查询词典 Species

Vegetation ecotype tend to be xerophyte and even hyper-xerophyte and finally replaced by annual plant. Community structure and species diversity also decrease as the ecological environment worsen, In this process, the height, coverage and biomass decreases by 56.6%、 80.8% and 74.2% respectively compared to steppe, and the indices of species richness, diversity and evenness decrease by 76.4%、 56.7% and 32.0%, but β diversity indices increase by 14.6 times, especially the decease of species gregariousness and the breadth and overlay of species Niche shows that grassland tend to be more sandy and vegetation retrogression succession take place.

其中，植被生态型逐渐由中旱生向旱生、超旱生过渡，并最终被一年生植被替代；群落结构及多样性呈明显递减规律，到严重沙化阶段，草群高度、盖度、生物量与典型草原相比，下降幅度分别达到56.6%、80.8%和74.2%；物种丰富度、多样性及均匀性分别降低76.4%、56.7%和32.0%；而群落β多样性增长14.6倍，特别是多年生物种群聚度降低和生态位宽度、生态位重叠值的下降，表明草地沙化，植被发生逆行演替。

Based on the investigation of vegetation and plant diversity, there are 2702 species of vascular plants belonging to 221 families, 974 genera in Xiaoxi national nature reserve, among which 8 families, 17 genera, 25 species were gymnosperm, and 172 families, 860 genera, 2381 species were angiosperm, 41 families, 87 genera, 296 species were fern.

对湖南省小溪国家级自然保护区中的植物多样性进行了研究，结果表明：保护区内有维管束植物221科974属2702种，裸子植物8科17属25种，被子植物172科860属2381种，蕨类植物41科87属296种。

The results of character evolution history reconstruction shows the SC in PT and AD clade might be a homoplasy character; also, the SC in PT clade might have multiple origins. SC in Pteridaceae has some special characteristics:(1) the cell long axes usually run parallel to the lateral veins;(2) Most of Pteris and Adianum species have VSC only in lower epidermis;(3) Species have ISC also have VSC.(4) Presence of spicular cells is highly correlated with the long veinal epidermal cells. Species have type III silica deposition type usually have longer and narrower veinal epidermal cell compared with ordinary epidermal cells; Species have type IV silica deposition type also have long epidermal cells, but not significantly different from ordinary epidermal cells.

本实验中亦发现凤尾蕨科之矽异形细胞具有几项特色：(1)矽异形细胞之长轴多与叶片侧脉方向平行(2)发现多数铁线蕨属以及凤尾蕨属植物仅下表皮具有脉上矽异形细胞；(3)具有脉间矽异形细胞的种类会同时具有脉上矽异形细胞；(4)长条形的侧脉上表皮细胞与矽异形细胞具有相关性，仅具脉上矽异形细胞的分类群之脉上表皮细胞均较一般表皮细胞细长；具有脉间矽异形细胞之物种之脉上表皮细胞亦为长条形但形态与一般表皮细胞常无明显形态差异。

Four items of water quality has been collected in field surveys, including PH value, dissolve oxygen, electric conductivity level and turbidity level. Furthermore, 19 species of freshwater fish have been found, of which 10 species are local strains, 4 species are foreign strains, and 1 species is a hybrid strain. The results of calculating and analyzing the water quality index and Index of Biotic Integrity indicate that WQI is estimated from excellent to fair, while IBI is estimated from fair to poor. It has been illustrated that two indexes show different assessment results. Of those WQI index is more reliable than the IBI. IBI index need further modification for the use of water quality assessment in the Tou-Bien-Ken Creek.

现场采集水质资料共4种，包含pH、溶氧、导电度及浊度，鱼类共计19种，其中原生种10种、外来种4种、杂交种1种，经计算之水质指数及生物整合指数研究分析结果发现，调查测站WQI水质评等由特优至中等，IBI评等由中等至差的等级，显示两种指数评分具有差距，WQI指数之评分结果较IBI正确，IBI指数须经修正才能更适用於头汴坑溪之水质评估。

From our results, we predict steady speciation rates, more species in one-dimensional environments than two-dimensional environments, three scaling regimes of species–area relationships and lognormal distributions of species abundance with an excess of rare species and a tail that may be approximated by Fisher\'s logarithmic series.

这些结果还表明，生物多样性可以在没有具体物理障碍的条件下出现——这种情况与在繁忙车流中所观察到的现象相似：只要有交通，就可能发生交通堵塞，并不需要明显的原因。

Many animal species, 350 bird species, about 100 species of mammals and 200 species of fish.

动物种类繁多，有350多种鸟类，约100种哺乳动物和200多种鱼类。

The community consists of 49 species of Mollusca,44 species of Crusracea,11 species of fishes and 7 other species.

群落平均鲜重生物量147.20g/m~2。靠陆林区76.14g/m~2，中部林区164.69g/m~2，靠海林区200.76g/m~2.54.5%生物量是贝类，23.07%是甲壳类。

Diploid species and hexaploid, octoploid species of triticeae had remarkable differences in micro-morphological characteristics of pollen grain and stomata. However, some differences between hexaploid species and octoploid species were not significant.

可见，小麦族二倍体物种与六倍体物种、八倍体物种在花粉粒和气孔的微观特征方面有明显差异，但六倍体和八倍体物种之间差异不明显。

I have calculated the species diversity for 3 layers (i.e. tree layer, shrub layer and herb layer) by means of various biodiversity index formulas and analyzed the relative species abundance using 9 models of the probability density distribution functions, such as, 3 Distribution (or Beta Distribution, Weibull Distribution, Lognormal Distribution, Poisson Distribution, Binomial Distribution, Negative Binomial Distribution ,Geometric Distribution, etc.. chi-square analyses were conducted on species distribution by using the chi-square test formulated by Pearson to test which distribution function is better, the result of chi square test made it possible to reject the other 8 distribution functions, theβdistribution function performs better than other probability density functions, it has a very close approximation, which can be used for the description of relative abundances of species in forest communities in this data set.

在相对多度研究上选用了九种概率分布模型，这九种概率密度分布函数依次为：贝塔分布、Weibull分布、对数正态分布、泊松分布、二项分布、负二项分布、几何分布、对数分布和奈曼A型分布，并进行了严格的卡方检验，结果表明：其它八种分布均被遭到拒绝，只有贝塔分布获得了通过，且拟合的结果非常理想。

Because there were many occasional species in the desert and the distribution of many species were dependent largely on the habitat, the paper concluded that neither the methods of sampling line and nest method for all species nor the sampling method of the pattern of plum blossom quadrat for the herbaceous species could be suitable for observation in the desert.

由于沙漠物种偶见种多，频度和密度较低，并且分布的环境特异性强，认为对沙漠植物群落观测，样线法、巢式样方法以及对草本观测的梅花样方法均具有一定局限性，建议对草本和灌木物种多样性观测，在确定合理的布样方向基础上，以4m 4m为基本样方。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。