生态群落

The benthic assemblage eco-positions of brachiopod communities in the early Early Carboniferous were between BA1 and BA2, and there were no BA3-BA5 deep-water communities in this area, which indicated that the sea water depth in this period was commonly less than 10 m.

本区早石炭世早期腕足动物群落的生态位介于BA1和BA2之间，缺乏BA3至BA5较深水群落（BA-Benthic Assemblage，底栖组合），说明该区早石炭世早期海水深度一般不超过10 m。

Macrobenthos in this area can be defined into five types by ecological character, dominant key species of each group are presented.

按照生态特征调查海域的底栖生物可以分为5个群落，各群落有自己的优势种。

The paper studies mostly: the community structure of Orthoptera, fauna analysis, species diversity, similarity of insect community in different habitats, the analysis of ecological species group, and the origin and evolution of insect and plant community in Daqinggou Nature Reserve.

主要内容包括：直翅目昆虫群落的结构、区系组成、以及物种多样性，不同生境中昆虫群落的相似性分析，昆虫生态种组的聚类分析，最后讨论了大青沟直翅目昆虫的区系起源演化和大青沟植物群落的起源问题。

Weed species which appeared Over 20% in plots of golf courses were Cyperus rotundus,Kyllinga brevifolia,Oxalis dellenii,Panicum repens,Eleusina indica,Paspalum conjugtum,Digitaria sanguinalis,Hydrocotyle s...

在 2 0 %以上的样带小样方中出现的杂草种类为13种，即香附子、水蜈蚣、黄花酢浆草、铺地黎、牛筋草、两耳草、马唐草、天胡荽、狗尾草、空心莲子草、马齿苋、鸡眼草和犁头草；13种主要杂草总的年消长动态是：1～ 3月份个体数量较少，4～ 10月份期间生长加快，但消长起伏不平，10月份后变缓；70 %以上的主要杂草在草坪-杂草群落中生态位宽度均在 0 。7左右，其中生态位宽度较高的杂草种类为香附子(0 。90 5 4 )、水蜈蚣(0 。86 18)和黄花酢浆草(0 。8381)，生态位最小的杂草种类为马齿苋(0 。392 2 )；13种杂草中，相似性指数最高的杂草种对为空心莲子草与马齿苋(0 。75 98)，最小的杂草种对为天胡荽与鸡眼草 0 。16 6 6

In the n-dimensional space, the fundamental niche is a hypervolume. The realized niche is described as the environmental characteristics that surround a species population in a particular community.

在n维生态位空间，物种的基础生态位为一实体，实现生态位则是在某一特定群落生境中一种群所处的环境参数所描述。

The population dominance index, Shannon-Wiener index, evenness, niche breadth and community similarity were used to analyze the diversity and eco-niche of soil moniliaceous hyphomycetes in five ecosystem-types.

利用种群优势度、Shannon-Wiener多样性指数、均匀度、生态位宽度、群落相似性等指标对该地区不同生境的土壤淡色丝孢菌物种的生态多样性及物种生态位进行了分析。

The larger the niche overlap of two species is, the more similarly resource space they occupy. the niche overlap of Leontopodium leontopodioides and Polygonum viviparum amounts to 0.892 (in the community Ⅰ). This proves that they are very similar in utilizing the resources. In the general community, the niche overlaps among species are very low.

两个种群的生态位重叠值越大，说明它们占据越相似的资源空间，珠芽蓼和火绒草的生态位重叠值高达0.892，说明它们利用资源的相似性程度很高；在总群落中，各种群之间生态位重叠值都很低。

The wild grass, bush community, artificial mixed forest were regarded and natural secondary forest were regarded as the research subject of different stages in the process of ecological construction aimed at soil and water conservation around Napahai Lake in the northwest of Yunnan Province. The change of those community structures was studied by using spatiotemporal substitution method.

在滇西北高原香格里拉县纳帕海周边区域，以荒草丛、自然恢复灌丛、自然恢复高山松次生林以及人工混交林等四种生态系统类型为研究对象，采用时空互代法，视它们为水土保持生态修复过程中不同阶段，研究不同生态系统的群落结构变化规律。

This paper concerns the analyses of niche breadths of and overlaps bet-ween several plant species in 3 Kobresia communities in the Haibei Research Station using the formula described by Levins and Pianka.

本文利用Levins和Pianka公式，在多维生态因子梯度上测定了海北地区高寒草甸三种嵩草群落中若干植物种的生态位宽度和生态位重叠。

In Kubuqi sandland of Erdos plateau, according to the investigating result of the component of rodent animal, vegetation and soil from the different habitat at 1995, we analyzed the connections between the community structure of sand land rodent animal and environment by COA, and described the spatial niche of the main rodent animal by the Levins index of niche width and Petraitis overlapping index of niche.

根据 1 995年在鄂尔多斯高原库布其沙地不同生境类型上鼠类构成、植被以及土壤因子的调查结果，以对应分析排序技术分析了沙地啮齿动物群落结构与环境因子的关系，以 Levins生态位宽度指数和 Petraitis种群生态位重叠指数对常见啮齿动物种群空间生态位进行定量描述。

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。