Data from: Tree functional diversity affects litter decomposition and arthropod community composition in a tropical forest

Disturbance can alter tree species and functional diversity in tropical forests, which in turn could affect carbon and nutrient cycling via the decomposition of plant litter. However, the influence of tropical tree diversity on forest floor organisms and the processes they mediate are far from clear. We investigated the influence of different litter mixtures on arthropod communities and decomposition processes in a 60-year-old lowland tropical forest in Panama, Central America. We used litter mixtures representing pioneer and old growth tree species in experimental mesocosms to assess the links between litter types, decomposition rates, and litter arthropod communities. Overall, pioneer species litter decomposed most rapidly and old growth species litter decomposed the slowest but there were clear non-additive effects of litter mixtures containing both functional groups. We observed distinct arthropod communities in different litter mixtures at 6 mo, with greater arthropod diversity and abundance in litter from old growth forest species. By comparing the decay of different litter mixtures in mesocosms and conventional litterbags, we demonstrated that our mesocosms represent an effective approach to link studies of litter decomposition and arthropod communities. Our results indicate that changes in the functional diversity of litter could have wider implications for arthropod communities and ecosystem functioning in tropical forests.

干扰可改变热带森林的树木物种组成与功能多样性，进而通过植物凋落物分解过程影响碳循环与养分循环。然而，热带树木多样性对森林地表生物及其介导的生态过程的影响，目前仍远未得到清晰阐明。本研究以中美洲巴拿马的一处60年生低地热带森林为研究对象，探究不同凋落物混合组合对节肢动物（arthropod）群落及分解过程的影响。本研究借助代表先驱树种与老龄林树种的凋落物混合组合，在实验中型生态系统（experimental mesocosms）中开展对照实验，以评估凋落物类型、分解速率与凋落物节肢动物群落三者间的内在关联。整体而言，先驱树种凋落物的分解速率最快，老龄林树种凋落物分解速率最慢，但同时包含这两类功能群的凋落物混合组合则呈现出显著的非加性效应。在培养6个月后，不同凋落物混合组合中的节肢动物群落结构存在显著差异，其中源自老龄林树种的凋落物内节肢动物的多样性与个体丰度均更高。通过对比实验中型生态系统与传统凋落物袋中不同凋落物混合组合的分解动态，本研究证实所采用的实验中型生态系统是联结凋落物分解与节肢动物群落研究的有效手段。本研究结果表明，凋落物功能多样性的变化，可能对热带森林的节肢动物群落与生态系统功能产生更为广泛的影响。