关键词: 川西高原, 雪被覆盖, 窄叶鲜卑花, 凋落物分解, 养分

Abstract: Soil-borne bag method was adopted to study the decomposition and nutrient dynamics of Sibiraea angustata leaf litter under different depths (0, 30 and 100 cm) of snow cover in western Sichuan plateau in January-May, 2010. In snow-free plot, the mass loss rate of the litter over the five months was 29.9%; in the plots with 30 and 100 cm snow cover, the litter mass loss rate was 33.8% and 35.2%, respectively. During the decomposition, definite N enrichment in the litter was observed, while the P enrichment fluctuated. The C content and C/N ratio of the litter decreased sharply at the early stage of decomposition, but increased gradually after then. Snow cover greatly contributed to the rapid decomposition of litter and the N enrichment in the litter, but had little effects on the litter C and P contents. In western Sichuan plateau, durable snow cover with a depth of >30 cm could alter the litter decomposition pattern, and substantially affect the soil nutrient turnover and plant community composition.

Key words: western Sichuan plateau, snow cover, Sibiraea angustata, litter decomposition, nutrient.