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 (i) strong interspecific differences in bark traits, (ii) that bark traits related to environmental buffering had profound effects on the abundance of specific invertebrate groups, and (iii) 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.

枯树干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。当它们倒伏于土壤表面时，会被一系列无脊椎动物类群定植，但目前仍不清楚哪些因素决定了其群落组成。
我们将群落组装理论（community assembly theory）应用于无脊椎动物对树倒木的定植过程。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，发挥着至关重要的作用。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就越大。
我们依托LOGLIFE共同花园（common garden）实验，研究11种温带常见树木的早期分解倒木的树皮性状对无脊椎动物群落的影响，以此验证上述假说。本次研究测定的树皮性状包括：树皮疏松度、裂隙指数、外树皮厚度、内/外树皮厚度比、抗穿刺性、储水能力及树皮pH值。本研究关注的优势无脊椎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）及鞘翅目（Coleoptera）。
我们的研究结果显示：（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就越大，且联合无脊椎动物科丰富度也越高。
整套树皮性状共同对无脊椎动物群落组装产生关键的枯死后效应，通过对早期分解倒木中的定植无脊椎动物进行强烈过滤，进而驱动其群落组成与多样性的变异。
我们的研究结果表明，林分中树木物种间的树皮性状差异，可能比单纯的树木物种多样性更能有效指示早期枯树干的无脊椎动物群落多样性。