生态群落

The niche breadths of same plants vary greatly among different communities and the competitive relations of the plant species in different communities vary depending on the combined actions of the niches of the species, stable landforms and soil conditions, and annual rainfall fluctuations.

同一种植物在不同群落中的生态位宽度变幅较大，不同群落内部植物种竞争关系的差异是由物种的生态位和由相对稳定的地貌、土壤条件以及随年际变动的降水条件共同作用的结果。

The forest was characterized with phanerophyte evergreen plants with single-mesophyll-leathery leaves, which reflected the nature of tropical Karst mountainous seasonal rain forest.(2). Community succession was divided into five stages by using Cluster method, PCA method; the succesion stages include herbaceous stage, scrub-shrub stage, small tree stage, arbor stage and climax seasonal rain forest stage.(3). Based on similarity theory, succession sere was constructed with the community similarity equation formed.

结果表明：(1)森林群落在外貌上，以常绿高位芽、单叶、革质、中型叶植物为主，反映了热带岩溶山地季雨林的特点；(2)运用聚类分析、PCA排序等方法将群落演替阶段划分为草本群落阶段、灌丛阶段、小乔木阶段、乔林阶段、顶极季雨林阶段；(3)运用相似学原理，组建群落间相似度方程并以此方程构建了群落演替系列；(4)研究表明桂西南岩溶区生态系统健康受到严重胁迫。

The whole reef-building process is closely related to occurrence and development of the metazoan reef-building communities.

群落的整体面貌、生态体系都是由群落内的关键种所决定的，如果将群落内起到核心作用的物种从群落内移走，那么群落的性质，生物的组成和功能都将发生变化。

Based the structure and function of Yangtze River Estuary Ecosystem, the energy expenditure of shorebird community staging at Yangtze River Estuary and the production of macro zoobenthos community were studied in this dissertation.

本文以长江河口湿地生态系统的结构和功能为基础，对鸻鹬群落在长江口地区中途停歇期间的能量需求和栖息地选择和利用进行了研究，探讨了底栖动物作为鸻鹬群落饵料的状况，并根据鸻鹬群落和底栖动物群落能量流动特点，构建了Stella计算模型，对鸻鹬群落中途停歇长江口期间所需要的栖息地面积进行了估算和探讨，以期为区域发展和鸻鹬栖息地保护提供依据。

The result indicated that: with the change of ecological factors and intensification of human activities,strong stability of grassland community structure of the local alpine meadow type along the highway in this region was found,proportion of medium xerophilous、rhizomous grass increased;alpine grassland community had relatively low stability,grassland community successed naturally to adapt to the new environment;...

结果显示：随着生态因子发生变化和人类活动的加剧，该区公路沿线高寒草甸类草地群落结构表现出了较强的稳定性，中旱生耐旱的根茎型禾草比重有所增加；高寒草原植物群落稳定性相对较差，草地群落为适应新的生境而发生了自然演替；沼泽化草甸亚类草地植物群落中群落伴生种的种类增加，优势种嵩草属植物在群落中的比重有所下降。

In recent years it has been exploited to be a famous scenic spot. To avoid vegetation degradation resulting from human activities and strengthen plant protection, Carpinus turczaninowii communities in great valley were selected as our research subject. The species diversity, interspecific association and correlation, niche breadth and niche overlap in these communities were studied using quantitative methods.

为了加强对该地区植被的保护，避免因人为干扰而导致的植被破坏和退化，本文以太行山南段的小叶鹅耳枥群落为研究对象，在分析了群落主要特征的基础上，应用数量生态学方法，分别从群落的物种多样性、优势种群的种间关系和生态位三个方面，客观定量地分析了植物群落的生态关系。

So in this work, we focused no the following aspects: 1 The ecological effect of ephemeral resource on the rodent community; 2 The ecological isolation and coexistence mechanism for the sympatric species; 3 The effect of ecological process in a regional scale on the specie richness to investigate the community Patterns and limitation Mechanism of the desert rodents in this region, the main results and conclusions were as follows

为此，本工作立足于以下方面：（1）限制性资源对荒漠啮齿类动物群落的生态效应；（2）同域物种的生态分离与共存机制；（3）局域尺度的群落过程对区域物种丰富度的影响；对该地区的荒漠啮齿动物群落格局及其相关的制约机制进行了研究。主要研究结果和结论如下

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。

Results on the effects of grazing by sheep on species and functional group diversities had not led to consensus in different communities: species richness, species diversity, diversities of life forms and water ecological type groups decreased with grazing intensity increased except in the Leymus chinensis + forbs community.

放牧对4种群落物种和功能群多样性的影响随不同的群落而表现不同：物种丰富度、物种多样性、生活型多样性和水分生态类型多样性除羊草杂类草群落外随放牧强度的加大而降低，但适度放牧增加了羊草杂类草群落的上述多样性指标。

MethodsFive indexes, ShannonWeaner diversity value, Pielou uniformity value, dominance value, Levins niche width value and Petraitis niche overlap value were calculated to describe the community structure and niche characteristics of the HFRS host rats in the experimental districts.

方法以ShannonWeaner的群落多样性指数、Pielou群落均匀度指数、优势度指数、Levins生态位宽度指数、Petraitis生态位重叠指数定量描述疫区内HFRS宿主鼠类的种群结构及生态位特征。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。