优势

The species diversity of Dipentodon sinicus communities in Yushe National Forest Park of Guizhou province was studied based on the quadrate method. The results showed that Rosaceae, Ericaceae, Betulaceae, Fagaceae, Theaceae, Lauraceae, Caprifoliaceae, Cornaceae were the dominant families in D. sinicus communities of Yushe National Forest Park. In the 10 sample plots, there were 8 which were absolutely dominated with D. sinicus population, the importance value came up to 135.69 on average, and it was far higher than the others. For D. sinicus communities, the abundance index (2.847), Simpson index (0.601), Shannon-Wiener index (1.523), probability of inter-specific encounter (0.601) and species evenness (0.569) of the tree layer were lower than those of the shrub layer (5.580, 0.830, 2.377, 0.829, 0.672, respectively) on the whole. It markedly showed a species diversity characteristic of the mixed broadleaved evergreen and deciduous forest in middle subtropics. In the 10 sample plots, the species diversity level of Q1 was the highest, followed by Q3, Q5 and Q6 was the lowest.

摘要运用样方法对贵州省玉舍国家级森林公园稀有保护植物十齿花群落的物种多样性进行了研究，结果表明：玉舍国家级森林公园十齿花群落以蔷薇科、杜鹃花科、壳斗科、桦木科、山茶科、樟科、忍冬科、山茱萸科等为优势科；10个样地中有8个样地以十齿花种群占绝对优势，其平均重要值高达135.69，远远高于其它种群；十齿花群落乔木层物种丰富度为2.847、Simpson指数为0.601、Shannon-Wiener指数为1.523、种间相遇机率为0.601、均匀度指数为0.569，总体上均小于灌木层(分别为：5.580、0.830、2.377、0.829、0.672)，表现为较明显的亚热带常绿落叶阔叶混交林的物种多样性特征。10个样地中，Q1的物种多样性程度最高，Q3次之，Q5和Q6最小，多样性程度最低，10个样地的物种多样性排序为Q1＞Q3＞Q9＞Q7＞Q2＞Q4＞Q10＞Q8＞Q5＞Q6。

This work dealt with formation mechanism of heterosis of cocoon quality characters bymeans of physiological,biochemical and biometrical techniques for the purpose to providetheory guidance for adequate and predicatable application of heterosis.

本研究用生理生化及生物数学的分析方法，探索家蚕茧质性状杂种优势的产生机理，以期为生产上合理地、有预见地利用杂种优势提供理论指导。

Poll shows a very tight raise race in Indiana and senator Obama's comfortable two digit leading in the polls in North Carlina has straight dwindled down to single digit s .

民调显示在印第安纳州另奥巴马放心的两位数优势已被追进，而北卡的民调显示优势已经缩小为一位数了。

Prattii- Ailanthus altissima deciduous broad-leaved forest community and Cerasus trichostorna-Cerasus dielsiana-Acer caudatum deciduous broadleaved forest community , had lower total richness and Shannon-Wiener index .

3人工林群落与次生林群落相比，人工林群落具有较低的物种丰富度指数和Shannon-Wiener多样性指数以及较高的优势度指数，次生林具有较高的物种丰富度指数和Shannon-Wiener多样性指数以及较低的优势度指数。

Between shrub and herb layers ,the difference of each index was not significant The total richness index and Shannon-Wiener index of Phellodendron amurense plantation community were all the highest than those of the other communities.(2) The total richness index of Machilus pingii- Quercus oxyodon evergreen broad-leaved forest community, Alnus cremastogyne-Betula luminifera-Quercus oxyodon evergreen-deciduous broad-leaved forest community and Rhus potaninii- Juglans sigillata- Quercus oxyodon evergreen-deciduous broad-leaved forest community all exceeded 31 .These communities , the dominance species in their shrub layers is Fargesia rufa ,such as Betula luminifera-Rhus chinensis-Quercus oxyodon evergreen-deciduous broad-leaved forest community, Quercus oxyodon-Litsea pungens-Cornus macrophylla evergreen-deciduous broad-leaved forest community, Cornus macrophylla- Acer caudatum var.

2润楠-曼椆常绿阔叶林、桤木-亮叶桦-曼椆常绿落叶阔叶混交林、青麸杨-野核桃-曼椆常绿落叶阔叶混交林群落的总体丰富度指数均大于31；在灌木层以青川箭竹为主的群落(亮叶桦-盐肤木-曼椆常绿落叶阔叶混交林、曼椆-木姜子-梾木常绿落叶阔叶混交林、梾木-川滇长尾槭-落叶阔叶林、川西樱桃-尾叶樱-川滇长尾槭落叶阔叶林)中，各群落总体丰富度指数和Shannon-Wiener多样性指数较小，总体优势度指数较大；8种次生林群落灌木层丰富度指数均高于乔木层，乔-灌层间丰富度指数差异性检验达显著水平；乔-草层间的丰富度指数差异性检验达极显著水平，Shannon-Wiener多样性指数差异达显著水平；灌-草层间的多样性指数和优势度指数差异性检验均达显著水平。

There were only 94 vascular plant species, belonging to 50 family and 75 genera. The dominant species in the communities were deciduous broadleaf species Liquidambar formosana, Robinia pseudoacacia, Ailanthus altissima, Acer buergerianum, and Celtis sinensis, evergreen broadleaf species Cinnamomum camphora and Elaeocarpus glabripetalus, and Phyllostachys heterocycla. Robinia pseudoacacia+Cinnamomum camphora community had the highest Shannon-Wiener index (1757) and Phyllostachys heterocycla+Acer buergerianum community had the highest Simpson index (0163), but no consistency was observed between the curves of H and D. For vertical structure, most communities had no significant understory stratification.

结果表明：辰山植物区系以泛热带和北温带占优势，具有典型亚热带和温带成分交汇和南北植物分布交错特征；但保育区内种类单一，维管束植物仅有49科69属94种；主要群落是以枫香、刺槐、臭椿、三角枫和朴树等为优势树种的落叶阔叶林，以香樟和秃瓣杜英等为优势树种的常绿阔叶林，以及毛竹林；物种多样性普遍较低，Shannon-Wiener多样性指数最高为刺槐+香樟群落（1.757），Simpson均匀度指数最高值为毛竹+三角枫群落（0.163）；多样性指数曲线和均匀度指数曲线不具有一致性的变化趋势；多数群落垂直结构中无明显林下分层现象；演替前期的落叶乔木种群后续个体不足。

The Eco-physiological Characteristics of Dominant SpeciesArtemisia halodendron, Artemisia scoparia and Cenchrus calyculatus were the dominant species in three types of vegetation.

优势植物种生理生态特性三种植被类型的优势种分别为差不嘎蒿、黄蒿和光梗蒺藜草。

The dominant species of them were Artemisia halodendron Setaria viridis respectively; The reconverted grazing land and the natural reconverted farmland consisted of herb layer and microbiotic crust layer, but itsmain layer was herb layer. The dominant species of them were Cenchrus calyculatus Artemisia scoparia respectively.

草本片层的现阶段优势种为狗尾草；放牧自然恢复地和退耕自然恢复地均由草本片层和生物结皮片层构成，但其主要片层均为草本片层，该层现阶段优势种分别为黄蒿和光梗蒺藜草。

And all the submerged macrophytes absorbed total phosphorous in water effectively and the removal rate of Ceratophyllum demersum with 9175％,9244％ in the Spring and Summer experiment respectively,was the best.

采用人工模拟方法，选取武汉市东湖的春季优势种金鱼藻、伊乐藻和菹草，夏季优势种类金鱼藻、狐尾藻和苦草，在春夏两个季节分别对东湖重度富营养化水体磷的去除效果进行了比较研究。

The AMF spore average density was 24.88 per 20 g soil , the species richness was 1.94 per soil sample, the species diversity index was 2.56, and the species evenness was 0.65. Glomus, but they all were of prominent genus in the investigation area and Acaulospora, Scutellospora were of common genus while Entrophospora was rarely found. In the 13 species AM fungi, G.mosseae was of prominent species, and G.geosporum, G.intraradices, G.etunicatum were of common speices, while the others were of rarely species. There were 87.5% sand fixation plant were infected with arbuscular mycorrhizal fungi, the highest spore density, the strongest infection strength of the whole roots and the best species richness belonged to Chenopodiaceae while Polygonacea was the lowest.

四属AM真菌中，Glomus为优势属， Scutellospora 、Acaulospora为常见属，Entrophospora则为稀有属；十三种AM真菌中，G.mosseae、G.geosporum分别为优势种、最常见种，G.intraradices，G.etunicatum为常见种，其余均为稀有种；五科固沙植物中，87.5%的植物能被菌根侵染，其中藜科植物孢子密度最高，整个根系侵染强度最强，种的丰度最高，蓼科植物孢子密度、整个根系侵染强度、种的丰度则最低；禾本科植物不仅具有最好的丛枝结构，且具有相对高的亲和性，能与12种AM真菌共生。

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。