title: [Seasonal dynamics of soil organic carbon mineralization for two forest types in Xiaoxing'an Mountains, China].
abstract: To investigate the seasonal dynamics of soil organic carbon (SOC) mineralization in Xiaoxing'an Mountain, we incubated soil samples collected from virgin Korean pine forest and broad-leaved secondary forest in different seasons in the laboratory and measured the SOC mineralization rate and cumulative SOC mineralization (Cm). We employed simultaneous reaction model to describe C mineralization kinetics and estimated SOC mineralization parameters including soil easily mineralizable C (C1), potentially mineralizable C (C₀). We also analyzed the relations between Cm, C₁and their influencing factors. Results showed that the incubated SOC mineralization rate and Cm for 0-5 cm soil layer decreased from early spring to late autumn, while for 5-10 cm soil layer the seasonal variation was not statistically significant for both forest types. The C₁ in 0-5 and 5-10 cm soil layers varied from 42.92-92.18 and 19.23-32.95 mg kg⁻¹, respectively, while the C₀ in 0-5 and 5-10 cm soil layers varied from 863.92-3957.15 and 434.15-865.79 mg · kg⁻¹, respec- tively. Both C₁ and C₀ decreased from early spring to late autumn. The proportions of C₀ in SOC for two forest types were 0.74%-2.78% and 1.11%-1.84% in 0-5 and 5-10 cm soil layers, respectively, and decreased from early spring to late autumn, indicating that SOC tended to become more stable as a whole from spring to autumn. The Cm and C₀ were significantly positively correlated to in situ soil water content and hot water-extractable carbohydrate content, but were not correlated to in situ soil temperature and cool water-extractable carbohydrate content. We concluded that soil labile organic carbon, soil physical and chemical properties contributed to the seasonal dynamics of SOC mineralization in the forests.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Wei
authors.initials: W
authors.lastname: Lin
authors.forename: Xiao-yang
authors.initials: XY
authors.lastname: Cui
mesh_terms: D002244:Carbon / Q000032:analysis*; D002681:China; D065928:Forests; D008903:Minerals; D028223:Pinus; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D013696:Temperature; D014867:Water
chemical_list: D008903:Minerals; D012987:Soil; D014867:Water; D002244:Carbon