查询词典 xeric

Basesd on the precipitation difference in Tsaidam Basin of Qinghai Province, three sampling areas, including Geremu, Delinghan and Doulan, were selected, and then three sapmling plots in each sampling area were selected to study the characteristics of plant community which dominated by Ceratoides lateens, Nitraria tangutorum, Tamarix chinensis, Kalidium gracile, Haloxylon ammodendron and Salsola arbuscula respectively. At the same time, the morphological and physiological features of above-mentioned 6 species were measured for probing their drought tolerance. By using the subordinative function method, grey correlative degree analyse and no-weight index comprehensive evaluation method, their drought tolerance were compared as well. The results were showed as follows: The main xeric vegetation types in the desert steppe of Tsaidam Basin were Nitraria tangutorum community, Tamarix chinensis community, Haloxylon ammodendron community, Kalidium gracile+Salsola arbuscula community, Ceratoides lateens+ Haloxylon ammodendron+Kalidium gracile community.

根据青海省柴达木盆地不同地区历年降水量差异，在研究区内选择格尔木、德令哈、都兰3个采样区，每个样区内确定3个采样点(表示为D11、D12、D13、D21、D22、D23、D31、D32、D33)，以样区内唐古特白刺、甘蒙柽柳、梭梭、木本猪毛菜、里海盐爪爪、驼绒藜等6种主要植物为研究对象，通过调查采样地区群落特征，观测植物形态解剖特征，测定植物脯氨酸、可溶性糖、叶绿素、超氧化物歧化酶、过氧化物酶和过氧化氢酶等生理指标，研究了柴达木盆地6种植物抗旱生理特性及抗旱特性，用模糊数学隶属函数法、灰色关联分析和非加权指数评价法分别对6种植物的各个抗旱性指标进行了综合评价。

This indicate most of those kinds are mature from the midst of July to the midst of August,but the aquatic Pteridophyte delay twenty days,especially it is diffirent in Sphenopsids and Xeric spore.

这在研究蕨类生理生态、生长发育、开发抗旱抗寒观叶蕨类，以及筛选抗旱抗寒基因植物等，都有独特的研究价值。

The differentiation states of costae indicates the ways they absorb and transport water, and their ability adapting to the dry conditions, which was elucidated by the following examples: Brachythecium plumosum, because of its thin cell-walls in the costae and the absence of hydrome, assistant and steroid cells, can absorb water and nutrition under shady and moist conditions; Plagiomnium rostratum, though often grows in shady and wet condition, has hydrome and steroid cells, a feature similar to those of xeric mosses, which endows it to grow in the conditions with periodical drought stress during its life cycle; Hygrohypnum luridum is characterized by its slender leaves with only one layer of cells, the thin cell-walls, the absence of filaments on the leaf surface, and the fewer layer cells in the costae, the absence of hydrome and steroid cells. These features make it adaptable to aquatic environments. For Pogonatum inflexum and Atrichum undulatum, their ventral surfaces covered with lamella, while for Racomitrium japonicum, Thuidium cymbifolium, Macromitrium ferriei, Diphyscium fulvifolium, Barbula unguiculata and Ceratodon purpureus, their leaves are strongly mammillose or papillos. Such appendiculate structures made them adaptable to thy conditions.

例如，荫湿生环境下的羽枝青藓Brachythecium plumosum，其中肋细胞胞壁较薄，无导水主细胞和副细胞的分化，也没有厚壁细胞分化，能够在阴湿环境下吸收水分和养分；钝叶匍灯藓Plagiomnium rostratum具有与旱生藓类植物相似的中肋结构，叶片较厚，中肋具导水主细胞，中肋背面具厚壁细胞，这些特点使该种藓类植物能够分布于间隙性干旱胁迫的环境中；水灰藓Hygrohypnum luridum叶片纤细柔弱，仅1层细胞，细胞胞壁薄，叶表无附属结构，中肋细胞层数少，无导水主细胞分化，也没有厚壁细胞，这些特点使得水灰藓'能够生长在水生环境中；东亚小金发藓Pogonatum inflerum和波叶仙鹤藓Atrichum undulatum的叶腹面覆盖着栉片，东亚砂藓Racomitrium japonicum、大羽藓Thuidium cymbifolium、福氏蓑藓Macromitrium ferriei、东亚短颈藓Diphyscium fuhifolium、扭口藓Barbula unguiculata和角齿藓Ceratodon purpureus的叶片表面有乳头状突起或疣状物，这些附属结构使它们能够适应于旱生的环境中。

Allium mongolicum Regel was pernennial and xeric plant in Allium of Liliaceae , it was an endernic species in Mongol plateau and distributed widely in Inner Mongolia.

沙葱，又名蒙古韭，是百合科葱属的多年生旱生植物，是蒙古高原的特有种，内蒙古自治区内广泛分布。

By the field survey which lasting a period of 3 grown seasons and by the means of remote sense and geographic information system, we ascertain the present vegetation pattern of Hunshan-Dake sand land, find out vegetation distribution principles on the different scales in the same time . From west to east, with the increasing of dry degree, the type of plant community changed form the xeric to the mesic. The vegetation of Sand land shows the characteristic of the zonal vegetation, but dont consistent with the traditional diversification principle. The vegetation of the middle part displays a high differential characteristic, which compresses the longitudinal zonation at a certain extent. So we can say that sand land vegetation is semi-zonal.

通过对浑善达克沙地历时三个生长季的地面考察并应用遥感及地理信息系统等手段，确定了浑善达克沙地植被分布现状及浑善达克沙地植被在不同尺度下的分异规律：由西向东，沙地植被随着干燥度的降低，由旱生群落为主的区段递变为以中生群落为主的区段，表现出具有一定的地带性植被特征，但与传统的地带性植被的递变规律不相一致，沙地中段的植被表现出了高度的特异性，在一定程度上压缩了植被的经向地带性，表现出沙地特有的地带性分布规律，所以认为沙地植被是一种半地带性植被。

These results can shed lights on revealing the mechanisms of plant's adaptation to xeric conditions, as well as the effects of anthropogenic disturbances on the local extinction of native species, and/or invasion of shrubs.

我们的研究结果从植物种、功能群和群落三个层次进一步揭示了植物对干旱生境的适应机制，并初步阐明了人类干扰特别是过度放牧对草原群落建群种和优势种的生态替代或/和灌丛入侵的影响。

Artemisia intramongolica is a kind of dominant shrub on sandy land in the typical grassland area o our country. It has been suitable to the hot and xeric habitat on sandy land for a long time and has formed series of characteristics that are adaptive to its habitat.

褐沙蒿是分布于我国典型草原带沙地中的优势灌木，由于长期生长在草原区沙地高温、干旱的环境中，形成了一系列与环境相适应的生物学特性。

Extracting high quality genomic DNA from single shoots of xeric bryophytes has been the bottleneck for further study on the genetic diversity.

：耐旱苔藓植物常常单个个体矮小、生物量低，如何从细小的单个个体中有效提取总DNA是进一步开展居群遗传多样性研究的关键。

Class200301, Biology , College of Life Science and Engineering, HNUAbstract: Under field conditions,The TPS-1 Portable Photosynthesis System of Britain was used to study the photosynthesis characteristics of the invasive exotic species Alternanthera philoxeroiders comparably under the aquatic and xeric environment.

摘 要：在野外条件下，运用英国TPS-1便携式光合作用测定仪，系统地比较研究了水生和旱生环境条件下外来入侵物种的空心莲子草叶片的光合特性。

The comparative research results showed that:(1)Thediurnal variation of the net photosynthetic rates in the aquatic leaves was a "double-peak", with an various "midday-decline", the time of the peak value appeared at about 10:00 A.M. and 13:00 P.M., while that in the xeric leaves was showed with invarious peak value and "midday-decline"; The diurnalvariation of transpiration ratesof both aquatic and xeric leaves appeared as a single-peak, the appearance time of peak value of the latter was earlier than the former and gradually decreased in the afternoon; The stomatal conductances appearance time of both of them were close to that of photosynthesisrate ,reached to the maximum in the morning and then gradually decreased: Diurnal variation of intercellular CO2 concentrationshows that: both aquatic and xeric leaves increased at first, and then exhibit a tendency of ascending within narrow range.(2) The net photosynthetic rates, photosyntheticallyactive radiation, stomatal conductances and transpiration ratesof both two kinds of leaves showed positive correlation, The correlation degree among them was prominent, there was significant negative correlation between The net photosynthetic rates and intercellular CO2 concentration.

研究结果表明：(1)水生叶片净光合速率的日变化曲线呈双峰型，出现明显的&午休&现象，峰值出现在10：00左右和13：00左右，但旱生叶片表现出的峰型和&午休&现象不明显；两种叶片的蒸腾速率日变化曲线表现为明显的单峰型，旱生叶峰值出现时间早于水生叶，中午过后逐渐下降；两种叶片气孔导度峰值出现时间和光合速率相近，均表现为上午升高至最高，随后逐渐下降的趋势；两种叶片胞间二氧化碳浓度日变化表现为：整体上先下降，然后有一上升趋势：(2)两种叶片的光合速率与光合有效辐射、气孔导度、蒸腾速率呈正相关，全部达到显著水平；光合速率与胞间CO2浓度显著负相关。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。