青藏高原大骨节病流行区环境、食物及人群硒水平研究

为了解青藏高原大骨节病流行区环境、食物及人群硒水平的分布现状,论文通过CNKI、Web of Science和Google Scholar等数据库检索收集了2000—2018年间发表的关于青藏高原大骨节病病区土壤、粮食、饮水及人发硒含量的文献,按拟定标准共筛选出33篇文献并提取有效数据进行统计分析。结果显示,青藏高原大骨节病病区自然环境总体仍处于低硒循环状态,其中耕作土壤、饮水平均硒含量分别为0.147 mg·kg^-1和0.54 μg·L^-1,高原自产青稞、小麦、糌粑平均含硒量分别为9.27、19.08、11.07 μg·kg^-1;而病区儿童整体硒营养水平较1990年以前有明显升高趋势,发硒平均含量为0.234 mg·kg^-1,已基本脱离硒缺乏状态(<0.20 mg·kg^-1);外源性大米的硒含量为43.29 μg·kg^-1;病区儿童发硒水平与土壤总硒含量无明显相关关系(r=0.125,P>0.05,N=23)。青藏高原大骨节病流行区儿童发硒水平与自然环境硒水平不一致的变化趋势提示,随着社会人文因素的干预,外源性硒的输入有所增加,并在一定程度上降低了病区人群对当地低硒环境的依赖性,这可能是青藏高原大骨节病病情稳定下降并得到有效控制的主要原因。     

多元素与大骨节病关系的稳定性研究

对内蒙古三个典型大骨节病区<15岁人群发中21个元素和病情进行了三年连续定期观察,统计分析结果表明:(1)病区食物对人体元素含量的影响可以分为二种情况,一是元素在食物链中含量过低,食物的变化虽可使机体该元素发生变化,但变幅甚小,致使其代谢处于缺乏状态;另一类是机体内这些元素的含量因食物的改变而发生较大变化,显示这些元素与病情无内在联系.(2)对发中硒等2l个元素与病情分别作单相关和多元逐步回归分析,结果证明,硒缺乏是导致大骨节病早期病变的基本因素,而其它元素与病情的关系具有不确定性.     

云南省楚雄地区克山病与生态环境中硒等生命元素关系的动态研究

本研究选定我国南方克山病重病区楚雄市东瓜镇进行了病情与生态系硒等生命元素三年的动态监测。结果表明,克山病病情呈逐渐下降势态,与人体硒水平逐渐上升之间成为显著负相关关系。同时还发现病区人发中As、Hg含量显著高于对照非病点,并认为它们可能是该病区与低硒复合的致病因素。从动态变化的研究为克山病病情与生态系硒的密切关系提供了新的科学依据。     

中国低硒带人群硒营养状态的变化趋势与成因分析

就近20年来中国低硒带人群硒营养状态的变化进行了对比分析,并对其成因作了探讨。自1974～1976年以来低硒带人群的硒营养水平明显提高,一般经济发展较快的地区提高幅度较大,边陲贫困地区仍处于较低水平。在人群中的变化也不均衡,发硒含量≤0.100μg/g的地区硒易感性疾病患病率仍较高,>0.150μg/g的人群占绝对优势的地区病情基本得到控制,病区自然消退。经济发展,物质交流。居民膳食结构改变以及外源性硒输入是低硒带人群硒营养水平提高的主要原因。我国克山病、大骨节病将随着居民硒营养水平的不断提高得到基本控制。     

山东省生态环境中硒及其有关元素与克山病关系*

山东省克山病主要分布于鲁中南低山丘陵棕壤与褐土的复合区,化学生态环境为微量元素缺乏区,尤其是元素硒的贫乏是克山病区的共同特征。在同一地点间隔十年的追踪调查表明,近几年来病情减轻的原因与人体硒水平上升有密切关系。1987年与1976年相比,由于病区居民硒摄入量随着膳食构成比例的变化而提高,未服硒地区的人发硒值与服硒点的人发硒值呈同样上升趋势。复合病因研究表明,克山病从环境到人体低Se外,低Mo高Mn、V等元素的不协调,可能起着与低Se复合致病作用。     

西藏大骨节病区的地理环境特征

西藏90%以上的大骨节病县分布在高山温带环境中,病区最暖月平均气温在10~18℃之间,≥0℃日数在180~350天之间;病区集中分布在喜马拉雅山与冈底斯山和念青唐古拉山之间以及横断山北段山间地带的山区或高山谷地地区,病县山地、丘陵占78.4%,非病县山地、丘陵面积占66.7%;就海拔高度而言,病区主要分布在3600~4000m之间;病区涉及多种类型的耕作土壤,其中酸性棕壤和暗棕壤、灰褐土和石灰性褐土、褐土性土等淋溶、半淋溶土壤类型是大骨节病集中分布区;在高山土壤类型中病区趋于分布在典型亚高山草甸土和山地灌丛草原土地带,而亚高山草原土带相对较少。西藏大骨节病区地理环境特征既与内地大骨节病区有很强的相似性,又因其独特的地域分异格局而具特殊性。     

人体发育过程中硒的动态及其与大骨节病的关系

大骨节病(Kaschin-Beck Disease)是一种慢性关节畸形病,主要表现为骨关节及其他组织营养不良性退行性病变。本病流行于我国低硒地带中的低硒环境,人体处于贫硒营养状态时,机体含硒酶一谷胱甘肽过氧化物酶(GSH-px)活性显著降低;临床实践证明亚硒酸钠和亚硒酸钠伍用维生素E对本病疗效极为显著。因此,作者认为大骨节病是低硒环境所产生的生物效应,而在正常硒环境并无本病流行。     

我国低硒带典型景观植物硒的研究

本研究在我国低硒带的东北端和西南端分别选取了针阔叶混交林景观和云南松林景观,并且在低硒带内的克山病和大骨节病非病区与东南非病带选取了落叶阔叶林景观和马尾松林景观为对照景观,系统地采集了上述各不同景观的主要植物和土壤,对硒进行了分析。结果发现,在我国低硒带的东北瑞和西南瑞景观的主要植物含硒量显著地低于对照景观,同时景观内土壤硒也明显地低于划分我国低硒生态景观的阈值,从天然植物的角度进一步对我国低硒带客观存在这一科学论断进行了补充。     

我国低硒地带人群全血硒含量及其与大骨节病关系的研究

本文指出我国低硒环境中人群硒的营养状态受环境控制。全血硒均值与动物硒反应症临界值(0.02微克/毫升)相同,其时空和在人群中的变化规律与大骨节病流行病学规律相一致。人体硒营养水平与发病率呈非常显著之负相关,提示大骨节病可能是典型的人体硒反应症。     

西藏山地淋溶土系列与大骨节病分布的关系

通过西藏大骨节病县与非病县棕壤与暗棕壤各土属、土种的分布面积的对比分析对西藏耕型棕壤和暗棕壤分布与西藏大骨节病区分布的关系进行研究.结果表明,西藏大骨节病的分布与棕壤、暗棕壤为主的耕型淋溶土壤的分布有一定的联系,但土壤母质和发育程度不同,对大骨节病的分布影响不同.对于残坡积土壤,病区趋于分布在泥质土壤环境,而麻砂质土壤基本是大骨节病的非病区.同样的母质环境,大骨节病区趋于分布在土壤厚度较小,发育程度较低的地区;就洪积土壤来说,其与大骨节病分布的关系似乎与土壤质地有一定的联系,底部砾石含量高的土壤多集中在大骨节病地区.总体而言,山地棕壤、暗棕壤环境是西藏大骨节病区的主要土壤类型之一,西藏未开发的自然棕壤和暗棕壤环境将是大骨节病潜在危险区,因此系统研究西藏典型大骨节病区的土壤分异对探讨未来西藏大骨节病的分布与流行有重要意义.     

空间分析与生物地球化学循环:西藏林周县大骨节病患病村与非患病村的比较研究

西藏林周县是我国大骨节病(KBD)患病较为严重的地区之一,本文将林周县作为研究区,通过使用地理探测器(GeoDetector)量化分析KBD患病率风险因子的影响,并使用环境化学方法验证空间分析结果。通过对10个潜在影响因子的分析以及对当地KBD患病村和非患病村的土壤-水-粮食-人这一生物地球化学循环的环境化学分析,结果表明:(1)林周县KBD由一组多重且交互作用的环境影响因子共同作用影响,其中最重要的控制因子是地层因子;(2)所有环境介质(土壤、水、谷物)及人体组织中的硒元素浓度在KBD患病区均低于非患病区;(3)当地居民对硒和铬的摄入严重不足,尤其是KBD患病村中居民硒元素平均日摄入量(ADD)大约仅为世界卫生组织(WHO)建议的成人基本摄入量下限的4%;(4)我们推测,当地居民患病主要是由于地层这一影响因子,这是由于通过生态系统的迁移转化导致当地人口严重硒缺乏,最终导致地方性生物地球化学硒缺乏。     

西藏山地半淋溶土壤分布与大骨节病关系研究

通过西藏大骨节病县与非病县山地耕型褐土和灰褐土各土壤亚类的对比分析表明，山地褐土和灰褐土环境是西藏大骨节病主要土壤类型。其中大骨节病县有3.2万公顷耕种褐土，占全部耕种褐土的89.4%，而非病县仅0.4万公顷，占10.6%；同样，近3.9万公顷的耕种灰褐土分布在病县，占全部耕种灰褐土的97.4%，而非病县仅0.1万公顷，占2.6%。相似的半淋溶耕型土壤环境，雅鲁藏布江南岸多为非病区，北岸多为病区，可能与北岸念青唐古拉山和南岸喜马拉雅山的岩性和成土物质来源差异有关。同时土壤水土流失也可能是影响大骨节病分布的重要因素，水土流失严重的地区多为病区，而非病区多分布在地势较平坦的地区。因此系统研究西藏典型大骨节病区的土壤分异及其土壤侵蚀程度的差异对探讨未来西藏大骨节病的分布与流行有重要意义。     

青藏高原边界地区天然水的水化学性质及其成因（英文）

The special geography and human environment of the Qinghai-Tibet Plateau has created the unique hydrochemical characteristics of the region's natural water, which has been preserved in a largely natural state. However, as the intensity of anthropogenic activities in the region has continued to increase, the water environment and hydrochemical characteristics of the Qinghai-Tibet Plateau have altered. In this study, water samples from the western, southern, and northeastern border areas of the Qinghai-Tibet Plateau, where human activities are ongoing, were collected, analyzed, and measured. The regional differences and factors controlling them were also investigated. The key results were obtained as follows.(1) Differences in the physical properties and hydrochemical characteristics, and their controlling factors, occurred in the different boundary areas of the Qinghai-Tibet Plateau. These differences were mainly the consequence of the geographical environment and geological conditions.(2) The water quality was good and suitable for drinking, with most samples meeting GB(Chinese national) and WHO(World Health Organization) drinking water standards.(3) The chemical properties of water were mainly controlled by the weathering of carbonates and the dissolution of evaporative rocks, with the former the most influential.(4) The biological quality indicators of natural water in the border areas were far superior to GB and WHO drinking water standards.     

Effects of Simulated Diurnal Asymmetrical Warming on the Growth Characteristics and Grain Yield of Winter Highland Barley in Tibet

There has been an obvious diurnal asymmetrical warming effect as a result of the overall climate warming in the Tibetan Plateau. To reduce the uncertainty caused by the diurnal asymmetrical warming effect on future food security predictions in the Tibetan Plateau, this study used winter highland barley (var. Dongqing No. 1) for the experimental materials, and the FATI (Free Air Temperature Increase) field open heating system to carry out a simulated diurnal asymmetrical warming experiment (AW: All-day warming, DW: Daytime warming, NW: Nighttime warming, CK: Control) for two growing seasons (2018-2019 and 2019-2020) at the Lhasa Agroecosystem Research Station. The growth characteristics and yield of Tibetan winter highland barley were investigated in this study. Compared to the control, all the AW, DW and NW treatments had significant effects on the phenological period of winter highland barley, with the advancement of the phenological phase and shortening of the whole growth period. The degree of influence was AW>NW>DW, and all the AW, DW and NW treatments shortened the interval from sowing to heading of winter highland barley and increased the interval from heading to maturity. The effect on the phenological phase was the most obvious for AW and reached a statistically significant level (P<0.05). During the generative growth phase, the biomass above-ground and plant height of winter highland barley had an increasing tendency under the different warming conditions. In the late growth period, the biomass above-ground and plant height of the NW treatment were significantly higher than those of the other treatments. In addition, the warming caused a decrease in the dry matter distribution proportions of leaves and stems at the mature stage, and an increase in the distribution ratios of roots and spikes; and the AW, NW and DW treatments increased grain yields by 16.4%, 24.6% and 9.5%, respectively, on average in the two years. The increasing effect on grain yields of the NW treatment reached a significant level compared with the control in 2019-2020 (t=-2.541, P=0.026). In terms of yield composition, the effective spike number and 1000-grain weight tended to increase. The grain number per spike tended to increase, except for the AW treatment, while panicle length and seed setting rate tended to decrease, except for the NW treatment. Therefore, the effects of different simulated diurnal asymmetrical warming treatments on the growth characteristics and yield of winter highland barley were variable in the Tibetan Plateau.     

Estimation of Critical Rainfall for Flood Disasters in the Qinghai-Tibet Plateau

According to the results of The Second Comprehensive Scientific Expedition on the Qinghai-Tibet Plateau, the balance of solid and liquid water on the Qinghai-Tibet Plateau is disturbed, and a large amount of solid water, such as glaciers and perpetual snow, is transformed into liquid water, which aggravates the risk of flood disasters in the Plateau. Based on the historical flood disaster records of the Qinghai-Tibet Plateau, this paper analyzed the temporal and spatial distribution characteristics of the flood disasters in the Plateau, and estimated the critical rainfall for the flood disasters combined with precipitation data from the meteorological stations in each basin of the Qinghai-Tibet Plateau. The results show that most of the flood disaster events in the Plateau are caused by precipitation, and the average annual occurrence of flood disasters is more than 30 cases and their frequency is on the rise. The high frequency areas of flood disasters in the Qinghai-Tibet Plateau are mainly in the Hehuang Valley and the Hengduan Mountains area; the secondary high frequency areas are located in the valley area of South Tibet and the peripheral area of the Hehuang valley. Finally, we found that the highest critical rainfall value of flood disasters in the Qinghai-Tibet Plateau is in the southern area of the plateau, followed by the eastern and southeastern parts of the plateau, and the lowest values are in the central, western and northern parts of the Plateau.     

Response of Microbial Communities in Soil to Multi-level Warming in a Highland Barley System of the Lhasa River

No studies have examined the effect of experimental warming on the microbial biomass and community composition of soil in agricultural ecosystem on the Qinghai-Tibet Plateau. Thus it is unclear whether the influences of experimental warming on microbial communities in soil are related to warming magnitude in croplands on this Plateau. This study performed warming experiment (control, low- and high-level) in a highland barley system of the Lhasa River in May 2014 to examine the correlation between the response of microbial communities in soil to warming and warming magnitude. Topsoil samples (0-10 and 10-20 cm) were collected on September 14, 2014. Experimental warming at both low and high levels significantly increased soil temperature by 1.02 ℃ and 1.59 ℃, respectively at the depth of 15 cm. Phospho lipid fatty acid (PLFA) method was used to determine the microbial community in soil. The low-level experimental warming did not significantly affect the soil’s total PLFA, fungi, bacteria, arbuscular mycorrhizal fungi (AMF), actinomycetes, gram-positive bacteria (G⁺), gram-negative bacteria (G^-), protozoa, the ratio of fungi to bacteria (F/B ratio), and ratio of G⁺ to G^- (G⁺/G^- ratio) at the 0-10 and 10-20 cm depth. The low-level experimental warming also did not significantly alter the composition of microbial community in soil at the 0-10 and 10-20 cm depth. The high-level experimental warming significantly increased total PLFA by 74.4%, fungi by 78.0%, bacteria by 74.0%, AMF by 66.9%, actinomycetes by 81.4%, G⁺ by 67.0% and G^- by 74.4% at the 0-10 cm depth rather than at 10-20 cm depth. The high-level experimental warming significantly altered microbial community composition in soil at the 0-10 cm depth rather than at 10-20 cm depth. Our findings suggest that the response of microbial communities in soil to warming varied with warming magnitudes in the highland barley system of the Lhasa River.     

青藏高原地区城乡虚拟水贸易格局与影响因素

青藏高原是亚洲水塔,其水资源与水生态环境保护意义重大。从虚拟水视角,研究青藏高原与外部的水资源贸易关系和影响因素,有助于理解该地区的水资源问题、制定虚拟水贸易策略、优化区域城乡水资源配置、保障亚洲水塔功能。依托2012年中国区域间投入产出表成果,本文测算了青藏高原与中国其他区域之间的虚拟水贸易关系,建立了中国区域城镇与农村地区的虚拟水贸易网络,采用对数平均迪氏指数模型分析了青藏高原对其他区域虚拟水贸易不平衡的影响因素。结果表明,青藏高原向中国其他区域净输出虚拟水2.25亿m³,其中向西南、华北、华中、华东、华南等5个区域净输出虚拟水,从西北和东北2个区域净输入虚拟水。城乡之间虚拟水贸易联系非常紧密,农村地区生产水足迹较高,而城镇地区由于人口密度较高、消费水平较高,是虚拟水最终消费的热点区域,青藏高原农村地区的虚拟水贸易量大于城镇地区的虚拟水贸易量。青藏高原贸易输出结构以农产品为主导,虚拟水净输出12.7亿m³;青藏高原与其他区域贸易存在逆差,贸易量因素导致虚拟水净输入8.6亿m³;用水效率在青藏高原与不同区域虚拟水贸易中的正负效应不一,总体带来青藏高原虚拟水净输入1.8亿m³。未来,应重点通过灌溉节水减少农业水足迹,引导城镇居民向低水足迹生活方式转变,鼓励内地为青藏高原提供物质与技术支援,实行水资源生态补偿政策,以保护青藏高原水资源,促进区域水资源可持续利用。     

青藏高原农业现代化时空分异及其驱动机制

农业现代化是当代农村建设的重要内容和社会经济文明发展的重要衡量标准。本文基于1990—2017年青藏高原统计数据,构建农业现代化综合指标体系,运用熵值法计算各指标权重,进而获得农业现代化指数和各项指标贡献度,以此评估高原农业现代化发展时空特征和驱动因子。研究结果表明：① 1990—2017年青藏高原农业现代化水平普遍偏低（全区平均农业现代化指数为0.15）,呈增加趋势;② 从空间上看,农业现代化水平相对较高的地区分散在高原北部、西南部、南部边缘和一江两河的德格县、湟中县、白朗县、浪卡子县等部分县域;③ 农业现代化指标中,单位耕地面积用电量、有效灌溉率和土地生产率对高原农业现代化水平影响最大（对农业现代化指数的贡献度分别为13%、12%和11%）,其中单位耕地面积用电量和土地生产率增加促进了农业投入水平和农业产出水平,是农业现代化的主要正向驱动因子;单位耕地面积农药使用量的增加不利于环境可持续发展,是农业现代化的主要负向驱动因子。