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1.
Weed flora in the Middle Valley of the Guadalquivir, Spain   总被引:1,自引:0,他引:1  
A floristic study of the weeds in irrigated crops in the Guadalquivir River Valley (southern Spain) revealed a total of 284 species in the 267 fields surveyed, of which about 100 can be considered highly harmful. The families with the highest numbers of species were Compositae, Gramineae, Leguminosae, Cruciferae and Umbelliferae. Although 77·8% of the species were therophytes, geophytes were important in spring-sown crops. Most species were of Mediterranean origin, especially in autumn-sown crops; Cosmopolitan and Neotropical species were more important in the spring-sown crops. At the early and late crop growth stages 7% and 10%, respectively, of the fields had severe or very severe infestations. The relationships between the main weed species and crops were studied by cluster analysis, using the corrected frequency of each species in each crop as the reference parameter. This allowed classification of the species into subgroups and hierarchical groups according to their agro-ecological preferences. A close relationship was found between a given crop, its cycle and the usual soil management practices and the phenology of certain species, reflecting the influence of these factors in restricting the germination period. The analysis differentiated the typically winter, summer and intermediate weed floras.  相似文献   

2.
江西抚河源头区域蜘蛛资源研究初报   总被引:7,自引:2,他引:5  
陈连水  袁凤辉  饶军  黄燕婷  曹波 《江西植保》2006,29(2):59-62,58
本文调查了江西抚河源头区域的蜘蛛种类,共获得蜘蛛标本1940个,经鉴定计22科71属159种,其中江西新记录种59种,未确定种21种。  相似文献   

3.
乌鲁木齐及附近地区蚁科区系的初步调查   总被引:4,自引:0,他引:4  
吴卫  李晓梅  郭宏 《干旱区研究》2004,21(2):179-182
对乌鲁木齐及附近地区蚁类的调查表明 ,计有 2亚科 1 3属 37种 ;区系组成以蚁属FormicaL .和弓背蚁属CamponotusMayr的种类较为丰富 ,分别有 1 5种和 6种 ;区系成分较为复杂 ,含古北种、新北种和广布种 ,其中 ,古北种有 30种 ,占总数的 81 % ;古北种下含泛古北种、中亚细亚种、欧洲种、欧洲中亚种、特有种、地中海种、欧洲—西伯利亚种、中央亚细亚种 ,而泛古北种最多 ,达 1 2种 ,占 32 .4 % ;其次为中亚细亚种有 7种 ,占 1 8.9% ;在所记录的种类中 ,草地蚁Formicapratensis,小林蚁 F .polyctena等多为中生性的种类 ,主要分布于森林地带或林间草地 ;草原箭蚁C .aenescens,草原原蚁P .epinotalis多分布在荒漠、半荒漠地带 ;褐色收获蚁Messorclivorum为乌鲁木齐地区的优势种 ,较为广泛地分布于乌鲁木齐及周边地区  相似文献   

4.
中国帕米尔高原菊科植物区系分析   总被引:2,自引:0,他引:2  
菊科是中国帕米尔高原第一大科,共有36属139种及1亚种5变种,植物生活型以地面芽植物为主,高达85.6%;中国帕米尔高原菊科植物区系地理成分多样,有8个分布类型和6个变型,温带性质明显,以北温带为主,缺乏热带分布型和中国特有分布型;与其它植物区系相比,西帕米尔与中国帕米尔的相似系数最高;该区菊科植物特有现象不明显.  相似文献   

5.
The objective of this study was to compare the floristic composition and species diversity existing in the seedbanks of forests and pastures. The seedbanks were sampled in three forest and three pastures areas in a community of smallholder farmers, in Pará state, Brazil. Seedling emergence in a glasshouse was used to quantify and identify the seeds. The total densities and diversity of the seedbanks were not significantly different among the pastures and forests, but the floristic composition was different. The herbaceous species predominated in both the pastures and the forests, but in the forest the abundance of shrub and tree was higher than herb. The seed density of several pioneer woody species was higher in the forests and the density of several herbaceous species was greater in the pastures. The influence of the forest species on the pastures and of the pastures species on the forests is a result of the initial process of human occupation and illustrates a dynamic that can lead to both the conservation of forest species and the spread of weed species. Actions should be carried out to avoid disturbance in the forests and improve biodiversity preservation in rural areas.  相似文献   

6.
Heteroptera is an important group among the insect orders,not only for its number of species,but also for its distribution and food preference.A total of 405 species of Heteroptera were identified in the desert areas of Kazakhstan,in which 158 species are distributed in the sandy deserts,105 species in the Solonchak deserts,75 species in the clay deserts,and 67 species in the rocky-rubbly deserts.  相似文献   

7.
The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants. However, research about delayed seed dispersal species in the desert of the United Arab Emirates (UAE) is lacking. This study aims to identify these delayed seed dispersal species and assess the relationships of the presence of delayed seed dispersal with plant growth form, habit, spatial dispersal, antitelechoric mechanism, and seed release time. The relationships between the presence of delayed seed dispersal and the above studied traits were assessed by using the Pearson Chi-square test and Nonlinear Principal Components Analysis (NLPCA). Results showed that a total of 46 delayed seed dispersal species were recorded (15.0% of 307 studied species) and the highest incidence occurred in the Fabaceae family (17.4%). Delayed seed dispersal species were predominantly perennial plants (73.9%) with spatial restricted dispersal (67.4%), which released seed in the dry season (45.7%). The dominant groups of delayed seed dispersal species were persistent fruits species and synaptospermy (28.3%). All graminoids showed persistent lignified fruits, while prostrate annuals were basicarpic species with myxospermy. Sandy habitats had the highest number of delayed seed dispersal species (54.3%), whereas salt flats had the lowest (23.9%). In the desert of the UAE, delayed seed dispersal species spread seeds until the end of the dry and windy season, thus breaking seed dormancy at this time and ensuring seed germination in the next arrival of the rainy season. This morphological and ecological adaptation of delayed dispersal species is essential to the survival and sustainable development of vegetation in desert environments.  相似文献   

8.
阴山山脉中段九峰山自然保护区大型真菌调查初报   总被引:1,自引:0,他引:1  
通过对九峰山自然保护区的专项调查,共获得大型真菌标本289号,根据Hawksworth和G.C.Alnsworth等(1983年)的分类系统,真菌中文名主要引用科学出版社出版《真菌名词及名称》和《中国真菌总汇》中使用的中文名,初步鉴定出95种,隶属于2个亚门4纲11目34科68属,其中食用菌49种,药用菌21种,毒菌12种,木腐菌32种,菌根菌5种;尚有部分标本因文献资料缺乏未能确定分类地位,有待进一步研究补充。  相似文献   

9.
新疆各类陆栖脊椎动物近 70 0种 ,占中国这一类动物种数的 32 %,其中鸟兽资源尤其丰富 ,计有 42 5种鸟类和 1 5 5种兽类 (哺乳类 ) ,占中国鸟兽种数的 31 %。本文主要以新疆三大山区———阿尔泰山、天山、昆仑 -阿尔金山地区鸟类和哺乳类动物的多样性及区系分布作综合性介绍和分析。根据实地考察和以往文献资料 ,新疆阿尔泰山区记录在 1 2 4种鸟类 ,其中古北界北方型鸟类 5 1种 (占 41 .1 %) ,中亚型鸟类 31种 (占 2 5 .0 %) ,广布种鸟类 2 7种 (占 2 1 .8%) ,其他类型1 5种 (占 1 2 .1 %) ,显出以北方型泰加林鸟类为主的鸟类区系特征 ;分布的 5 0种兽类 ,区系上以古北界北方泰加林为主 ,即北方型兽类占该山区种数的 5 2 %。天山山区记录的鸟类大约2 81种 ,北方型种类占绝对优势 ,即北方型 1 0 6种 (占 37.72 %) ,北方广布型 76种 (占 2 7.0 4 %) ,中亚型 39种 (占 1 3.88%) ,高地型 1 8种 (占 6.41 %) ,广布型 33种 (占 1 1 .74%) ,东北型 9种 (占 3.2 1 %)。兽类分布有 62种 ,北方型兽类区系占优势 ,有 30种 (占 48.40 %) ,广布型 1 2种 (占 1 9.40 %) ,中亚型 1 1种 (占 1 7.70 %) ,特有种 9种 (占 1 4.5 0 %)。昆仑—阿尔金山地区 96种鸟类中 ,中亚类型成份占 2 8.1 %,高地型成分占 2 6%,北方型成?  相似文献   

10.
化防田与综防田蜘蛛群落物种组成及优势类群动态分析   总被引:3,自引:0,他引:3  
洞庭湖平原地区共有稻田蜘蛛10科27属41种,其优势种为拟水狼蛛、食虫沟瘤蛛、八斑鞘腹蛛和锥腹肖蛸。在两类防治田的早稻田中,蜘蛛优势种没有变化,主要为拟水狼蛛和食虫沟瘤蛛;晚稻田中,蜘蛛优势种存在更替现象。在综防田和化防田中,蜘蛛种类和个体数量存在较大差异。同时,对蜘蛛控制害虫生物量进行了定量测定。  相似文献   

11.
Shada Mountains in Saudi Arabia, separated by Maleel Wadi into twin mountains(i.e., Shada Alalah and Shada Asfal), are rich in biodiversity. We investigated the diversity of endemics and endangered species of the mountains based on the data collected from 38 stands falling in 8 elevational zones ranging from 500 to 2215 m a.s.l. Results indicated that 495 plant species falling in 314 genera and 76 families occurred in the Shada Mountains, including 19 endemic species and 43 endangered species, and accounting for 22% of the total flora in Saudi Arabia. Canonical correlation analysis indicated that physiographic features, particularly altitude play an important role in the frequency and abundance of species. Endemics were not evenly distributed in the Shada Mountains and mostly restricted in the elevation zone of 1000–1500 or 1500 m a.s.l. When the altitude reached up to 2000 m a.s.l., the endemics decreased substantially due to the significantly low temperature. The endangered species existed three different distribution patterns:(i) most endangered species distributed in the altitudes of 1000–1800 m a.s.l.;(ii) endangered trees, lianas, and shrubs occupied the altitudes 1000–1300 m a.s.l.; and(iii) endangered subshrubs and herbs inhabited the altitudes 1500–2100 m a.s.l. The results demonstrated that the biodiversity of endangered species in the Shada Mountains is high and undisturbed by invasive species, and protective measures should be taken against human disturbances to the small-scale hotspot.  相似文献   

12.
寒地稻田节肢动物群落多样性调查   总被引:1,自引:0,他引:1  
王丽艳  朱莹  丛斌  李德刚 《植物保护》2009,35(3):102-105
经田间调查与室内鉴定,发现黑龙江寒地水稻田节肢动物种类有2纲10目49科65种。稻田节肢动物中各目、科的种类数量所占比例差异很大,在植食性昆虫中鞘翅目所占比例最大;在天敌中以蜘蛛类最多;在中性昆虫中,以双翅目比例最大;同时在物种、功能集团和营养层3个组织层次水平上分析了稻田节肢动物群落的结构和多样性。结果表明:在寒地稻田中顶位物种的丰盛度变化不大,而中位物种和基位物种的丰盛度变化明显;种的多样性整体变化幅度最大,8月9日最高,功能团多样性变化幅度不大,营养层多样性有一定波动。  相似文献   

13.
科尔沁沙地70种草本植物个体和构件生物量比较研究   总被引:7,自引:1,他引:6  
比较分析了科尔沁沙地70种草本植物盛花期时的个体和构件生物量特性。结果表明:43种植物个体生物量小于5.0 g,大部分物种根、茎、叶、花等构件的生物量均小于2.0 g,62种植物的根冠比小于1,说明70种草本植物中的大部分物种以地上生物量为主,只有少数物种具有较发达的地下根系。植物各构件生物量之间呈显著正相关,对个体生物量的贡献率为:茎>叶>根>花。多年生和1~2年生物种的个体生物量以及各构件生物量均无显著差异,但1~2年生物种的茎和地上生物量对个体生物量的贡献率显著高于多年生物种,而多年生物种的地下生物量对个体生物量的贡献率显著高于1~2年生物种,不同构件对生物量贡献率的差异有利于不同生活型植物的种群扩散和繁衍。  相似文献   

14.
A field survey of the Orobanchaceae family members and their hosts in Jordan was carried out from 2003 to 2007. The intensity of parasite infection on different hosts and the severity of the infestation were evaluated. The results showed the presence of seven species of Orobanche and three species of Cistanche . The Orobanche species were found parasitizing 86 plant species belonging to 24 botanical families. Most of the species attacked by Orobanche were from the Compositae (20 species), Solanaceae (11 species), Leguminosae (nine species), Umbelliferae (seven species), Cruciferae (seven species), Cucurbitaceae (four species), Labiatae (four species), and Rosaceae (four species) families. Other families were represented by one-to-three species. Cistanche attacked 20 species of forage wild shrubs, fruit trees, and forest trees of seven families, mostly belonging to the Chenopodiaceae (seven species) and Leguminosae (three species) families. Previously unreported hosts for both genera include: Amygdalus communis , Olea europaea , and Quercus coccifera , which were parasitized by Orobanche palaestina ; A. communis , O. europaea , Prunus armeniaca , and Prunus persica , which were parasitzed by Orobanche cernua ; O. europaea and A. communis , which were parasitzed by Orobanche schultzii ; Haloxylon persicum , which was parasitzed by Cistanche lutea ; Punica granatum , Alhagi maurorum , Casuarina equisetifolia , Centaurea postii , and Prosopis farcta , which were parasitzed by Cistanche tubulosa ; and Achillea spp., Anabasis syriaca , H. persicum , Haloxylon salicornicum, Suaeda spp., and Zilla spinosa , which were parasitzed by Cistanche salsa . Certain Orobanche species were completely destructive to the cultivated crops. The results indicated the high potential of both parasitic genera to spread and to attack new hosts, while the threat they impose to agriculture in Jordan will probably result from poor management and deficiences in farmers' training.  相似文献   

15.
新疆霍城县大、小西沟野果林种子植物组成及资源   总被引:6,自引:2,他引:6  
王磊  许正  晁海  廖康  赵永生 《干旱区研究》2006,23(3):446-452
新疆伊犁霍城大、小西沟野果林是以野樱桃李群落为主的野果林,共有种子植物60科233属500余种.林区野生植物资源丰富,统计表明:有野生果树38种、食用植物30种、饲用植物60种、蜜源植物111种、观赏植物128种、香料植物50种、药用植物113种.其中包括国家重点保护植物9种;新疆维吾尔自治区重点保护植物9种;中国珍稀濒危保护植物3种.通过多次实地调查分析,阐明了霍城野果林野生果树的分布、繁衍规律和植被、生境状况;综述了植物资源类型和用途及野生樱桃李群系生存的濒危程度.并提出在霍城大、小西沟野樱桃李集中分布区建立自然保护区的建议.  相似文献   

16.
阜康北部梭梭荒漠早春物种多样性研究   总被引:2,自引:1,他引:1  
通过对梭梭荒漠2种植物群落早春的物种组成、垂直结构及物种多样性的对比研究发现:梭梭(Haloxylon ammodendron)群落和白梭梭(Haloxylon persicum)群落具有结构简单、群落优势度高、均匀度和物种多样性较低、旱生性植物占绝对优势及短生植物成为群落重要组成部分等特征。同时,二者存在以下差异:①物种多样性差异, Shannon-Wiener多样性指数、均匀度指数及优势度指数梭梭群落(0.74,0.08和0.81)均高于白梭梭群落(0.61, 0.06和0.77);②主要伴生种不同,前者以草本植物为主要伴生种,后者以灌木为主要伴生种;③短生物种丰富度差异分别占前者的64.7%(11种)及后者的60%(15种)。2种梭梭群落的特点与差异可能与古尔班通古特沙漠南缘早春适宜的水热配置、群落生境的沙土含水量、沙面稳定程度及物种本身的生物学特性等因素有关。  相似文献   

17.
随着经济全球化的加速,外来生物入侵现象日益严重。外来入侵生物一直被认为是世界范围内对生物多样性最大威胁之一,其对全球的经济发展、生态环境及人类健康造成了巨大的危害。由于复杂独特的地貌和各种气候类型,中国的外来生物入侵问题也正在面临巨大的挑战。针对这一现状笔者浅析了我国外来生物入侵的立法概况,指出我国在外来入侵生物立法过程中存在的问题,如立法地位低、制度薄弱、立法本意的背离、对长期利益的忽视和法律责任制度不明确等。为了完善我国外来入侵生物的法律制度,本文结合外来入侵生物的国际公约和外国法律,如美国、日本等法律法规,提出相关建议,包括立法化以防止外来生物入侵;整合行政资源,建立专门机构以限制外来生物的使用;建立对外来入侵生物和应急反应机制的跟踪和监控措施。  相似文献   

18.
湖北省罗田县板栗害虫种类调查   总被引:1,自引:0,他引:1  
2013-2014年度系统调查了湖北省罗田县板栗害虫种类,经分类整理与鉴定,罗田县板栗害虫共计5目61科192种,其中枝干害虫23科62种,叶芽花序害虫49科153种、果实害虫8科15种;板栗新纪录害虫4目37科81种(已命名种),其中枝干害虫13科24种,叶芽花序害虫28科60种,果实害虫4科7种。对板栗生产造成严重危害的主要有:果实害虫板栗剪枝象[Cyllorhynchites cumulatus(Voss)]、栗实象(Curculio davidi Fairmaire)、栗雪片象(Niphades castanes Chao)和桃多斑野螟[Conogethes punctiferalis(Guenée)];枝干害虫昆明兴透翅蛾(Synanthedon kunmingensis YangWang)、勐腊兴透翅蛾(Synanthedon menglaensis YangWang)和板栗大蚜[Lachnus tropicalis(van der Goot)];叶芽害虫栎掌舟蛾[Phalera assimilis(BremerGrey)]和板栗瘿蜂(Dryocosmus kuriphilus Yasumatsu)。  相似文献   

19.
A review is given on observations ofPythium spp. so far published. In personal investigations about 4000 isolates ofPythium species were obtained from soil, water, Daphnias and plants during 1966–1972. Special attention was paid to the progressive colonization of the newly reclaimed polder Zuidelijk Flevoland: the numbers of species per sample increased from 0 in 1966 to 13 in 1972. The percentage of samples which did not contain anyPythium decreased from 54 in 1968 to 0 in 1972. From Zuidelijk Flevoland altogether 21 species were isolated, from Oostelijk Flevoland 22, of which 19 occurred in both the polders. The soil depth down to 10 cm had little influence on the occurrence ofPythium species. From soils near Rhenen and Zutphen 12 and 19 species respectively were isolated, from flax and flaxfields 11, from forests 8, from roots of different plants 17 and from water 11. Besides species already previously recorded, 15 new records ofPythium species for the Netherlands are documented. Species with filamentous non-swollen sporangia preferentially occurred in water and wet soils while species with spherical sporangia or hyphal swellings dominated in cultivated soils, forests and in the roots of phanerogams. In 1968 species with filamentous non-swollen sporangia comprised 89% of the isolations from Zuidelijk Flevoland; this percentage decreased to 9 in 1972. The percentage of isolates with spherical sporangia or hyphal swellings from cultivated soils, forest soils or plant material was mostly over 90.P. rostratum Butler, though found in all kinds of soils, was often the only species which could be isolated from dry sandy soil samples.P. sylvaticum Campbell & Hendrix was the most common species in cultivated soils in the Netherlands (37% of the isolates in 1968–1972), followed byP. oligandrum Drechsler (22%) andP. paroecandrum Drechsler (11.5%).  相似文献   

20.
ABSTRACT The identity of a Puccinia species occurring on the introduced weed dyer's woad (Isatis tinctoria) was studied using sequences from the internal transcribed spacer of the nuclear ribosomal DNA. The relationship of this fungus to other Puccinia species occurring on the family Brassicaceae in Europe and North America was examined, and we tested the hypothesis that P. thlaspeos and P. monoica are correlated species. The data suggest that the Puccinia species from dyer's woad is closely related to the North American species P. consimilis and may be derived from an indigenous strain of P. consimilis that switched hosts. Thus, the Puccinia species from dyer's woad is probably native to North America and is unlikely to cause disease epidemics on indigenous plants if used as a biological control agent against dyer's woad. P. thlaspeos appears to be polyphyletic and, therefore, P. thlaspeos and P. monoica do not appear to be correlated species. Additional DNA sequence data will be needed to clarify further the phylogeny of Puccinia species on the family Brassicaceae.  相似文献   

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