1960-2008年黑河流域地表干湿状况的时空变化分析

利用1960-2008年黑河流域16个气象站的逐日气象资料,采用FAO推荐的Penman-Monteith公式计算最大可能蒸散量,进而计算该流域的湿润指数,对地表干湿状况的时空变化特征及其主要影响因素进行分析。结果表明：黑河流域及其上、中、下游地区的湿润指数总体呈上升趋势,地表湿润状况有所改善,且湿润指数的年际波动性较明显,变异系数分别为14.97%、13.63%、25.47%、37.72%。除下游地区外,夏季的湿润指数变化速率最快,冬季的变化速率最慢;春季,黑河流域地表以变干趋势为主,其他季节均以变湿趋势为主。影响黑河流域地表干湿状况的主要因素是降水量,其他气候因子的变化对地表干湿状况起增强或削弱作用。     

近46 a六盘山东西两侧参考作物蒸散量特征

基于六盘山东西两侧甘肃平凉市7个气象站1965-2010年逐日气象要素,采用Penman Monteith模型计算了逐日参考作物蒸散量,应用Mann Kendall非参数检验法,分析了年际变化和季节变化特征。结果表明：① 1965-2010年,平凉市参考作物蒸散量多年平均在890～1 142 mm,全市西南部蒸散量最小,东部最大,年内夏季达到最大值,春、秋季次之,冬季最小;② 近46 a来,平凉市大多数站点参考作物蒸散量呈显著下降趋势;③ 影响平凉市参考作物蒸散量季节变化的主要气候因子是风速和日照,其中,风速是影响全市蒸散量呈下降趋势的主导因子。     

陇东地表湿润指数的年际变化特征

利用能够代表陇东气候类型的三个代表站1971~2005年月平均气温和降水资料,分析该地地表湿润指数的时空变化特征。结果表明:地表湿润指数变化多年平均,东南部的正宁最大,中部的西峰次之,北部的环县最小,呈现由东南向中部和北部逐渐干旱的空间变化特征;东南部的正宁和中部的西峰地表湿润指数以0.0028/a和0.0034/a的速率减小,地表趋于干旱化,北部的环县以0.005/a的速率增加,地表湿润程度有所增加;地表湿润指数的季节分布以春季最小,秋季次之,夏季最大,且春季和秋季有逐年减小的趋势,干旱化程度逐年加重,夏季呈增加趋势,地表湿润状况有所改善;地表湿润指数变化主要依靠降水的影响,但同时也受温度变化的影响,温度高,地表水分蒸发蒸散量大,地表易于变干,温度低,水分蒸发蒸散量小,地表不易变干。     

基于湿润指数的新疆甘家湖地表干湿状况变化趋势

利用1953—2013年甘家湖梭梭林自然保护区内精河和乌苏气象站的逐月气象资料,采用伊凡诺夫公式计算出了逐月潜在蒸散量和湿润指数,分析了地表干湿状况的年际变化、季节变化及其主要影响因素。结果表明:1冬半年、夏半年和全年的多年平均潜在蒸散量分别为298、1 107 mm和1 407 mm,潜在蒸散量在冬半年随时间呈下降趋势,在夏半年和全年潜在蒸散量呈明显上升趋势。2春、夏季湿润指数的年际变化呈减小趋势,秋、冬季和全年湿润指数的年际变化呈增加趋势。根据湿润指数相对应的气候区划标准,春季甘家湖自然保护区为半干旱地区,夏季和秋季为极干旱区-干旱区,冬季为干旱区的亚湿润区-湿润区。3湿润指数与降水量、水汽压和相对湿度呈正相关,与风速、气温和日照时数呈负相关;相对湿度变化对湿润指数变化影响最大,其次是日照时数、气温、水汽压和降水量,影响最小的是风速。     

青藏高原不同植被类型草地蒸散量长期变化与适应性模型研究

文中利用遥感数据潜热通量LE和气象数据年均气温T计算出2006-2021连续16年间青藏高原灌丛、荒漠、草甸和沼泽四种草地植被类型实际蒸散量的变化，并利用Penman-Monteith模型、Priestley-Taylor模型、Mahringer模型、Irmak-Alle模型、Dalton模型等5种常用模型计算出4种草地植被类型参考蒸散量的变化，选出4种植被类型拟合较高的模型。结果表明：连续16年间，4种草地植被类型蒸散量均呈极显著上升趋势。且相对于其他植被类型，灌丛、沼泽和草甸蒸散量显著高于荒漠。气象因子中，相对湿度、温度、2m高风速和土壤热通量4种对蒸散量变化的贡献率最大，且分别可解释71.21%、71.29%、71.37%和71.55%的灌丛、荒漠、草甸和沼泽蒸散量的变化。模型计算结果显示Mahringer和FAO 56 Penman-Monteith两种模型与实际蒸散量之间的相关性最高。推荐适宜的蒸散量计算模型，精确模型研究，以期提供蒸散量变化研究的理论基础。     

气候变化对渭河流域自然植被净初级生产力的影响研究(Ⅰ)——地表干湿状况时空演变特征分析

采用1959～2010年23个气象站的逐日气象资料,利用FAO Penman-Monteith公式计算出渭河流域各气象站的潜在蒸散量,由此计算出各站的湿润指数。采用样条曲线插值法(Spline)、气候倾向率、标准化指数、相关分析等方法对流域湿润指数的时空变化特征以及影响其变化的气象要素进行了分析。结果表明:近52a渭河流域地表湿润指数整体下降,由南向北干旱程度逐渐增加。北部黄土高原丘陵沟壑区最干,南部秦岭山地和关中地区最湿。湿润指数年际间波动较大,与潜在蒸散量的变化趋势呈反相位关系,泾河和北洛河流域干湿分布规律与渭河流域整体类似。干旱化速率较大的为华山和宝鸡,关中部分地区微弱变湿。流域整体在春季和秋季变干,夏季除关中和陇东部分地区外也逐渐变干,冬季呈变湿趋势。影响湿润指数的因素主要为降水(正相关)和温度(负相关),风速的增加也会加剧干旱化的趋势。     

西藏参考作物蒸散量时空变化特征与影响因素

为深入认识西藏参考作物蒸散量(ET_0)的变化特征,采用联合国粮农组织1998年推荐的Penman-Monteith公式计算西藏37个气象站点32 a(1981—2012年)的逐日ET_0,通过联合国防治荒漠化公约提出的全球干旱指数(UNEP)进行气候评价,利用空间插值及Mann-Kendall趋势检验法对西藏及各气候区ET_0时空变化特征进行分析,并通过偏相关分析法对其主要影响因素进行探讨,结果表明:西藏共分为特干旱、干旱、半干旱、干旱半湿润、湿润半湿润和湿润气候区,主要为半干旱气候区。近32 a参考作物蒸散量整体呈减小趋势,变化趋势为-1.508 mm·a~(-1),可将32 a分为3个时段,1981—1989年处于高蒸散阶段,1989年后处于低蒸散阶段,2005年起又持续回升。西藏西部到东部,年际ET_0呈减小趋势。各气候区气象因子的影响基本符合平均气温日照时数平均风速相对湿度,且平均气温、日照时数及平均风速在干旱区的影响较湿润区更为显著。     

东北地区主要树种的分布与Thornthwaite指标的关系

根据树种的分布资料和气象资料,采用桑斯威特(Thornthwaite)方法计算东北地区50种主要树种的潜在可能蒸散(PE)和湿润指数(IM),利用半峰宽法计算热量指数PE的最适范围,并构建Thornthwaite气候指标与树种分布的地理三维要素(纬度、经度和海拔高度)的回归模型,分析东北地区主要树种水热分布规律。综合潜在可能蒸散(PE)和湿润指数(IM)两个气候指标,将东北地区主要树种划分为寒温湿润型,寒温潮湿型,中温耐旱型,中温湿润型,中温潮湿型,暖温耐旱型、暖温湿润型和暖温潮湿型等8个水热指标类群,并论述了东北地区主要树种的水热分布格局。     

1961-2017年柴达木盆地干湿状况及其影响因子

根据1961—2017年柴达木盆地8个气象站数据资料,采用联合国粮农组织FAO推荐的Penman-Monteith模型计算潜在蒸散量,继而算得湿润指数,辅以气候倾向率、M-K检验、Morlet小波周期和主成分分析等方法,探究柴达木盆地干湿变化特征及影响因素。结果表明:1961—2017年,柴达木盆地整体具有变湿趋势,变化倾向率为0.007·(10a)~(-1)(α≥0.001),且湿润指数年际变化波动较大,变异系数为30.73%,春、夏、秋、冬四季湿润指数均呈上升趋势,倾向率分别为0.003·(10a)~(-1)、0.009·(10a)~(-1)、0.004·(10a)~(-1)、0.003·(10a)~(-1);空间变化差异显著,盆地东部地区变湿趋势大于西部,德令哈和都兰变湿趋势最为显著;湿润指数在1981年和1986年发生突变,且存在2.8 a和3.6 a(α≥0.05)的变化周期,与大气环流2～4 a周期较吻合;主成分分析表明,降水量和平均气温是柴达木盆地湿润指数的主要影响因子。此外,湿润指数与北半球极涡面积和强度及亚洲区极涡面积和强度关系密切,相关系数分别为-0.46、-0.36、-0.49、-0.47,均通过99%的显著性检验。     

基于混合型线性双源遥感蒸散模型的南疆绿洲地区干旱研究

利用MOD16蒸散产品数据以及2001—2014年新疆气象站点数据,基于混合型线性双源遥感蒸散模型估算南疆绿洲地区地表蒸散,并对比验证MOD16蒸散产品、反演蒸散量与研究区气象站蒸发皿实测蒸发量之间的关系。定义了蒸散干旱指数EDI,计算EDI距平,分析绿洲地区干旱分布特点,同时对比降水距平来检验干旱监测的准确程度。结果表明:MOD16蒸散产品蒸散量、模型估算蒸散量与蒸发皿实测蒸发量数据的相关性较好,说明利用MOD16蒸散产品数据估算蒸散量可行,也说明估算的蒸散量可信度高;由于绿洲地区北部水分供应更充足,EDI值空间上由南至北呈减小趋势,EDI值年际变化明显且均大于0.6;EDI距平与EDI同向变化,与降水距平反向变化;南疆绿洲地区在2001、2007、2008、2009、2014年的EDI值大于0.66。因此,EDI距平定义了干旱轻重程度界限:EDI临界值为0.66;EDI值越大,EDI距平越大,降水距平越小,干旱程度越严重。     

Richtlinien der Verbände des ökologischen Landbaus zum Vorratsschutz

Zusammenfassung Verbände des ökologischen Landbaus wie z. B. Bioland, Gäa, Demeter; Naturland, Ernte für das Leben oder Bio Suisse beschränken ihre Mitglieder bei der Wahl von Vorratsschutzmaßnahmen. Vorrang besitzen Maßnahmen zur Vermeidung von Schädlingen gegenüber Bekämpfungsmaßnahmen. Fallen müssen zur Befallsüberwachung eingesetzt werden, um einen Befall durch Vorratsschädlinge frühzeitig zu erkennen. Diese Maßnahmen sollen den weitgehenden Verzicht auf chemisch-synthetische Mittel ermöglichen. In diesem Beitrag werden die Empfehlungen der Verbände mit den derzeit verfügbaren chemischen Mitteln für den Vorratsschutz abgeglichen. Erfahrung in der praktischen Umsetzung von physikalischen und biologischen Verfahren werden diskutiert und Defizite bei der Befallsüberwachung und Bekämpfung beschrieben.     

Development of protocols for detection of Colletotrichum acutatum and monitoring of strawberry anthracnose using real-time PCR

Real-time PCR (TaqMan®) assays were developed for the specific detection and discrimination of Colletotrichum spp., C. acutatum and C. gloeosporioides causing anthracnose in strawberry using the most divergent area of the internal transcribed spacers (ITS1 and ITS2) and 5·8S ribosomal RNA (rRNA) gene region. The specificity of the new assays was tested using DNA from six species of Colletotrichum and nine fungal species commonly found associated with strawberry material, and additionally by comparing the sequences with those from databases using a blast search. The sequences only showed identity with homologous sequences from the desired target organisms. The new assays were 10–100 times more sensitive than conventional PCR methods previously published for the diagnosis of strawberry anthracnose. When real-time PCR was compared with ELISA methods, PCR improved the sensitivity of the identification by obtaining positive results for samples of strawberry plant material that tested negative with ELISA. The development of C. acutatum was monitored using artificially infected strawberry crowns from two strawberry cultivars (Camarosa and Ventana) and a real-time PCR assay specific for this species between January and June 2006. The amount of C. acutatum detected using real-time PCR varied significantly by month ( P  < 0·001), but not by cultivar ( P  = 0·394). The new assays were shown to be useful tools for rapid detection and identification of these pathogens and to allow rapid and accurate assessment of the casual agents of anthracnose in strawberry.     

A systematic review of the literature reveals trends and gaps in integrated pest management studies conducted in the United States

Integrated pest management (IPM) is a broad‐based approach for addressing pests that negatively affect human and environmental health and economic profitability. Weeds, insects and disease‐causing pathogens (diseases) are the pests most often associated with IPM. A systematic review, widely used in other scientific disciplines, was employed to determine the most commonly studied IPM topics and summarize the reasons for these trends and the gaps. In a field synopsis of the literature, 1679 relevant published papers were identified and categorized into one of the following five broad areas: IPM and organic (organic), climate change and pests (climate), rural and urban IPM (rural and urban), next‐generation education (education) and advanced production systems (technology). Papers were examined in greater detail for at least one of the three main pests in a systematic review. A majority (85%) of IPM papers have been in the area of rural and urban IPM, primarily addressing agriculture (78%). Professionals, landowners and the general public were the focus of a majority (95%) of IPM papers on education. Technology is an increasing area of focus in the literature. Over the past 40 years, IPM papers have primarily (75%) addressed insects and been limited mostly to rural and urban settings. Climate change, technology and education specific to pest management studies are increasingly being published and will help broaden the focus that could result in increased adoption and development of IPM. © 2017 Society of Chemical Industry     

Thermal and hormonal regulation of the dormancy–germination transition in Amaranthus tuberculatus seeds

The transition from seed dormancy to germination is a multi‐step process. However, distinguishing between physiological processes involved in seed dormancy alleviation and those involved in germination has been difficult. We studied the seed dormancy alleviation process in Amaranthus tuberculatus, an important weed species in midwestern USA. Using three A. tuberculatus biotypes that differ in dormancy level, it was determined that stratification reduced seed dormancy from a high to a low level. Temperature alternation alleviated low seed dormancy and triggered germination. Exogenously applied abscisic acid (ABA) and gibberellic acid (GA) had no effect on seeds with high dormancy. However, ABA and paclobutrazol (a GA biosynthesis inhibitor) significantly reduced germination of seeds with low dormancy. Hormones could not replace the effects of stratification or temperature alternation on dormancy alleviation. Based on our results, we propose a seed dormancy–germination transition model in which the dormancy of A. tuberculatus seeds is progressively reduced from a high to a low level; but environmental conditions (i.e. stratification) can accelerate the dormancy alleviation process. Under low dormancy levels, the seed is more sensitive to environmental cues that are responsible for removing dormancy and triggering germination (i.e. temperature alternation). Finally, ABA and GA regulation occurs primarily during the final transition from low dormancy to germination rather than the alleviation of high dormancy.     

Description ofPauesia (Pauesia)anatolica (Hymenoptera: Braconidae, Aphidiinae) sp. nov., a parasitoid of the cedar aphidCinara cedri

The first parasitoid species reared from a population of the cedar aphid,Cinara cedri Mimeur, 1935 (Hemiptera: Aphididae), from the peninsula of Anatolia in Turkey is described.Pauesia anatolica (Hymenoptera: Braconidae, Aphidiinae) is closely related to some species of thelaricis group ofPauesia from which it differs in the number of antenomers, the propodeum and features of the female genitalia. Its potential use as a natural enemy in areas where the aphid has been introduced is discussed. http://www.phytoparasitica.org posting Aug. 28, 2005.     

Current statistical issues in Weed Research

The correct design of experimental studies, the selection of the appropriate statistical analysis of data and the efficient presentation of results are key to the good conduct and communication of science. The last Guidance for the use and presentation of statistics in Weed Research was published in 1988. Since then, there have been developments in both the scope of research covered by the journal and in the statistical techniques available. This paper addresses the changes in statistics and provides a reference work that will aid researchers in the design and analysis of their work. It will also provide guidance for editors and reviewers. The paper is organised into sections, which will aid the selection of relevant paragraphs, as we recognise that particular approaches require particular statistical analysis. It also uses examples, questions and checklists, so that non-specialists can work towards the correct approach. Statistics can be complex, so knowing when to seek specialist advice is important. The structure and layout of this contribution should help weed scientists, but it cannot provide a comprehensive guide to every technique. Therefore, we provide references to further reading. We would like to reinforce the idea that statistical methods are not a set of recipes whose mindless application is required by convention; each experiment or study may involve subtleties that these guidelines cannot cover. Nevertheless, we anticipate that this paper will help weed scientists in their initial designs for research, in the analysis of data and in the presentation of results for publication.     

Electrophoretic and serological comparisons of pathogenesis-related (b) proteins from different plant species

Preparations of pathogenesis-related (b) proteins (PRs) from differentNicotiana species, tomato,Gynura aurantiaca, bean, and cowpea were compared to each other and to bean chitinase and a constitutive apple agglutinin by electrophoresis in polyacrylamide gels both in the absence and in the presence of SDS, and by serological double diffusion analysis using antisera against tobacco PRs and bean chitinase. PRs from different plant genera displayed a similar but not identical range of relative mobilities in both native and SDS gels, whereas bean chitinase and apple agglutinin were clearly different. None of the antisera reacted with any of the PR preparations from plant genera other than the one from which the antigen(s) had been derived. Whilst PRs within the genusNicotiana are serologically related and can be identical, PRs from different plant genera seem to be sufficiently different to be considered as genus-specific.     

Contribution of Biological Control to Integrated Pest Management of Tephritid Fruit Flies in the Tropics and Subtropics

The biological control of pest tephritid flies using parasitoids has been successful in relatively few subtropical and tropical regions. The best documented successes were in Hawaii and Florida, USA, Fiji and southern Europe. There were relatively limited successes in Australia, Costa Rica and Mexico. With the accidental establishment of new pest tephritids, such as Bactrocera latifrons (Hendel) in Hawaii or Bactrocera papayae Drew and Hancock in Australia, foreign exploration for new parasitoids is essential. A renewal of interest in classical biological control has recently occurred, although not at the same level as in the 1940s and 1950s. New parasitoid species are currently being obtained for several tephritids, such as Ceratitis capitata (Weidemann), B. latifrons and Anastrepha suspensa (Loew). The advances in mass rearing and quality control technology for parasitoids has enabled researchers to perform large-scale field testing of these parasitoids to determine the potential of augmentative releases. Numerous studies on the augmentative release of parasitoids have been done. Historically, the larval—pupal parasitoid Diachasmimorpha longicaudata (Ashmead) has been the most frequently studied parasitoid, due to the ease of rearing this species. However, recent successes in rearing other species with different biologies, e.g. the egg—pupal parasitoid Biosteres arisanus (Sonan), the gregarious eulophid, Tetrastichus giffardianus (Silvestri) and the pupal parasitoid, Coptera sp., will enable researchers to broaden the repertoire of parasitoid species for the future. Both successes and failures in augmentative releases have occurred. Without knowledge of the behavioural ecology of parasitoids, the reasons for success or failure can only be surmised. Recent research on the dispersal and host habitat finding of tephritid parasitoids will provide insights into improving augmentation and conservation strategies. The integrated pest management (IPM) of tephritid flies in the tropics has been less well-developed than research and programmes for tephritids in temperate zones. Significant emphasis is now being placed on the development of quarantine treatment methods that are environmentally sound; thus IPM will take a larger role. Several existing pest management strategies are reviewed which show the potential for compatibility with the activities of tephritid parasitoids. These include trap cropping, insecticides with selective toxicity to the target pests, mass trapping with parapheromones, the sterile insect technique and field sanitation.     

Population dynamics of white grubs in the upland rice and maize environment of Northern Mindanao,Philippines

Soil sampling over a two-year period in Claveria, Northern Mindanao, Philippines, revealed the presence of five white grub species (Coleoptera: Scarabaeidae) in the deforested, infertile, and highly eroded grassland environment being converted to small farms. Population dynamics data point to Leucopholis irrorata (Chevrolat), Holotrichia mindanaoana Brenske, and H. flachi Brenske being biennial with Adoretus luridus Blanchard and Anomala humeralis Burmeister being annual species. The three biennial species are synchronized to even-numbered years. Small subpopulations of the biennial species show evidence of annual or allochronic cycles. L. irrorata has an annual cycle in other areas of the Philippines on sugarcane but takes two years to develop in Claveria probably due to infertile soils and a longer feeding period. Other subpopulations of young larvae and emerged adults occurring in the late rainy season were 'attempts' at multiple generations or delayed development, but were considered suicidal due to the impending dry season. Synchronization of life stages occurs with pupation and adult emergence with early rains. Habitat preferences of the five species were elucidated by topography, cultivation, and presence of trees. L. irrorata and H. mindanaoana adults were found in 30 flight trees. Most (81%) of the larval stages were found within the top 20 cm of soil but some dug to 70 cm depth. Peak third instar larval densities reached 25.5/m 2 for all five species combined, but due to the biennial cycles of the major species, white grubs present economic importance to upland rice and maize only in odd numbered years. Control efforts are most economically directed during even numbered years giving a two-year benefit in population reduction.