layers of sand and gravel distributed along the southern slopes of Nianqing-Tanggula and Gangdise Mountains, cross sections of deposits near a number of interior lakes in Xizang, past glacial variations on the southern slope of Nianqing-Tanggula Mountain, and landform changes south of the Yaluzangbu River. Such geologic evidence suggests a division of five climatic periods since the beginning of the Holocene: (1) The Wumadung interval, 10,000–7500 yr B.P., slightly cold and dry; (2) Qilongduo interval, 7500-3000 yr B.P., warm and moist; (3) the mid-Neoglacial period, 3000-1500 yr B.P., cold, except between 2500 and 200 yr B.P. when it was warmer; (4) the Dawelong interval, 1500-300 yr B.P., mild; and (5) the Little Ice Age, 300-0 yr B.P., cold. These changes progressed in a similar but not identical pattern as those in the northeastern part of China and in the northern region of Europe.

Present State of Landuse and Significance of Forestation in the Northeastern Part of china

Present State of Landuse and Significance of Forestation in the Northeastern Part of china