Sánchez-Galindo Laura M, Sandmann Dorothee, Marian Franca, Krashevska Valentyna, Maraun Mark, Scheu Stefan
JFB Institute of Zoology and Anthropology University of Göttingen Göttingen Germany.
Centre of Biodiversity and Sustainable Land Use University of Göttingen Göttingen Germany.
Ecol Evol. 2021 Jan 29;11(5):2360-2374. doi: 10.1002/ece3.7208. eCollection 2021 Mar.
In tropical forest ecosystems leaf litter from a large variety of species enters the decomposer system, however, the impact of leaf litter diversity on the abundance and activity of soil organisms during decomposition is little known. We investigated the effect of leaf litter diversity and identity on microbial functions and the abundance of microarthropods in Ecuadorian tropical montane rainforests. We used litterbags filled with leaves of six native tree species (, , , , , and spp.) and incubated monocultures and all possible two- and four-species combinations in the field for 6 and 12 months. Mass loss, microbial biomass, basal respiration, metabolic quotient, and the slope of microbial growth after glucose addition, as well as the abundance of microarthropods (Acari and Collembola), were measured at both sampling dates. Leaf litter diversity significantly increased mass loss after 6 months of exposure, but reduced microbial biomass after 12 months of exposure. Leaf litter species identity significantly changed both microbial activity and microarthropod abundance with species of high quality (low C-to-N ratio), such as , improving resource quality as indicated by lower metabolic quotient and higher abundance of microarthropods. Nonetheless, species of low quality, such as spp., also increased the abundance of Oribatida suggesting that leaf litter chemical composition alone is insufficient to explain variation in the abundances of soil microarthropods. Overall, the results provide evidence that decomposition and microbial biomass in litter respond to leaf litter diversity as well as litter identity (chemical and physical characteristics), while microarthropods respond only to litter identity but not litter diversity.
在热带森林生态系统中，来自多种物种的落叶进入分解者系统，然而，落叶多样性对分解过程中土壤生物的丰度和活性的影响却鲜为人知。我们研究了厄瓜多尔热带山地雨林中落叶多样性和落叶种类对微生物功能以及微型节肢动物丰度的影响。我们使用装有六种本地树种（、、、、、和种）树叶的落叶袋，在野外培养单一培养物以及所有可能的二物种和四物种组合，培养时间为6个月和12个月。在两个采样日期测量了质量损失、微生物生物量、基础呼吸、代谢商、添加葡萄糖后微生物生长的斜率，以及微型节肢动物（蜱螨目和弹尾目）的丰度。落叶多样性在暴露6个月后显著增加了质量损失，但在暴露12个月后降低了微生物生物量。落叶种类显著改变了微生物活性和微型节肢动物丰度，高质量（低碳氮比）的树种，如，通过较低的代谢商和较高的微型节肢动物丰度表明其改善了资源质量。尽管如此，低质量的树种，如种，也增加了甲螨目的丰度，这表明仅落叶化学成分不足以解释土壤微型节肢动物丰度的变化。总体而言，结果表明，落叶中的分解和微生物生物量对落叶多样性以及落叶种类（化学和物理特征）有响应，而微型节肢动物仅对落叶种类有响应，对落叶多样性无响应。
