河龙区间坝库参数与减沙效益关系研究

对黄河中游河龙区间晋西北片、陕北片坝库控制面积占比、坝库单位面积库容等参数与水利水土保持措施减沙效益关系进行了研究，结果表明：（1）晋西北片若没有坝库工程，仅靠水土保持坡面治理措施只能取得14％的减沙效益；每增加100km^2的坝库控制面积，即可提高2％的减沙效益；每增加400万m^2的库容，即可提高1％的减沙效益;坝库单位面积库容每提高1万m^2／km^2，减沙效益即可提高约10％。（2）陕北片减沙效益主要由坝库工程产生。减沙效益提高10％，坝库单位面积库容需要提高5万m^2／km^2。要使流域水土保持综合治理减沙效益达到20％以上，坝库单位面积库容应在6万m^2／km^2以上。（3）在黄河中游多沙粗沙区，要实现40％左右的减沙效益，坝库单位面积库容应达到167／m^2／km^2以上。     

依靠科技创新 打造示范精品

黄河水土保持生态工程韭园沟示范区位于陕西省绥德县无定河中游左岸，包括韭园沟、辛店沟两条流域，总面积74.65km^2，以小流域沟道坝系建设为主要措施，坚持高起点、高标准、高质量、高效益的原则，开展水土流失综合治理示范区建设。     

陕西省水土保持发展方向及对策

陕西省地跨黄河、长江两大流域,总土地面积20．56万km^2,其中水土流失面积13．75万km^2,占总土地面积66．9％。截至目前,全省累计初步治理水土流失面积86397．6km^,治理度达62．6％。在分析水土保持存在问题的基础上,提出了强化重点治理工程规划设计前期工作、加强以基本农田为主的综合治理、强化建设生产项目监管、建立水土保持生态补偿制度和完善配套法规政策等对策措施。     

榆林沟流域坝系建设调查

榆林沟流域坝系建设调查郭玉梅，张庆伟（黄委会绥德水土保持科学试验站，陕西绥德县７１８０００）寇俊峰，武哲（黄委会黄河上中游管理局）榆林沟流域是无定河中游左岸的一条支流，流域面积６５．８ｋｍ２，其中沟谷地占５１．１３％，沟间地占４８．８７％，主沟道长１...     

青海省黄河水保生态工程建设的成效及经验

截至2006年底,黄河水土保持生态工程西宁、互助项目区共完成水土流失治理面积263.9 km2,建成骨干坝29座、中小型淤地坝211座,修建谷坊341座、沟头防护120处,13条小流域坝系已建成淤地坝152座,其中骨干坝28座、中型淤地坝44座、小型淤地坝80座,共实施生态修复面积7 539 km2,为减少入黄泥沙、改善局部生态环境和农牧民的生产生活条件、调整农业生产结构、加快山区脱贫致富、促进当地经济社会的可持续发展做出了重要贡献。介绍了青海黄河水土保持生态工程建设的具体成效及经验。     

临汾市坝系建设经验概述

临汾市地处山西省西南部黄河中游地区，沟谷纵横，水土流失严重，打坝淤地历史悠久。目前已建成骨干坝40座，中小型淤地坝1．5万座，坝系建设初具规模，不但效益十分显著，而且积累了丰富的坝系建设经验，为当地今后的坝系建设奠定了坚持的基础。     

无定河流域水土保持生态环境建设方略初探

无定河流域地处毛乌素沙漠与黄土高原的交接地带，水土流失面积23137km^2．占总面积的76．5％，土壤侵蚀模数11132t/km^2．a，多年平均输沙量14667万t，是黄河中游水土流失最为严重的地区之一。根据无定河流域地形、地貌、地面物质组成和水土流失特点．将全流域划分为河源涧地区、风沙区、黄土丘陵沟壑区等三个类型区，并根据分区特征．科学地提出了水土保持生态环境建设方略及分区措施配置模式。     

松嫩平原水土保持价值的量化研究

近几十年来，松嫩平原的生态环境严重恶化，荒漠化迅速发展，这与区域水土保持功能持续下降有关。本文应用生态学、经济学和生态环境科学等学科的有关理论，以TM／MODIS／DEM数据为基础，应用3S技术建立了松嫩平原水土保持价值的复合计算模型。计算表明，全区2001年水土保持总价值为662．63亿元，就单位面积的水土保持价值而言．林地最高，为173．59万元／km^2，草地次之，为70．42万元／km^2，耕地很低，为24．53万元／km^2，难利用地仅为2．89万元／km^2。水土保持价值分布的总趋势从东北向西南递减，从193．86万元／km^2降至18．87万元／km^2。研究指出，进行林地、草地建设是提高区域水土保持功能的关键，中、西部尤应加强水土保持工作。本文不仅解决了水土保持价值的量化问题，而且为绿色GDP的核算提供了基础数据。     

建立多元化管理机制提高坝系工程效益

隰县地处晋西黄土残塬的壑区，沟壑密度1．54km/km^2，建坝资源丰富，至2002年底，共建骨干坝13座，中小型淤地坝245座，已淤成坝地340hm^2，有5条流域已形成较为完整的坝系，为了管好用好坝系工程，使其充分发挥效益，采用了拍卖制，联村管护制，股份制等多种运行管理方式，收到了良好效果。     

坝系农业是黄土高原持续农业的发展方向

截至 １９９５年底，黄土高原 １０余万座淤地坝累计烂泥７１．２７亿 ｔ，占水保措施保土烂泥量的 ６６．９％；现有坝地３８．１万ｈｍ２，仅占耕地总面积的９．３％，但由于水肥条件好，其粮食产量却占总产量２０．５％，坝系建设较好的小流域，坝地产量占总产量的比例更大。黄土高原建坝资源丰富，坝地发展潜力巨大，坝系农业是极富竞争力的持续农业发展方向。     

Transformation of the Bryansk Paleosol in Microdepressions in the Center of the East European Forest-Steppe during the Maximum of Valdai Glaciation and in the Holocene

Eurasian Soil Science - Recent and Late Pleistocene soils of the central forest-steppe in the East European Plain have been studied. The main objective of the work is to reveal changes in the...     

Changes in the structure of the rhizosphere complex of actinomycetes in the ontogenesis of winter rye

Changes in the taxonomic structure of actinomycetes in the rhizosphere of winter rye (Secale cereale L.) growing on acid soddy-podzolic soil were studied. During the first stages of ontogenesis of winter rye, the rhizosphere complex of mycelial prokaryotes was characterized by a relatively level generic structure (with respect to the indices of abundance and frequency of particular genera), low values of the species diversity, and low domination frequency of the species from the Streptomyces genus. The numbers and species diversity of the streptomycetes increased during the further growth of the winter rye, so that streptomycetes became a dominant group in the complex of the rhizosphere actinomycetes. According to the two-way ANOVA, the population density of the Micromonospora and the Streptosporangium genera in the rhizosphere was mainly dictated by the winter rye variety, whereas the population density of the streptomycetes depended on the particular stage of the winter rye development. The differences between the actinomycetal complexes characteristic of different varieties of winter rye at the early stages of its development was leveled by the end of the winter rye growth.     

Evolution of forest pedogenesis in the south of the forest-steppe of the Central Russian Upland in the Late Holocene

The Late Holocene stage of forest pedogenesis has been studied on the interfluves along river valleys in the forest-steppe zone of the Central Russian Upland. The development of gray forest soils from the former chernozems as a result of the Late Holocene advance of forest vegetation over steppes is discussed. It is argued that the climatic conditions of the Subatlantic period were unstable, so that multiple alternation of forest and steppe vegetation communities took place. This specified a complex character of soil evolution upon contrasting substitution of forest pedogenesis for steppe pedogenesis. On the interfluves near the natural drainage network (balkas, ravines, and steep slopes of river valleys), the climate-driven dynamics of forest and steppe vegetation with corresponding changes in the character of pedogenesis could take place during the entire Holocene, which is reflected in a lower thickness of humus profiles and deeper leaching of carbonates from chernozems of the Early Iron Age in comparison with their analogues formed under steppe cenoses in central parts of the interfluves. Two variants of the evolution of gray forest soils can be suggested: the pulsating evolution typical of balkas and interfluves near river valleys and the continuous progressive evolution typical of automorphic (plakor) positions in central parts of the interfluves.     

Accumulation of chemical elements in the raised peatbogs of the subtaiga Trans-Urals in the Holocene

The results of studying the variability of the geochemical parameters of the layers of the Sartamskii upland peatbog in the south of Tyumen oblast based on the radiocarbon time scale are given. Four basic types of peat and stages of peat deposits formation in the Holocene are distinguished: the organomineral layer of the sediments in a paleolake (up to 5065 ± 60 years ago), the low moor layer (4300–4900 years ago), the transitional layer (3100–4300 years ago), and the high moor peat (250–3100 years ago). The upper peat layer (last 200–300 years) significantly differs from its main portion; in particular, it is characterized by an increased ash content and the accumulation of a number of elements. The relationship between the various characteristics of the deposit is analyzed using principal component analysis, and the conditions of the formation of the peat deposit in different time periods are estimated, including the climatic conditions (in relative units). The anthropogenic signal of the accumulation of some elements in wetland systems is identified.     

论图书馆数字馆藏资源建设中亟待解决的问题

论述数字馆藏的产生、概念和特点,分析数字馆藏资源建设中存在的问题,探讨数字馆藏资源建设中应采取的策略。     

Variations in the composition of the sap of zea mays with the increase in osmotic pressure of the nutritive solution

The alterations are studied which are produced in the content of mineral elements and organic fractions of sap with the increase in the osmotic pressure of the nutritive solution at levels of 2.0; 3.5 and 5.0 atm., obtained through the addition to the nutritive solution either of magnesium sulphate or PEG‐4000.

Through the effect of the osmotic pressure, the transformations are modified of the nitrogen and mineral phosphorus at organic fractions experience a series of modifications which produce different values in the Nm%TSN and Pm%TSP ratios with respect to control. Through action of the specific effect of magnesium sulphate, the reducing sugars concentrations in sap having an important increase.     

Seasonal changes in the communities of microorganisms and algae in the litters of tree plantations in the steppe zone

Specific structural and dynamic parameters of communities from various ecological and trophic groups of microorganisms and algae in the litter of artificial tree stands were studied using the example of the Staro-Berdyansky Forest in the steppe zone of Ukraine. The composition of the communities was shown to vary by seasons and depend on the forest-forming woody species. In spring, in all the litters, the maximal number of actinomycetes and aminotrophs was recorded; in the leaf litter, the number of phosphate-mobilizing organisms was also the largest. In summer, the development of cellulolytic organisms, ammonifiers, and nitrogen-fixers was intensified; in autumn, the number of micromycetes and oligotrophic organisms decreased. The composition of dominants, the species richness of algae and their abundance also varied by seasons. Representatives of the Chlorophyta division predominated. The highest species richness of algae was characteristic of the spring litter samples, and their number, for the spring and autumn ones. The positive correlation was established between the numbers of micromycetes and oligotrophs, micromycetes and algae. The negative correlation was found between the numbers of micromycetes and actinomycetes, cellulose-decompose bacteria and algae in the litters.     

Changes in the physical properties of soils in the Kamennaya Steppe under the impact of shelterbelts

The physical properties of ordinary chernozems and meadow-chernozemic soils under different land management practices (maple, larch, birch, and pine sections of the shelterbelts; continuous (since 1959) fallow; and arable field (since 1952)) were studied in the Kamennaya Steppe. The soils had favorable physicochemical properties, light clayey texture, and high microaggregation independently from the type of land management. The long-term impact of the shelterbelts improved the soil structure in the upper part of the humus horizon: the content of agronomically valuable aggregates increased, the content of coarse aggregates (>10 mm) decreased, the aggregation coefficient increased by 3.7–4.3 times, and the water stability of the aggregates became by 8–12% higher. The soils under the shelterbelts were characterized by minimum values of the bulk density and solid phase density and by maximum values of the total, active, and air porosities. At the same time, no considerable differences between water reserves in the studied range of soils were detected. The ratio of the optimum productive water range to the active (productive) water range (OPWR/AWR) within the upper soil meter varied from 0.42–0.44 to 0.45–0.54. This points to changes in the character of perched water: the content of intra-aggregate capillary-perched water decreases, and content of film perched water increases down the soil profile.     

近50年博斯腾湖水位变化特征分析

以干旱区博斯腾湖为研究对象,依据博斯腾湖1956—2012年期间的水位监测数据,采用小波分析及MannKendall(M-K)趋势检验等统计学方法,揭示了近50a博斯腾湖水位变化趋势及规律。结果显示:博斯腾湖1956—2012年水位变化分为3个阶段下降(1956—1987年)—上升(1988—2002年)—下降(2003—2012年),其中1956—1987年水位下降了3.39m;1988—2002年上升了3.7m;2003—2012年再次下降了3.21m。水位总体上呈现出显著的下降趋势,且通过了α=0.05时的显著性检验。就其周期性变化规律而言,博斯腾湖水位存在18a的主周期,而38a的周期由于水位资料序列有限难以确定,需要更长的资料序列进行分析验证。     

稳定同位素在植物源性农产品产地溯源研究进展

产地溯源是保护农产品品牌及地区特色产品、防止欺诈、保护消费者权益的有效保障。稳定同位素指纹分析是用于食品产地溯源的有效技术之一,具有高效、准确、可靠的特点。本文系统分析了近5年来,稳定同位素指纹分析技术在植物源性初级农产品、加工农产品溯源中的应用以及稳定同位素在食品加工过程中分馏变化的研究进展。在此基础上,展望了今后稳定同位素在植物源性农产品产地溯源中的研究重点和发展方向。