在探讨生物多样性时，我们常常提到两个重要的辛普森指数：辛普森多样性指数（Simpson's diversity index）和辛普森相似性指数（Simpson similarity index），这两个指数在物种多样性评估中扮演着关键角色，但它们关注的焦点不同。辛普森多样性指数主要用于评估物种丰富度和相对丰度（alpha多样性），而辛普森相似性...
β多样性(Beta Diversity)探究不同生境群落组成差异或沿环境梯度的更替特征,即生境间的多样性(between-habitat diversity)。β多样性越大代表群落间的共有物种越少且物种组成差异越大,往往用来指示不同生境的物种隔离程度,且与α多样性共同构成了总体多样性或特定生境的生物异质性。Beta多样性分析往往通过计算样本间的...
在宽泛的物种多样性的领域内有两个辛普森指数,虽然名字相似,但是本质不同,Simpson's diversity index 用于计算物种丰富度和相对丰度(alpha多样性),而Simpson similarity index 或 Simpson similarity index 用于计算不同的取样单位内的物种相似性(beta 多样性)。
在微生物组研究中，alpha diversity即“分析在单个样本中有多少种不同的序列”；beta diversity即“分析在一定范围内样本中，各种不同序列的分布情况”。网页链接 网页链接
This work aimed at evaluating changes in alpha and beta diversity of major Mediterranean macroalgal assemblages across gradients of human pressure. To achieve these goals, data from four different experiments, both correlative and manipulative, were used. In particular, patterns of alpha and beta ...
之后计算Beta多样性 这里的代码使用的是官网上201802的,和之前2017的有一点点区别,主要是分组的时候 --m-metadata-category 要改为 --m-metadata-column qiime diversity beta-group-significance \ --i-distance-matrix core-metrics-results/unweighted_unifrac_distance_matrix.qza \ --m-metadata-file sample-...
Despite the increasing attention to native bees as pollinators of cucurbit crops, little is known about the diversity of bees that visit or pollinate these crops in many regions. Based on collections from 11 observational plots of C. pepo established in five localities and maintained by the ...
Distance-related diversity (i.e., beta) is low across both spatially adjacent and distant plots. Floodplain habitats show a slightly higher decay of similarity with distance than either terra firme habitats or cross-habitat comparisons. Cross-habitat comparisons are significantly less similar than ...
This command will generate UniFrac beta diversity plots (weighted and unweighted): beta_diversity_through_plots.py -m map.txt -t clustering/rep_set.tre -i final_otu_tables/otu_table.biom -o plots/bdiv_otu You will be able to open the generated HTML files (e.g. plots/bdiv_otu/weigh...
Attention is drawn to some useful but not generally known properties of principal components analysis (PCA). Noncentered PCA of proportion data gives site ordinations that display approximate alpha diversities of sites and beta diversities of groups of sites, as measured by the Simpson index and me...