Litter mass loss and nutrient release influenced by soil fauna of Betula ermanii forest floor of the Changbai Mountains, China

Abstract

The objective of this study was to examine the litter mass loss of single and mixed plant species, and the nutrient release influenced by soil fauna on the Betula ermanii Cham. (BE) forest floor of the Changbai Mountains, China. A 24 month experiment of litter decomposition was conducted using litterbags with two mesh sizes (0.01 and 2mm), for three litter species incubated separately or in 1:1 and 1:1:1 combinations. Following the 24 month experiment, it was found that the faunal effect on the litter mass loss varied between 8.91 % and 19.9 %. Parasenecio komarovianus (Pojark.) Y.L. Chen (PK) litter decomposed fastest, however, B. ermanii had the highest faunal effect. During the experiment, C loss was found in all litter species and their mixtures, while N accumulation was found in B. ermanii, Rhododendron aureum Georgi (RA), and BE+RA litterbags of both mesh sizes only after 6 months. Soil fauna limited release of C was also found in all litter species and their mixtures after 6 months. By the 24th month of the experiment, soil fauna limited the release of C and N in the R. aureum litterbags, but the C and N release was enhanced in all other litter incubations. Our results illustrate that the mixed–species litter accelerated the mass loss for the low-quality litter, but reduced the soil fauna effect on the mass loss when it was mixed with the high-quality litter. The soil fauna contributed to the C and N release in all litter incubations, both single and mixtures, during the 24 month experiment, with the exception of R. aureum. The rate of litter mass loss, and the nutrient release attributable to the soil fauna, depended on the composition of the litter. The mechanism can be explained by litter heterogeneity, as well as by soil faunal interactions.