关键词: 杉木, 可溶性有机质, 微生物生物量碳, 森林类型

Abstract: Mulching with organic matters (rice straw and rice hull) in winter is a management technology to promote the early growth of bamboo shoots. To understand the occurrence of leafeating insects under the influence of mulching management, the effects of mulching on leaf nutrition quality and leaf palatability to the leafeating insects were analyzed. The contents of C, N, P, structural carbohydrates, nonstructural carbohydrates, chemical defense substances in leaves of 1-3 years old Phyllostachys violascens from bamboo stands with different mulching managements, including the respitemulching (3-year mulching + 3-year respite), long-term mulching (consecutive 6-year -ulching) and non mulching (CK) were determined. The results showed that, compared with CK, the respitemulching treatment did not affect C concentration in leaves of 1-3 years old culms, but led to a decline in starch, cellulose and phenolic acids. Other indexes of 2 and 3 years old culms and lignin, oxalic acid of 1 year old culms in respitemulching treatment were higher compared to CK, while no difference was found in other indexes of 1 year old culms. On the other hand, the long-term mulching treatment did not change leaf phenolic acid concentration of 1 and 2 years old culms, but lead to an increase in P, oxalic acid and lignin, and a decrease of other indexes. P, sucrose, lignin, oxalic acid, phenolic acid increased, while other indexes of 3 years old culms decreased in the long-term mulching treatment. Furthermore, long-term mulching treatment influenced the nutrient balance of leaf C, N, and P obviously. All results indicated that the mulching management had a significant influence on the leaf nutrition quality and leaf palatability to leaf-eating insects. Leaf nutrition quality and defense ability were enhanced in the respite-mulching stand while the long-term mulching stand was easier to induce the occurrence and outbreak of leaf-eating insects.

Key words: forest type, soil microbial biomass carbon, Cunninghamia lanceolata., soil dissolved organic matter