Abstract Protocols for sampling soil fauna are usually designed to increase the number of species found when one or a few plots are heavily sampled. However, no previous study has evaluated how the number of plots sampled affect the power of statistical tests associating community composition and the environment. We test the effect of the number of transects (plots) and the sampling effort in each transect on the representation of trophic groups and on the association of termite species composition with environmental variables. Data were collected in 30 250m-long transects located in central Amazonia. Each transect was subdivided into 10 non-contiguous sections of 5 m × 2 m each (separation of 22 m between sections). We rarefied the data to determine arrangement of transects and sections that 1) best characterizes the distribution of species in trophic groups and 2) maximizes the chances to detect true associations between termite species composition and environmental predictor variables. When more than six transects (plots) were sampled with at least five non-contiguous sections each, the distribution of trophic groups was similar to the known distribution for the area. However, the detection of the association between termite species composition and environmental variables was more easily detected by increasing the number of transects sampled (plots) than the sampling effort per transect. Our results suggest that spreading sampling effort into at least 15 transects (plots) improves the ability to detect trophic groups and the performance of regression tests associating the composition of species with the environment.

中文翻译：

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为生态研究定义白蚁采样协议：提高统计功效的有效方法

摘要 土壤动物取样协议通常旨在增加在一个或几个地块大量取样时发现的物种数量。然而，之前的研究没有评估采样的地块数量如何影响与社区组成和环境相关的统计检验的功效。我们测试了横断面（地块）数量和每个横断面中的采样工作对营养群的表示以及白蚁物种组成与环境变量的关联的影响。数据是在位于亚马逊河中部的 30 条 250m 长的断面中收集的。每个断面被细分为 10 个不连续的部分，每个部分为 5 m × 2 m（部分之间的间隔为 22 m）。我们对数据进行了精简，以确定横断面和剖面的排列，1) 最好地描述了物种在营养组中的分布，2) 最大限度地提高了检测白蚁物种组成与环境预测变量之间真正关联的机会。当对六个以上的断面（地块）进行采样时，每个断面至少有五个不连续的部分，营养组的分布与该地区的已知分布相似。然而，通过增加采样（地块）的数量而不是每个断面的采样工作量，更容易检测白蚁物种组成和环境变量之间的关联。