The influence of litter mixing on decomposition and soil fauna assemblages in a Pinus koraiensis mixed broad-leaved forest of the Changbai Mountains, China

Although much research aiming to determine in what ways aboveground systems may affect belowground processes and communities has been conducted, the effects of litter mixing on decomposition processes and decomposer communities remain controversial. In this study, a litter mixing experiment was conducted using litterbags in a Pinus koraiensis mixed broad-leaved forest of the Changbai Mountains, in which the treatments consisted of litter monocultures of each of four canopy tree species, namely P. koraiensis, Fraxinus mandshurica, Tilia amurensis and Acer mono, as well as mixtures of two and four different species. It was found that the different litter species decomposed in monoculture at different rates. The litter mixing had idiosyncratic effects on the decomposition, which depended on the field incubation time and composition species. Litter species identity was an important determinant of abundances and diversity of soil fauna, while litter mixing had weak or no significant effects on the soil fauna communities. The study results also showed that soil fauna has an important influence on litter decomposition; however, the extent of the relationship between decomposition and soil fauna was not stronger in the litter mixtures than in the monocultures. It is concluded that litter mixing had effects on decomposition, with relatively minor effects on soil fauna communities in comparison to the effects of litter species identity.

► We examine effects of litter mixing on decomposition and soil fauna assemblages. ► Litter mixing has idiosyncratic effects on decomposition rates during the study. ► Litter quality is an important determinant of soil fauna community. ► Litter mixing has weak or not significant effects on soil fauna assemblages. ► The effect of soil fauna on litter decomposition is not stronger in the litter mixtures.