论我国反腐败刑事司法协助中的证人制度——以《联合国反腐败公约》为视角

反腐败刑事司法协助是国际打击与惩罚腐败犯罪的重要制度之一。证人制度是其中不可或缺的组成部分。《联合国反腐败公约》对刑事司法协助中的证人制度规定较为具体,如电视会议作证方式、污点证人作证、证人作证刑事责任豁免制度等。我国仅在《刑事诉讼法》中规定了普通刑事案件的证人制度,在刑事司法协助中的证人规定上存在明显不足。以《联合国反腐败公约》为视角,梳理该公约对刑事司法协助证人制度的规定,指出我国制定《刑事司法协助法》、引入高科技作证方式、构建污点证人及证人作证刑事责任豁免制度等具有迫切的现实必要性。     

Humic acids as electron acceptors in wetland decomposition

Decomposition of organic matter in inundated wetland soils requires a number of interdependent microbial processes that ultimately generate CO₂ and CH₄. Largely as the result of anaerobic decomposition, wetland soils store globally significant amounts of organic carbon and are currently net sources of CH₄ to the atmosphere. Given the importance of wetlands in the global carbon cycle, it is important to understand controls on anaerobic decomposition in order to predict feedbacks between wetland soils and global climate change. One perplexing pattern observed in many wetland soils is the high proportion of CO₂ resulting from anaerobic decomposition that cannot be explained by any measured pathway of microbial respiration. Recent studies have hypothesized that humic substances, and in particular solid-phase humic substances in wetland soils, can support anaerobic microbial respiration by acting as organic electron acceptors. Humic substances may thus account for much of the currently unexplained CO₂ measured during decomposition in wetland soils. Here we demonstrate that humic acids extracted from a variety of wetland soils act as either electron donors or electron acceptors and alter the ratio of CO₂:CH₄ produced during anaerobic laboratory incubations. Our results suggest that soil-derived humic substances may play an important, and currently unexplored, role in anaerobic decomposition in wetland soils.     

A geospatial and temporal framework for modeling gaseous N and other N losses from forest soils and basins,with application to the Turkey Lakes Watershed Project,in Ontario,Canada

This article quantifies pre- to post-harvest gaseous N emissions and other N losses from forest soils and basins geospatially and temporally via digital elevation and hydrological modeling, using daily rain, snow and air temperature records, annual atmospheric N deposition rates, and basin-specific soil and forest specifications as input. The approach relates gaseous N losses from soils to soil temperature and water-filled pore space (WFPS) as affected by the depth-to-water (DTW) below the soil surface. The approach is applied to the Turkey Lakes Watershed Project (TLW) in Ontario, 60 km north of Sault St. Marie, where basin-wide N losses due to denitrification would mostly be restricted to the wetland portions of the basin. Basin-wide N losses via denitrification and stream export (mineral N and dissolved organic N) were empirically related to upland N mineralization and soil leaching as controlling processes. The calibrated model calculations, set to conform to the field-monitored N concentrations in TLW streams, suggest that the harvest-induced nitrification and denitrification pulses would be strongest near the end of the first post-harvest year, dropping to background levels within about 4–5 years later. The article concludes with assessing basin-specific denitrification efficiencies in relation to atmospheric N deposition and basin-to-basin wetland coverage.     

闽江口湿地的气候变化及其对生态环境的影响

利用闽江口湿地分布区4个常规气象观测站1971-2004年的气象资料,分析了闽江口湿地日照、气温、极端最低气温、降水量的年际变化特征及其对闽江口湿地生态环境的影响情况。结果表明：年平均气温和季平均气温显著上升,冬季增温幅度最大,夏季最小;日照时数总体下降,极端最低气温、年降水量和季降水量（春季除外）呈上升趋势,但趋势都不显著;日照时数和降水量年际波动大。气象因子的年际变化给区域生态环境带来不同程度的利弊影响。研究结果对于闽江口湿地的保护、合理开发和利用具有重要的指导意义。     

三江平原环形湿地昆虫种类多样性与季节动态

以三江平原典型环形湿地为研究对象,在小叶章群落、沼柳小叶章群落、漂茷苔草群落、塔头毛苔草群落,采用黄盘诱集法和扫网法定期对湿地昆虫群落进行采集,研究了该区内的昆虫生物多样性及其季节性变化特征.共采集昆虫标本25945号,其中双翅目和同翅目数量最多,其次为膜翅目、缨翅目、弹尾目、鞘翅目、半翅目、直翅目等.各个植物群落昆虫种群的数量,Shannon-Wiener指数、Pielou指数受季节性影响显著.6月下旬湿地昆虫数量最多,但是Shannon-Wiener指数,Pielou指数最低.Shannon-Wiener指数在塔头苔草群落最高,在小叶章植物群落最低.     

大兴安岭主要沼泽湿地土壤碳氮垂直分布特征

为了研究大兴安岭北部两类主要沼泽湿地(柴桦-笃斯越桔和落叶松-杜香)土壤有机碳和全氮的垂直分布特征与积累特征,采用重铬酸钾-外加热法、凯氏定氮仪分别测定了土壤有机碳、全氮质量分数,并用环刀法测定了土壤密度.结果表明:两类湿地剖面有机碳分布均具有明显的储碳层和淀积层;上层的储碳层厚度约为10 cm,有机碳平均质量分数分别...     

沿黄河下游湿地不同土地利用方式植物多样性

以沿黄河下游湿地林下草本,滩地中的花生地、玉米地,水稻田及湖滨湿地为研究对象,以样方法调查各利用方式下的植物群落,分析各个利用方式下的物种组成、优势种变化、植物多样性及群落物种相似度.结果表明,不同利用方式下的湿地由85个植物物种组成,分别隶属于26科66属,其中林地物种数最丰富,湖滨湿地次之;不同利用方式下除花生地与...     

我国进口《濒危野生动植物种国际贸易公约》管制树种贸易动态

使用2009—2015年《濒危野生动植物种国际贸易公约》（CITES）管制树种贸易数据分析我国进口CITES管制树种的种类、来源国、贸易目的和树种来源。研究结果显示,中国进口CITES管制树种呈现出进口种类集中、进口树种数量和来源国不断增加的趋势,且进口CITES管制树种基本来源于野外并用于商业性用途。针对贸易现状,文中从保护野生树种资源的角度对进一步规范CITES贸易活动提出了针对性建议。     

湖泊湿地生态旅游资源评价——以兴凯湖国家级自然保护区为例

针对湖泊湿地生态旅游资源的特点,依据生态学、旅游学、经济学理论设立评价指标,采用层次分析法(AHP)建立了湖泊湿地生态旅游资源的评价体系.评价体系由3个层次构成,A层为目标层,B层为项目层,包括生态价值、生态旅游资源价值、资源开发价值、湖泊湿地特色价值4个指标,C层为因素层,由22个指标构成.采用该评价体系对兴凯湖国家级自然保护区的生态旅游资源进行评价,得分为75.35分,属优良级.与当前兴凯湖国家A从级旅游区的评定结果一致,证实该评价体系可行.     

太阳岛湿地景观生态安全综合评价

基于地理信息系统技术及景观生态学原理,在利用综合指数法初步构建的景观生态安全综合评价模型基础上,利用RS和GIS技术对遥感影像及其他带有空间属性的数据进行了处理、分析,并根据太阳岛湿地景观生态安全评价结果将太阳岛湿地生态安全状况划分为3个层次:生态安全程度相对较高的区域,主要为水域、天然草地、部分林地等自然景观;生态安全程度中等区域,主要为部分草地、片林和风景旅游区等半自然景观;生态安全程度相对较低区域,主要为部分未利用地、城镇居民点和耕地等半自然景观和人工景观。根据评价结果,对太阳岛相应区域提出了具体的保护和恢复措施。