Objective Taking 6 tree species in an evergreen broad-leaved forest in Jinyun Mountain National Nature Reserve as object to study the stoichiometric characteristics and seasons of litter C, N and P and analyze the relationship between them and the amount of litter.

Method The grid method was used to evenly arrange 172 litter leaf collection frames in the plot. At the end of each month, the leaf litter in the collection frame were regularly collected for classification and weighing in laboratory. After crushing, the contents of C, N, P element were measured.

Result (1) The seasonal variation of leaf litter of the six tree species were different. The litter peaks of the evergreen broad-leaved tree species Castanopsis fargesii and Machilus nanmu, and evergreen coniferous species Cunninghamia lanceolata appeared in spring; the litter peak of deciduous tree species Alniphyllum fortune appeared in summer; the wither peak of deciduous tree species Liquidambar formosana appeared in winter; while the evergreen coniferous tree species Pinus massoniana had no obvious wither peaks throughout the year. (2) The C, N and P contents of the litter of the six tree species were 481.35~542.23, 5.64~11.85, and 0. 39~0.72 g·kg ⁻¹, the N: P range was 13.05~19.15. The deciduous broad-leaved tree species had higher N and P contents, and the evergreen coniferous species had lower N and P contents. (3) The seasonal dynamics of C, N and P contents of the six tree species were obvious. There was a significant positive correlation between the C content of Pinus massoniana and the yield of litter (P < 0.05), the N content of Alniphyllum fortune and the yield of litter was significantly positively correlated (P < 0.05), the P content of Castanopsis fargesii and Pinus massoniana litter leaves showed a significantly negative correlation with the yield of litter leaves (P < 0.05), and the N: P of litter leaves of Pinus massoniana showed a positive correlation with the yield of litter (P < 0. 05).

Conclusion The seasonal dynamics of the litter of six tree species in the evergreen broad-leaved forest of Jinyun Mountain are different. These six species show a pattern of low N and low P. The overall performance is limited by N and P together, and the N limiting effect is stronger than the P limiting. Within a growing season, the C, N, and P stoichiometric characteristics of the six species vary greatly from month to month, and the relationship between the amount of litter and the C, N, and P contents of the litter is related to the species characteristics. The relationship between quantity of litter and its stoichiometry is not obvious.