Geographic distribution of Pelteobagrus fulvidraco and Pelteobagrus vachelli in the Yangtze River based on mitochondrial DNA markers

Three populations of Pelteobagrus vachelli and Pelteobagrus fulvidraco of the Yangtze River were examined by PCR-RFLP analysis of mitochondrial DNA fragments. ND5/6 and D-loop fragments were digested by 10 restriction endonucleases. Significant geographic variations between upstream and mid-downstream populations in the haplotype frequencies and restriction patterns were revealed. This suggested that the diversity of P. vachelli was high; 11 haplotypes were obtained from all the samples. The upstream population shared seven haplotypes and the middle and downstream populations shared another four haplotypes. Among all of the haplotypes, one haplotype was shared in 30 samples of the populations from middle and downstream, but it was not found in the upstream population. Any haplotype found in the upstream population was not detected in the middle and downstream populations. Genetic diversity of P. fulvidraco was low and only five haplotyes were detected from all 60 samples. Phylogenic relationships also indicated that the fishes from upstream and mid-downstream were apparently divided into two populations.

白豆杉的地理分布格局及潜在分布区估计

　　根据物种的分布信息结合环境因子估计物种的分布区对珍稀濒危物种的保护有着重要的意义。白豆杉Pseudotaxus chienii为第三纪孑遗植物，我国东南部地区特有，分布区狭窄。本文通过对白豆杉的标本记录研究它的地理分布，找出影响其分布的关键因子并对其潜在分布区进行估计，并解释其分布区形成的原因。全球升温将对物种分布造成重要影响，通过温度升高情况下2100年的气候数据模拟白豆杉未来的潜在分布区，估计温度升高对白豆杉的影响，将对白豆杉的保护有着重要的意义。 　　根据白豆杉的标本信息结合Diva-Gis软件对白豆杉的地理分布进行研究。以海拔图层和植被图层为底图对白豆杉的分布格局进行研究，并对白豆杉种群的多度进行统计分析。用Diva-Gis软件的气候数据提取功能提取白豆杉分布点的气候信息，并运用主成分分析对影响白豆杉分布的气候因子进行分析，找出影响白豆杉分布的主要环境因子。根据白豆杉的分布信息和气候数据，运用Diva-Gis内嵌的BIOCLIM模型和DOMAIN模型对白豆杉在不同气候条件下的潜在分布区进行估计，评价温度升高对白豆杉分布区的影响。 　　白豆杉分布格局研究结果表明，白豆杉分布在我国东南部地区中低海拔山区，白豆杉的分布和植被类型及海拔有着密切的关系。白豆杉的分布与海拔的关系表现为，由东到西，分布的最低海拔升高，海拔范围缩小。白豆杉分布地的植被类型为常绿灌木林，常绿阔叶林及针、阔叶混交林。白豆杉由东向西的海拔变化趋势与植被类型的由东向西的海拔变化趋势相一致。PCA分析结果表明白豆杉的分布与温度相关因子有着密切的关系。 　　现在气候对潜在分布区的估计表明,白豆杉的潜在分布区散布于浙、闽、粤、赣、湘，桂及黔几省各自交界之处即从浙江南部山区沿武夷山山系至南岭山系（向北到沿湘赣交界的罗宵山系）至大瑶山山系（向北沿雪峰山）。潜在分布区南部有三处分布的热点地区，即浙江南部、湖南南部和广西北部地区。三个主要分布区之间仅有有星散的潜在分布区存在，或没有潜在分布区出现，处在一种高度的隔离状态。造成这种潜在分布格局形成的原因可能有二，一是第四纪冰期的到来使白豆杉的分布区向南迁移，局部性气候的变化和地质变化可能导致了部分白豆杉的生境的消失，从而使得原来连续的分布区破碎化，形成了现在的星散分布；二是白豆杉的潜在分布区预测结果与中国东南部地区的山脉走势非常一致，山脉地带小生境多样化能够为白豆杉在垂直地带上的迁移提供更大的可能性。 　　未来气候数据对白都杉的潜在分布区估计表明，温度升高后白豆杉最适生分布区显著缩小。白豆杉的潜在分布区的地理分布格局发生了明显的变化，原来在南部的适生区明显缩小，星散程度更高。除已知的分布地外，在江西西南部武夷山、南岭山脉的湖南、广西、广东三省交界的地方都是白豆杉的适生区。江西和湖南交界的罗宵山山脉北部到井冈山都有白豆杉分布可能性较大，可以作为野外调查的重点地区。气候变化会使白豆杉在浙江、湖南南部的最适生境破碎化从而影响白豆杉的分布。生境保护对白豆杉的保护起着关键作用。

西北干旱区多种植物地理分布与气候的相关性及其可能潜在分布预测

　　作为西部大开发的关键地区，西北干旱区由于地理位置和环境条件的独特性、生态系统的脆弱性以及人类活动的长期干扰，对其周边乃至全国的生态环境有较大的影响，在这一地区研究植物种分布与气候的关系，并模拟预测其可能的潜在分布范围，具有理论上和实践上的重要意义。 　　通过广泛收集了西北干旱区优势种和常见种的地理分布资料，共选择128个植物种，利用Holdridge的生命地带分类系统，计算各植物种的生物温度(BT)、可能蒸散(PE)、降水量(P)及可能蒸散率(PER)，分析植物种与气候的相互关系，并将所有植物种进行经验归纳分类。随后，对这砦植物种及其气候信息进行TWINSPAN定量分类，并与经验分类结果相比较，得出西北干旱区128种植物的生态气候分类，分属于以下几大类型：高寒草甸、森林一草原过渡带、草原（典型草原、荒漠草原）、荒漠（草原化荒漠、荒漠、高寒荒漠）。具体来说，包括以下17个生态气候类型： 1)高寒草甸：异针茅。 2)森林一草原过渡带：牛尾蒿、鬼箭锦鸡儿、沙棘。 3)草原a：沙蒿。 4)草原b：长芒草、百里香（变种）、多叶隐子草、贝加尔针茅、大针茅。 5)草原c：羊茅、小叶锦鸡儿、荒漠锦鸡儿、线叶菊、华北岩黄芪、廿青针茅、碱蒿、内蒙古沙蒿、裂叶蒿、狭叶锦鸡儿、山竹岩黄芪、女蒿、小蓬、两伯利亚杏、沙地柏、角果碱篷、霸王、糙隐子草。 6)草原d：紫狐茅、紫花针茅。 7)草原一荒漠草原a：包括沙竹、琵琶柴、吉尔吉斯针茅。 8)草原一荒漠草原b：华北米蒿、差巴嘎蒿、星星草、长芒针茅、铁竿蒿、柠条锦鸡儿。 9)荒漠草原：沙生冰草、蒙古冰草、羊草、冷蒿、中亚紫菀木、刺旋花、老瓜头、木贼麻黄、西伯利亚白刺、唐古特白刺、戈壁针茅、石生针茅、盐地碱蓬、冰草、蓍状亚菊、油蒿、木蓼、刺针枝蓼、长枝木蓼、中间锦鸡儿、尖叶盐爪爪、黄花琵琶柴、松叶猪毛菜、珍珠猪毛菜、东方针茅、囊果碱蓬、四合木、白滨藜、短脚锦鸡儿。 10)草原化荒漠，荒漠a：川青锦鸡儿、优若藜、苦艾蒿、无芒隐子草、沙冬青、籽蒿、地白蒿、菭草、齿叶白刺、绵刺、盐角草、多枝柽柳、盐生假木贼。 11)草原化荒漠．荒漠b：蒿叶猪毛菜、短花针茅、芨芨草、灌木亚菊、博乐蒿、小蒿、喀什蒿、南山短花菊、盐爪爪、木本猪毛菜、针茅、细枝盐爪爪。 12)草原化荒漠．荒漠c：白梭梭、白羊草、无叶假木贼。 13）干旱荒漠a：戈壁短花菊、荒漠细柄茅、刺蓬、沙生针茅、多花柽柳、细枝柽柳。 14)干旱荒漠b：梭梭柴、铃铛刺、天山猪毛菜、帕米尔麻黄、座花针茅、旱蒿、克氏狐茅、短叶假木贼、准格尔沙蒿、长穗柽柳、刚毛柽柳。 15)高寒荒漠植被：匍生优若藜。 16)干旱荒漠c：粉花蒿、白杆沙拐枣、膜果麻黄、花花柴、灌木紫菀木、裸果木、合头草、塔里木沙拐枣。 17)超干旱荒漠植被：沙拐枣、胡杨、盐穗木、灰杨、盐节木、圆叶盐爪爪。 　　综合分类结果表明：多数植物种的生态气候类型与实际生境相符，但也有少数植物种有明显偏差，主要原因有三点：首先，某些种的分布范围超出了西北干旱区，在东北、华北、甚至全国范围内分布，所计算的植物种的气候范围本身存在局限性;其次，西北干旱区的研究资料如植物种的分布范围、分布点的气象资料等有许多缺失：最后，由于文献中对某些植物种分布范围的描述比较笼统，无法确定其精确的地理分布界限，使得植物种所对应的分类结果与其真正所属的植 被类型有一些偏差。 　　本文还进一步在这128种植物中选取了10种分布明确、资料齐备的代表性植被类型的优势种，根据它们的降水和生物温度指标，模拟预测了它们的可能潜在分布区，包括其主要中心分布区和最大可能分布区，并与实际分布范围进行比较。结果表明．其潜在分布区的分布范围与实际调查所得资料所处范围基本一致，特别是中心分布区的预测图，而最大可能分布区与实际有一定误差。

城市增温效应及其受地理、气候和城市化发展的影响

城市增温的原因包括全球变暖和城市热岛效应两个方面，二者对城市环境、社会经济和市民健康均有相当程度的影响。本文的研究目的是：(1)通过比较处于不同气候带上同样规模城市的气温变化趋势和速率差异，探讨地理位置对城市增温现象的影响；(2)通过分析近期人类活动和城市发展规模与城市增温现象的相关性，搞清楚城市化发展过程中显著影响热岛效应的因素。了解城市增温的地理分异规律及其受城市化发展的影响，对全面认识城市增温现象、积极寻求应对城市增温所造成的环境危害的策略具有重要的科学和实践意义。 本文按照经纬度在全国范围内选取6个特大城市：济南、西安、兰州、广州、上海和北京为研究对象，按城市所处地理位置分为代表水分梯度的同纬度经向分布城市，近海到内陆依次为济南、西安和兰州，以及代表温度梯度的纬向分布城市，低纬度到高纬度依次为广州、上海和北京，借助统计学方法，对各城市分别进行了年均气温比较分析，并对近期人类活动对不同城市增温效应的影响进行了分析。结果表明： 1．各城市气温均呈上升趋势，其中年均最低气温上升幅度最大，年均气温上升幅度次之，年均最高温度上升幅度最小；温度普遍升高的前提下高纬度地区温度升幅较大，内陆地区增温比近海地区大，即城市增温幅度与水分梯度和温度梯度呈负相关关系；不同城市在不同年代冷暖变化的强度和峰谷相位不尽一致，北京、西安和广州从上世纪50年代到70年代气温整体趋势变冷，其他城市缓慢升温，进入80年代后6个城市均进入加速增温阶段。 2．城市热岛效应对最低气温影响最明显，即城市最低气温与参照站差值增长趋势最为显著，其次为年均温，市区最高气温与参照站差值增长趋势最缓慢；自1978年改革开放以来，6个城市年均最低气温和年均温城乡差值均达到极显著水平，兰州最高，达0.69℃/lOa和0.49℃/lOa;从近海到内陆随着年降水量减少，3个城市（依次为济南、西安和兰州）热岛效应依次增加，从高纬度到底纬度随着温度升高（北京、上海和广州），城市热岛效应有减小趋势。 3．不同城市增温均表现出与人口（包括市辖区年末总人口、市辖区人口密度）、市辖区地区生产总值、年末实有道路面积、建成区面积和第二产业占GDP比重等代表城市发展因素的指标呈显著正相关，与绿地有关的因素，包括园林绿地面积和年末耕地面积呈显著负相关，而同样的因素对同一个城市不同气候参数的影响也不相同，最低气温对增温因子的敏感度高于其他气温参数，而对降低增温效应因子的敏感度小于其他气候参数，同样的因素对不同城市气候参数也有不同效应。 本项研究的结果证实了城市增温是一个比较复杂的过程，其中即反映了全球气候变化的大背景，也受到了影响水热环境的地理因素的制约，同时又与城市化发展的进程密切相关。

The ADH1B Arg47His polymorphism in East Asian populations and expansion of rice domestication in history

Background: The emergence of agriculture about 10,000 years ago marks a dramatic change in human evolutionary history. The diet shift in agriculture societies might have a great impact on the genetic makeup of Neolithic human populations. The regionally restricted enrichment of the class I alcohol dehydrogenase sequence polymorphism (ADH1BArg47His) in southern China and the adjacent areas suggests Darwinian positive selection on this genetic locus during Neolithic time though the driving force is yet to be disclosed. Results: We studied a total of 38 populations (2,275 individuals) including Han Chinese, Tibetan and other ethnic populations across China. The geographic distribution of the ADH1B*47His allele in these populations indicates a clear east-to-west cline, and it is dominant in south-eastern populations but rare in Tibetan populations. The molecular dating suggests that the emergence of the ADH1B*47His allele occurred about 10,000 similar to 7,000 years ago. Conclusion: We present genetic evidence of selection on the ADH1BArg47His polymorphism caused by the emergence and expansion of rice domestication in East Asia. The geographic distribution of the ADH1B*47His allele in East Asia is consistent with the unearthed culture relic sites of rice domestication in China. The estimated origin time of ADH1B*47His allele in those populations coincides with the time of origin and expansion of Neolithic agriculture in southern China.

The Drosophila obscura species-group (Diptera, Drosophilidae) from Yunnan Province, Southern China

Three new and two known species of the Drosophila (Sophophora) obscura species-group are reported from Yunnan Province, southern China. The sinobscura species-subgroup is newly established by D. sinobscura, D. hubeiensis and D. luguensis sp. nov. Geographic distribution of the obscura group in and around China is discussed, and a key to 10 Chinese species of the obscura group is provided.

Development and use of parasitoids (Hymenoptera : Aphidiidae & Aphelinidae) for biological control of aphids in China

A review of aphid parasitoids in China with special emphasis on their production, utilization, and conservation is presented with a brief history of Chinese biological control. Twenty genera, 99 species of Aphidiidae and two genera, 11 species of Aphelinidae were recorded in China. Each parasitoid is listed with a brief description of aphids, host plants, areas of study such as taxonomy, biology, bionomics, geographic distribution, rearing, and literature citations. Achievements, status, and problems in aphid parasitoid production, utilization, conservation, and future prospects are detailed for dominant aphid parasitoids such as Aphidius gifuensis Ashmead, A. ervi Haliday and Aphelinus mali Haldeman. Finally, opportunities and challenges of commercialization commercialization of natural enemies, especially aphid parasitoids, in China, are analyzed and discussed.

Molecular phylogeny of three subspecies of common carp Cyprinus carpio, based on sequence analysis of cytochrome b and control region of mtDNA

The complete cytochrome b and the control region of mtDNA (about 2070 bp in total) of 10 strains belonging to three subspecies of the common carp, including three wild subspecies (the Yangtze River wild common carp - Cyprinus carpio haematopterus, Yuanjiang River wild common carp Cyprinus carpio rubrofuscus and Volga River wild common carp - Cyprinus carpio carpio) and seven domestic strains (Xingguo red carp, Russian scattered scaled mirror carp, Qingtian carp, Japanese Koi carp, purse red carp, Big-belly carp, German mirror carp) were sequenced. Phylogenetic analysis indicated that the 10 strains form three distinct clades, corresponding to C. c. haematopterus, C. c. rubrofuscus and C. c. carpio respectively. Purse red carp, an endemic domestic strain in Jiangxi province of China, showed a higher evolution rate in comparison with the other strains of C. c. haematopterus, most probably because of intensive selection and a long history of domestication. Base variation ratios among the three subspecies varied from 0.78% (between C. c. haematopterus and C. c. rubrofuscus) to 1.47%(between C. c. carpio and C. c. rubrofuscus). The topography of the phylogenetic tree and the geographic distribution of three subspecies closely resemble each other. The divergence time between C. c. carpio and the other two subspecies was estimated to be about 0.9 Myr and about 0.5 Myr between C. c. haematopterus and C. c. rubrofuscus. Based on phylogenetic analysis, C. c. rubrofuscus might have diverged from C. c. haematopterus.

Status of sturgeon aquaculture and sturgeon trade in China: a review based on two recent nationwide surveys

The authors reviewed the aquacultural history of Acipenseriformes in China, related the legal status and examined the current status of the cultured species or hybrids, origins of seedlings, quantities of production, geographic distribution in farming, and the sustainability for both restocking programmes and human consumption. The census shows that since 2000, the production of cultured sturgeons in China appears to have become the largest in the world. As of 2000, the rapid growth of sturgeon farming in China mainly for commercial purposes has shifted harvests in the Amur River from caviar production to the artificial culture of sturgeon seedlings. This dramatic development has also caused a series of extant and potential problems, including insufficient market availability and the impact of exotic sturgeons on indigenous sturgeon species. Annual preservation of sufficient higher-age sturgeons should be a national priority in order to establish a sustainable sturgeon-culture industry and to preserve a gene pool of critically endangered sturgeon species to prevent their extinction.

Intraspecific phylogeography of Carchesium polypinum (Peritrichia, Ciliophora) from China, inferred from 18S-ITS1-5.8S ribosomal DNA

Based on the variation of site 34, 46, 241, 305 and 322 in the 18S-ITS1 rDNA sequence, 19 Carchesium polypinum populations collected from eight provinces of China were separated into northern and southern population along the delineation between the Yangtze River and the Pearl River. This geographic distribution pattern of Carchesium polypinum maybe results from two factors: the vicariance resulting from the formation of the delineation between the Pearl River and the Yangtze River accompanied with the uplift of Qinghai-Xizang Plateau, and the different dispersal paths of C. polypinum affected by the climate.

Morphological and genetic study of Prorocentrum donghaiense Lu from the East China Sea, and comparison with some related Prorocentrum species

In this paper, the detailed morphology of Prorocentrum donghaiense Lu from both field samples and cultures was examined, and a taxonomic comparison was made between P donghaiense and some related Prorocentrum spp. using morphological and molecular data and other published information. There were distinct differences among these species in morphological characteristics that historically have been presented as conservative features. The discrepancies extended beyond that of individual variations within the same species due to environmental factors. Therefore, these morphological features may not be conservative but, rather, polymorphic depending on environmental conditions. Based on this analysis, we suggest that the high-biomass bloom-forming species in the East China Sea, previously reported as Prorocentrum dentatum Stein, is P donghaiense Lu. The species reported from the East China Sea and Japanese and Korean waters appear to be the same species. Molecular data also suggest that P. dentatum (CCMP1517) and P. donghaiense are genetically identical. Therefore, the geographic distribution of P. donghaiense may be much wider than expected. (C) 2004 Elsevier B.V. All rights reserved.

Spatial variations of size-fractionated chlorophyll, cyanobacteria and heterotrophic bacteria in the Central and Western Pacific

Geographic and vertical variations of size-fractionated (0.2-1 mu m, 1-10 mu m, and >10 mu m) Chlorophyll a (Chl.a) concentration, cyanobacteria abundance and heterotrophic bacteria abundance were investigated at 13 stations from 4 degrees S, 160 degrees W to 30 degrees N, 140 degrees E in November 1993. The results indicated a geographic distribution pattern of these parameters with instances of high values occurring in the equatorial region and offshore areas, and with instance of low values occurring in the oligotrophic regions where nutrients were almost undetectable. Cyanobacteria showed the highest geographic variation (ranging from 27x10(3) to 16,582x10(3) cell l(-1)), followed by Chl.a (ranging from 0.048 to 0.178 mu g l(-1)), and heterotrophic bacteria (ranging from 2.84x10(3) to 6.50 x 10(5) cell l(-1)). Positive correlations were observed between nutrients and Chl.a abundance. Correspondences of cyanobacteria and heterotrophic bacteria abundances to nutrients were less significant than that of Chl.a. The total Chl.a was accounted for 1.0-30.9%, 35.9-53.7%, and 28.1-57.3% by the >10 mu m, 1-10 mu m and 0.2-1 mu m fractions respectively. Correlation between size-fractionated Chl.a and nutrients suggest that the larger the cell size, the more nutrient-dependent growth and production of the organism. The ratio of pheophytin to chlorophyll implys that more than half of the > 10 mu m and about one third of the 1-10 mu m pigment-containing particles in the oligotrophic region were non-living fragments, while most of the 1-10 mu m fraction was living cells. In the depth profiles, cyanobacteria were distributed mainly in the surface layer, whereas heterotrophic bacteria were abundant from surface to below the euphotic zone. Chl.a peaked at the surface layer (0-20 m) in the equatorial area and at the nitracline (75-100 m) in the oligotrophic regions. Cyanobacteria were not the principle component of the picoplankton. The carbon biomass ratio of heterotroph to phytoplankton was greater than 1 in the eutrophic area and lower than 1 in oligotrophic waters.