Soil mesofauna effects on litter decomposition in the coniferous forest of the Changbai Mountains, China

Spatial and temporal variations of abundance and community structure of soil fauna have an influence on litter decomposition. In this paper, litterbags with two different mesh sizes (1 mm and 0.01 mm) were used to exclude soil animals of specific body size. The decomposition of the litter of Abies nephrolepis and Picea jezoensis were examined in the coniferous forest of the Changbai Mountains. In addition, the effect of soil mesofauna and habitat (with different altitudes) on litter decomposition was also determined. It was found that the remaining mass between the 1 mm and 0.01 mm mesh size litterbags varied significantly among the incubation times. The remaining mass of A. nephrolepis was lower than that of P. jezoensis after one year of decomposition. The elevation gradient had no effect on the litter decomposition. The contribution of soil mesofauna to litter mass loss of P. jezoensis in the lower coniferous forest was higher than that in the upper coniferous forest (p < 0.05). Litter species, habitat and incubation time had clear effects on soil mesofauna community composition. The dominant groups of soil mesofauna in the litterbags were Collembola and Acarina, of which the abundances were significantly correlated with the litter mass loss in the 1 mm mesh size litterbags at the two sites. Moreover, the litter mass losses were shown to be distinctively related to the richness and abundance of soil mesofauna. However, the Shannon–Wiener index was correlated with the P. jezoensis litter mass loss in the lower coniferous forest. Therefore, it was concluded that the soil mesofauna and litter species clearly impacted the litter decomposition, but the effects of their interactions on the litter decomposition were not significant in the coniferous forest of the Changbai Mountains.