1.The similarity hypothesis may explain how biodiversity loss influences variability in biomass of plant communities but remains untested.We collected data over a three-year period (1999～2001),at the end of July during the peak of plant growing season,from 74 permanent plots in a natural alpine meadow located in the eastern Qinghai Tibetan Plateau.The objective was to test how similarity in species composition can explain the effects of species diversity on interannual variability in total aboveground biomass.Variability in total aboveground biomass per plot,decreased as species richness increased,and it also showed an overall decline as evenness increased although it appeared to stay at about the same level over the intermediate range of evenness.Similarity in species composition explained most of the variability in total aboveground biomass,and increased similarity in species composition reduced interannual variation in total aboveground biomass.Species richness and evenness were unrelated to similarity in species composition.These results indicate that the causal relationship between similarity and variability in total aboveground biomass may be robust,although biodiversity loss may not necessarily lead to decreased similarity in species composition in species-rich communities such as the alpine meadows of the Eastern Tibetan Plateau.Therefore,understanding how similarity influences the effects of biodiversity on variability in ecosystem functioning would require directly manipulated experiments for similarity in species composition.
相似性假说通过物种构成的相似性来解释物种丧失是如何影响生物量的变异性的,但还没有得到检验.本研究通过设置在青藏高原东部地区的高寒草甸植物群落中的74个永久样方,采集3年(1999～2001)植物生长高峰期的群落数据,试图检验物种构成的相似性是如何解释物种多样性对地上生物量年际变异性的影响.结果表明:随着物种丰富度增加,生物量变异性降低;而随着均匀度的增加,生物量的变异性尽管在均匀度中等程度时似乎保持在同一水平,但总体上呈下降趋势;物种构成上的相似性解释了地上生物量变异性的大部分,而且随着物种构成上的相似性的增加,生物量的变异性降低;物种丰富度和均匀度均与物种构成上的相似性没有显著相关关系.这些结果表明:尽管生物多样性的丧失可能不必导致物种丰富群落中物种构成上的相似性,但相似性与地上生物量的变异性的因果联系可能是稳健的,由于本研究是在自然群落中进行的,对物种构成的相似性没有进行直接控制,因此,要深入理解相似性是如何影响生物多样性对生态系统功能变异性的效应的机制,可能还需要直接对物种构成的相似性进行控制的实验研究.
2.Through theoretical treatment,the authors suggest that a samlpe length of 250 meters isreasonable or taking the value of short term evenness as the total evenness of the yarn,anddeduce a formula to express he relation between the CV% of the sample L_w which is lessthan 250 meters,and the total evenness as ollows:γ=([1-((?)
本文用理论推导得出:以250m 作为试样长度,用其所测定的短片段不匀率值替代纱条总不匀率值,是合理的。 并且导出了取小于250m 长度片段L_W 时,所测定的CV%(变异系数)值占总不匀率的比率γ的关系式γ=([1-((?)
3.The test mechanisms of capacitor evenness tester and EIB photoelectric yarn appearance tester are analyzed. The capacitor evenness tester gives out the mean volume or mass of yarn section in test scope, but the EIB photoelectric yarn appearance tester reveals the diameter variation of yarn projection area, these two methods reflect the different property of yarn evenness, and their results are not in be in accordence.
分析了电容式条干均匀度仪和EIB光电式纱线外观测试分析仪的测试原理 ,指出 :电容式条干均匀度仪测试的是测量区内一段纱条的体积或质量的平均值 ,而EIB光电式纱线外观测试分析仪测试的是纱线某一投影面上的直径变异。 两者反映了纱线条干均匀度不同的内容 ,不完全一致
4.(2) The diversity, richness and evenness of tree layer and bush layer descended when altitude rose, however, the diversity and evenness of grasses rose from 1 700 m to 1 900 m with rise of altitude, and the richness rose from 1 900 m to 2 700 m.
(2 )群落不同层次表现为 :乔木层和灌木层多样性、丰富度和均匀度随海拔升高而下降 ,草本多样性和均匀度表现为上升趋势 ,丰富度下降到 190 0m后开始上升 ;
5.Simpson index,Shannon一Wiener index,PIE and Evenness are used to study the species diversity of mangrove community in Futian, Shenzhen in the paper. The results are as fol-lows:Simpson index is 1.40,Shannon一Wicner index 0.78,Evenness 48. 98%.
本文以Simpson指数、Shannon一Wiener指数、种间相遇率（PIE）和均匀度公式研究了深圳福田红树林群落的物种多样性，结果为：Simpen指数为1．40，Shannon一Wiener指教为0．78，PIE为0．28，均匀度为18．98％。
6.Analysis on the species richness and diversity index, community evenness in different plots and layers of evergreen broad-leaved forest in Shiyang Forest Center in Wencheng, Zhejiang province resulted that species richness and diversity index, community evenness of the second sublayer of tree layer was much greater than that of the first sublayer in the vertical structure of the community.
对文成县石??林场常绿阔叶林的不同样地、不同层次的物种丰富度、物种多样性指数和群落均匀度进行了分析,结果表明:在群落垂直结构中,乔木层第2亚层的物种丰富度、物种多样性指数、群落均匀度显著大于第1亚层。
7.It was found that: (1) In all 17 plots, herb layers had the highest species abundance,and tree layers had the highest species evenness.
结果如下：（）门个样方中物种丰富度指数是草本层最高，均匀度指数是乔木层最高。
8.e. their fibre evenness became fine and their fibres diameter became uniform when F 3,F 4,so the fibres produced by F 3,F 4 were used on textile manufacture as mohair produced by angora goats.
纤维细度变化与纤维分类基本一致，即级进到F3 后，被毛的同质性变好，体躯各部位的细度变匀，所产毛纤维可与安哥拉山羊所产马海毛一样用于纺织业
9.Based on the samples taken from more than 30 representative large-and middle -sized reservoirs in Shandong province in 1989 and 1990, the species composition,the percentage and average biomass of each phylum, species frequency class and major species of the phytoplankton are investigated. The species diversity and evenness indices, the biomass of nannophytoplankton and netphytoplankton and dominant groups or species of each representative reservoir, and their relation to the total biomass of the phytoplankton of each reservoir are presented.
报道1989～1990年山东省大中型水库浮游植物种类组成百分数和生物量、种类频级和主要种类，提出代表性水库的种类多样性指数和均匀性指数、微型浮游植物和小型浮游植物组成、优势类群或优势种以及它们与各水库总浮游植物生物量之间的关系。
10.Abstract: The spectrogram characteristic of cotton yarn with defects and the basic concept of relation between the spectrogram and the defective installation are described in this paper.Simultaneously ,the general method for building a specialist software system of diagnoses cotton yarn evenness defects is pointed out.
文摘:论述了纱条条干疵病在波谱图上的表现及波谱图与设备故障的关系的基本概念,提出了建立条干疵病诊断专家系统的一般方法.
