Abstract Litter decomposition is a fundamental ecosystem process that is essential to nutrient cycling, to the flow of energy through the decomposer food web, and to soil carbon sequestration. For a given climate, litter quality is a major controller of decomposition via its impacts on the activities of decomposer communities, including those of microarthropods and microorganisms. In nature, litter quality can be strongly affected by the composition of mixtures of litter from different plant species or litter of varying age. In contrast with the decomposition of single litter types, the decomposition of litter mixtures may be non-additive, making its prediction difficult. Positive, non-additive decomposition may occur, for example, when microarthropod density is increased in one litter type due to the presence of a second litter type, or when microbial activity in one litter type is stimulated by the presence of a second litter type. We tested the involvement of microarthropod and microbial communities in positive, non-additive decomposition using a model clover litter - oat straw mixture. We found that positive, non-additive decomposition was not associated with changes in microarthropod density, but was associated with significant increases in microbial activity.

中文翻译：

---

微生物活动、微节肢动物和混合凋落物的阳性、非加成分解现象

摘要 凋落物分解是一个基本的生态系统过程，对养分循环、通过分解者食物网的能量流动和土壤碳固存至关重要。对于给定的气候，凋落物质量是分解的主要控制者，它影响分解者群落的活动，包括微节肢动物和微生物的活动。在自然界中，凋落物质量会受到来自不同植物物种或不同年龄的凋落物混合物组成的强烈影响。与单一凋落物类型的分解相反，凋落物混合物的分解可能是非可加性的，因此难以预测。可能会发生正的非加成分解，例如，当一种垃圾类型中的微节肢动物密度由于第二种垃圾类型的存在而增加时，或者当一种垫料中的微生物活动受到第二种垫料类型的刺激时。我们使用模型三叶草凋落物 - 燕麦秸秆混合物测试了微节肢动物和微生物群落在积极的非加成分解中的参与。我们发现，积极的非加成分解与微节肢动物密度的变化无关，但与微生物活动的显着增加有关。