Arthropod diversity in shallow subterranean habitats of the Appalachian Mountains, morphospecies images, Part I

Subterranean arthropods are important components of soils and contribute essential food-web functions and other ecosystem services, however, their diversity and community composition has scarcely been assessed. Subterranean pitfall traps are a commonly used method for sampling soil habitats in Europe but have never been widely implemented in the Americas. We used subterranean pitfall traps to sample previously unsurveyed arthropod communities in southwestern Virginia, U.S. Traps were placed in shallow subterranean habitats (SSHs), underground habitats close to the surface where light does not penetrate, and more specifically at the interface between the soil and underlying milieu souterrain superficiel—a microhabitat consisting of the air-filled interstitial spaces between rocks (abbreviated MSS). In total, 2,260 arthropod specimens were collected constituting 345 morphospecies from 8 classes, 33 orders, and 94 families. A region of the mitochondrial cytochrome c oxidase subunit I (COI) gene was amplified and sequenced, and objective sequence clustering of 3% was used to establish molecular operational taxonomic units (mOTUs) to infer observed species richness. In all, 272 COI barcodes representing 256 mOTUs were documented for rare soil-dwelling arthropod taxa and are published to build a molecular library for future research in this system. This work is the first taxonomically extensive survey of North American soil-dwelling arthropods greater than 10 cm below the soil surface.

地下节肢动物作为土壤的重要组成部分，对食物网功能及其他生态系统服务贡献了不可或缺的作用，然而，其多样性和群落组成却鲜有评估。在欧洲，地下陷阱是一种常用的土壤生境采样方法，但在美洲却未曾得到广泛应用。本研究利用地下陷阱对美国弗吉尼亚州西南部的未调查节肢动物群落进行采样。陷阱置于浅层地下生境（SSHs），即靠近地表、光线无法穿透的地下生境，更具体地，位于土壤与地下表层环境之间的界面——一个由岩石间充满空气的孔隙空间构成的微生境（简称MSS）。总计收集到2,260个节肢动物标本，包括来自8个纲、33个目和94个科的345个形态种。通过扩增和测序线粒体细胞色素c氧化酶亚基I（COI）基因的区域，并使用3%的客观序列聚类方法建立了分子操作分类单元（mOTUs），以推断观察到的物种丰富度。总共记录了272个COI条形码，代表256个mOTUs，涉及稀有土壤节肢动物类群，并已发表以构建该系统的分子库，为未来的研究提供基础。这项工作是对北美土壤中10厘米以下生境的节肢动物进行的首次广泛分类学调查。