*2.4. Statistical Analysis*

A two-way ANOVA was performed to evaluate the effects of the collection time and plant species on the initial C quality and hydrophobicity indices. Multiple comparisons were used to assess the significance of the differences among the various plant species. The above analyses were performed in SPSS 22.0 (IBM SPSS Statistics Inc., Chicago, IL, USA). Linear analysis was used to determine the effects of methoxyl C, aromatic C and phenolic C in newly shed foliar litter on C loss during litter decomposition. Stepwise regression analysis was conducted to evaluate the effects of the environmental conditions and litter quality on the initial C quality. The above analyses were performed in Origin Pro 9.0 (OriginLab, Northampton, MA, USA). All graphics were generated in Origin Pro 9.0 (OriginLab, Northampton, MA, USA). C loss data for fir and willow litter in the 4-year decomposition process were collected from Ni et al. [41], which were used to detect the effects of the C quality of newly shed fir and willow foliar litter on C loss during litter decomposition.
