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

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.

地栖节肢动物作为土壤的重要组成部分，对生态系统服务，尤其是食物网功能的维持发挥着至关重要的作用。然而，其物种多样性和群落组成的研究尚显不足。在欧洲，地栖陷阱捕集法是土壤生境采样的一种常用方法，但在美洲却鲜有应用。本研究采用地栖陷阱对美国弗吉尼亚州西南部未曾调查过的节肢动物群落进行采样。陷阱置于浅层地下生境（SSHs），即地表附近光线无法穿透的地下生境，尤其是土壤与下伏地表之间的界面——由岩石间的充满空气的孔隙空间构成的微小生境（简称MSS）。共收集到2,260个节肢动物标本，构成345个形态物种，涉及8个纲、33个目和94个科。通过扩增和测序线粒体细胞色素c氧化酶亚基I（COI）基因的特定区域，并利用3%的序列聚类方法建立分子操作分类单元（mOTUs），从而推断观测到的物种丰富度。共记录了272个COI条形码，代表256个mOTUs，这些数据为稀有土壤节肢动物类群构建了分子库，以供未来研究之用。这项工作是首次对北美土壤表面以下10厘米以上的地栖节肢动物进行的广泛分类学调查。