Effects Of Forest Litter Decomposition On Soil Properties In Maoershan Region

Forest litters decomposition was an important process of nutrient cycling in forest ecosystems, and played a central role in soil organic matter formation and nutrients release。 The nutrition elements released from decomposition of forest litters was an important material sources to vegetation grow, and was extremely important to the maintenance of forest soil fertility. Furthermore, forest litters had major impact on the physical and chemistry properties of forest soil, which could improve physical structure of soil, supply soil nutrients constantly and stabilize forest productivity。 Decomposition of three different forest litters and season changes of physical and chemistry properties of forest soil in Maoershan Mountain were studied in the paper. The decomposition characters of forest litters, the release rule of nutrients, and the effects on physical and chemistry properties of forest soil were also discussed. Main results were as follows:(1) Total litters contents of Korean pine plantations was the largest, followed by needles leafy mixed forest and leafy secondary forest. Among the composition of litters, leaf was in absolute superiority and accounted for 79.28%~89.68% in the proportion of total litters.(2) It was different for existing litters contents among different forest types, and needles leafy mixed forest > leafy secondary forest > Korean pine plantation. The proportions of fresh fallen and hemi-decomposed layers in different forest types were also different, in which needles leafy mixed forest varied little, fresh fallen layer of Korean pine plantation was in absolute superiority, and fresh fallen litters of leafy secondary forest was slightly higher.(3) The rates of weightlessness of different forest types were different: fresh fallen and hemi-decomposed layers litters of natural secondary forest were larger, and the rates of weightlessness of Korean pine needles and leafy mixed forest plantations in same layer litters varied little.(4) Nitrogen concentrations of hemi-decomposed layers were higher than fresh fallen litters in three forest types. And nitrogen concentrations in fresh fallen and hemi-decomposed layers of different forest types were: leafy secondary forest > Korean pine plantation > needles leafy mixed forest. P concentrations of leafy secondary forest were much higher than Korean pine plantation and needles leafy mixed forest, and P concentrations of three forest types increased with the prolong of decomposition time. K concentrations of leafy secondary forest were highest, followed by needles leafy mixed forest and Korean pine plantation respectively.(5) Soil bulk density of three forest types increased with the increase of soil depth, and the differences among three forest types were little. Soil porosity was worse with the increase of soil depth, and the differences among three forest types were little. Soil moisture contents decreased with the increase of soil depth. The pH values of surface soil of needles leafy mixed forest and leafy secondary forest were higher than subsoil, and pH values in two layers soil of Korean pine plantation varied slightly. The pH values of three forest types in different seasons varied little.(6) Soil organic matter, total nitrogen and alkaline nitrogen contents decreased with the increase of soil depth of three forest types. Organic matter contents of surface soil in needles leafy mixed forest were higher than leafy secondary forest and Korean pine plantation. Organic matter contents of surface soil in three forest types varied little, and showed different pattern in different forest types. Total nitrogen contents of surface soil in three forest types changed with seasons distinctly, and overall extents were not big. Total P contents of different soil layers in three forest types didn't show distinct rule, only leafy secondary forest showed slightly increase. Total K contents of different soil layers in three forest types didn' t show distinct rule, the differences among different forest types was little, and K seasonal changes also didn't show distinct rule, which leafy secondary forest varied bigger than other forest types. Alkaline nitrogen contents of three forest types distinctly decreased with the increase of soil depth, and there were some differences in alkaline nitrogen contents of three forest types in different seasons. Available phosphorus contents of needles leafy mixed forest and leafy secondary forest decreased with the increase of soil depth, and available phosphorus contents of three forest types increased with the prolong of time. "...