基于高通量测序和代谢组学解析重金属污染对农田微生物群落组成和功能的影响

重金属污染会影响微生物组成和群落结构,其与微生物的相互关系一直是重金属污染生态学研究的热点.河南省新乡市是中国著名的电池生产城市,因电池生产废水污灌造成严重的土壤重金属污染.目前有关新乡市长期灌溉电池废水造成的重金属污染对微生物群落组成和代谢功能的影响鲜见报道.采集了新乡市某长期生产电池厂旁3个重金属污染位点,重金属含量测定表明Cd和Pb超过相关标准,分别超标34~66倍和1.5~2.32倍.采用高通量测序分析了细菌和真菌群落组成,结果表明细菌由芽孢杆菌属、节杆菌属、鞘氨醇单胞菌属和类诺卡氏菌属等优势属,真菌由油壶菌属、小不整球壳属、Gibellulopsis和被孢霉属等优势属组成,表明经过长期的重金属胁迫,新乡长期重金属污染土壤富含重金属抗性细菌和真菌.环境因子和微生物群落相关性分析表明,总量Cu、DTPA提取态Cu和水溶态Pb显著影响细菌群落组成,总量Cd、Ni、Pb、Zn、DTPA提取态Cu和水溶态Pb显著影响真菌群落组成.目前,关于重金属污染对微生物群落代谢影响的研究较少,采用非靶向代谢组学分析表明,不同位点间代谢产物具有差异.通路富集分析表明,这些差异代谢物涉及代谢过程、环境信息处理和翻译等遗传信息加工等,在微生物缓解重金属导致的胁迫和环境适应中可能起到作用.     

新时代国土空间功能的科学认知与研究框架

中国正面临着城乡土地结构失衡、国土空间开发失序、地域主体功能失调等诸多问题,这给新时代国土空间开发、保护与治理带来巨大压力和挑战。国土空间功能作为架构国土空间规划理论体系与实践框架的重要内容,也是考察人与自然和谐共生的重要刻度。基于当前重大战略决策的理论与现实诉求,指出地域功能是衍生国土空间功能概念的逻辑起点,人地关系地域系统理论是构建国土空间功能理论体系的内核,而空间整合是国土空间功能理论体系演进的重要向度;从战略决策、主体功能、底线管控、用途管制、分区管治、空间协同等六个方面构建了国土空间功能理论认知模型（雪花模型）,辨析了新时代国土空间功能研究的科学价值;对新时代国土空间功能研究的学理认知、分类识别、演化机制、动态权衡等基本问题域进行讨论,初步构建了国土空间功能的研究框架。     

Conversion Margins for the Major Uses of Agricultural Land and Their Variations in Shandong Province, China

It is of practical significance for the decision-making on country food security and farmland protection to analyze the conversion margins for the major uses of agricultural land and their variations. Based on the panel data of wheat, corn, vegetable, fruit, and forests productions from 520 investigated farmer households of 13 investigated villages in Shandong Province from 2003 to 2009, and using Cobb-Douglas production function, the revenue conversion margins can be obtained separately, between different grain-crops (wheat, corn) and different non-grain crops (vegetable, fruit, forests), and the conversion relationship between growing grain( wheat, corn) and going out for non-farm work. The results show that from 2003 to 2009, growing wheat and corn are more economically and reasonably for farmers, compared with growing vegetable, but growing wheat and corn are becoming less economically and less reasonably day by day, compared with planting forests. Moreover, the conversion margin between wheat and fruit shows obvious scissors difference. Just from 2007, farmers’ growing fruit became economically and reasonably, but until 2009, compared with going out to work after abandoning farm8land, growing wheat had no economic rationality. From 2003 to 2009, farmers’ growing corn is more profitable than growing fruit and going out for non-farm work after abandoning farmland. The subsidies for wheat and corn have increased farmers’ comparative income from food production remarkably, but the subsidies cannot change the general tendency that farmers transform food (wheat, corn) production into non-food (especially forests) production. The revenue difference between growing wheat, corn and vegetable and growing fruit and forests is being pulled ceaselessly bigger, and the tendency that farmers transform wheat, corn and vegetable growing lands into fruit and forests growing lands has become increasingly apparent.     

Measuring eddy covariance fluxes of ozone with a slow-response analyser

Ozone (O₃) fluxes above a temperate mountain grassland were measured by means of the eddy covariance (EC) method using a slow-response O₃ analyser. The resultant flux loss was corrected for by a series of transfer functions which model the various sources of high- and, in particular, low-pass filtering. The resulting correction factors varied on average between 1.7 and 3.5 during night and daytime, respectively. A cospectral analysis confirmed the accuracy of this approach. O₃ fluxes were characterised by a comparatively large random uncertainty, which during daytime typically amounted to 60%. EC O₃ fluxes were compared against O₃ flux measurements made concurrently with the flux-gradient (FG) method. The two methods generally agreed well, except for a period between sunrise and early afternoon, when the FG method was suspected of being affected by the presence of photochemical sources/sinks. O₃ flux magnitudes and deposition velocities determined with the EC method compared nicely with the available literature from grassland studies. We conclude that our understanding of the causes and consequences of various sources of flux loss (associated with any EC system) has sufficiently matured so that also less-than-ideal instrumentation may be used in EC flux applications, albeit at the cost of relatively large empirical corrections.     

拉市海流域胁迫因子及其影响

拉市海流域位于云南丽江市玉龙县境内，其内的拉市海湿地是我国重要的高原湿地之一。拉市海湿地在调节气候、提供水源和提供珍稀物种栖息地等方面发挥着重要生态作用。分析了拉市海流域的主要胁迫因子：气候、农业活动、火烧、围堰及其它水利工程。在这些胁迫因子综合作用下，拉市海湿地生态系统的结构与功能发生了明显的变化。目前，拉市海湿地水域部分，出现“孤岛化”现象，湿地生物多样性剧减，湿地生态功能显著下降。在分析胁迫因子及其影响下，提出目前应尽快拆除围堰，注重湿地保护和合理利用，建立区域生态补偿机制的策略。     

Prenatal evaluation of fetal renal function based on serum beta2-microglobulin assessment

The relationship between fetal renal function (FRF) and fetal serum beta₂-microglobulin (B2MG) was investigated by comparing its value in 112 unaffected fetuses with that of 23 fetuses presenting with urinary tract malformations (UTM). Fetal serum level of B2MG was totally unrelated to gestational age; its value increased in cases of severe impairment of FRF but was similar to controls in all mild uropathies (p<0.05). Evaluating serum B2MG could be beneficial in fetuses with severe renal damage, but is of no use in unilateral UTM since only the global FRF is tested and not the function of each single kidney. Copyright © 2001 John Wiley & Sons, Ltd.     

耕地生态经济系统集约度的测算

农业生产中生物、工程等科学技术间的相互作用的耕地生态经济系统是人们参与控制的自然与生物间物质与能量交换的主要载体 ,它也是自然再生产和经济再生产有机结合及其与自然条件相互联系、相互协调的有机整体。科学的评价该系统的集约化程度是耕地、劳动力和资金等资源优化配置以及耕地保护有关政策的关键内容 ,将为土地集约利用是实现经济增长方式根本转变提供科学依据。根据耕地生态经济系统的经济增长特点 ,利用耕地生态经济系统的全要素生产函数 ,导出以科学相关的资源生产率为基础的耕地经营的集约度和以资源数量变化相关粗放度的测算方法 ,在此基础上建立了耕地生态经济系统经营模式评价模型。并对江西临川耕地生态经济系统集约经营模式分析和验证。     

土地利用结构变化及其生态服务功能响应——以广东省湛江市为例

为了分析土地利用结构变化对生态系统服务价值的影响,以湛江市为例,利用1996-2005年土地利用变更调查数据,采用谢高地等提出的生态系统服务价值当量因子表,分析了生态系统服务价值对土地利用结构变化的响应.结果表明,湛江市在1996-2005年间土地利用结构的多样性和均匀度增加而优势度降低;生态系统服务价值有较明显变化,但不规律,表现出时增时降的波动态势;生态系统服务价值与土地利用多样化指数、多样性指数、优势度指数、均匀度指数等没有明显的相关性.     

西溪国家湿地公园水质时空分异特征研究

西溪湿地公园作为第一个国家湿地公园和城市湿地公园的代表,具有特殊的功能特征.利用2009年春夏两季对西溪湿地水质的月监测数据,揭示城市湿地公园水质时空分异和污染特征.结果表明,①湿地水质空间分异与公园功能特征密切相关.其中,自然水塘的TN、TP平均值分别为0.78 mg/L和0.07 mg/L;观赏水塘TN、TP平均值分别为1.37 mg/L和0.17 mg/L;自然河溪水质TN、TP的平均值分别为2.91 mg/L和0.18 mg/L;游览水道TN、TP平均值分别为1.91 mg/L和0.09 mg/L;②湿地水体富营养化程度时间变化显著.西溪湿地水质的春季富营养化程度小于夏季,总体处于中度富营养化状态;③不同功能湿地水体富营养化程度差异明显.水塘水体富营养化程度低于河溪富营养化程度,其中,自然水塘水质的富营养化程度低于观赏水塘的水质,相反,游览河溪水质富营养化程度低于自然河溪的水质.因此,加强对观赏水塘和自然河溪的管理,是提高西溪湿地水质的有效方法.     

地级以上城市的城市职能分类——以江浙沪地区为例

城市职能是城市在区域发展中所承担的分工。在国家或区域范围内,按照城市职能的相似性和差异性,研究城市与城市之间的分工,可以得到城市体系的职能结构。要得到城市体系的职能结构,首先要进行城市职能分类。对城市职能分类的方法经历了从简单到复杂、从定性到定量、从单指标到多指标的过程。以江浙沪地区25个地级以上城市为例,按照多因素分析和统计分析相结合的方法,研究得到这一城市体系的城市职能结构。上海是处于第一层级的综合性巨型城市,南京、杭州是处于第二层级的综合性特大城市,宁波、温州、绍兴、苏州、无锡是处于第三层级的综合性或专业化大城市,南通、盐城、徐州、金华是处于第四层级的综合性或专业化中等城市,其它12个城市则是处于第五层级的小城市。