Data from: The devil is in the detail: estimating species richness, density, and relative abundance of tropical island herpetofauna

Background: One of the basic premises of drawing samples from populations is that the samples are representative of the populations. However, error in sampling is poorly recognized, and it goes unnoticed especially in community ecology. By combining traditional open quadrats used for sampling forest floor herpetofauna with intensive bounded quadrats, we explore the effect of sampling error on estimates of species richness, diversity, and density in the Andaman Islands. Results: Fisher’s α measure of species diversity and second order jackknife estimate of species richness were not sensitive to number of individuals sampled. Sampling error resulted in underestimation of density in both frogs and lizards. It influenced relative abundance of individual species resulting in underestimation of abundance of small or camouflaged species; and also resulted in low precision in lizard species richness estimates. Conclusions: Sampling error resulted in underestimation of abundance of small, fossorial or camouflaged species. Imperfect detection from less intensive sampling method results incorrect estimates of abundance of herpetofauna. Fisher’s α for species diversity and second order jackknife for species richness were robust measures. These have strong implications on inferences made from previous studies as well as sampling strategies for future studies. It is essential that these shortfalls are accounted for while communities are sampled or when datasets are compared.

背景：从种群中抽取样本的基本前提之一是样本能够代表该种群。然而，采样误差尚未得到充分认知，尤其在群落生态学领域中极易被忽视。本研究结合用于调查林地表层两栖爬行动物（herpetofauna）的传统开放式样方与高强度有界样方，以安达曼群岛为研究区域，探究采样误差对物种丰富度、多样性及种群密度估算结果的影响。
结果：费希尔α物种多样性指数（Fisher’s α）与二阶刀切法（second order jackknife）物种丰富度估算结果均不受采样个体数量的影响。采样误差会导致蛙类与蜥蜴类的种群密度被低估。该误差会改变单一物种的相对丰度，使得小型或具有保护色的物种的丰度被低估；同时还会降低蜥蜴类物种丰富度估算结果的精度。
结论：采样误差会导致小型、穴居或具有保护色的物种的丰度被低估。采用低强度采样方法会导致检测不彻底，进而使得两栖爬行动物的丰度估算出现偏差。费希尔α物种多样性指数与二阶刀切法物种丰富度估算均为稳健性指标。上述结论对既往研究的推论逻辑以及未来研究的采样策略均具有重要指导意义。在开展群落采样或进行数据集对比时，必须充分考虑上述采样缺陷带来的影响。