On the origin of elevated levels of persistent chemicals in the environment

In general, contamination levels tend to be highest close to sources of a chemical and decline with increasing distance as a result of dilution, dispersion and degradation. However, contrary to this, circumstances have been described when contamination levels are higher further away from sources than at the sources themselves. Examples are elevated levels of persistent, hydrophobic, organic chemicals in the Arctic, in mountain regions and in forest soils. In order to address the questions of why and when such an inversion of environmental levels is occurring, this paper seeks to identify, name and categorise principles of general validity leading to such behaviour. By compiling and analysing various causes of elevated contamination levels in the environment, three main categories became apparent, 1. equilibrium partitioning effects, 2. effects resulting from changes in phase composition, volume or temperature, and 3. dynamic or kinetic effects. These principles are illustrated with several examples. The case can be made that understanding, quantifying and predicting these causes could provide a general conceptual framework for studying the fate of chemicals in the environment.     

世纪之交土壤学研究的挑战和契机──从第16届世界土壤学大会看土壤学的未来

第１６届国际土壤学大会包括全会和４５个分会,内容涵盖土壤学所有分支并反映了本世纪土壤学的进展。本文综述了土壤学在全球资源与环境问题中的重要地位,分析了世纪之交土壤学面临的挑战和契机,提出土壤学只有拓展与其它学科以及社会的联系,服务于社会的可持续发展,保持自己的特色并在基础研究和应用研究中不断创新,才能在未来更好地生存和发展。     

关于对流层大气N2O氮、氧稳定同位素负荷平衡的初步探讨

对流层大气Ｎ２Ｏ的氮、氧稳定同位素负荷由地表和海洋释放的富轻同位素的Ｎ２Ｏ与平流层回流的富重同位素的Ｎ２Ｏ来平衡,但Ｋｉｍ和Ｃｒａｉｇ的计算方案无法使之平衡＾〔１〕。笔者根据全球Ｎ２Ｏ释放源最近的年释放量估算值,对Ｋｉｍ和Ｃｒａｉｇ＾〔１〕的计算方案进行了初步改进,在考虑土壤Ｎ２Ｏ生成过程中氮、氧稳定同位素的分馏效应和氧同位素的纬度变化效应后,推论出全球Ｎ２Ｏ释放源最近的年释放量估算值能使对流层大     

陇东黄土高原农业物候对全球气候变化的响应

通过对多年来陇东黄土高原董志塬主要农作物冬小麦和主要果树苹果、梨发育物候和气候变化的同步观测,分析了陇东黄土高原农作物发育物候对气候变化的生态响应。分析发现,董志塬近35年来年平均气温呈显著增加的趋势,且以冬季和春季增温为主(冬小麦越冬期增温线性趋势达0.0672℃a/),和全球气候变暖趋势基本一致。增温线性趋势达0.0507℃a/,远高于全国20世纪60年代以来平均增温幅度,也高于陇东黄土高原近35年平均增温幅度(0.0348℃a/),是陇东黄土高原增温中心地带。气候变暖对董志塬冬小麦和果树的生态影响主要体现在春季发育期普遍提前,冬小麦越冬期显著缩短(缩短的线性趋势达0.674d a/),而冬小麦和果树春季各发育期间隔并未出现缩短的趋势。而且由于当地种植冬小麦品种为强冬性、长日照型品种,发育期提前导致日长缩短,对发育有一定抑制作用,抵消了一部分增温的影响,因此果树春季各发育期提前的线性趋势比冬小麦明显。就果树而言,梨树春季发育期提前的线性趋势又比苹果树明显。结论认为气候变化对农业的影响有利有弊,农业管理部门应根据当地气候变化特征,及时调整种植结构,优化种植模式,趋利避害,充分挖掘气候资源潜力,提高农业经济效益。     

稻麦作物净初级生产力模型研究:模型的建立

以植物生理学、农业气象学和土壤环境学的基本原理为基础 ,建立了稻麦作物净初级生产力模型 .该模型包括 2个主要功能模块 :光合作用和呼吸作用 ;土壤 作物系统氮素运移 .前者综合考虑了环境因子和作物氮含量的影响 ,后者包括了作物氮素吸收、土壤氮矿化和化肥氮释放的动态模拟 .     

气候变化下中国粮食和水资源的风险分析

介绍了全球气候变化对环境经济影响的复杂性研究的基本框架及模型,给出了用这些模型对中国经济安全模拟的结果。结果表明,全球气候变化条件下,若不考虑不确定性,中国的粮食安全是可以保证的;若考虑不确定性,则在最严重的情况下,中国未来的粮食生产存在7％－8％的缺口。采用最大强度开源的方法,在全球气候变化和保持原有产业结构的条件下,要实现我国2030年的经济目标是不行的。但是,通过调整产业结构,降低单位产出水耗,在保证水资源安全的条件下则是可行的。     

从海牙气候会议的失败看全球环境合作的障碍

文章在介绍海牙气候会议背景的基础上,分析了会议上产生的分歧,全球环境合作的障碍。同时,阐述了会议的尖锐矛盾和激烈斗争预示的中国今后在环境与发展问题上将面临的严峻挑战,并对此提出需要采取的有效对策。     

推进中国环境治理体系和治理能力现代化——PACE 2019学术年会会议综述

环球中国环境专家协会（PACE）于2019年6月27~29日在中国人民大学组织召开第四届中国环境治理学术年会，主题为推进国家环境治理体系和治理能力现代化，国内外环境公共治理领域顶级专家以及国家和地方相关政府官员出席了会议，并分理论方法、实践应用、行政执法、社会治理、经济政策以及全球环境治理等专题进行了深入研讨。会议认为，作为国家治理体系的重要组成部分，我国环境治理体系，在生态文明建设框架下，已取得长足进步，特别是以目标为导向的治理战略，已形成鲜明国际特色。中国环境治理模式正从传统的自上而下的政府行政管理转向政府主导、企业主体、社会参与和市场调节相结合并由自下而上机制相补充的多元共治现代公共治理模式，治理能力近年来显著加强，但在环境社会治理以及参与全球环境治理等方面仍存在显著薄弱环节，在政府执法机制以及经济政策使用等方面仍有许多需要改进的地方。     

长江三角洲城市群发展研究

概观当代城市发展的趋势,全球化促进了全球城市发展,区域化正在形成巨型城市区域,地方化使城市集群各具特色。长江三角洲城镇群在国家具有特别重要的地位与作用,也是中国融入全球化进程首要的全球区和全球城市形成地区。长江三角洲城镇空间布局应该顺应这些潮流,发展全球城市,建设巨型城市区,组建网络城市,规划走廊城市。     

The challenge of managing threatened invasive species at a continental scale

The European Union's (EU) environmental legislation establishes common measures to prevent the entry and spread of invasive non-native species and to minimize their impacts. However, species that are native to at least one member state but non-native and potentially invasive in others (NPIS) are in limbo because they are neither legally regulated at the EU level nor in most member states. We used the Communication and Information Resource Centre for Administrations, Businesses and Citizens (CIRCABC) raw data on NPIS (317 taxa) to analyze their distribution across the EU and identify which biogeographical regions are the main sources of invasions. We additionally evaluated the conservation challenge posed by NPIS that are threatened within their native ranges. We performed a pairwise analysis summarizing the number of species that are native to a given member state but non-native to another and vice versa. Although distribution patterns of NPIS varied across taxa groups, overall, southern and central EU countries were both donors and recipients of NPIS. Eastern countries were mainly a source, and western and northern countries mostly received NPIS. Around 27% of NPIS were threatened in some of their EU native ranges, which is a challenge for conservation and management because some of them have serious negative effects on European biodiversity, but hitherto remain outside the scope of the EU regulation of invasive non-native species. This highlights an unresolved paradox because efforts to manage species as invasive conflict with efforts to protect them as threatened within the same territory.