东部平原矿区复垦土壤微生物群落特征及其组装过程

复垦对恢复矿区土壤生产力极为重要,但复垦土壤生产力重建的微生物学机制尚不清晰.为此,采集复垦8 a、复垦11 a、复垦14 a和复垦17 a这4个复垦时长和1个未复垦对照共75个表层土样进行16S rRNA扩增子高通量测序,分析微生物群落组成、潜在功能及其组装机制.结果表明：(1)群落丰富度随复垦时间增加而增加,且高于对照样.但群落多样性和均匀度却随复垦时间增加而降低(P<0.05);(2)复垦土壤中酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)占主导地位,且前两者相对丰度显著高于对照样(P<0.05),后两者则相反(P<0.05);(3)复垦土壤中辅酶转运与代谢、翻译、核糖体结构与生物发生等8种功能呈正向演替,随复垦时长不断增强;(4)平原矿区微生物群落生态网络模块性良好,且关键类群多属酸杆菌门和拟杆菌门.群落组装以确定性过程为主导,同质性选择贡献最大,主要受当地特殊环境操控.这些发现为改善复垦土壤生产力和生态服务提供了理论依据.     

外源Fe调控根系微生物群落结构和功能对水稻Cd积累的影响

探究外源铁（Fe）在水稻镉（Cd）阻控效应方面的研究对保障粮食安全具有重要意义.通过水培实验,研究了3种Fe浓度（5、50和500 μmol·L^-1 EDTA-Na₂Fe）对水稻Cd的积累效应和根系微生物群落结构的影响.结果表明,环境Fe浓度的增加促使水稻根表铁膜的形成,缺Fe和Fe充裕情况下均会促进根表铁膜对Cd的吸附固定.和正常Fe相比,缺Fe促进根Cd和地上部Cd累积,分别增加了49.76%和15.68%;而Fe充裕促进了根Cd的积累,增加了18.39%,但显著降低地上部Cd的含量,降低幅度为35.95%.采用16S rRNA高通量测序测定根系微生物群落结构并通过PCA、LEfSe和RDA等分析方法发现,和正常Fe相比,缺Fe环境会降低根系微生物的丰富度和均匀度,在门水平下Proteobacteria和Bacteroidetes为优势菌群,缺Fe抑制Bacteroidetes相对丰度的增加,Fe充裕使Proteobacteria相对丰度降低.而在属水平功能微生物Ensifer、Rhodopila、Bdellovibrio和Dyella等的相对丰度在不同处理下发生改变,可能通过影响根表铁膜的形成和其他生化过程继而影响水稻对Cd的吸收和积累.并且缺Fe环境对微生物功能影响高于Fe充裕环境.为探寻不同Fe环境下调控水稻根系微生物的群落结构变化,以降低水稻对Cd的吸收转运能力,进而为Fe对Cd的阻控机制提供理论依据,并为我国南方稻田Cd污染治理提供重要参考.     

Biogeographic distribution patterns of algal community in different urban lakes in China: Insights into the dynamics and co-existence

Urban lake ecosystems are significant for social development, but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale. In this study, we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community. The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas. Chlorophyta was the dominant phylum, followed by cyanobacteria in all areas. The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas, respectively. Redundancy analysis and structural equation model revealed that nutrients and pH were dominant environmental factors that affected the algal community, and they showed higher influence than that of iron, manganese and COD _Mn concentration. Importantly, algal community and density exhibited longitude and latitude relationship. In general, these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes, thereby having potential applications for management of the lakes.     

西安市春季生物气溶胶的分布特征和健康影响

西安春季经常出现大量飞絮,易造成空气污染并引发居民哮喘等健康风险.采集西安市春季不同观测点(交通样点和校园样点)生物气溶胶、 PM_2.5和飞絮样品,通过恒温培养和高通量测序等方法研究可培养生物气溶胶的浓度变化、粒径分布,PM_2.5和飞絮携带的微生物的来源、群落结构和健康影响.结果表明,可培养细菌浓度在交通样点高于校园样点(P=0.027);交通样点可培养细菌浓度为真菌的2.7倍,而校园样点可培养真菌浓度高于细菌(1.4倍).可培养细菌和真菌日内最高浓度均出现在08:00;可培养细菌粒径呈双峰分布,真菌为单峰分布.土壤和植被是大气微生物的主要来源(占比85.9%),变形菌门(Proteobacteria)是飞絮和PM_2.5中共有的、丰度最高的菌门,在飞絮中占比达到91.3%(交通样点)和99.1%(校园样点);在PM_2.5样品中放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、蓝藻门(Cyanobacteria)和异常球菌-栖热菌门(D...     

四川森林资源的可持续发展

四川森林是我国三大林区之一“青藏高原东部林区”的重要组成部分，该区的森林植被是维系长江流域生态平衡的主要天然屏障。本区森林资源能否持续发展整关长江流域的生态安全。通过对四川森林资源的现状，特点和存在问题的分析表明，四川森林资源丰富，具很高的生物多样性，发展潜力大，是重要的生态屏障，但天然林多、人工林少、林地土中退化严重，资源分布不均，树种单一，森林结构不合理，引种与林副产品的开发也存在许多问题，经济、生态效益差，也是森林植被生态系统的脆弱区之一。要促进该省森林资源的可持续发展，保护其生物多样性，发挥潜力，增强生态屏障作用，必须走以保护为主，多渠道开发，经济与生态效益并重的综合发展之路。     

Hybrid economy research in remote Indigenous Australia: seeing and supporting the customary in community food economies

Hybrid economy research in remote Indigenous Australia is what Gibson-Graham [2008. Diverse economies: performative practices for “other worlds”. Progress in Human Geography, 32 (5), 613–632] describe as a performative ontological project. This research seeks to address the marginalisation of customary economic activities that contribute to the well-being of Indigenous Australians. It aims to make the customary sector more real, more credible and more viable as an object of policy and activism, challenging the dual dominance of the state and the market as the focus of development (cf. Gibson-Graham 2008 Gibson-Graham, J. K. 2008. Diverse economies: performative practices for “other worlds”. Progress in Human Geography, 32(5), 613–632. doi: 10.1177/0309132508090821[Crossref], [Web of Science ®] , [Google Scholar]). This paper outlines how hybrid economy research has sought to broaden views of the economic landscape in remote Indigenous Australia amid the withdrawal of key policy and programmatic support by the Australian Government. This research draws on Canadian national surveys of Indigenous peoples, harvest studies and programmatic support for customary harvest – hunting, fishing and gathering of bush foods – to identify ways in which the Australian Government might better see and support Indigenous community food economies.     

贵阳市生态文明绿色社区建设与探索

贵阳市有93个社区,27个社区达到了贵阳市市级生态文明绿色社区创建要求。但是,在建设过程中,各个社区特色仍不突出,建设内容的针对性不明显。通过对贵阳市生态文明绿色社区创建机遇、现状及存在问题的调查分析,针对生态文明理念建设、绿化系统建设、垃圾处理、排污系统及创建实施保障建设进行探索研究,并就存在问题提出了建议措施。     

桂林市菜地土壤和蔬菜铅含量调查与污染评价

从桂林市采集566个蔬菜样品以及相对应的160个菜地土壤样品,同时还采集了背景土壤样品32个,测试其w(Pb),结合GIS制图和数理统计,对土壤铅空间分布特征、土壤和蔬菜中Pb的含量与富集特征进行了分析. 结果表明:桂林市土壤w(Pb)空间差异大,呈西南低、东部和北部高的特点;桂林市菜地土壤w(Pb)的范围、算术平均值和几何平均值分别为10.14～249.00、43.80和38.62 mg/kg,与背景土壤相比,菜地土壤铅积累显著(P为0.001). 蔬菜(以鲜质量计)中w(Pb)范围、中值和几何平均值分别为0.001～1.425、0.050和0.042 mg/kg,综合超标率为6.71%;叶菜类蔬菜w(Pb)显著高于根茎类和瓜果类,甘蓝、萝卜、西红柿和豆类的抗铅污染能力最强,而辣椒和茼蒿的抗铅污染能力则较差;桂林市居民人均通过蔬菜消费摄入铅的量为13.0 μg/d,不存在明显的健康风险.      

基于能值方法的甘薯燃料乙醇产业生态系统分析

发展燃料乙醇已成为替代能源战略下的成熟模式,但传统燃料乙醇生产的污染问题严重影响了燃料乙醇的生存和发展,因此建立以燃料乙醇生产为核心企业,包括由原料种植者、乙醇生产者、分解者、资源回收利用者等一系列利益相关者组成的产业生态系统,已成为燃料乙醇可持续发展的有效途径. 根据燃料乙醇生产过程中对废物处理和资源化利用情况,将其划分成传统生产方案(方案Ⅰ)、废物处理生产方案(方案Ⅱ)和产业生态系统方案(方案Ⅲ),并采用改进后的能值分析方法及指标体系对3种生产方案进行比较分析. 结果表明:与方案Ⅰ相比,通过废物处理和中水回用,方案Ⅱ的ε_EYR(能值产出率)提高了59.37%,ε_ELR(环境负荷率)降低了75.39%;延长产业链,增加循环利用方式后,方案Ⅲ比方案Ⅰ的ε_EYR提高了86.19%,ε_ELR降低了82.98%. 3种生产方案的可持续发展能力为方案Ⅰ<方案Ⅱ<方案Ⅲ.      

Sulphamethazine in poultry manure changes carbon and nitrogen mineralisation in soils

Antibiotics are newly emerging organic pollutants in manure, soil, vegetables and water. Animal manure application might be leading to the accumulation of antibiotics in the farmland. However, the effect of sulphamethazine (SMZ) on the soil microbial community was scarcely investigated. This study was aimed to evaluate the impact of SMZ on poultry manure, on the structure and function of microbial community, carbon mineralisation, and changes in nitrogen forms in soil via an incubation experiment lasting 56?d. The treatments consisted of poultry manure at 1% wt (PM), PM containing 20?mg?kg^?1 SMZ (PM?+?20SMZ) and PM containing 100?mg?kg^?1 SMZ (PM?+?100SMZ), along with the untreated soil (control). Solid phase extraction was performed to measure the SMZ concentration in soils using high-pressure liquid chromatography. The cumulative CO₂-C was increased in all treated soils over the incubation period compared to the control. The PM?+?100SMZ had the highest increase in cumulative CO₂-C from the soil at 56?d of incubation. The treatment of PM?+?20SMZ showed a short-term decrease in nitrification rate in the soils at 1?d by altering the microbial community composition with 17% dissimilarity and decreasing the abundance of bacteria compared to PM-treated soil. The PM?+?100SMZ increased C mineralisation in the soil.