Data from: Forest plant community as a driver of soil biodiversity: experimental evidence from collembolan assemblages through large-scale and long-term removal of oak canopy trees Quercus petraea

Plant–soil interactions are increasingly recognized to play a major role in terrestrial ecosystems functioning. However, few studies to date have focused on slow dynamic ecosystems such as forests. As they are vertically stratified by multiple vegetation strata, canopy tree removal by thinning operations could alter forest plant community through tree canopy opening. Very little is known about cascading effects on soil biodiversity.

We conducted a large-scale, multi-site assessment of collembolan assemblage response to long-term canopy tree removal in sessile oak Quercus petraea temperate forests. A total of 33 experimental plots were studied covering a large gradient of canopy tree basal area, stand age and local abiotic contexts.

Collembolan abundance strongly declined with canopy tree removal in early forest successional stage and this was mediated by negative effect of understory plant community composition changes, i.e. shift from moss and forb to tree seedling, fern, shrub and grass species. Negative effect of this composition shift on collembolan species richness was largely offset by positive effect of the increase in understory plant species richness. This gives support to both the plant mass-ratio and functional diversity hypotheses. Collembolan functional groups had contrasting response patterns, which were mediated by different ecological factors. Epedaphic (r-strategist) abundance and species richness increased with canopy tree removal in relation with the increase in understory plant species richness. In contrast, euedaphic (K-strategist) abundance and species richness declined with canopy tree removal in early forest successional stage in relation with changes in understory plant community composition and species richness, as well as microclimatic conditions.

Overall, our study provides experimental evidence that forest plant community can be a strong driver of collembolan assemblages. It also emphasizes the role of trees as foundation species of forest ecosystems that can shape soil biodiversity through their regulation of understory plant community and ecosystem abiotic conditions.

植物-土壤互作（Plant–soil interactions）日益被认为在陆地生态系统功能中发挥核心作用。然而迄今为止，鲜有研究关注森林等慢动态生态系统。由于森林由多层植被垂直分层，疏伐作业导致的冠层树木移除可通过林冠开放改变森林植物群落。目前人们对其对土壤生物多样性（soil biodiversity）的级联效应知之甚少。
我们在无梗花栎（Quercus petraea）温带森林中开展了大规模多站点评估，探究弹尾虫（collembolan）群落对长期冠层树木移除的响应。研究共纳入33个实验样地，覆盖了冠层树木胸高断面积、林分年龄以及局地非生物环境的广泛梯度。
在森林早期演替阶段，弹尾虫的丰度随冠层树木移除显著下降，这一效应由林下植物群落组成变化的负面影响所介导，即群落从苔藓和非禾本科草本转向树木幼苗、蕨类、灌木与禾本科草本物种。该组成变化对弹尾虫物种丰富度的负面影响，在很大程度上被林下植物物种丰富度增加所带来的正面效应所抵消。这一结果同时支持植物质量比假说与功能多样性假说。弹尾虫功能群呈现出截然相反的响应模式，且分别由不同生态因素介导。表栖弹尾虫（Epedaphic，r-策略者）的丰度与物种丰富度随冠层树木移除而增加，这与林下植物物种丰富度提升相关。与之相反，在森林早期演替阶段，真土栖弹尾虫（euedaphic，K-策略者）的丰度与物种丰富度随冠层树木移除而下降，这与林下植物群落组成、物种丰富度的变化以及微气候条件相关。
总体而言，本研究提供了实验证据，证明森林植物群落可作为弹尾虫群落的重要驱动因子。本研究同时强调，树木作为森林生态系统的建群种，可通过调控林下植物群落与生态系统非生物环境，进而塑造土壤生物多样性。