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1.
新疆自然保护区现状评价及2000年发展预测和建议   总被引:1,自引:0,他引:1  
现代,自然保护区所占国土面积比例大小,已是衡量一个国家文明程度高低的标志之一。自然保护区的规划与建设,则是环境保护和国土整治工作的一个重要组成部分。位于欧亚大陆腹地的新疆,占我国总面积的六分之一,加之位于我国极端干旱区,其自然保护工作的水平,将直接对我国自然保护工作产生重要的影响。本文仅就1988年底新疆自然保护区现状及2000年发展预测加以探讨,并提出一些建议。  相似文献   

2.
柽柳属植物镜下器官特征描述及分类学意义   总被引:11,自引:2,他引:9  
新疆柽柳属植物为新疆重要的固沙植物,有18种1变种。面积大(553万hm^2),分布广,由于花器小不易观察,种间易杂交,使本属植物成为有花植物中分类最为困难的属之一。为精确分类,为该属植物分类提供解剖学依据,本实验将新疆的14种柽柳植物的叶、花、种子等器官在解剖镜下放大二十倍,进行观察描述,并对关键特征拍照。总结出结构典型、特征稳定、专属性强的识别特征,且易掌握、好记忆,使种间性状的相识性明显区分  相似文献   

3.
黄花刺茄原产北美,2005年首次在新疆乌鲁木齐县萨尔达坂乡和昌吉市三工镇发现。采用样方法,对不同生境中黄花刺茄分布相对集中的14个样地所有物种的多度、频度和重要值进行观测和分析,进一步明确黄花刺茄在新疆的分布区及其群落特征,并揭示其最适生境。结果表明:黄花刺茄分布于新疆乌鲁木齐市(县)、昌吉市、石河子市、吐鲁番市和托克逊县,分布在海拔-12~1 325 m处。生境类型包括荒漠草原、荒漠和绿洲。在3种生境中,黄花刺茄的相对多度均处于首位,且在绿洲中达到最大值,是入侵区域最为重要的物种;在相对盖度上均为第一,且绿洲(54.27%)>荒漠草原(35.07%)>荒漠(26.40%)。基于重要值数据的分析表明,黄花刺茄在3种生境中的综合适应力均最大,且以绿洲中尤为突出,表明黄花刺茄在新疆荒漠草原和荒漠生境中尚处于局部危害阶段,但在绿洲中已处于蔓延期。  相似文献   

4.
为了探讨禁牧对植物个体功能性状的影响,在新疆呼图壁县、玛纳斯县及昌吉市阿什里乡对短期禁牧下蒿类荒漠草地建群种伊犁绢蒿(Seriphidium transiliense)的个体表型特征、构件生物量及其分配比进行了测定。结果表明:伊犁绢蒿个体功能性状对短期禁牧的响应因禁牧地点的差异而有所不同,呼图壁和玛纳斯样地的大多性状如株高、地上生物量、叶片数、叶生物量均呈显著增加(P 0. 05),而昌吉样地多数功能性状虽为增加,但均不显著。总体分析可知,短期禁牧后伊犁绢蒿的株高、地上生物量、叶片数、茎生物量、叶生物量依次显著增加21. 32%、48. 97%、104. 50%、50. 18%、100. 00%(P 0. 05),根颈直径、一级及三级分枝数出现显著下降,而二级分枝数、生殖生物量、各构件生物量分配比变化不显著。伊犁绢蒿个体表型性状与其构件生物量及分配比间均具有显著的联动效应,且短期禁牧可引起其部分个体功能性状间的相关关系发生显著改变。研究表明,短期禁牧促进伊犁绢蒿个体功能性状的恢复,利于退化蒿类荒漠草地的恢复。  相似文献   

5.
北疆棉区食蚜蝇种类及其生境选择特性   总被引:1,自引:0,他引:1       下载免费PDF全文
食蚜蝇是北疆地区棉花蚜虫的一类常见天敌。本研究于2014-2015年系统调查棉田及其周边生境中不同植物上食蚜蝇种类和种群数量。结果表明,细腹食蚜蝇属、小蚜蝇属、粗股蚜蝇属为优势属,短翅细腹食蚜蝇、宽尾细腹食蚜蝇、短舌小蚜蝇和黄环粗股蚜蝇为优势种,黑带食蚜蝇为常见种;在两年的调查中,各食蚜蝇均喜选择有蚜虫或开花的植物,其中,宽尾细腹食蚜蝇、短翅细腹食蚜蝇、短舌小蚜蝇、阔斑食蚜蝇、黄环粗股蚜蝇等均比较偏好访问被蚜虫侵染的植物。本文还提出了食蚜蝇田间保护的可行性建议,为下一步发展北疆棉区食蚜蝇种群保育与利用对策提供了科学依据。  相似文献   

6.
Frequent periods of drought conditions are known to limit plant performance,primary production,and ecosystem stability in arid and semi-arid desert steppe environments.Plants often avoid competition by shifting their water use seasonally,which affects the water-use patterns of dominant species as well as the composition and structure of plant communities.However,the water-use strategies of dominant herbaceous species,which grow under natural field conditions in the desert steppe region of Ningxia Hui Autonomous Region,China,are poorly known.Here,we explored the possible sources of water uptake and water-use efficiency(WUE)of three dominant herbaceous plant species(Stipa breviflora,Agropyron mongolicum,and Glycyrrhiza uralensis)in a native desert steppe in the semi-arid area of Ningxia through an analysis of multiple parameters,including(1)the stable isotopic oxygen and hydrogen(δ18O andδ2H)compositions of precipitation,soil water,and stem water,(2)the carbon isotope(13C)composition of leaves,and(3)the soil water contents,based on field sampling across varying water conditions from June to September,2017.Frequent small precipitation events replenished shallow soil water,whereas large events only percolated down to the deep soil layers.Changes in soil water availability affected the water-use patterns of plants.Generally,during light precipitation periods,the deep root system of G.uralensis accessed deeper(>80 cm)soil water,whereas S.breviflora and A.mongolicum,which only have shallow roots,primarily absorbed water from the shallow and middle soil layers.As precipitation increased,all three plant species primarily obtained water from the shallow soil layers.Variation in soil water uptake between the dry and wet seasons enabled plants to make better use of existing satoil water.In addition,theδ13C values of G.uralensis and S.breviflora were higher than those of A.mongolicum.Theδ13C values of the three plant species were significantly negatively correlated with soil water content.Therefore,G.uralensis and S.breviflora maintained a higher WUE through their conservative and water-saving strategies across the entire growing season.In contrast,A.mongolicum,with a relatively low WUE in the wet season but a high WUE in the dry season,exhibited a more flexible water-use strategy.The different water-use strategies of these dominant plant species demonstrated the mechanisms by which plant communities can respond to drought.  相似文献   

7.
为明确宁夏四类主要草原的蝗虫物种组成、多样性和对天敌、植被、土壤及其气候等生物和非生物因子的响应,2019-2020年在宁夏温性草甸草原、温性草原、温性荒漠草原和温性草原化荒漠四类草原对蝗虫及天敌物种进行了调查采集,通过物种数、个体数、多样性指数、优势度指数、丰富度指数及均匀性指数分析蝗虫、天敌和昆虫的多样性,并就草原蝗虫优势种和多样性对天敌、植被、土壤及气候等生物和非生物因子的响应进行分析。结果表明,共采集鉴定草原蝗虫和天敌个体数分别有743头和3592头,物种数分别有27种和24种;温性草原上发生的蝗虫和天敌物种和数量均最多,蝗虫和天敌的物种分别为23种和21种,数量分别为432头和1682头;温性草原化荒漠上发生的蝗虫和天敌物种和数量均最少,蝗虫和天敌的物种分别为8种和7种,数量分别为34头和132头。蝗虫优势种有白纹雏蝗Chorthippus albonemus、短星翅蝗Calliptamus abbreviatus和亚洲小车蝗Oedaleus asiaticus三种,天敌优势种有直角通缘步甲Pterostichus gebleri、麻步甲Carabus brandti和短翅伪葬步甲Pseudotaphoxenus brevipennis三种。温性草原无论是在草原蝗虫群落中,还是整个昆虫和天敌群落中,其丰富度指数均显著高于其他三类草原;草原蝗虫多样性指数和丰富度指数与天敌多样性指数和丰富度指数间均存在极显著正相关关系,与天敌优势度指数间存在极显著负相关关系;短星翅蝗和亚洲小车蝗发生均与天敌直角通缘步甲呈显著正相关关系,白纹雏蝗与禾本科植被盖度、高度、生物量,菊科植被盖度、生物量、频度、高度、土壤饱和持水量、毛管持水量、田间持水量、毛管孔隙度、总孔隙度、有机质、碱解氮、海拔和降水量间均呈显著正相关关系,与土壤容重、pH、平均气温和最高气温间均呈极显著负相关关系。  相似文献   

8.
闻志彬  冯缨 《干旱区研究》2011,37(1):185-192
猪毛菜属(Salsola L.)是藜科中最大的属之一,在新疆植物区系和植物资源开发利用中占有重要地位。通过对新疆猪毛菜属32种植物的果时花被片附属物和叶片解剖结构的特征及其地理分布的分析,结果表明:① 果期花被片的附属物可分为两类,其中具翅状附属物的形态更加丰富;② 得到4种叶片解剖结构类型,包括C3-SYMP型、C3-C4中间型、C4-SALS+H型和C4-SALS-H型。依据叶片解剖结构类型判断,新疆猪毛菜属中C4植物占到绝大多数;③ 在新疆分布的猪毛菜属种类以草本植物居多,其生境主要以旱生和盐生环境为主;④ 猪毛菜属植物分布在新疆的6个地理分布地区,其中以准噶尔亚地区分布最多,塔城伊犁亚地区分布次之; ⑤ 新疆猪毛菜属植物与国外邻近地区的共有种明显多于国内邻近地区。  相似文献   

9.
利用光学显微镜,对新疆荒漠中针禾属植物大颖针禾(Stipagrostis grandiglumis)和羽毛针禾(Stipagrostis pennata)叶片进行微观形态结构特征的观察与比较.结果表明:大颖针禾和羽毛针禾的叶都具有典型的适应干旱及沙漠环境的形态结构特征;2种针禾叶片表面均具有角质层,但厚度不同;两者上表...  相似文献   

10.
 γ-变形菌纲(γ-Proteobacteria)的黄单胞菌属(Xanthomonas)的大多数种类可引起植物病害,多数是我国检疫对象。与其他革兰氏阴性植物病原细菌一样,植物病原黄单胞菌可通过高度保守的III型分泌系统(type-III secretion system, T3SS)分泌效应蛋白(T3SS-secreted effectors, T3SEs)进入植物细胞,在非寄主植物和抗病寄主植物上产生过敏反应(hypersensitive response, HR)以及在感病寄主植物上具有致病性。尚不清楚哪些种类的黄单胞菌具有T3SS和缺少哪些T3SE是否可作为检疫的依据。搜集7种检疫性植物病原黄单胞菌,通过PCR和Southern杂交试验结果发现:香蕉细菌性青枯病菌(X. campestris pv. musacearum)的ICMP287和ATCC49084菌株、甘蔗流胶病菌(X. axonopodis pv. vasculorum)ATCC13901菌株、洋葱细菌性叶枯病菌(X. axonopodis pv. allii)的LMG576和LMG578菌株中不含有tale基因,并且ATCC13901菌株既不含有T3SS基因也不含有hpa1xopQ基因;菜豆细菌性疫病菌(X. campestris pv. phaseoli)ATCC49119菌株不含有hpa1基因。相应地,推测含有2~12个tale基因的黄单胞菌有:大豆斑疹病菌(X. axonopodis pv. glycines)ICMP5732和ATCC43911菌株、豌豆细菌性疫病菌(X. axonopodis pv. vignicola)ATCC11648菌株、棉花细菌性角斑病菌(X. campestris pv. malvacearum)ATCC12131和(X. campestris pv. phaseoli)ATCC49119菌株。大豆细菌性斑疹病菌ATCC43911菌株尽管含有hpa1xopQhrcC基因,但在非寄主烟草上不能激发HR反应;而甘蔗流胶病菌ATCC13901菌株不含有hpa1xopQhrcC基因,却激发烟草产生HR反应。这些结果对于分析比较不同植物病原黄单胞菌的致病性因子和设计特定的植物检疫靶点提供了科学线索。  相似文献   

11.
For a plant species to complete its life cycle in arid and saline environments, each stage of the life cycle must be tolerant to the harsh environmental conditions. The aim of the study was to determine the effects of water stress (water potentials of -0.05, -0.16, -0.33, -0.56, -0.85 and -1.21 MPa) and NaCl stress (50, 100, 200, 300, 400, 500 and 600 mmol/L NaCl) on seed germination percentage, seedling survival and growth, juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge (Brassicaceae), an cold desert annual that grows in the Junggar Basin of Xinjiang, China in 2010. Results indicated that low water stress (-0.05 and -0.16 MPa) had no significant effect on seed germination percentage. With a decrease in water potential, germination percentage decreased, and no seeds germinated at -0.85 and -1.21 MPa water stresses. Germination percentage of seeds was significantly affected by NaCl stress, and higher germination percentages were observed under non-saline than saline conditions. An increase in NaCl concentrations progressively inhibited seed germination percentage, and no seeds germinated at ≥400 mmol/L NaCl concentration. Non-germinated seeds were transferred from both PEG (polyethylene glycol-6000) and NaCl solutions to distilled water for seed germination recovery. The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased. About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration. Thus, seed germination, seedling establishment and reproductive stage in the life cycle of L. lehmannii are water- and salt-tolerant, with seedlings being the least tolerant. These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.  相似文献   

12.
2016—2017年,利用扫网法系统调查了北疆棉田周边的非作物生境中9科13种常见植物上的食蚜蝇种群发生情况。研究发现,食蚜蝇种群密度在不同植物上有显著差异,种群发生高峰主要集中在各种植物开花期,种群消长还与这些植物上的蚜虫发生有明显跟随关系。5—6月,食蚜蝇在大部分植物上都有发生,但主要集中于新疆大蒜芥和罗布麻等;7—8月,在碱蓬、大麻、顶羽菊等上种群密度高;9月,主要在甘草、顶羽菊、罗布麻等上。本研究为今后充分利用棉田周边非作物生境,提升对食蚜蝇种群保育功能及棉花害虫生态控制水平提供了科学依据。  相似文献   

13.
农作物病害诊断对于及时发现并采取防控措施具有重要意义.本研究针对苹果、玉米、番茄、葡萄等典型农作物的常见叶片病害问题,使用了两种目前使用最广泛的卷积神经网络——VGG 16及Resnet50,对典型农作物叶片病害进行识别.使用AI Challenger比赛的农作物叶片病害数据集图像,并对这些图像进行预处理,构建了47 ...  相似文献   

14.
阐明斑块尺度上物种共存格局,对于深入认识荒漠草原破碎化草地生物多样性的维持机理具有重要意义。按斑块的土壤生境退化程度,选取短花针茅荒漠草原3类典型群落斑块为研究对象,对比分析不同斑块的物种构成、多样性及物种间的共存关系格局。结果表明:① 斑块A属单优种短花针茅(Stipa breviflora)群落;斑块B为短花针茅+草木樨状黄耆(Astragalus melilotoides)群落;斑块C为苦豆子(Sophora alopecuroides)+老瓜头(Cynanchum komarovii)+猪毛蒿(Artemisia scoparia)群落。② 群落结构中斑块A和斑块B多样性相近,均高于无短花针茅生长的斑块C。③ 基于零模型的分析结果显示,物种共存格局的复杂性和强度为:斑块A>斑块B>斑块C,且下降趋势明显,斑块A存在的16组显著物种对中有4组为显著竞争关系,而斑块C中的物种对减少到7组,且仅存在猪毛蒿与苦豆子组显著竞争物种对。结论:表明未沙化的土壤生境斑块是荒漠草原破碎化草地生物多样性维持的一个重要前提,土壤生境的退化显著降低了斑块内部群落组织的复杂性和物种间相互作用的强度,不利于群落的自我维持。  相似文献   

15.
为明确稻水象甲主要生物学特性及发生规律,探索稻水象甲暴发的原因,为新疆荒漠绿洲生态区稻水象甲的防控提供依据,调查其越冬场所、寄主植物、不同生境中的种群消长动态、年生活史、发生与环境的关系等。稻水象甲越冬成虫于4月上旬末开始活动,4月中旬在杂草、小麦等旱地作物上取食,5月中、下旬随水稻移栽迁入稻田,之后进入产卵期;一代成虫羽化始期为7月中旬,自8月上旬起,一代成虫又开始向其越冬场所附近的杂草丛转移,逐渐入土越冬。稻水象甲在新疆荒漠绿洲生态区一年发生一代,以滞育成虫在土表和浅土层中越冬,越冬的主要场所为稻田附近的林带和田埂。  相似文献   

16.
CHEN Juan 《干旱区科学》2022,14(9):1038-1054
Water is a limiting factor in the restoration and construction of desert steppe. Exploring plant water sources is necessary to understand soil-plant interactions and species coexistence; however, water sources of major plant communities within the desert steppe of Ningxia Hui Autonomous Region, China remain poorly understood. In this study, we analyzed the water uptake of plants in four typical communities: Agropyron mongolicum Keng.; Sophora alopecuroids Linn.; Stipa breviflora Griseb., and Achnatherum splendens (Trin.) Nevski communities. Stable isotopes δD and δ18O in the xylem of plant and soil water at different soil depths were analyzed. An IsoSource model was used to determine the soil depths from which plants obtained water. Results showed that A. mongolicum community obtained water predominantly from 0-20 and 40-80 cm depth, S. alopecuroids community from 0-20 cm depth, S. breviflora community from 0-40 cm depth, and A. splendens community from 0-20 and 80-140 cm depths. S. alopecuroides had a wider range of soil depths for water extraction, i.e., utilizing different water sources depending on habitat, and the plasticity of its water uptake pattern determined its role in different communities. Water source of plants relayed heavily on the distribution of their roots. Competition for soil water exists between different plant life forms in the sierozem habitat (A. mongolicum, S. alopecuroids, and S. breviflora communities), and in the sandy soil habitat (A. splendens community). The use of soil water by A. splendens community is more spatially differentiated, and shrubs and herbs can coexist stably. Under the pattern of extended drought period in the future, sierozem habitat may be more favorable for the formation of a dominant monoculture community type of perennial fibrous plants. In aeolian sandy soil habitat, A. splendens had a strong competitive advantage, and the growth of shallow-rooted plants was easily suppressed.  相似文献   

17.
Lesions of tea (Camellia sinensis) leaves are detrimental to the growth of tea crops. Their adverse effects include further disease of tea leaves and a direct reduction in yield and profit. Therefore, early detection and on-site monitoring of tea leaf lesions are necessary for effective management to control infections and prevent further yield loss. In this study, 1,822 images of tea leaves with lesions caused by three diseases (brown blight, Colletotrichum camelliae; blister blight, Exobasidium vexans; and algal leaf spot, Cephaleuros virescens) and four pests (leaf miner, Tropicomyia theae; tea thrip, Scirtothrips dorsalis; tea leaf roller, Homona magnanima; and tea mosquito bug, Helopeltis fasciaticollis) were collected from northern and central Taiwan. A faster region-based convolutional neural network (Faster R-CNN) was then trained to detect the locations of the lesions on the leaves and to identify the causes of the lesions. The trained Faster R-CNN detector achieved a precision of 77.5%, recall of 70.6%, an F1 score of 73.91%, and a mean average precision of 66.02%. An overall accuracy of 89.4% was obtained for identification of the seven classes of tea diseases and pests. The developed detector could assist tea farmers in identifying the causes of lesions in real time.  相似文献   

18.
为明确不同自然保护区外来入侵草本植物及其与本地植物多样性之间的关系,以我国生物多样性丰富的云南省为研究对象,于2014年对云南省6个国家级自然保护区的82个1 m2小样方(78个100 m2大样方)中外来入侵草本植物和本地植物物种丰富度和密度进行调查,并分析外来入侵草本植物物种丰富度与本地草本植物物种丰富度、外来入侵草本植物密度与本地草本植物密度的关系及对不同自然保护区外来入侵草本植物物种丰富度的差异进行分析。结果显示,共调查发现22种外来入侵草本植物,其中纳板河流域国家级自然保护区种类最多,达14种,金平分水岭国家级自然保护区仅有2种;6个国家级自然保护区本地草本植物的物种丰富度与外来入侵草本植物的物种丰富度之间、本地草本植物密度与外来入侵草本植物密度之间均呈现正、负2种相关关系,其中哀牢山国家级自然保护区本地草本植物的物种丰富度与外来入侵草本植物物种丰富度呈显著负相关,其它5个国家级自然保护区的相关性均不显著。简单回归分析表明自然保护区外来入侵草本植物物种丰富度与本地草本植物物种丰富度、本地草本植物盖度、本地乔灌木物种丰富度呈显著负相关,多元回归分析结果表明乔灌木物种丰富度和经纬度是造成不同自然保护区外来入侵草本植物物种多样性差异的主要原因。  相似文献   

19.
2015―2018年,利用百网和“Z”形取样法系统调查了博尔塔拉蒙古自治州草原七个草地类型的蝗虫群落多样性,明确其蝗虫的群落结构特征和多样性组成。经过调查分类鉴定,确定博州草原蝗虫有 65种,隶属于5科30属,优势种为黑腿星翅蝗、黑条小车蝗和小米纹蝗。在博州,黑条小车蝗垂直海拔分布的范围最广(257~2382 m),亚洲飞蝗和绿纹蝗垂直海拔的分布范围最为狭窄,仅为187~195 m;小翅曲背蝗和西伯利亚蝗多分布于高海拔地区(2000~2200 m),红斑翅蝗则多分布于低海拔区域(750~1200 m)。温性荒漠的特有种为简蚍蝗、红翅瘤蝗和红斑翅蝗,低地草甸的特有种为亚洲飞蝗、小垫尖翅蝗和绿纹蝗。蝗虫群落的Shannon-Wiener多样性指数在温性荒漠、温性草原化荒漠和温性荒漠草原要显著高于低地草甸;Pielou均匀度指数和Simpson优势度指数在七个草地类型间无显著性差异。温性荒漠草原和温性草原的蝗虫群落最为相似,两者Jaccard相似系数为0.56。  相似文献   

20.
中国珍稀濒危荒漠植物区系地理相似性的定位研究   总被引:2,自引:0,他引:2  
本文以中国西北部 ( 1 )准噶尔盆地、( 2 )塔里木盆地、( 3 )东疆哈 -吐盆地、( 4)柴达木盆地、( 5)河西地区、( 6)阿拉善高原、( 7)阿拉善东部地区作为珍稀濒危荒漠植物区系定量分析单位。应用 Jaccard、Ciechanowski( Sprensen)和 Ochari相似系数 ,根据 50种珍稀濒危荒漠植物的地理区系分布进行统计分析 ,建立 7个植物区系间的相似矩阵 ,进行聚类分析。结果表明 :中国西北地区珍稀濒危荒漠植物区系之间的相似关系 ,以准噶尔和东疆吐 -哈盆地间相似关系最为紧密 ,阿拉善东部地区较为孤立  相似文献   

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