湘西北长果安息香种群数量与分布格局

对湖南石门壶瓶山景关门、桑植龙潭坪茅垭村样地的长果安息香(Changiostyrax raxdolichocarpa)种群数量和分布格局进行调查和分析。结果表明：长果安息香种群的年龄结构呈衰退型，个体数量主要集中在小树(IV龄段)，幼龄级株数和老龄级株数匮乏；长果安息香种群在进入生理死亡年龄前有2个死亡高峰，第1个峰值产生于幼树(II、III龄段)，主要原因是种内和种间竞争(主要是光照)，第2个峰值产生于中树长成大树阶段(V、VI龄段)，除种内、种间对环境的竞争外，生长地土层浅薄、大树倒伏及人为砍伐亦加剧了该峰值的产生；种群整体呈聚集分布类型，小树向中树、大树变化过程表现出聚集分布向随机分布转变，导致长果安息香濒危的主要原因是种子萌发率极低、种群竞争能力较差以及人为干扰等。     

滇西北退耕还林后续政策分析及发展对策

滇西北是云南省最为贫困的少数民族聚集地区之一,实行退耕还林政策10多年来取得了巨大的成效,随着退耕还林政策补助陆续到期,部分退耕农户生计将出现困难。对退耕还林后续政策进行分析,认为退耕还林补偿标准与现有物价水平不符,套种的规定过于保守,针对政策上的不足与实施过程中存在的作业设计不够规范、监管不力、档案管理不够规范等问题提出相关对策和建议。     

Inoformation Transfer in a Global Economy

No abstract available for this article.     

不同气候模态下西北太平洋柔鱼渔场环境特征分析

柔鱼冬春生群体广泛分布于西北太平洋,其种群分布与大小受气候变化和环境因子调控。本实验根据中国鱿钓组提供的1995—2011年渔业捕捞数据和海洋环境数据包括海表温度(SSTA)、海表面高度(SSHA)和混合层深度(MLDA)的距平值,分析不同气候模态下(PDO暖期和PDO冷期)柔鱼渔场环境的变化。结果显示,PDO暖期时,柔鱼CPUE高;PDO冷期时,CPUE变低。柔鱼渔场SSTA、SSHA和MLDA年间变化显著,各环境变量的时间变化与PDO冷暖相位对应。SSTA和SSHA与PDO指数负相关,滞后时间分别为–9~10月和–20~17月,且均在0月时相关系数最大;而MLDA与PDO指数呈正相关,滞后时间为–6~5月,在–1月相关系数最大。利用经验正交函数分析了SSTA、SSHA和MLDA时空变化的主要模态,前5个模态特征向量分别反映了西北太平洋柔鱼渔场SSTA、SSHA和MLDA分布场78.73%、32.82%和64.57%的信息。研究表明,气候模态变化驱动柔鱼渔场环境的变化,进而对西北太平洋柔鱼资源丰度产生显著影响。     

Potential effects of global warming on northern European freshwater fish and fisheries

Abstract Global warming is expected to result in considerable changes in northern European freshwater fish populations, fisheries and aquaculture. Shifts towards cyprinid and percid dominance in fish assemblages are expected, together with a decrease and collapse of salmonid and other coldwater fish populations. Most of the evident changes will occur in shallow lakes, where no thermal stratification occurs. The potential ranges of some fish species will shift northwards but pronounced changes will occur in the relative abundance of individual fish species. Total fish production will increase but because of changed composition of fish communities the commercial and recreational value of catches will decrease. Salmonid aquaculture productivity will increase provided that fish farmers adapt to new circumstances and cold, oxygenated water is available in larger quantities during summer.     

欧、美中华绒螯蟹源于中国长江水系中华绒螯蟹的遗传证据

用包括Z2和Opp17两个10碱基随机引物在内的10个引物,对来自荷兰斯科克莱（Skodely)、美国加州圣何塞（San Jose)的中华绒螯蟹群体与中国长江水系中华绒螯蟹群体进行RAPD遗传比较分析。结果发现：（1）中华绒螯蟹群体特有的Z2引物扩增的700bp标记带（Z2^700bp）,在荷兰与美国2个中华绒螯蟹群体中同时出现,而不出现日本绒螯蟹南流江种群中特有的880bp标记带（Z2^880bp）,表明欧洲、美国中华绒螯蟹与中国中华绒螯蟹为同种Eriocheir sinensis,而非日本绒螯蟹Eriocheir japonicus;（2）Opp17引物扩增的947bp片段在中国长江、荷兰及美国3个中华绒螯蟹群体内的出现频率均达100%。结合Z2引物扩增结果,欧洲与美国中华绒螯蟹群体极可能是从中国长江水系中华绒螯蟹引入繁衍的。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

Fish-based methods for assessing European running waters: a synthesis

Abstract  The European Union, Water Framework Directive (WFD) requires monitoring of riverine fish fauna. When the WFD came into force in 2000, most of the EU member states did not have fish-based assessment methods compliant to WFD requirements. Therefore, the objectives of FAME ( http://fame.boku.ac.at ), a project under the fifth R&D Framework Programme of the European Commission were to develop, evaluate and implement a standardised fish-based method for assessing the ecological status of European running waters. This paper synthesises the outputs of FAME and defines future research needs. Two different methodologies were used: the so-called spatially based modelling and the site-specific modelling, the latter leading to the European Fish Index (EFI). The advantage of the EFI is that, despite being a single index, it is applicable to a wide range of environmental conditions across Europe precluding the need for inter-calibration. The EFI will support the WFD towards harmonised/standardised assessment and management of running waters in Europe, thus enabling comparative analyses of the ecological status of running waters across Europe.     

不同干扰方式对桂西北灌草植被物种多样性和生产力的影响

灌草植被在生态系统功能的维持中发挥着重要作用,不同的干扰方式可能改变退化土地灌草植被的多样性及其分布格局,甚至多样性与生产力的关系。以未受干扰的植被作为对照,研究放牧和火烧两种主要干扰对桂西北灌草植被的物种多样性和生产力的影响,并分析了两者之间的关系。结果表明:放牧和火烧处理均降低了灌木的物种丰富度和Shannon-Wiener多样性指数,但放牧处理的均匀度指数与对照相比无显著差异,火烧处理反而显著增加了其均匀度指数。对草本而言,放牧不影响物种丰富度指数,但显著降低了Shannon-Wiener多样性指数和均匀度指数;火烧显著降低了物种丰富度指数,但不影响Shannon-Wiener多样性指数和均匀度指数。与对照相比,放牧和火烧均降低了灌木的地上和地下部分生物量,但两者对草本的地上和地下生物量却产生了正面影响或无影响。此外,这两种干扰方式对灌木和草本多样性与生产力间关系的影响具有不一致性。     

桂西北喀斯特地区不同土地利用类型土壤抗蚀性研究

土壤抗蚀性是反映土壤抵抗侵蚀能力的重要参数之一,是土壤侵蚀研究的重要内容。本文选取土壤有机质、水稳性团聚体、团聚体结构破坏率、团聚状况、团聚度、分散率和<0.05 mm粉黏粒含量等7个指标,通过单因素方差分析及主成分分析,探讨了桂西北喀斯特地区5种不同土地利用类型土壤抗蚀性的差异。结果表明:原生林和次生林土壤有机质含量显著(P<0.05)高于撂荒地、坡耕地和人工林,撂荒地土壤有机质含量较坡耕地和人工林高,但差异不显著。原生林、次生林及撂荒地土壤>0.25 mm水稳性团聚体总量及团聚状况显著高于坡耕地及人工林,但其土壤团聚体结构破坏率及分散率显著低于坡耕地;人工林土壤团聚体结构破坏率显著高于次生林,但与原生林、撂荒地和坡耕地差异不显著;人工林土壤分散率则与坡耕地类似,显著低于原生林、次生林及撂荒地;原生林、次生林土壤团聚度与撂荒地、坡耕地差异不显著,但显著高于人工林;次生林、撂荒地及人工林<0.05 mm粉黏粒含量与原生林、坡耕地差异不显著,但坡耕地土壤<0.05 mm粉黏粒含量显著高于原生林。由主成分分析综合评分得到土壤抗蚀性强弱顺序为:原生林>次生林>撂荒地>坡耕地>人工林。因此,喀斯特地区人为干扰严重降低了土壤的抗蚀性,耕地通过撂荒方式能够提高土壤抗蚀性。