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| 1 | 降雨强度和坡度双因子对紫色土坡面侵蚀产沙的影响显示文摘利用室内模拟降雨试验研究了降雨强度和坡度双因子对紫色土坡面侵蚀产沙过程的影响。试验结果表明:坡面产沙过程和侵蚀形态的演变与降雨强度和坡度的变化密切相关,降雨强度和坡度增大使径流量很快达到细沟发生的临界流量并加剧细沟形态的演变过程,产沙率由于细沟的产生和发展而急剧增加,并呈现跳跃性的波动。各降雨强度下,在5°~25°范围内,侵蚀量随坡度的增大而增大,30°时开始减小,在25°附近存在坡面侵蚀的临界坡度。降雨强度和坡度两个因子对侵蚀量的贡献率存在对比消长关系。降雨强度和坡度都较小时,坡度对侵蚀过程起主导作用;当降雨强度较大或者达到临界坡度以后,则降雨强度对侵蚀过程起主导作用。 | 耿晓东 郑粉莉 刘力 | 2010 | 泥沙研究2010，35，6： | 66 |
| 2 | Ecosystem carbon stocks and their changes in China's grasslands显示文摘The knowledge of carbon(C) stock and its dynamics is crucial for understanding the role of grassland ecosystems in China's terrestrial C cycle.To date,a comprehensive assessment on C balance in China's grasslands is still lacking.By reviewing published literature,this study aims to evaluate ecosystem C stocks(both vegetation biomass and soil organic C) and their changes in China's grasslands.Our results are summarized as follows:(1) biomass C density(C stock per area) of China's grasslands differed greatly among previous studies,ranging from 215.8 to 348.1 g C m-2 with an average of 300.2 g C m-2.Likewise,soil C density also varied greatly between 8.5 and 15.1 kg C m-2.In total,ecosystem C stock in China's grasslands was estimated at 29.1 Pg C.(2) Both the magnitude and direction of ecosystem C changes in China's grasslands differed greatly among previous studies.According to recent reports,neither biomass nor soil C stock in China's grasslands showed a significant change during the past 20 years,indicating that grassland ecosystems are C neutral.(3) Spatial patterns and temporal dynamics of grassland biomass were closely correlated with precipitation,while changes in soil C stocks exhibited close associations with soil moisture and soil texture.Human activities,such as livestock grazing and fencing could also affect ecosystem C dynamics in China's grasslands. | Anwar MOHAMMAT | 2010 | Science China(Life Sciences)2010，53，7： | 52 |
| 3 | Influence of variation of soil spatial heterogeneity on vegetation restoration显示文摘Numerous hypotheses and conceptional models dealing with the grassland deserti-fication or degradation processes recognize that the invasion of shrubs in grasslands is the most striking feature of the variation of vegetation patterns in the grassland degradation or desertifica-tion processes in arid and semiarid regions. This is because the invasion of shrubs in grasslands increases the heterogeneity of the temporal and spatial distribution of primary vegetation and soil resources. As a result, the biological processes of the soil-vegetation system are increasingly concentrated in the “fertile islands” under shrub canopies, and the soil between shrubs gradually turns into bare area or moving sand under the influences of prolonged wind and water erosion. Most of relative researches support this bio-ecological interpretation for the degraded process of grassland. However, as viewed from the other aspect, the shrub vegetation distributed in patches also serves as the “trigger spots” for the grassland restoration or desertification reversion, and this has been demonstrated by the practices of combating desertification in China. Nearly 50 years of succession of artificial sand-binding vegetation in the Shapotou area and the regional restoration of eco-environment are the theoretical verification and successful example for the desertification reversion. The establishment of artificial vegetation in the region began with the installation of sand fences and planting xerophytic shrubs relying on less than 200 mm of annual precipitation under the non-irrigation condition, this made the moving sand, an originally uni-formly distributed soil resource, occur the variation of spatial heterogeneity. Through the redis-tribution of precipitation and dustfall by the canopy of xerophytic shrubs, litter accumulation and cryptogamic crust development, soil-forming processes under shrub canopies were accelerated; in the meantime, it also created a favorable condition for the invasion and colonization of annual and perennial plant species. However, with the depletion of soil moisture in the deep layer in the sand stabilization area the coverage of shrubs in the sand-binding vegetation lowered from the highest value of 33% to 6%, the dominant position and leading effect of shrubs in the communi-ties were weakened, furthermore they were gradually taken out from the vegetation composition. This correspondingly weakened the spatial heterogeneity of soil resource distribution. The propagation of numerous cryptogams on fixed sand surface and the colonization of annual and perennial plant species promoted the succession and restoration of the vegetation towards herb-dominated vegetation, which are similar to the primary vegetation types of the adjacent steppified desert and desert steppe. This paper, taking nearly 50 years of succession of sand-binding vegetation in the Shapotou region as an example and using the geostatistical method, puts forward and explains the conceptional model of vegetation restoration or desertifi-cation reversion of grassland in arid zones. | LI Xinrong | 2005 | Science China Earth Sciences2005，48，11： | 49 |
| 4 | Invasive mechanism and control strategy of Ageratina adenophora (Sprengel)显示文摘In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion,interaction and competition between inter-and intra-species and community resistance, thereby providing important references to researches on other invasive alien species. | WAN FangHao1, LIU WanXue1, GUO JianYing1, QIANG Sheng2, LI BaoPing2, WANG JinJun3, YANG GuoQing1, NIU HongBang1, GUI FuRong1, HUANG WenKun1, JIANG ZhiLin1 & WANG WenQi3 1State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China 2College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China 3Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China | 2010 | Science China(Life Sciences)2010，53，11： | 42 |
| 5 | Changes in soil organic carbon of terrestrial ecosystems in China:A mini-review显示文摘The present study provides an overview of existing literature on changes in soil organic carbon(SOC) of various terrestrial ecosystems in China.Datasets from the literature suggest that SOC stocks in forest,grassland,shrubland and cropland increased between the early 1980s and the early 2000s,amounting to(71±19) Tg·a-1.Conversion of marshland to cropland in the Sanjiang Plain of northeast China resulted in SOC loss of(6±2) Tg·a-1 during the same period.Nevertheless,large uncertainties exist in these estimates,especially for the SOC changes in the forest,shrubland and grassland.To reduce uncertainty,we suggest that future research should focus on:(i) identifying land use changes throughout China with high spatiotemporal resolution,and measuring the SOC loss and sequestration due to land use change;(ii) estimating the changes in SOC of shrubland and non-forest trees(i.e.,cash,shelter and landscape trees);(iii) quantifying the impacts of grassland management on the SOC pool;(iv) evaluating carbon changes in deep soil layers;(v) projecting SOC sequestration potential;and(vi) developing carbon budget models for better estimating the changes in SOC of terrestrial ecosystems in China. | HUANG Yao*,SUN WenJuan,ZHANG Wen & YU YongQiang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China | 2010 | Science China(Life Sciences)2010，53，7： | 46 |
| 6 | Soil carbon pool in China and its global significance显示文摘SoilcarbonpoolinChinaanditsglobalsignificance￥FangJingyun,LiuGuohua,XuSongling(ResearchCenterforEco-EnvironmentalScience,Chin... | Fang Jingyun, Liu Guohua, Xu Songling(Research Center for Eco-Environmental Science, ChineseAcademy of Sciences, Beijing 100085, China) | 1996 | Journal of Environmental Sciences1996，8，2： | 46 |
| 7 | A temperature prediction-correction method for estimating surface soil heat flux from soil temperature and moisture data显示文摘Surface soil heat flux is a component of surface energy budget and its estimation is needed in land-atmosphere interaction studies. This paper develops a new simple method to estimate soil heat flux from soil temperature and moisture observations. It gives soil temperature profile with the thermal diffusion equation and, then, adjusts the temperature profile with differences between observed and computed soil temperatures. The soil flux is obtained through integrating the soil temperature profile. Compared with previous methods, the new method does not require accurate thermal conductivity. Case studies based on observations, synthetic data, and sensitivity analyses show that the new method is preferable and the results obtained with it are not sensitive to the availability of temperature data in the topsoil. In addition, we pointed out that the soil heat flux measured with a heat-plate can be quite erroneous in magnitude though its phase is accurate. | Kun Yang JieMin Wang | 2008 | Science China Earth Sciences2008，51，5： | 39 |
| 8 | Phosphogypsum stabilization of bauxite residue:Conversion of its alkaline characteristics显示文摘Reduction of the high alkalinity of bauxite residue is a key problem to solve to make it suitable for plant growth and comprehensive utilization. In this study, phosphogypsum, a waste product from the phosphate fertilizer industry, was used to drive the alkaline transformation of the bauxite residue. Under optimal water washing conditions(liquid/solid ratio of 2 mL/g, 30°C, 24 hr), the impact of quantity added, reaction time and reaction mechanism during phosphogypsum application were investigated. Phosphogypsum addition effectively lowered p H levels and reduced the soluble alkalinity by 92.2%. It was found that the concentration of soluble Na and Ca ions in the supernatant increased gradually, whilst the exchangeable Na+and Ca^(2+)in solid phase changed 112 mg/kg and 259 mg/kg, respectively. Ca^(2+)became the dominant element in the solid phase(phosphogypsum addition of 2%, liquid/solid ratio of 2 mL/g, 30°C, 12 hr). X-ray diffraction data indicated that cancrinite and hydrogarnet were the primary alkaline minerals. SEM images suggested that phosphogypsum could promote the formation of stable macroaggregates, whilst the content of Ca^(2+)increased from 5.6% to 18.2% and Na reduced from 6.8% to 2.4%. Treatment with phosphogypsum could significantly promote the transformation of alkalinity cations by neutralization, precipitation and replacement reactions.This research provided a feasible method to promote soil formation of bauxite residue by phosphogypsum amendment. | Shengguo Xue Meng Li Jun Jiang Graeme J.Millar Chuxuan Li Xiangfeng Kong | 2019 | Journal of Environmental Sciences2019，31，3： | 35 |
| 9 | The effect of land use structure on the distribution of soil nutrients in the hilly area of the Loess Plateau,China显示文摘The irrational land use is one of the main reasons for the soil erosion and nutrient loss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in the loess hill slope are selected to study the effect of land use structure on the distribution of soil nutrients. From hill bottom to hill top, the patterns of land use types are:, grassland-slope farmland-forest, slope farmland-grassland-forest, terrace-grassland-forest and slope farmland-forest-grassland. By measuring the contents of the total N, total P, available N, available P and organic matter of soils, the results show that the land use structure types of slope farmland-grassland-forest and terrace-grassland-forest have a better capacity to maintain the soil nutrients. | Bojie Fu Keming Ma Huafeng Zhou Liding Chen | 1999 | Chinese Science Bulletin1999，44，8： | 32 |
| 10 | Changes in plant biomass and species composition of alpine Kobresia meadows along altitudinal gradient on the Qinghai-Tibetan Plateau显示文摘Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of species composition, species richness, the type of different growth forms, and plant bio-mass structure for Kobresia meadow ecosystems, few studies have been focused on the relationship between biomass and environmental gradient in the Kobresia meadow plant communities, particularly in relation to soil moisture and edaphic gradients. We measured the plant species composition, her-baceous litter, aboveground and belowground biomass in three Kobresia meadow plant communities in Haibei Alpine Meadow Ecosystem Research Station from 2001 to 2004. Community differences in plant species composition were reflected in biomass distribution. The total biomass showed a de-crease from 13196.96±719.69 g/m2 in the sedge-dominated K. tibetica swamp to 2869.58±147.52 g/m2 in the forb and sedge dominated K. pygmaea meadow, and to 2153.08±141.95 g/m2 in the forbs and grasses dominated K. humilis along with the increase of altitude. The vertical distribution of below-ground biomass is distinct in the three meadow communities, and the belowground biomass at the depth of 0-10 cm in K. tibetica swamp meadow was significantly higher than that in K. humilis and K. pygmaea meadows (P<0.01). The herbaceous litter in K. tibetica swamp was significantly higher than those in K. pygnaeca and K. humilis meadows. The effects of plant litter are enhanced when ground water and soil moisture levels are raised. The relative importance of litter and vegetation may vary with soil water availability. In the K. tibetica swamp, total biomass was negatively correlated to species richness (P<0.05); aboveground biomass was positively correlated to soil organic matter, soil moisture, and plant cover (P<0.05); belowground biomass was positively correlated with soil moisture (P<0.05). However, in the K. pygnaeca and K. humilis meadow communities, aboveground biomass was posi-tively correlated to soil organic matter and soil total nitrogen (P<0.05). This suggests that the distribu-tion of biomass coincided with soil moisture and edaphic gradient in alpine meadows. | WANG ChangTing1,3, CAO GuangMin1, WANG QiLan1, JING ZengChun1, DING LuMing1 & LONG RuiJun2 1 Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China 2 College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730070, China 3 Graduate University of the Chinese Academy of Sciences, Beijing 100039, China | 2008 | Science China(Life Sciences)2008，51，1： | 31 |
| 11 | Soil water depletion depth by planted vegetation on the Loess Plateau显示文摘Evapotranspiration of much planted vegetation exceeds precipitation, and this can deplete soil water and cause a deep dry layer in the soil profile, which is a serious obstacle to sustainable land use on the Loess Plateau, China. This study aimed to determine water depletion depth of planted grassland, shrub, and forest in a semiarid area on the Loess Plateau. Soil moisture of five vegetation types was measured to >20 m in depth. The vegetation types were crop, natural grasse, seven-year-old planted alfalfa (Medicago sativa L.), 23-year-old planted caragana (Caragana microphylla Lam.) shrub, and 23-year-old planted pine (Pinus tabulaeformis L) forest land. Through comparing moisture of planted alfalfa grass, caragana shrub, and pine forest to crop and natural grassland, the depth and amount of soil water consumed by grassland, caragana brush and pine forest was determined. The depth of soil water depleted by alfalfa, caragana brush, and pine forest reached 15.5, 22.4 and 21.5 m, respectively. | WANG ZhiQiang LIU BaoYuan LIU Gang ZHANG YongXuan | 2009 | Science China Earth Sciences2009，52，6： | 29 |
| 12 | Quantification of soil organic carbon sequestration potential in cropland:A model approach显示文摘Agroecosystems have a critical role in the terrestrial carbon cycling process.Soil organic carbon(SOC) in cropland is of great importance for mitigating atmospheric carbon dioxide increases and for global food security.With an understanding of soil carbon saturation,we analyzed the datasets from 95 global long-term agricultural experiments distributed across a vast area spanning wide ranges of temperate,subtropical and tropical climates.We then developed a statistical model for estimating SOC sequestration potential in cropland.The model is driven by air temperature,precipitation,soil clay content and pH,and explains 58% of the variation in the observed soil carbon saturation(n=76).Model validation using independent data observed in China yielded a correlation coefficient R2 of 0.74(n=19,P<0.001).Model sensitivity analysis suggested that soils with high clay content and low pH in the cold,humid regions possess a larger carbon sequestration potential than other soils.As a case study,we estimated the SOC sequestration potential by applying the model in Henan Province.Model estimations suggested that carbon(C) density at the saturation state would reach an average of 32 t C ha-1 in the top 0-20 cm soil depth.Using SOC density in the 1990s as a reference,cropland soils in Henan Province are expected to sequester an additional 100 Tg C in the future. | QIN ZhangCai & HUANG Yao* State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China | 2010 | Science China(Life Sciences)2010，53，7： | 26 |
| 13 | 紫色土和红壤坡面径流分离速度与水动力学参数关系研究显示文摘土壤剥蚀是土壤侵蚀、搬运和沉积过程中的一个重要子过程,对其定量研究是建立具有明确物理意义侵蚀模型的理论基础。采用放水冲刷法,在3.0m长、1.0m宽的土槽上,通过4个不同坡度(5°、10°、15°、20°)、5个不同放水流量(1.3l/min、3.0l/min、5.5l/min、6.5l/min、8.5l/min)的组合实验,对红壤和紫色土坡面径流分离速度与径流剪切力、单位水流功率、水流功率、过水断面单位能量之间的关系进行了研究。结果表明:在一定的坡度条件下,分离速度随放水流量的增大而增大,而对于相同的放水流量,分离速度呈现出先增大后减小,然后趋于稳定的趋势,且有随放水流量的增大达到峰值的时间有提前趋势。径流剪切力、单位水流功率、过水断面单位能量及水流功率四个参数与分离速度均存在着明显的线性关系,但相对而言,水流功率更能准确反应坡面分离速度的变化情况。实验条件下,红壤坡面土壤剥蚀的临界水流功率值为0.0083N/(m.s),紫色土坡面土壤剥蚀的临界水流功率值为0.062N/(m.s)。 | 丁文峰 | 2010 | 泥沙研究2010，35，6： | 25 |
| 14 | Characterizing the dynamics of soil organic carbon in grasslands on the Qinghai-Tibetan Plateau显示文摘Carbon dynamics of grasslands on the Qinghai-Tibetan Plateau may play an important role in regional and global carbon cycles. The CENTURY model (Version 4.5) is used to examine temporal and spatial variations of soil organic carbon (SOC) in grasslands on the Plateau for the period from 1960 to 2002. The model successfully simulates the dynamics of aboveground carbon and soil surface SOC at the soil depth of 0-20 cm and the simulated results agree well to the measurements. Examination of SOC for eight typical grasslands shows different patterns of temporal variation in different ecosystems in 1960-2002. The extent of temporal variation increases with the increase of SOC of ecosystem. SOC increases first and decreases quickly then during the period from 1990 to 2000. Spatially, SOC density obtained for the equilibrium condition declines gradually from the southeast to the northwest on the plateau and showed a high heterogeneity in the eastern plateau. The results suggest that (i) SOC den-sity in the alpine grasslands shows remarkable response to climate change during the 42 years, and (ii) the net carbon exchange rate between the alpine grassland ecosystems and the atmosphere increases from 1990 to 2000 as compared with that before 1990. | ZHANG YongQiang TANG YanHong JIANG Jie YANG YongHui | 2007 | Science China Earth Sciences2007，50，1： | 25 |
| 15 | 加速溶剂萃取-高效液相色谱串联质谱法测定土壤中农药残留显示文摘1引言土壤中农药残留可分为杀虫剂、除草剂和杀菌剂残留。常见杀虫剂有克百威和甲氰菊酯等,常见除草剂有苯噻酰草胺、乙草胺、丙草胺、喹禾灵和草酮等,常见杀菌剂有烯酰吗啉和稻瘟灵等。克百威是广谱性杀虫剂,它与胆碱酯酶结合不可逆,因此毒性很高;乙草胺是使用量极大的除草剂之一。这两种农药的毒性远高于其它几种常见农药。快速的前处理及稳定的仪器检测是研究土壤中农药残留的关键,尤其是各类型农药的同时检测,不仅可以提高检测效率。 | 闫蕊 邵明媛 鞠福龙 宋大千 张寒琦 于爱民 | 2013 | 分析化学2013，41，2： | 26 |
| 16 | 1980s-2010s中国陆地生态系统土壤碳储量的变化(英文)显示文摘Soil stores a large amount of the terrestrial ecosystem carbon(C) and plays an important role in maintaining global C balance. However, very few studies have addressed the regional patterns of soil organic carbon(SOC) storage and the main factors influencing its changes in Chinese terrestrial ecosystems, especially using field measured data. In this study, we collected information on SOC storage in main types of ecosystems(including forest, grassland, cropland, and wetland) across 18 regions in China during the 1980 s(from the Second National Soil Survey of China, SNSSC) and the 2010 s(from studies published between 2004 and 2014), and evaluated its changing trends during these 30 years. The SOC storage(0–100 cm) in Chinese terrestrial ecosystems was 83.46 ± 11.89 Pg C in the 1980 s and 86.50 ± 8.71 Pg C in the 2010 s, and the net increase over the 30 years was 3.04 ± 1.65 Pg C, with an overall rate of 0.101 ± 0.055 Pg C yr^(–1). This increase was mainly observed in the topsoil(0–20 cm). Forests, grasslands, and croplands SOC storage increased 2.52 ± 0.77, 0.40 ± 0.78, and 0.07 ± 0.31 Pg C, respectively, which can be attributed to the several ecological restoration projects and agricultural practices implemented. On the other hand, SOC storage in wetlands declined 0.76 ± 0.29 Pg C, most likely because of the decrease of wetland area and SOC density. Combining these results with those of vegetation C sink(0.100 Pg C yr^(–1)), the net C sink in Chinese terrestrial ecosystems was about 0.201 ± 0.061 Pg C yr^(–1), which can offset 14.85%–27.79% of the fossil fuel C emissions from the 1980 s to the 2010 s. These first estimates of soil C sink based on field measured data supported the premise that China's terrestrial ecosystems have a large C sequestration potential, and further emphasized the importance of forest protection and reforestation to increase SOC storage capacity. | 徐丽 于贵瑞 何念鹏 | 2019 | Journal of Geographical Sciences2019，29，1： | 25 |
| 17 | Changes in cropland topsoil organic carbon with different fertilizations under long-term agro-ecosystem experiments across China's Mainland显示文摘Topsoil soil organic carbon(SOC) data were collected from long-term Chinese agro-ecosystem experiments presented in 76 reports with measurements over 1977 and 2006.The data set comprised 481 observations(135 rice paddies and 346 dry croplands) of SOC under different fertilization schemes at 70 experimental sites(28 rice paddies and 42 dry croplands).The data set covered 16 dominant soil types found in croplands across 23 provinces of China's Mainland.The fertilization schemes were grouped into six categories:N(inorganic nitrogen fertilizer only),NP(compound inorganic nitrogen and phosphorus fertilizers),NPK(compound inorganic nitrogen,phosphorus and potassium fertilizers),O(organic fertilizers only),OF(combined inorganic/organic fertilization) and Others(other unbalanced fertilizations such as P only,K only,P plus K and N plus K).Relative change in SOC content was analyzed,and rice paddies and dry croplands soils were compared.There was an overall temporal increase in topsoil SOC content,and relative annual change(RAC,g kg-1 yr-1) ranged -0.14-0.60(0.13 on average) for dry cropland soils and -0.12-0.70(0.19 on average) for rice paddies.SOC content increase was higher in rice paddies than in dry croplands.SOC increased across experimental sites,but was higher under organic fertilization and combined organic/inorganic fertilizations than chemical fertilizations.SOC increase was higher under balanced chemical fertilizations with compound N,P and K fertilizers than unbalanced fertilizations such as N only,N plus P,and N plus K.The effects of specific rational fertilizations on SOC increase persisted for 15 years in dry croplands and 20 years in rice paddies,although RAC values decreased generally as the experiment duration increased.Therefore,the extension of rational fertilization in China's croplands may offer a technical option to enhance C sequestration potential and to sustain long-term crop productivity. | WANG ChengJi1,PAN GenXing1*,TIAN YouGuo2,LI LianQing1,ZHANG XuHui1 & HAN XiaoJun1 1Institute of Resources,Ecosystem and Environment of Agriculture,Nanjing Agricultural University,Nanjing 210095,China 2Center of Soil and Fertilizer Quality Monitoring and Test,Agricultural Ministry of China,Beijing 100026,China | 2010 | Science China(Life Sciences)2010，53，7： | 24 |
| 18 | Quantitative relationships between vegetation and several pollen taxa in surface soil from North China显示文摘According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept | LI Yiyin, ZHANG Xinshi & ZHOU Guangsheng1. Department of Urbon and Environmental Sciences, Peking University, Beijing 100871, China 2. Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 3. School of Urban and Environmental Sciences, Northeast Normal University, Changchun 130024, China Correspondence should be addressed to Li Yiyin | 2000 | Chinese Science Bulletin2000，45，16： | 24 |
| 19 | U.S. GEOLOGICAL SURVEY PROGRAMS AND INVESTIGATIONS RELATED TO SOIL AND WATER CONSERVATION显示文摘The U.S. Geological Survey has a rich tradition of collecting hydrologic data, especially for fluxes of water and suspended sediment, that provide a foundation for studies of soil and water conservation. Applied and basic research has included investigations of the effects of land use on rangelands, croplands, and forests; hazards mapping; derivation of flood and drought frequency, and other statistics related to streamflow and reservoir storage; development and application of models of rainfall-runoff relations, chemical quality, and sediment movement; and studies of the interactive processes of overland and channel flow with vegetation. Networks of streamgaging stations and (or) sampling sites within numerous drainage basins are yielding information that extends databases and enhances the ability to use those data for interpretive studies. | W. R. OSTERKAMP and J. R. GRAY Research Hydrologist, U. S. Geological Survey, 1675 W. Anklam Road, Tucson, AZ 85745 U. S. A. Hydrologist, U. S. Geological Survey, 415 National Center, Reston, VA 20192 U. S. A. | 2001 | International Journal of Sediment Research2001，16，3： | 22 |
| 20 | REE TRACER METHOD FOR STUDIES ON SOIL EROSION显示文摘REETRACERMETHODFORSTUDIESONSOILEROSIONTIANJunliang;ZHOUPeihuaandLIUPuling(TheEnglishtextiseditedbyMrs.SUUanandDr.DINGLianzhen... | TIAN Junliang ZHOU Peihua and LIU Puling( Northwestern Institute of Son and Water Conservancy. Acadernia Sinlca and Ministry of WaterResources. Yangling. Shaanxi 712 100. China) | 1994 | International Journal of Sediment Research1994，9，2： | 22 |
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