群落

There are 69 species turf weeds in worse management lawn community, 38 species in general and 37 species in better. In worse management lawn community Viola prionantha and Digitaria ischaemum are dominant weeds.

管理水平较差的草坪群落中有杂草69种；管理水平一般的草坪群落中有杂草38种；管理水平较好的草坪群落中有杂草37种。

Variation of important value of dominant weed is that in spring and fall the dominant weed is Viola prionantha while in summer it is Digitaria ischaemum. In general management lawn community it is Leymus secalinus that is the dominant weed in spring and fall and Digitaria ischaemum in summer.

管理水平较差的草坪群落中，春季和秋季是早开堇菜占优势，夏季是止血马唐占优势；管理水平一般的草坪群落中春、秋季节是赖草占优势，夏季也是止血马唐占优势；管理水平较好的草坪群落中整个生长季是鼠掌老鹳草、鹅绒委陵菜、赖草占优势，且以鼠掌老鹳草的优势度最大。

It is made up of two excluding each other ichnocoenosis, namely epibenthic and endobenthic ichnocoenosis; The third one is quite monotony in fossil types, mainly of trails left behind by sediment-eating or detrital-eating animals grazing or feeding along the surfacial layer or on the surface of the sediments.

包括两个相互排斥的群落，底表生物遗迹群落和底内生物遗迹群落；第三个遗迹组合类别十分单调，主要为食沉积物或食碎屑性动物沿沉积物表面或表层牧食或觅食过程中留下的痕迹。

Additionally,we specially tested seeds antioxidant enzyme and protein of Hedysarum scoparium under drought stress or recover condition,and the Peganum harmala characteristics of seed traits and communities distribution to find out the mechanism of resist-drought.

同时，我们还研究了骆驼蓬的种子特性及群落分布特点，这些研究结果均有助于我们进一步了解植物种子的抗旱生理生化机制和群落分布规律，为荒漠治理及优势群落的发展与保护等提供理论依据。

From Imperata cylindrical community to bare land,species of plants changed greatly, the importance value of annual herbaceous plants increased gradually and the importance value of perennial herbaceous plants went down gradually. The number of companion species went down gradually, the species richness and plant diversity index reduced. Community structure was from complex to simple.

从白茅群落到光板地，植物的种类发生了较大变化，一年生草本植物的重要值逐渐升高，多年生草本植物的重要值逐渐降低，群落中伴生种的数量逐渐降低，物种丰富度及多样性指数减少，群落结构由复杂到简单。

In successional process of wetlands, bare land Suaeda salsa community, Tamarix chinensis community organic matter content decreased by 81.0%、67.4% and 59.5% separately compared to Imperata cylindrical community,total N decreased 61.1%,59.6%,41.2%,available N decreased 69.2%,60.1%、46.8%,available P decreased

在湿地演替过程中，光板地、翅碱蓬群落、柽柳群落有机质含量与白茅群落相比，降低了81.0%、67.4%、59.5%，全氮含量降低了61.1%，59.6%，41.2%。

In this study, with the psammophilous Caragana Korshinskii-Artemisia ordosica communities on semifixed dunes and fixed dunes in Shapotou region at the southeastern fringe of the Tengger Desert as the observation sample plots, the survey quadrats were arranged in the vegetation community areas with different types and coverages of soil microbiotic crusts.

本文以腾格里沙漠东南缘的沙坡头地区半固定沙丘柠条一油蒿群落和固定沙丘柠条一油蒿群落为观测样地，选择具有不同类型生物土壤结皮分布的植被群落为观测样方。

The species diversity index of the Potaninia mongolica community was higher than that of three other communities and lower than that of Oxytropis bicolor community, and Potaninia mongolica, its dominant tree was stabile, therefore the community was a stabile community.

绵刺+珍珠猪毛菜+泡泡刺群落物种多样性指数比较高，生态优势度也较高，该群落比较稳定，其建群种的绵刺种群同样处于稳定阶段，所以群落是比较稳定的。

Scripus mariqueler community, Scirpus triquerter community and Phragmites australis community are three main wetland flora types.

海三棱藨草群落、藨草群落和芦苇群落是三种主要的湿地植物群落类型。

Through the comparative analysis of the arthropod community between intercropping system and the three control systems～the weeding jujube yard system, not weeding jujube yard system and the system of farmland, it is showed that the intercropping system have a more richer neutral arthropod groups. Compared to Weeding jujube yard system and system of farmland the intercropping system have more advantages in natural enemies groups and more disadvantaged phytophagy groups. And the intercropping system can rebuild the arthropod community more faster than the other systems after the system was seriously disturbed, so it is than compared to other three systems the intercropping system have more proper structure and more stronger regulation ability and also more stronger ability to control pest.

对枣粮间作系统和三种对照系统，即除草枣园系统、未除草枣园系统和农田系统的节肢动物群落进行对比分析发现枣粮间作系统具有更为丰富的中性节肢动物类群，比起除草枣园系统和农田系统有更优势的天敌类群和更劣势的植食性类群，且在遭受生境的巨大变化后新生境重新形成时枣粮间作系统的各亚系统能更迅速的形成节肢动物群落和各种功能类群，说明枣粮间作系统比三种对照系统的节肢动物群落有着更合理的结构、更强的调控能力和更强的控害能力。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。