中国兴安落叶松天然林地理分布及其气候适宜性

准确评估兴安落叶松林潜在分布及其气候适宜性对科学指导森林经营和管理具有重要的现实意义。基于可能影响兴安落叶松林地理分布的8个气候变量:最冷月平均温度(Tc)、最暖月平均温度(Tw)、气温年较差(DTY)、≥5℃积温(GDD5)、年均降水量(P)、秋冬季平均降水量(Paw)、湿润指数(MI)和年辐射量(RAD),利用最大熵模型确定了影响中国兴安落叶松林地理分布的主导气候因子,并构建了兴安落叶松林地理分布与气候的关系模型。结果表明:影响中国兴安落叶松林地理分布的主导气候因子是Tc、DTY、RAD和GDD5,累积贡献率达87.8%,表明热量(温度与辐射)是兴安落叶松林存在与否的决定因素,而水分限制作用相当有限。中国兴安落叶松林主要分布在中、低气候适宜区域,其气候特征为:-28.8℃≤Tc≤-19.5℃;39.0℃≤DTY≤46.2℃;2871.7 MJ·m-2≤RAD≤3519.8 MJ·m-2;1000.0℃·d≤GDD5≤2100.0℃·d。     

中国云杉林的地理分布与气候因子间的关系

为了揭示中国云杉林的地理分布与气候因子间的关系, 在中国云杉林15个群系的地理分布范围内选取613个地理坐标点, 其中包括云杉各个种分布的海拔上限和下限坐标点各235和228个。通过数字地球系统确定每个点的海拔高程, 从中国气象插值数据库获取每个点的气候数据。数据分析分别采用线性回归、变异系数比较和主成分分析(PCA)法。结果显示, 中国云杉林分布范围内, 年平均气温、最冷月平均气温、最热月平均气温、≥5 ℃积温、≥0 ℃积温、年降水量、土壤水分含量和干燥指数α的平均值分别是3.38 ℃、-9.75 ℃、14.78 ℃、1 227.83 ℃·d、2 271.19 ℃·d、712.23 mm、80.02%和0.50; 各气候因子与中国云杉林垂直分布的上下限间均具有显著的回归关系; 除了年平均气温和最冷月平均气温变异系数较大外, 其他6个气候因子的变异系数均较小, 且彼此间无显著差异; 无论是云杉分布的上限还是下限, ≥5 ℃积温和≥0 ℃积温在PCA第一主分量具有较高的载荷, 而年降水量和土壤水分含量在第二、三主分量具有较高的载荷。影响中国云杉林分布的主要气候因子是生长季节积温, 其次是年降水量和土壤水分含量。     

蒜头果地理分布与水热关系分析

利用温度指数(WI)、湿润指数(HI)等气候因子,研究了蒜头果(Malana oleifera Chun et S.Lee)地理分布与气候因子的关系.结果表明,极端最高温、7月均温、年均温、≥10℃年积温和年均降水量是蒜头果分布的主要限制因子;由半峰宽(PWH)计算法确定蒜头果生长的最适温度为18.0～22.0℃,年降水量为1106.5～1 585.1 mm;水热组合较好的乐业地区是蒜头果的主要分布区.极端高温和干燥的气候可能是蒜头果分布区逐渐缩小并濒危的重要因素.     

亚洲季风区铁杉属现代分布区及其气候特征

铁杉属在亚洲主要分布于亚洲季风区东部,间断分布于中国大陆、台湾岛以及日本列岛（除北海道）。在中国大陆间断分布在西南山区（横断山区和部分东喜马拉雅）、中部山区（秦岭-大巴山区）和东南山区（华东山地）。亚洲季风区铁杉属的现代分布环境要求年降水量范围为720～2103mm,生长季降水量为635～1489mm;年均温范围为5．8～18．2℃,冬季月均温为-2．7～11．5℃,年最冷月均温为-3．7-10．9℃,年最暖月均温为13．0—28．2℃,气温年较差为9．7～25．4℃。亚洲季风区铁杉属的现代地理分布与气候要素值相互关系的分析表明,无铁杉分布的朝鲜半岛及其邻近的我国东北山地和山东山地降水量均大于700mm,基本上能够满足铁杉属生长的水分条件;而朝鲜半岛及其邻近的我国东北山地和山东山地的气温年较差明显大于铁杉属分布区的值,同时两地的冬季月均温和年最冷月均温明显低于铁杉属分布区的值,这也是这些地区没有铁杉属分布的主要气候原因。总之,这些亚洲季风区水分条件能够满足铁杉属生长需要,但冬季温度（包括冬季月平均温度和年最冷月均温）和气温年较差无法满足铁杉属生长需要,导致这些地区无铁杉属现代分布记录。     

中国兜兰属宽瓣亚属植物地理分布格局及其主导气候因子

为明确兜兰属宽瓣亚属(Paphiopedilum Subgen. Brachypetalum)植物在中国的自然地理分布格局及其主导气候因子,该研究以7种宽瓣亚属植物为研究对象并利用ArcGIS技术提取其在中国194个地理分布点的气候数据, 采用描述性统计分析宽瓣亚属植物在中国分布区的气候特点, 采用逐步回归拟合各气候因子与其经纬度分布的线性关系, 最后通过冗余分析(RDA)和蒙特卡洛(Monte-Carlo)检验量化各气候因子对宽瓣亚属植物地理分布的贡献率。结果表明: (1)宽瓣亚属植物在中国主要分布于滇东南、黔西南、黔南、黔东北、滇西北、桂北与黔南交界处以及桂西北至桂西南地区。(2)该亚属植物在中国分布区的昼夜温差月均值、年平均气温变化范围、最暖季度平均气温、最冷季度平均气温4项热量因子的平均值分别为8.13、23.70、23.62和9.23 ℃, 降水量变异系数、最湿季度降水量、最干季度降水量、干旱指数4项水分因子平均值分别为75.66%、673.10 mm、73.97 mm和26.12%, 整体上具有湿热的气候特点; 各物种间, 狭域分布的物种与广布种间的气候因子存在显著差异。(3)逐步回归分析表明, 各拟合方程均达到极显著水平, 昼夜温差月均值、最暖季度平均气温、最冷季度平均气温、降水量变异系数、最干季度降水量、干旱指数是影响中国宽瓣亚属植物沿经度分布的主要因子; 最冷季度平均气温、最湿季度降水量、年平均气温变化范围、最干季度降水量、降水量变异系数是影响中国宽瓣亚属植物沿纬度分布的主要因子。(4) RDA结果显示, 气候因子在第1轴的解释率为73.32%, 在第2轴的解释率为21.29%, 累计解释率为94.61%, 各气候因子的解释率大小排序为: 昼夜温差月均值(57.8%) >最暖季度平均气温(41.5%) >年平均气温变化范围(38.3%) >最干季度降水量(23.1%) >最冷季度平均气温(16.9%) >降水量变异系数(13.7%) =最湿季度降水量(13.7%) >干旱指数(3.0%)。因此, 昼夜温差月均值、最暖季度平均气温、年平均气温变化范围3个气候因子是影响中国宽瓣亚属植物分布的主导气候因子。     

中国橡胶种植北界

基于中国橡胶的地理分布信息及其相应的气候资料,结合最大熵模型,明确了影响中国橡胶种植的5个主导气候因子,即最冷月平均温度、极端最低温度平均值、月平均温度≥18℃月份、年平均气温和年平均降水量。在此基础上,给出了80%气候保证率下中国橡胶树稳产高产的种植北界,该北界准确覆盖了目前中国橡胶主产区的实际种植区域。研究结果可为中国橡胶种植优势区域布局规划及防灾减灾提供科学决策依据。     

我国春玉米潜在种植分布区的气候适宜性

根据中国气象局216个春玉米农业气象观测站资料与1971—2000年10 km×10 km空间分辨率的气候资料,基于全国区域和年尺度筛选出了影响我国玉米种植分布的潜在气候指标,利用最大熵(Maximum Entropy,MaxEnt)模型和ArcGIS空间分析技术,构建了春玉米潜在种植分布与气候因子关系模型,研究了影响我国春玉米潜在种植分布区的主导气候因子及其气候适宜性。结果表明,影响我国春玉米潜在种植分布的主导气候因子有:≥10℃积温、≥10℃的天数、最热月平均温度、年平均温度、年降水、湿润指数和气温年较差;结合春玉米存在概率,将我国春玉米潜在种植分布区划分成4个等级:气候不适宜区、次适宜区、适宜区和最适宜区,给出了各气候适宜区的气候特征。选取作物在待预测地区的存在概率这一综合反映各主导气候因子影响的指标来划分作物潜在种植分布区,有助于更加准确地进行气候区划,从而可为制定玉米应对气候变化措施提供科学依据。     

南盘江流域云南松径向生长对气候暖干化的响应

全球气候变暖背景下, 西南地区气候呈现出明显的暖干化特征, 但区域优势树种云南松(Pinus yunnanensis)对气候暖干化的响应存在不确定性。该研究根据树木年代学方法选择研究区域87株云南松样本进行树芯采集, 构建云南松树轮年表, 结合1952-2016年的气温和降水等气象资料, 利用响应分析、多元回归分析以及滑动相关分析等方法研究了影响南盘江流域云南松径向生长的关键气候因子及其对气候暖干化的响应规律。研究结果表明: 1985年以来, 研究区域气候暖干化特征明显, 气温上升和降水量下降的速率是1984年前的5和6倍, 年平均气温、年平均最高气温、年平均最低气温的上升速率为0.044、0.041和0.050 ℃·a ^-1, 年降水量的下降速率为 6.02 mm·a ^-1。气候暖干化使云南松的生长对温度响应的敏感度降低, 对水分响应的敏感度增强, 气温的解释率由暖干化前的44.95%下降到21.97%, 水分的解释率由暖干化前的55.05%上升到78.03%。暖干化增强了当年气候因子对径向生长的影响, 减弱了上年气候因子的影响, 与径向生长显著相关的当年气候因子增加了3个, 当年气候因子对径向生长的解释率增加了16.05%。暖干化减弱了云南松生长的“滞后效应”, 气候变化对树木生长影响的时效性增强。在5-7月和9-11月, 气候变暖使径向生长与气温、水分的响应关系变得不稳定。该研究可为气候暖干化区域云南松林的经营、管理以及区域气候重建提供理论依据和基础数据。     

气候暖干化对甘肃省谷子产量的影响及对策

基于甘肃省甘州（河西温和干旱绿洲灌溉区）、安定（陇中温和半干旱旱作区）、西峰（陇东温和半湿润旱作区）气温、降水和谷子产量资料,计算出各区域谷子生育期内≥0 ℃、≥5 ℃、≥10 ℃、≥15 ℃、≥20 ℃活动积温以及生育关键期平均气温和降水量,用正交多项式拟合分离出谷子气候产量,并采用线性倾向、累积距平、Mann-Kendall法分析研究区气候和谷子气候产量的变化特征,以及气候变化对谷子产量的影响.结果表明：气候暖干化是甘肃各区域现代气候变化的主要特征,各地气温从20世纪90年代初开始呈显著上升趋势,降水从20世纪80年代后期开始显著减少;该区谷子产量与温度、降水量呈显著相关关系,旱作区谷子产量随生育关键期内气温增高、降水量增多而提高,河西走廊绿洲灌区谷子产量随气温增高而提高;气候暖干化严重影响谷子产量,西峰、安定、甘州谷子产量的气象波动指数分别占实际产量变异系数的73%、72%和54%,变暖后（1993-2008年）较变暖前（1985-1992年）所占百分率明显增大;气候变暖有利于谷子产量增加,与气候变暖前相比,气候变暖后西峰、安定、甘州谷子年均气候产量的增加量分别为30.6、43.1和121.1 kg·hm^-2.针对甘肃省未来气候继续暖干化的趋势,应进一步扩大谷子种植面积、调整谷子种植结构,同时,要根据不同气候类型区域、不同气候年型选种不同特性的品种,采取不同的种植措施.     

中国水稻潜在分布及其气候特征

基于全国层次和年尺度筛选的影响中国水稻分布的潜在气候指标,结合水稻地理分布信息,利用最大熵模型和ArcGIS软件的空间分析功能,分析了中国水稻潜在分布及其气候特征.结果表明:年降水量(P)、湿润指数(MI)、稳定通过18℃持续日数( N18)和≥10℃积温(∑T10)4个因子是影响水稻分布的主导气候因子,其累积贡献百分率达97.6％.采用主导气候因子作为环境变量重建气候水稻分布关系的最大熵模型,利用重建的最大熵模型给出的中国水稻存在概率,对中国水稻潜在分布区的气候适宜等级进行了划分,并分析了各适宜区的气候特征.研究结果可为中国水稻生产布局及制定应对气候变化政策提供参考.     

Plant-Parasitic Nematodes of South Viet Nam

Between 1974 and 1978, 2,842 identifications of plant-parasitic nematodes were made from more than 1,700 soil and plant samples collected in eight provinces of South Viet Nam. Species in nine genera—Helicotylenchus, Criconemoides, Meloidogyne, Pratylenchus, Tylenchorhynchus, Hoplolaimus, Hirschmanniella, Xiphinema, and Rotylenchulus—comprised 96.1% of the identifications; the remaining 3.9% were species of 11 genera. Fourteen genera were associated with rice which was grown on about 2,500,000 ha in 1970. Of these, Ditylenchus, Hirschmanniella, and Meloidogyne were most important. Ditylenchus angustus caused severe damage to about 50,000 ha of flooded rice in the Mekong Delta in 1976. Hirschmanniella spp. were found in all samples examined from flooded rice fields. Meloidogyne spp. were common in rice seedbeds, upland rice, and rice not kept flooded continuously. Meloidogyne and Pratylenchus spp. were found in roots of 22 of the 32 crop plants sampled. Little or no attempt was made in South Viet Nam to control nematodes.     

Identification key for European strand-forming house-rot fungi

An identification key for 20 common strand-forming indoor wood decay fungi is given. The key is based on observations of material from affected buildings and on wood samples that have been incubated in the laboratory. The key is with macro- and microscopic photographs.     

Parasites, emerging disease and wildlife conservation

In this review some emerging issues of parasite infections in wildlife, particularly in Australia, are considered. We discuss the importance of understanding parasite biodiversity in wildlife in terms of conservation, the role of wildlife as reservoirs of parasite infection, and the role of parasites within the broader context of the ecosystem. Using a number of parasite species, the value of undertaking longitudinal surveillance in natural systems using non-invasive sampling and molecular tools to characterise infectious agents is illustrated in terms of wildlife health, parasite biodiversity and ecology.     

Phylogenetic relationships among Southeast Asian climbing bamboos (Poaceae: Bambusoideae) and the Bambusa complex

A phylogenetic analysis of Bambusa and allies based on the plastid DNA non-coding regions rps16-trnQ, trnC-rpoB, trnH-psbA and trnD-T, and a partial nuclear GBSSI gene, was carried out. This included representatives from all four Bambusa subgenera (including type species), a group of segregate Southeast Asian genera distinctive by their climbing–scrambling culms (Dinochloa, Holttumochloa, Kinabaluchloa, Maclurochloa, Soejatmia, Sphaerobambos), and two other Bambusinae genera (Dendrocalamus, Gigantochloa). The results do not support the present subgeneric classification of Bambusa. The climbing Southeast Asian genera, all of which include species previously placed in Bambusa, are distinct from the “core Bambusa group” (type species and alliance) and the Bambusa complex generally.     

Two common and problematic leucochrysine species – Leucochrysa (Leucochrysa) varia (Schneider) and L. (L.) pretiosa (Banks) (Neuroptera,Chrysopidae): redescriptions and synonymies

We dedicate this article to the memory of Sergio de Freitas, FCAV-UNESP, Jaboticabal, São Paulo, Brazil (deceased, 2012). He was an active and enthusiastic Neuropterist and the cherished mentor and friend of Francisco Sosa.Leucochrysa McLachlan is the largest genus in the Chrysopidae, yet it has received relatively little taxonomic attention. We treat two problematic and common Leucochrysa species – Leucochrysa (Leucochrysa) varia (Schneider, 1851) and Leucochrysa (Leucochrysa) pretiosa (Banks, 1910). Both are highly variable in coloration and were described before the systematic importance of chrysopid genitalia was recognized. Recent studies show that these species occur within a large complex of cryptic species and that they have accumulated a number of taxonomic problems. We identify new synonymies for each of the species–for Leucochrysa (Leucochrysa) varia: Leucochrysa (Leucochrysa) ampla (Walker, 1853), Leucochrysa internata (Walker, 1853), and Leucochrysa (Leucochrysa) walkerina Navás, 1913; for Leucochrysa (Leucochrysa) pretiosa: Leucochrysa (Leucochrysa) erminea Banks, 1946. The synonymy of Leucochrysa delicata Navás, 1925 with Leucochrysa (Leucochrysa) pretiosa is stabilized by the designation of a neotype. The following species, which were previously synonymized with Leucochrysa (Leucochrysa) varia or Leucochrysa (Leucochrysa) pretiosa, are reinstated as valid: Leucochrysa (Leucochrysa) phaeocephala Navás, 1929, Leucochrysa (Leucochrysa) angrandi (Navás, 1911), and Leucochrysa (Leucochrysa) variata (Navás, 1913). To help stabilize Leucochrysa taxonomy, lectotypes are designated for Allochrysa pretiosa and Allochrysa variata. Finally, Leucochrysa vegana Navás, 1917 is considered a nomen dubium.     

The identification of microRNAs in the whitespotted bamboo shark (Chiloscyllium plagiosum) liver by Illumina sequencing

MicroRNAs are indispensable players in the regulation of a broad range of biological processes. Here, we report the first deep sequencing of the whitespotted bamboo shark (Chiloscyllium plagiosum) liver. We mapped 91 miRNAs in the Callorhinchus milii genome that have previously been described in the Danio rerio, Fugu rubripes, Oryzias latipes, Xenopus laevis, Xenopus tropicalis, Homo sapiens, and Mus musculus. In addition, 156 new putative candidate (PC) C. plagiosum miRNAs were identified. From these 247 miRNAs, 39 miRNA clusters were identified, and the expression of these clustered miRNAs was observed to vary significantly. A total of 7 candidate miRNAs were selected for expression confirmation by stem-loop RT-PCR. This study resulted in the addition of a significant number of novel miRNA sequences to GenBank and laid the foundation for further understanding of the function of miRNAs in the regulation of C. plagiosum liver development.     

Gene polymorphism analysis of Yersinia enterocolitica outer membrane protein A and putative outer membrane protein A family protein

Background

Yersinia enterocolitica outer membrane protein A (OmpA) is one of the major outer membrane proteins with high immunogenicity. We performed the polymorphism analysis for the outer membrane protein A and putative outer membrane protein A (p-ompA) family protein gene of 318 Y. enterocolitica strains.

Results

The data showed all the pathogenic strains and biotype 1A strains harboring ystB gene carried both ompA and p-ompA genes; parts of the biotype 1A strains not harboring ystB gene carried either ompA or p-ompA gene. In non-pathogenic strains (biotype 1A), distribution of the two genes and ystB were highly correlated, showing genetic polymorphism. The pathogenic and non-pathogenic, highly and weakly pathogenic strains were divided into different groups based on sequence analysis of two genes. Although the variations of the sequences, the translated proteins and predicted secondary or tertiary structures of OmpA and P-OmpA were similar.

Conclusions

OmpA and p-ompA gene were highly conserved for pathogenic Y. enterocolitica. The distributions of two genes were correlated with ystB for biotype 1A strains. The polymorphism analysis results of the two genes probably due to different bio-serotypes of the strains, and reflected the dissemination of different bio-serotype clones of Y. enterocolitica.