Data from: Faunal community consequence of interspecific bark trait dissimilarity in early-stage decomposing logs

Dead tree trunks have significant ecosystem functions related to biodiversity and biogeochemical cycles. When lying on the soil surface they are colonized by an array of invertebrate fauna, but what determines their community composition is still unclear. We apply community assembly theory to colonization of tree logs by invertebrates. During early decomposition, the attached bark is critically important as an environment filter for community assembly through habitat provision. Specifically, we hypothesized that the more dissimilar bark traits were between tree species, the more their faunal community compositions would differ. We tested this hypothesis by investigating the effects of bark traits on the invertebrate communities in the early decomposing logs of 11 common, temperate tree species placed in the ‘common garden’ experiment LOGLIFE. Bark traits included bark looseness, fissure index, outer bark thickness, ratio of inner to outer bark thickness, punch resistance, water storage capacity and bark pH. The predominant faunal groups studied were Annelida, Isopoda, Chilopoda, Diplopoda, Diptera and Coleoptera. Our results showed (1) strong interspecific differences in bark traits, (2) that bark traits related to environmental buffering had profound effects on the abundance of specific invertebrate groups, and (3) the higher the overall bark trait dissimilarity between tree species, the more dissimilar these tree species were in faunal community composition, and the higher was the joint invertebrate family richness. A suite of bark traits together has fundamental afterlife effects on invertebrate community assembly, strongly filtering the colonizing invertebrates in early decomposing logs, driving variation in their community composition and diversity. Our findings indicate that bark trait dissimilarity among tree species in forest stands is likely a better indicator of early-phase dead trunk fauna diversity than tree species diversity per se.

枯倒木（dead tree trunks）具有与生物多样性及生物地球化学循环密切相关的重要生态系统功能。当它们倒伏于地表时，会被一系列无脊椎动物类群（invertebrate fauna）定殖，但目前仍未明确调控其群落组成的关键因素。本研究将群落组装理论应用于无脊椎动物对倒木（tree logs）的定殖过程。在分解早期，附着的树皮通过提供生境，作为群落组装的环境过滤因子发挥关键作用。具体而言，我们提出假说：树木物种间的树皮性状差异越大，其无脊椎动物群落组成的差异也会越大。为验证该假说，本研究以开展于"LOGLIFE"同质园（common garden）实验中的11种温带常见树木的早期分解倒木为研究对象，探究树皮性状对其无脊椎动物群落的影响。本次研究涉及的树皮性状包括：树皮疏松度、裂隙指数、外树皮厚度、内/外树皮厚度比、抗穿刺强度、持水能力以及树皮pH值。本研究的优势动物类群包括环节动物门（Annelida）、等足目（Isopoda）、唇足纲（Chilopoda）、倍足纲（Diplopoda）、双翅目（Diptera）以及鞘翅目（Coleoptera）。研究结果显示：（1）树皮性状存在显著的种间差异；（2）与环境缓冲功能相关的树皮性状对特定无脊椎动物类群的丰度具有显著影响；（3）树木物种间的整体树皮性状差异越大，其无脊椎动物群落组成的差异也越高，且无脊椎动物科的总丰富度也越高。一系列树皮性状共同对无脊椎动物群落组装产生根本性的死后遗留效应，在早期分解倒木中强力过滤定殖的无脊椎动物，进而驱动其群落组成与多样性的变化。本研究结果表明，林分中树木物种间的树皮性状差异，或许比树木物种多样性本身更能有效指示早期枯倒木动物群落的多样性。