优势种

The results showed that fishes of 11 orders, 18 families, and 46 species were represented in Changshu section of the Yangtze river. After the season, the total catch per unit effort increased sharply in the section; the dominant species were mainly commercial fishes such as Coilia ectenes, Mugil cephalus and Parabramis pekinensis and the annual change of dominant species was not obvious. The CPUE of Coilia ectenes had risen up and the trend of resource deterioration had been kept within limits. The caught rate of pintsized and juvenile fish rose markedly. The Margalef's index and Wilhm's index had an evident tendency of rising, while McNaughton's index and Pielou's index waved slightly.

研究结果表明：4~6月间常熟江段出现的鱼、虾、蟹类渔获物共有11目、18科、46种；春禁后，该江段总CPUE显著增加；优势种更替不明显，历年以刀鲚、鲻鱼、长春鳊等经济鱼类为主；刀鲚CPUE有所回升，资源衰退受到遏制；小型鱼类、幼鱼在渔获物中的比例明显上升； Margalef物种丰富度指数、Wilhm改进指数呈明显上升趋势，均匀度指数J′、优势度数Dw在窄幅范围波动。

The dominant species were Cerithidea cingulata , Batillaria cumingi , Cyclotellina remies and Potamocorbula rubromuscula of Mollusca. The mean biomass of benthic macrofaunu in summer and in winter was 133.0 g/m2 and 63.0 g/m2, respectively.

冬季优势种是珠带拟蟹手螺、古氏滩栖螺和环肋樱蛤；夏季优势种是珠带拟蟹手螺、环肋樱蛤和红肉河蓝蛤。

The ordination graph of dominant species in the plant community is very similar to that of plant community types.

主要优势种的DCA排序图与样方的DCA排序图有很大的相似性，根据二者的结合研究可以得出优势种的分布格局在很大程度上决定着植物群落分布格局的结论。

Results showed that seasonal variation of species composition was not remarkable. The species whose dominance was the highest in those seasons were Sagitta enflata in summer, Sagitta nagae in winter and spring and Sagitta bedoti in autumn.

结果表明，毛颚类优势种季节交替不明显，优势度最高的种分别是：夏季肥胖箭虫、冬、春季海龙箭虫和秋季百陶箭虫。

According to the quantity occurred of the pests and the degree of the lawn destroyed, we have known the dominant species of the pest in the lawn. and the reason and dynamic of these species have been analyzed. It is important to the pests management of the Trifolium repens in the level of community.

同时，根据害虫的发生数量和对草坪的危害程度，从群落的角度确定了白三叶草坪上害虫的优势种，并分析了这些优势种产生的原因和动态，为白三叶草坪在群落水平上进行综合治理提供了重要的依据。

The plant community composition changed and the community coverage increased over the wetland succession from primary swamp, through swampy meadow, to meadow. The number of associated species increased, while the dominant species abundances decreased. Through succession, the content of soil organic matter and total nitrogen declined. In contrast, the soil enzyme activity of catalase, protease and invertase increased; however urase declined.

随着湿地原生沼泽向沼泽化草甸、草甸的演替，湿地植物群落盖度增加、物种组成增多，群落优势种优势度减小，伴生种数量增加，植物多样性呈增加趋势；湿地土壤有机质、全氮含量不断减少，过氧化氢酶、蛋白酶、蔗糖酶活性增加，脲酶活性降低。

It was revealed that the total cell density increased from early March to May, with a variation of 3 order of magnitudes in cell richness; Amphidinium britannicum and Adenoides eludens were two dominant species in the spring, however Gyrodinium viridescence and Peridinium quinquecorne might be abundant in the early summer; the cell density of dominant species inclined from the high-tide zone to middle- and low-tide zone. Finally, the importance of sonification treatment in precise cell enumeration of nature samples was discussed.

发现初春甲藻数量少，而春末夏初数量显著增多，由春初的0～20个/1 000 g湿砂增加到春末夏初的几千个/10 g湿砂，相差3个数量级以上；Amphidinium britanicum和Adenoides eludens为春季优势种；Gyrodinium viridescense和Peridinium quinquecorne在5月份数量明显增多，与温度升高以及底栖藻类各类群总量增加有密切关系；底栖甲藻的总细胞密度和主要优势种的细胞密度呈现由高潮带向中、低潮带增加的趋势。

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 results show that the construction of the railway has an obvious effect on the warm steppe,but the characteristics of community,such as the coverage,ecological dominance and species richness of communities have been improved after its natural restoration,and some species,such as Elymus nutans,Aconitum gymnandrum and Thermopsis lanceolata,play an important role in the restoration communities.An assistant measure taken by human beings will benefit to the restoration.There is no any evidence of exotic invading plants in the restoration of the warm steppe in the study area.

结果显示，青藏铁路修筑过程对铁路两侧一定区域的温性草原有较大影响，但随着受影响区域植被的自然恢复，群落盖度、生态优势度和物种多样性等反应群落特征的指标都有一定程度的改善，一些在原生植被中很少出现或伴生种在恢复后的群落中有可能成为群落的优势种或建群种，如露蕊乌头和鹅绒委陵菜等；人为辅助措施将有利于受损植被的恢复；修筑铁路过程中受到影响的温性草原其恢复过程中尚未出现外来入侵植物。

The zooplankton was mainly contributed by copepods, and its dominant species were mostly eutrophication indicators: Keratella cochlearis, Polyarthra trigla.

水库的主要优势种为轮虫，而且优势种所出现的种类多为富营养化指示种，如：螺形龟甲轮虫Keratella cochlearis、针簇多肢轮虫Polyarthra trigla。

Do not gum up the work by telling mother what we are going to do .

别告诉母亲我们要干的事，那会把事情搞糟的。

In recent years, application of the partial prestressed concrete beam s is developed.

近年来，随着部分预应力砼梁应用的推广，发现我国规范所采用的名义拉应力法的计算结果不稳定。