湿旱生的

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。

The drought tolerance of wild Axonopus compressus germplasm resources was studied and the drought resistance of each A. compressus plant was found to have a direct relationship with its habitat. The A. compressus plants which had better drought tolerance were usually distributed on sloping ground, waysides etc., while plants which had poor drought tolerance were usually distributed in damp habitats such as river banks and bottoms.

对我国不同来源地毯草野生种质资源抗旱性的研究结果表明，各供试地毯草的抗旱性与生境有着直接的关系，基本表现为分布于山坡地和路边等旱生环境中的地毯草，其抗旱性也相对较好，而那些在综合评判中表现为抗旱性较差的地毯草，大多是从河滩等湿生环境中采集到的材料。

The single-celled phytoplankton included 116 inshore wide distribution species, 31 inshore warm-water species and 26 inshore temperate species, and the vascular plants were of 6 ecological groups, i.e., halophtes (24 species), hydrophtes (22 species), amphiphytes (35 species ), mesopllytes (103 species), zerophytes (6 species), and psammons (4 species). Halophtes, hydrophtes, and amphiphytes were the edificators and dominants, reflecting the azonal feature of the wetland vegetations. The vascular plants were divided into 5 life-forms, including 20 phaenerophytes, 4 chamaephytes, 54 hemicryptophytes, 48 geophytes and 68 therophytes, among which, hemicryptophytes and geophytes accounted for 52.58%, reflecting the relatively important function of cold and wet climate and local water-accumulated bottomland environment on the vascular flora formation.

区系中的单细胞浮游藻类包括近岸广布种116种、近岸暖水种31种、近岸温带种26种；维管束植物被划分为6大生态类群，包括盐生植物24种、水生植物22种、湿生植物35种、中生植物103种、旱生植物6种、沙生植物4种，保护区内湿地植被的建群种、优势种均为水生植物、湿生植物或盐生植物，反映了湿地植被的隐域性；维管束植物按照生活型划分，有20种高位芽植物、4种地上芽植物、54种地面芽植物、48种地下芽植物和68种1年生植物，其中地面芽植物、地下芽植物占区系植物总种数的比例较高，占52.58%，反映冷湿气候和局部低洼积水环境对区系的形成起较重要作用。

With the deflected succession of aquatic ecotype plant functional group,the dominance of mesophytes and xerophytes increased,while the dominance of aquatic and hygric plants decreased. However,there are only planting crops in the reclaimed wetland. In the composition of plant biotype functional group,the hydrophytes reduced quickly with the deflected succession and the dominance of perennial herbs is mostly marked,and there are only annual herbs in reclaimed wetland. Compared with primary swamp,the species diversity index of meadow is the highest,the swampy meadow follows,and the reclaimed wetland is the lowest.

植物的水分生态型功能群组成随湿地的逆行演替，水生、湿生类植物功能群的优势度不断减少，中生、旱生类植物功能群的优势度逐步增加，而在垦后湿地只有农作物；植物生活型功能群组成随湿地的逆行演替，水生草本迅速减少，陆生多年生草本增加占据优势，而在垦后湿地均为一年生草本；湿地植物物种丰富度、多样性指数由原生沼泽、沼泽化草甸到草甸依次增加，草甸为最大值，而垦后湿地则最低。

Flooding,as a kind of disturbance events,occurred with higher and higherfrequency over the world.To investigate the effects of flooding disturbance ongrassland vegetation and the soil,a comparatively thorough study was conducted onAneurolepidium chinense grassland in Songnen plain,Northeast China.The studysite was located in Sanjiadian National Rangeland in the territory of Da'an city,Jilirprovince,which was partly flooded in 1998.On the study site,Several transectssubjected to different flooding durations and intensities were designed for thecomparative study among them on such aspects as vegetation characteristics,seedbanks,vegetative propagation of rhizomatous plants,distribution patterns ofpopulations,interspecific relations,and physio-chemical properties of soil.Theresults were as follows:(1)Of the functional group composition of the vegetation,with the elongation of the flooding duration or the increase of flooding severity,theratio of hygric and hygro-mesic plants increase,while that of mesic and mesoxericplants decrease,of Therophytes changed unimodally,of Geophytes increased,whileof Hemicryptophytes decreased.

为弄清草地植被及其土壤环境对水淹干扰的响应，在松嫩平原羊草草地1998年部分遭受水淹的吉林省大安市三家甸子草场内设置了经历不同水淹干扰持续时间和不同水淹强度的样带，并在这些样带之间从植被特征、种子库特征、根茎植物的营养繁殖性能、种群分布格局、种间关系及土壤的理化性质等多个方面展开对比研究，主要结果如下：(1)在植被的功能群组成中，随干扰强度的增加和水淹干扰持续时间的延长，湿生、湿中生类植物功能群的优势度比例基本上是逐渐增加的，中生、中旱生类植物功能群的优势度比例则逐渐减小，而一年生植物的优势度比例呈单峰型变化，地下芽植物比例增加，地面芽植物比例减小。

Based upon the ecoanatomical method, leaf anatomical characters of eleven populations of six evergreen species (Cyclobalanopsis glauca, C. myrsinaefolia, C. gracilis, Castanopsis sclerophylla, C. eyrei and Lithocarpus glaber) from the eastern subtropical area of China were analyzed and compared with SPSS, DCA and TWINSPAN. The results are: 1. Although the leaf structures of the eleven populations still belong to the mesophyll type, they all express the trend of xerophilization. 2. There are some differences in leaf anatomical characters among populations, species and genera, which occur as the results of their adaptation to different habitats. 3. Different leaf anatomical characters have different variations among populations, species and genera, of which leaf thickness and palisade tissue thickness (considered as ecological adaptation characters) have greater variation than sponge tissue thickness, lower cuticle thickness and lower epidermis thickness (as systematical evolution characters). 4. The leaves of C. sclerophylla and C. glauca with thicker lamina, palisade tissue and cuticle (a multilayered upper epidermis in C. sclerophylla) are thought to better adapt to their dry habitat. The leaves of C. eyrei with thicker sponge tissue, although characterized by a multlayered upper epidermis, adapt to their humid and warm habitat. The leaves of C. myrsinaefolia and C. gracilis characterized by a thinner lamina, a less palisade tissue and a moderate cuticle thickness adapt to the humid and cool habitat in a middle mountain.

选取亚热带东部替代分布明显的壳斗科6种常绿树种（青冈、小叶青冈、细叶青冈、苦槠、甜槠和石栎）的11个种群叶片进行生态解剖，并用SPSS， DCA和TWINSPAN比较分析，结果表明：①尽管6种11个种群叶的结构仍属中生叶型，但有着不同程度的趋旱适应；②叶的解剖性状在属间、种间和种群间均存在着不同程度的差异，这是它们适应各自生境的结果，青冈和石栎的种内差异较大，反映出它们对环境变化有较强响应能力；③叶片的不同解剖性状在属、种类和种群间的变化并不同步，其中叶片和栅栏组织厚度等性状差异突出，反映它们更易受环境的饰变，是生态适应性状，而海绵组织、下角质膜，特别是下表皮厚度等性状差异较小，显示出这些性状的稳定性，可以认为是系统演化性状；④苦槠、青冈具有较厚的叶片、栅栏组织、角质膜和发达输导和机械组织，苦槠还具有复表皮，表现出对旱化生境的适应；甜槠尽管具有复表皮和较厚的叶片，但这是海绵组织增厚的结果，是对中生生境的适应；小叶青冈和细叶青冈具有较薄的叶片和栅栏组织、角质膜厚度居中等特点，可能是对中山凉湿生境的适应。

From 6860 to 3170 cal.yr BP,semi-desert steppeexpanded,regional montane forest steppe retreated,suggesting a prolonged warm and dryclimate.Between 3170 and 2340 cal.yr BP,regional forest steppe expanded whereassemi-desert steppe retreated,indicating the climate became cool and wet gradually and thehumidity reached the maximum at the end of this stage.During 2340～1600 cal.yr BP,Poaceae steppe dominated whereas wetland meadow expanded and the montane forest stepperetreated,suggesting a cool and wet climate prevailed,wormwood grass steppe prevailed andthe climatic instability increased after 1600 cal.a BEThe climate and environmental reconstructions by pollen were supported by the diatomrecords.A relative high lake level and moister climate prevailed between 8660 and 7230 cal.yr BP as inferred by the dominance of planktonic diatom genera and high planktonic/benthicratio (〉40).low lake level and dry climate sustained during 7230～2330 cal.yr BP assuggested by the low abundance of planktonic diatom and low planktonic/benthic ratio ～20and the lake returned to high level during 2330～930 cal.yr BP as inferred by there-dominance of the planktonic diatom and the high value of palnktonic/benthic ratio.The pollen-based climate reconstruction was also consolidated by the grain size andPediastrum concentration records.

Ugii Nuur湖周围现代孢粉研究表明：松属为空气传播的外来花粉，其含量变化可能指示了远山森林草原发育状况；禾本科具显著低代表性，母体植物建群时含量通常在10％以下：藜科花粉含量可以指示区域气候干旱程度。2、以现代孢粉研究为基础、可靠AMS~(14)C年代为框架，Ugii Nuur孢粉记录高分辨率地重建了蒙古国中部地区过去8660 cal.yr BP以来的植被和气候变化。8660～7800 cal.yr BP研究区植被为禾草草原，湖畔及河谷低地发育苔草草甸，远山发育松属针叶林和森林草原，气候温和略湿润；其中8350～8250 cal.yr BP湿生草甸扩张，旱生植物成分减少，气候凉湿。7800～6860 cal.yr BP旱生成分增加，气候转向暖干。6860～3170 cal.yrBP半荒漠草原扩张，远山森林草原退缩，山地草原和河谷及湖畔湿生草甸退缩，气候持续暖干。3170～2340 cal.yr BP半荒漠草原退缩，远山森林草原扩张，气候转凉变湿，末期湿度条件达最佳。2340～1600 cal.yr BP禾草草原发育，湖畔及河谷低地湿生草甸扩张，远山森林草原略有退缩，气候总体较凉湿。1600 cal.yr BP以来研究区发育禾草-冷蒿草原，气候波动较大。

The dominant and co-dominant species in shrub and herb layers were mostly helophytes and hygrophytes. With decreasing latitude, the helophytes and hygrophytes decreased or disappeared, while mesophytes increased.

研究区沟谷冻土湿地植物群落的灌木层和草本层的优势种和共优种多为适应湿地环境的沼生和湿生植物，随着纬度的减小，喜冷湿环境的沼生和湿生植物种类逐渐减少，甚至消失，而耐旱的中生植物的比重则逐渐加大。

H and M c are wetter than middle soil water content, belongs to mesophytes; The optimal water niche of Mosla scabra, on photosynthesis is more wetter than that of M.h and Me, the optimal water niche between mesophytes and hygrophytes, and leaning to hygrophytes; The photosynthetic water condition of M.d is arid environments, and its ecotype exits between mesophytes and xerophytes, and leaning to xerophytes.5 M.h and M.s are locating between shade plants and sun plants, while M.c and M.d obviously belong to sun plants.

杭州石荠苧与华荠苧光合的最适水分条件是中等偏湿，其水分生态类型应属于中生植物；石荠苧光合的最适水分条件比杭州石荠苧与华荠苧光合的最适水分条件要求更湿，其水分生态类型介于中生和湿生植物之间，更偏向湿生；小鱼仙草光合作用的水分生态条件是干旱条件，其水分生态类型介于中生与旱生植物之间，更偏向旱生。

In wetter habitats, hygromeso-and hygrophytes were more abundant and accounted for the majority of aboveground biomass, whereas xero-and mesoxerophytes became more important in dryer habitats; the mean δ〓C values of xerophytes was the highest, and those of meso-, hygromeso-and hygrophytes the lowest; From xerophytes to hygrophytes, their proline content markedly increased.

3依照植物的水分生态类群，将锡林河流域主要植物种划分为六个植物功能群：旱生植物、中旱生植物、旱中生植物、中生植物、湿中生植物和湿生植物。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。