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1.
山西省气候变化的多尺度诊断   总被引:4,自引:4,他引:0  
利用山西省108个地面气象站1957-2003年逐月降水、平均气温以及蒸发量等气象要素资料,采用主成分分析和聚类分析法进行气候分区,选取10个代表站的降水和平均气温序列,运用Morlet小波分析方法,对山西省47年气候变化以及不同时间尺度降水和气温变化的空间差异进行了诊断分析.结果表明:①山西省降水和气温存在多层次结构,不同时间尺度,存在不同的周期振荡行为.②山西省降水和气温总的变化趋势是20世纪80年代中期以前变冷变湿,且变化剧烈,之后变暖变干,且变化趋于缓和;21世纪初降水有恢复性增加趋势,气温有回落迹象.③山西省降水的空间差异明显,而气温变化的空间差异则相对较小.④从季节分布来看,21世纪初,春季降水偏少,冬季偏多,夏秋季降水则为偏少趋势中有小幅增加阶段;春季气温仍为偏高趋势,秋季有回落迹象,冬夏季为偏高趋势中有小幅回落阶段.  相似文献   

2.
山西省春季降水异常时空特征研究   总被引:5,自引:0,他引:5  
采用主成分分析(EOF)、旋转主成分分析(REOF)、小波分析方法,对山西省1960~2004年春季降水标准化距平场进行分区,并对春季降水异常的空间分布特征、时间变化规律进行分析。结果表明:山西省春季降水的主要空间异常型表现为全省一致的多雨或少雨型,这是山西省春季降水异常的主要特征。降水异常区域大致可划分为3个区,即北部区、中部区、南部区。各异常区春季降水都存在10 a以上长周期和3~10 a短周期振荡,但其显著周期及其年代变化差异较大。  相似文献   

3.
山西省太原市1951-2008年气候变化态势分析   总被引:2,自引:0,他引:2  
利用太原气象观测站1951-2008年的气温和降水资料,采用数理统计分析方法对太原市近58年的气候变化的特征和规律进行分析。结果表明:58年来太原市年平均气温呈现非连续性上升趋势,线性倾向值为0.34℃/10年,各季的变暖趋势相同,但增幅依次为冬季、春季、秋季、夏季。58年来降水总体为波动中明显减少的趋势。各季降水量也呈减少的趋势。综合气温与降水变化状况,太原市气候呈现暖干化的趋势。太原市降水和气温的年代分布具有明显的阶段性,显示气候变化具有阶段性、季节差异性特征。  相似文献   

4.
气候变化对山西省冬小麦种植的影响   总被引:6,自引:2,他引:4  
以1961-2005年地面气象观测资料和冬小麦生长发育资料为基础,分析了山西省气候要素及关键界限温度等变化趋势和特征。结果表明:山西省年平均气温增温明显,最冷月平均气温稳定上升,其倾向率为0.42℃/10 a;冬、春两季增温明显,其中冬季气温上升尤为显著;年平均气温和极端最低气温等值线北移较明显;降水量总的趋势在减少,秋、夏两季节降水量下降趋势以及阶段性都较明显,冬、春季总降水趋势不太明显,但阶段性起伏比较大;年平均日照时数也呈下降趋势。≥0℃积温、降水量和日照时数较1960年代在区域分布上东南部地区则较正常,其余地区呈增加、减少趋势。经M-K检验可知,自上世纪70年代末、90年代初开始温度升高、降水减少趋势开始明显,并在1998年通过U0.05显著性检验,从1990年代开始的气候暖干旱化趋势明显。气候变化使冬小麦播种和越冬期推迟,从返青开始各发育期均有提前,冬小麦种植北界较1960年代北移约15km左右。  相似文献   

5.
1951-2012年科尔沁沙地气温、降水变化特征   总被引:1,自引:0,他引:1  
科尔沁沙地是中国沙漠化典型区域,生态与环境问题突出,研究其驱动力之一的气候变化特征十分必要.利用1951-2012年62 a气温和降水资料,对科尔沁沙地空间和区域平均气温、降水变化特征进行了分析.结果表明:空间多年平均气温以开鲁、通辽为中心向东西方向递减,自北向南逐渐升高,且各站点均呈显著增加趋势;空间多年平均降水量以开鲁、阿鲁科尔沁旗为中心向四周逐渐增加,除库伦站降水量显著减少外,各站点降水量变化均不显著.区域平均气温上升速率为[0.319℃·(10a)-1],区域平均最高气温的上升速率[0.223℃·(10a)-1]低于区域平均最低气温[0.525℃·(10a)-1],春季气温增幅最大,冬季次之.最低气温的升高可能是导致总体气温上升的主要动力之一.区域平均降水量年际间波动较大,但总体无明显变化趋势;各季节区域平均降水量均无显著变化.年区域平均降水量与年区域平均气温、夏季区域平均降水量与夏季区域平均气温呈显著负相关,整体呈阶段性对称变化.  相似文献   

6.
近52年来磴口地区气候变化分析   总被引:1,自引:1,他引:0  
本文分析了磴口52年(1954-2005)逐月平均气温和降水量。结果表明:年平均气温逐年代递增,低温年发生在50至70年代,暖温年发生在80年代后,体现为"前凉后暖"的特点;年平均气温及各季平均气温均呈明显上升趋势,增长幅度依次为冬季>全年>春季>秋季>夏季。降水量年代际变化比较明显,60年代与90年代降水明显偏多,其它年代偏少,而且70年代是降水偏少的转折时期。年际间降水变化趋势不明显,丰水年与枯水年分别为36.5%和27.0%。降水的年际变幅夏季最大,秋季次之,冬季最小。降水主要集中在夏季,而且年降水的波动形态与夏季基本一致。  相似文献   

7.
利用2000—2014年MODIS EVI数据、27个气象站点逐月气温和降雨量、MOD16蒸散量数据,分析了山西省15年来的植被覆盖变化及其对气温、降水和蒸散量的响应特征。结果表明:(1)山西省植被总体呈现上升趋势,增速为2.6%·10a~(-1),不同生态分区中Ⅱ东部大行山山地Ⅲ中部盆地Ⅳ西部山地Ⅰ晋北山地Ⅴ晋西黄土丘陵区。(2)山西省植被覆盖具有较大的区域差异,其中东南部的EVI明显高于西北部,EVI频度图呈现"单峰结构",全省绝大部分地区呈现不变或增加趋势,显著面积比例为25.95%,严重退化面积比例为1.04%。(3)基于年尺度的EVI与降水、蒸散量呈正相关,与温度负相关,基于月尺度的EVI与气温、蒸散量呈显著正相关,蒸散量与EVI的相关性好于降水、温度单一因子,而降雨量对EVI变化存在一个阈值。(4)从生长季考虑,从春季到夏季各大生态区蒸散量与EVI均为正相关并且逐渐加强,秋季除Ⅲ中部盆地外其它自然区均为负相关。  相似文献   

8.
文中利用山西省107个国家站站点1981—2018年春季逐日平均气温、地温资料,采用相关分析、M-K非参数检验等方法,研究了山西省春季各层地温的变化趋势以及地温与气温和春季崩塌、滑坡地质灾害的相关关系。结果表明:M-K突变分析得出:春季平均气温在1998年出现由冷转暖的突变,0cm地温在1999年发生突变,5cm地温突变点为2003年,10cm地温突变点为2001年,15cm和20cm突变点均为1997年。山西春季崩坍、滑坡发生频次从2005年开始呈高频增长趋势,其中2005-2009年发生频率呈显著增多趋势,2016-2018年发生频次减少。0cm地温与崩塌、滑坡频次呈显著正相关。0cm地温升高时,崩塌、滑坡有增多的迹象。通过小波能量谱分析春季崩塌滑坡地质灾害与0cm地温呈现出同位相显著正相关。选取历史上山西省春季出现崩塌滑坡地质灾害的个例分析得出,春季地质灾害发生前平均气温和0cm地温出现两种情况:第一类持续异常偏高或突然转为偏高,第二类前期偏高或异常偏高,临近转为偏低,由于0cm地温的变化特征几乎与平均气温的变化特征一致,所以可以利用平均气温的数据作为判别春季崩塌、滑坡地质灾害高...  相似文献   

9.
利用西安市1961-2009年的月平均气温与降水资料,对西安市气候特征及动态变化进行分析。结果显示:年平均气温及春、秋、冬季气温呈上升趋势,增温率分别为0.3℃/10 a,0.54℃/10 a,0.23℃/10 a和0.42℃/10 a,春、冬季升温明显。1月平均气温总趋势上升,升温率为0.23℃/10 a,20世纪80年代开始7月升温明显。年降水量有减少倾向,春、秋季降水明显减少,其中春季减少率为-14.8 mm/10 a,而夏季降水明显增加,增长率为21.8 mm/10 a,冬季降水小幅度增加。80年代及2001-2009年汛期年均降水较多。春、夏、秋季气温与降水有较好的相关性,而全年及冬季气温与降水相关规律不明显。  相似文献   

10.
西安市气温和降水变化趋势分析   总被引:4,自引:0,他引:4  
利用西安市1961-2009年的月平均气温与降水资料,对西安市气候特征及动态变化进行分析。结果显示:年平均气温及春、秋、冬季气温呈上升趋势,增温率分别为0.3 ℃/10 a,0.54 ℃/10 a,0.23 ℃/10 a和0.42 ℃/10 a,春、冬季升温明显。1月平均气温总趋势上升,升温率为0.23 ℃/10 a,20世纪80年代开始7月升温明显。年降水量有减少倾向,春、秋季降水明显减少,其中春季减少率为-14.8 mm/10 a,而夏季降水明显增加,增长率为21.8 mm/10 a,冬季降水小幅度增加。80年代及2001-2009年汛期年均降水较多。春、夏、秋季气温与降水有较好的相关性,而全年及冬季气温与降水相关规律不明显。  相似文献   

11.
Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.  相似文献   

12.
Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.  相似文献   

13.
The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.  相似文献   

14.
Plant Viruses Transmitted by Whiteflies   总被引:18,自引:0,他引:18  
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.  相似文献   

15.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

16.
A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  相似文献   

17.
The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.  相似文献   

18.
In the summer of 2004 an epidemic of sclerotinia blight of peanut, a disease caused by Sclerotinia minor, occurred in Texas in fields where the disease was never previously detected. The disease was observed on many plants within one of the fields (>3000 disease foci), although most foci were <1 m. It is hypothesized that these observations were inconsistent with the recent introduction of a monocyclic pathogen, even if disease developed under conducive environmental conditions. The pattern of disease is most suggestive of the presence of foliar (ascospore) infections, although air temperature was above the known limits for apothecia development if the pathogen had arrived in the field in 2004 peanut seed. To further examine this epidemic, 232 isolates were collected, across a variety of spatial scales spanning this field and other Texas peanut fields, and evaluated for aggressiveness, fungicide sensitivity and genotypic diversity. There was wide variation among isolates for the phenotypic characteristics measured, but there was no evidence that a genotypically unique, highly aggressive, and fungicide resistant isolate had been introduced or evolved. The predominant genotype, TX1, which contained 154 isolates, was found in every county and field population.  相似文献   

19.
Four species so far classified in Pseudocercosporella or Ramulispora (hyphomycetes) are associated with eyespot disease symptoms of cereals. Two of these have been linked to teleomorphs that were described in Tapesia. Sequence data derived from the Internal Transcribed Spacer region (ITS1, 5.8S and ITS2) of the rDNA operon showed, however, that the eyespot fungi associated with Tapesia are not congeneric with Ramulispora sorghi, the type of Ramulispora. The genus name Tapesia is now rejected in favour of the conserved name Mollisia, which appears to comprise heterogeneous fungi. Tapesia yallundae is not closely related to the type of Mollisia, M. cinerea, but clusters separately, being more closely allied to species with Cadophora anamorphs. A new holomorph genus, Oculimacula, is therefore proposed for teleomorphs of the eyespot fungi, while the anamorphs are accommodated in Helgardia gen. nov.  相似文献   

20.
In 1975 many tumours were observed in plants ofBegonia Schwabenland grown in Aalsmeer. Submersion of the roots ofNicotiana megalosiphon seedlings in a homogenate of tumorous tissue, induced tumours after two weeks. Short periods of submergence yielded results similar to those obtained after longer periods. Tumour homogenates lost their infectivity after ten min at 50°C. Aphids transmitted the infectious agent.Treatment with propylene oxide did not inhibit infectivity completely. Filtration through a 450 nm filter removed the infectious agent.Tobacco tumor virus or a viroid could not be isolated. Cultures ofCorynebacterium fascians, isolated from tumours ofN. megalosiphon were highly infectious and induced tumours in healthyN. megalosiphon andBegonia. Tumorous tissue homogenates ofPelargonium zonale, Dahlia sp.,Gladiolus sp., andLilium sp. also caused tumours inN. megalosiphon, from whichC. fascians was isolated. It was not possible to produce tumours inN. megalosiphon with homogenates from roses with symptoms of bud proliferation.Samenvatting In 1975 werden vele tumoren waargenomen inBegonia Schwabenland op Aalsmeerse bedrijven (Fig. 1). De infectiositeit van tumorweefsel kon goed en snel worden vastgesteld door de wortels van zaailingen vanNicotiana megalosiphon in een homogenaat van tumorweefsel te dompelen. Tumoren ontstonden na twee weken, de eindbeoordeling geschiedde na een maand (Fig. 2). Ook verschillende andereNicotiana spp.,Melilotus officinalis (Fig. 3) enPisum odoratum (Fig. 4) werden aangetast.Bij de infectiositeitstoets gaven zeer korte dompeltijden even goede resultaten als langere (Tabel 1). Infectieus sap verloor zijn infectievermogen na 10 min verhitting bij 50°C. Bladluizen brachten de smetstof over. Propyleenoxide verminderde de infectiositeit wel, doch onderdrukte deze niet totaal. Bij filtratie door een 450 nm filter bleef het infectieuse agens op het filter achter. Het tumor-inducerende agens was ook aanwezig in die delen van planten met tumoren welke gezond leken en het ging voor een gering deel over met zaad (Tabel 2).Uit tumoren konden wij geen tabakstumorvirus of een viroïde isoleren. Culturen vanCorynebacterium fascians, geïsoleerd uit tumoren vanN. megalosiphon bleken zeer infectieus en veroorzaakten tumoren inN. megalosiphon enBegonia. Homogenaten van tumorweefsel vanPelargonium zonale, dahlia (Fig. 5), gladiool (Fig. 6) enLilium Mid Century Hybrid Enchantment (Fig. 7) veroorzaakten ook tumoren opN. megalosiphon, waaruitC. fascians werd geïsoleerd. Met sap van kroeskopzieke rozen konden wijN. megalosiphon niet besmetten.  相似文献   

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