中国中东部地区暴雨气候及其农业灾情的风险评估

利用中国中东部292个站点1961-2008年的暴雨气候资料和各省的农业灾情资料,采用主成分分析、软直方图估计、灰色关联法、正态信息扩散等方法,分别构建了暴雨气候指数、农业相对灾情指数及其风险估算模型,对中国中东部地区暴雨气候及其农业灾情的风险进行了研究.结果表明:中国中东部地区的暴雨气候风险,由南向北逐渐减少,高值区位于海南和广东、广西的沿海地区,其次是广西和广东的中北部,江淮地区的湖北、安徽、江西以及湘赣地区的湖南,低值区主要位于除辽宁沿海区域外的东北地区以及华北北部的河北和山西;农业相对灾情风险的高值区位于江淮地区的安徽、湖北,湘赣地区的湖南,东南沿海的广东,低值区是华北地区的河北、河南,东北地区的辽宁;除广东省外,各代表省的暴雨气候指数与农业相对灾情指数的相关系数均达到0.6以上(P＜0.Ol).经多年实际农业灾情验证,暴雨气候指数和农业相对灾情指数能较好地评估实际暴雨的强度及其对农业的影响.     

The amounts and properties of transported air at two norwegian stations as functions of wind direction and weather type

Based on monthly means of climatic variables during the period 1937–65, the climate at two Norwegian meteorological stations in January and July was classified by principal component analysis. The new variables were interpreted as pairs of alternating weather types, or airmasses. Four airmasses were identified, covering 20–30% of the transported air at each station. The significance, properties and amounts of air transported by each airmass was calculated and distributed according to wind direction. Differences between air circulation pattern and airmass distribution and properties during the summer and winter season were pointed out. One of the major differences is the tendency to form high pressure over inland areas in winter vs. low pressure in the summer season.     

Influence of environmental conditions on the distribution of Amphipoda,Talitridae, in the lagoon complex of Ghar El Melh (north‐east of Tunisia)

The study of the spatiotemporal distribution of talitrid amphipods was carried out along a transect in three stations belonging to the lagoon complex of Ghar El Melh, namely the supralittoral zones of the old harbour of Ghar El Melh, the opposite to Boughaz and Sidi Ali Mekki lagoon. Four species belonging to Talitridae family with two different genera were identified at all stations. These species are Orchestia gammarellus, Orchestia mediterranea, Orchestia stephenseni and Platorchestia platensis. The first two species were collected during the four seasons. The study of the density showed that the most important global mean density in talitrid was found in the supralittoral zone of opposite to Boughaz. In addition, statistical analysis showed a significant difference in the seasonal distribution of amphipods based on plant associations. Furthermore, the highest diversity of talitrid was observed in the winter in the supralittoral zone of opposite to Boughaz and in summer in the supralittoral zones of Sidi Ali Mekki lagoon and the old harbour of Ghar El Melh. Results showed that at all stations, a highly significant correlation of amphipod community with Cymodocea banquette was observed. Moreover, principal component analysis showed that the distribution of the different species depends on climatic and edaphic factors.     

Climatic Niche Evolution in New World Monkeys (Platyrrhini)

Despite considerable interest in recent years on species distribution modeling and phylogenetic niche conservatism, little is known about the way in which climatic niches change over evolutionary time. This knowledge is of major importance to understand the mechanisms underlying limits of species distributions, as well as to infer how different lineages might be affected by anthropogenic climate change. In this study we investigate the tempo and mode climatic niche evolution in New World monkeys (Platyrrhini). Climatic conditions found throughout the distribution of 140 primate species were investigated using a principal component analysis, which indicated that mean temperature (particularly during the winter) is the most important climatic correlate of platyrrhine geographical distributions, accounting for nearly half of the interspecific variation in climatic niches. The effects of precipitation were associated with the second principal component, particularly with respect to the dry season. When models of trait evolution were fit to scores on each of the principal component axes, significant phylogenetic signal was detected for PC1 scores, but not for PC2 scores. Interestingly, although all platyrrhine families occupied comparable regions of climatic space, some aotid species such as Aotus lemurinus, A. jorgehernandezi, and A. miconax show highly distinctive climatic niches associated with drier conditions (high PC2 scores). This shift might have been made possible by their nocturnal habits, which could serve as an exaptation that allow them to be less constrained by humidity during the night. These results underscore the usefulness of investigating explicitly the tempo and mode of climatic niche evolution and its role in determining species distributions.     

Use of direct gradient analysis to study the climate-vegetation relationships in Galicia,Spain

This paper reports a bioclimatic analysis of plant species in Galicia, NW Spain. A set of floristic data obtained from 150 plots located at euclimatopes (sites with monitored climate) was analysed using direct gradient analysis and clustering with respect to the 8 climatic variables thought to play a major role in regulating the distribution of the species considered in the study area. Principal component analysis (PCA) and hierarchical clustering were based on a matrix of species by climatic variables. Indicator taxa for the variables were identified on the basis of their Indicator values (Brisse & Grandjouan 1978) and grouped by cluster analysis. The groups produced were compatible with the results of principal component analysis and the frequential analysis of the species, which identified their phytoclimatic nature. The groups were then characterized by determining their climatic positions and indicator values with respect to the chief climatic variables. The first three PCA axes, which were associated with Oceanity, Mean minimum temperatures and the temperature range in the coldest month, together accounted for 97.2% of the variance of the data.     

广西英罗港红树植物群落的非线性排序

采用主分量分析 (PCA)、无偏主分量 (DPC)和非度量多维调节 (NMDS)等方法对广西英罗港 2 2个红树植物群落样地进行了排序。PCA和 DPC分析结果表明 ,取样数据具有明显的非线性结构。通过 NMDS分析 ,得到二维 NMDS排序格局 ,它能较好地反映了红树植物群落与环境因子之间的相互关系。     

Climate and vegetation at the Eurosiberian-Mediterranean boundary in the Iberian Peninsula

Abstract. The Northern Iberian Peninsula is dominated by various types of vegetation from deciduous oak and ash to evergreen oak woodlands. A recent vegetation map of Spain portrays vegetation series which are characterized in terms of their phytogeographic region or bioclimatic (altitudinal) belt. The aim of this paper is to determine whether the areas comprised by both phytogeographic regions (Eurosiberian and Mediterranean) in the study area, as established from the phytogeographic characterization of the vegetation, can be discriminated by climatic variables using multivariate methods, and to compare these with other conventional approaches. In addition, bioclimatic (altitudinal) belts and the main vegetation types were tested for discrimination by climatic variables. Conventional climatic criteria as well as discriminant and principal component analysis were applied to climatic data from 205 meteorological stations for which vegetation information had been taken from the vegetation map. Conventional criteria are good predictors of the phytogeographic division (Mediterranean and Eurosiberian regions) in the study area. Results were improved by multiple discriminant analysis based on climatic data of the dry period of the year (June to September). Both regions in the study area can be predicted with over 95 % accuracy. Using the same multivariate procedure and temperature data the bioclimatic (altitudinal) belts of the study area can be predicted with over 90 % accuracy. The main vegetation groups of the study area can also be predicted with over 80 % accuracy. Ordination analysis supported the results of the discriminant analysis. Empirical models have been generated to predict the phytogeographic- and belt character of any station in the area. The significance of the various periods of the year for discriminating regions and belts is evaluated. The responsiveness to climatic events during the year may be region specific. This study confirms the strong relationship between climate and vegetation in the Northern Iberian Peninsula, particularly regarding the Eurosiberian-Mediterranean boundary.     

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。     

Climate Signals from Tree Ring Chronologies of the Upper and Lower Treelines in the Dulan Region of the Northeastern Qinghai-Tibetan Plateau

The radial growth of trees In mountainous areas is subject to environmental conditions associated with changes In elevation. To assess the sensitivity of tree-ring growth to climate variation over a wide range of elevations, we compared the chronological characteristics of Sabina przewalskii Kom. and their relationships with climatic variables at the upper and lower treellnes In the Dulan region of the northeastern Qlnghal-Tlbetan Plateau. It was found that the radial growth in this region was controlled primarily by precipitation in late spring and early summer （from May to June）. In addition, a higher temperature from April to June could Intensify drought stress and lead to narrow tree rings. The significant similarity In climate-tree growth relationships at both the upper and lower treellnes Indicated that tree rings of S. przewalskU In this region are able to provide common regional climate information. However, the chronologies at the lower forest limits showed a higher standard deviation and more significant correlations with climatic factors, suggesting that the radial growth there was more significantly Influenced by climate variation. The first principal component of the four chronologies showed a common growth response to local climate. The second principal component showed a contrasting growth response between different sampling sites. The third principal component revealed different growth patterns In response to altitudinal variation. Further analysis Indicated that the precipitation In late spring and early summer controlled the growth of S. przewalskii on a regional scale and that other factors, such as mlcroenvlronment at the sampling sites, also affected the strength of the climatic response of tree growth.     

Analysing environments for plant breeding purposes as exemplified by multivariate analyses of long term wheat yields

Summary A previous attempt to relate long term yields from the Western Australian wheat belt to climatic factors proved only partially successful. Here, principal component analysis has been used to examine the patterns of variability created by those socio-economic factors which may have obscured any underlying relationship which existed between yield and climate. In fact, these analyses revealed the existence of variation peculiar to particular groups of years, a result which could explain why many attempts to relate crop yields directly to climatic factors have proved unsuccessful. The plant breeding implications of these genotype x environment interactions are considered.     

四川江津四面山常绿阔叶林永久样地的非线性排序

 本文以四川省江津四面山1 ha永久样地的常绿阔叶林为研究对象,利用样地内20个样方优势乔木种的重要值数据,采用主分量分析(PCA),无偏主分量分析(DPC)和非度量多维调节(NMDS)等方法进行分类和排序。PCA分析结果发现样方坐标数据具有非线性,DPC检测证实其非线性相当明显。通过NMDS分析,经过39次反复迭代,获得结果清楚地反映了群落优势种与环境因子的相互关系,为以后的次生演替研究提供了基础资料。     

Visualising the environmental preferences of Pinus tecunumanii populations

A network of 92 pedigreed ex situ conservation plantings of Pinus tecunumanii, established as replicated progeny within provenance trials, is used to present a principal components-based analysis that illustrates the climatic preferences of 23 populations from the species’ native range. This meta-analysis quantifies changes in the relative productivity, assessed as individual-tree volume, of populations across climatic gradients and associates the preference of a population with increased volume production along the climatic gradient. Clustering and ordination on the matrix containing estimates of change in productivity for each population summarise differentials in productivity associated with climatic gradients. The preference of populations along principal components therefore reflects the adaptive profiles of populations, which may be used with breeding-value estimates from routine genetic evaluations to assist with the development of deployment populations targeting different environments. As well, the approach may be used to test whether the preference of a population, estimated as population loadings for growth differentials, is affected by the climate in the native range of the population. This relationship may be interpreted as an estimate of how much local climate shapes the adaptive profiles of populations. The amount and seasonality of precipitation most clearly differentiate the adaptive profiles of populations, with less variation in the population responses explained by temperature differentiation. As expected from type-B correlation estimates, most populations exhibited small changes in relative productivity across climatic gradients. However, patterns of similarities in adaptive profiles among populations were evident using spatial orientation to display population responses to the climatic variables experienced in the provenance trials. Clustering and ordination of population responses derived from empirical data served to identify populations that responded positively or negatively to climatic variables; this information may help guide conservation genetics efforts, direct the deployment of germplasm, or identify seed sources that are sensitive to changes in climatic variables. Linking response patterns to the climatic data from the native range of each population indicated little effect of local climate shaping adaptive profiles.     

主成分分析在指导红薯施肥中的应用--以漂白湿润淋溶土为例

漂白湿润淋溶土表层的有效钾、全磷、有效磷含量显著高于表下层,其它养分上下两层的含量差异尽管没有达到的显著性水平,但都有向表层集中的趋势.主分量分析结果表明,第一主分量是含氮有机质形成过程强度的量度,表层和表下层有机质、全氮、全磷、有效氮、表下层有效磷均对第一主分量有较大的正向负荷量.第二主分量表示含氮有机质形成过程强度大致相同的情况下,各种养分对红薯产量促进作用的量度,其中表层和表下层有效钾、表下层有效磷对第二主分量的负荷量最大,远远超出其它因素的作用.相关分析也表明,三者与红薯产量呈极显著正相关.这间接表明,将钾肥施入表层和表下层均能提高红薯产量,磷肥只有施入表下层才有增产效果,而氮肥目前不表现增产作用.以上结论为肥料三要素组合试验所证实.这意味着在不改变变量属性的前提下,把多个变量按照变量的特性组合成少数新变量用来解决多因素复杂问题的主分量分析方法,能够科学地、合理地指导作物施肥。     

Bioclimatic evaluation of the human discomfort level for several Antarctic regions

A set of unfavorable climatic factors determines how extreme the environment is for humans in particular regions. The Arctic and Antarctic (polar) regions are generally considered to be the most extreme environments. Assessing the extreme conditions is of importance for developing life support systems and personal protective equipment, implementing proper labor management, and preventing frostbite. Several methods are currently used to assess the climate severity, but none of them addresses the level of discomfort for humans. Two indices, the Wind Chill Index (WCI) and Bioclimatic Index of Severity of Climatic Regime (BISCR), were previously developed to estimate the level of bioclimatic discomfort. With the indices, bioclimatic parameters were evaluated for eight Antarctic stations: Amundsen–Scott, Bellingshausen, Byrd, McMurdo, Mirny, Molodezhnaya, Novolazarevskaya, and Vostok. Monthly and annual data on air temperature, wind speed, relative humidity, altitude, and air pressure were used to calculate the WCI and BISCR. The BISCR, which includes hypoxia as a component of bioclimatic discomfort, was found to better predict the impact of meteorological conditions on the human body in Antarctica and to allow comparisons of outdoor climatic conditions and indoor microclimate for Antarctic stations. The WCI proved to detect no difference between stations from different climatic zones, especially in indoor conditions, thus being unsuitable for comparisons. The findings can be used for labor management at inland Antarctic stations to minimize possible health risks.     

Temporal fluctuations and experimental effects in desert plant communities

In the Chihuahuan Desert of the southwestern United States we monitored responses of both winter and summer annual plant communities to natural environmental variation and to experimental removal of seed-eating rodents and ants for 13 years. Analyses of data on population densities of the species by principal component analysis (PCA) followed by repeated measures analysis of variance (rmANOVA) on PCA scores showed that: (1) composition of both winter and summer annual communities varied substantially from year to year, presumably in response to interannual climatic variation, and (2) community composition of winter annuals was also significantly affected by the experimental manipulations of seed-eating animals, but the composition of the summer annual community showed no significant response to these experimental treatments. Canonical discriminant analysis (CDA) was then applied to the data for winter annuals to more clearly identify the responses to the different classes of experimental manipulations. This analysis showed that removing rodents or ants or both taxa caused distinctive changes in species composition. There was a tendency for large-seeded species to increase on rodent removal plots and to decrease on ant removal plots, and for small-seeded species to change in the opposite direction. In the winter annual community there was a significant time x treatment interaction: certain combinations of species that responded differently to removal of granivores also showed opposite fluctuations in response to long-term climatic variation. The large year-to-year variation in the summer annual community was closely and positively correlated across all experimental treatments. The use of multivariate analysis in conjunction with long-term monitoring and experimental manipulation shows how biotic interactions interact with variation in abiotic conditions to affect community dynamics.     

Application of projection pursuit based robust principal component analysis to ECG enhancement

The paper presents an application of principal component analysis (PCA) to ECG processing. For this purpose the ECG beats are time-aligned and stored in the columns of an auxiliary matrix. The matrix, considered as a set of multidimensional variables, undergoes PCA. Reconstruction of the respective columns on the basis of a low dimensional principal subspace leads to the enhancement of the stored ECG beats. A few modifications of this classical approach to ECG signal filtering by means of a multivariate analysis are introduced. The first one is based on replacing the classical PCA by its robust extension. The second consists in replacing the analysis of the whole synchronized beats by the analysis of shorter signal segments. This creates the background for the third modification, which introduces the concept of variable dimensions of the subspaces corresponding to different parts of ECG beats. The experiments performed show that introduction of the respective modifications significantly improves the classical approach to ECG processing by application of principal component analysis.     

The relationship between phytoplankton distribution and water column characteristics in North West European shelf sea waters

Phytoplankton underpin the marine food web in shelf seas, with some species having properties that are harmful to human health and coastal aquaculture. Pressures such as climate change and anthropogenic nutrient input are hypothesized to influence phytoplankton community composition and distribution. Yet the primary environmental drivers in shelf seas are poorly understood. To begin to address this in North Western European waters, the phytoplankton community composition was assessed in light of measured physical and chemical drivers during the "Ellett Line" cruise of autumn 2001 across the Scottish Continental shelf and into adjacent open Atlantic waters. Spatial variability existed in both phytoplankton and environmental conditions, with clear differences not only between on and off shelf stations but also between different on shelf locations. Temperature/salinity plots demonstrated different water masses existed in the region. In turn, principal component analysis (PCA), of the measured environmental conditions (temperature, salinity, water density and inorganic nutrient concentrations) clearly discriminated between shelf and oceanic stations on the basis of DIN:DSi ratio that was correlated with both salinity and temperature. Discrimination between shelf stations was also related to this ratio, but also the concentration of DIN and DSi. The phytoplankton community was diatom dominated, with multidimensional scaling (MDS) demonstrating spatial variability in its composition. Redundancy analysis (RDA) was used to investigate the link between environment and the phytoplankton community. This demonstrated a significant relationship between community composition and water mass as indexed by salinity (whole community), and both salinity and DIN:DSi (diatoms alone). Diatoms of the Pseudo-nitzschia seriata group occurred at densities potentially harmful to shellfish aquaculture, with the potential for toxicity being elevated by the likelihood of DSi limitation of growth at most stations and depths.     

Geographical and climatic differences in long-term effect of organic and inorganic amendments on soil enzymatic activities and respiration in field experimental stations of China

Soil enzymatic activities and basal respiration are two important bio-indicators of soil quality and are closely related to soil fertility and sustainable crop growth. We collected soil samples from four long-term experimental stations of China differing both geographically and climatically – Shenyang Agro-Ecological Experimental Station (brown soil), Fengqiu State Key Agro-Ecological Experimental Station (fluvo-aquic soil), Taoyuan Agro-Ecological Experimental Station (paddy soil) and Qiyang Red Soil Experimental Station (red soil) – to investigate the effect of long-term application of chemical fertilizer and/or organic manure on soil enzymatic activities and basal respiration. In general, soil enzymatic activities and basal respiration increased in soils with long-term application of chemical fertilizers and manures, especially organic manure. Among stations, soil enzymatic activities were not consistently increased with organic manure alone (e.g. the sucrase and phosphatase activities in the paddy soil from Taoyuan and red soil from Qiyang). As well, soil enzymatic activities were characterized by distinct zonality. Soil cellulase and urease activity were the two main indicators of soil fertility as evaluated by principal component analysis. Regression analysis of the major abiotic factor(s) influencing enzyme activity revealed a dependence on the specific enzyme tested and the activity of specific soil enzymes depended on the location of the experimental station. Environmental factors, mainly soil temperature, moisture and pH, as well as soil texture, should be taken into account in evaluating the effects of long-term fertilization on soil biological activity and soil fertility in field experimental stations differing geographically and climatically.     

Changes in the ciliate assemblage along a fluvial system related to physical, chemical and geomorphological characteristics

Samples were collected monthly from the water-sediment interface at six stations along the Mincio River (northern Italy) during a 1-year study of the ciliated protozoan communities. Four stations were located upstream of the Mantua lakes in the hyporhithron fluvial zone and two stations were located in the potamon fluvial zone between the Mantua lakes and the confluence with the Po River. A total of 133 species of active trophic ciliates belonging to 76 genera were found. Community structures revealed in this data were analysed using some statistical methods (similarity index, and categorical principal component analysis (CATPCA)) and this allowed the determination of differences between stations and between ciliate communities characteristic of stations. Species typical of the ecotypes located in both rhithron and potamon fluvial zones were defined. The saprobic index and valency analysis methods were used to quantify organic input and to follow changes in saprobicity along the river. A change in the ciliate communities was observed between stations located upstream and stations located downstream of the town of Mantua. The former were composed mainly of beta-mesosaprobic species, typical of the hill zone of running waters, while in the latter increased numbers of alpha-mesosaprobic species are associated with the higher anthropogenic pressures. Our results reiterate the high sensitivity shown by ciliated protozoa as indicators of organic load in watercourses.     

红松的生长与气候生态因子关系的研究

本文在研究中采用了树高指数作为气候因子对红松生长影响的数量指标。经过多元线性逐步回归分析和主分量分析得出如下结果.红松是对气候因子反应比较敏感的树种。由于各类气候因子不是孤立存在, 而是相互影响, 相互制约的, 所以气候生态因子对红松生长的影响是错综复杂的。各个因子通过单优势性、协同作用、拮抗作用等形式对红松生长产生直接影响和间接影响。气候生态因子对红松生长的影响是各因子的综合效应, 然而各因子对红松生长影响的大小并不相同。≥10℃积温影响最大占52.79%, 降雨量次之占18.62%, 二者的影响占71.41%是影响红松生长的主导因子。回归方程为Y=0.2924577+6.26395531×10^-5x₂+6.45308913×10^-5x₄.x₂=降雨量, x₄=10℃积温)。