改善杉木人工林的林地质量和提高生产力的研究

杉木人工林在我国亚热带森林生态系统中和木材生产上占有十分重要的地位。但杉木纯林在整个生长发育过程中,林地养分被大量消耗,土壤微生物数量逐年减少,生化活性和氧化代谢功能下降,致使林地质量退化,生产力降低。特别是杉木纯林连栽,地力递减,香草醛类有毒物质积累,环境退化更加严重,生产力下降30％以上。试验证明,杉木火力楠混交林不仅能减轻杉木纯林诸多弊端,而且表现了良好生态、经济效益,是解决上述问题的一个重要途径。

Researches on improving the quality of forest land and the productivity of artificial Cunninghamia lanceolata stands.

Artificial C. lanceolata stand dominates in the forest ecosystems of subtropical zone in China and occupies very important status in the production of timber. However , long term's practices and researches have manifested that, pure C.lanceolata plantations exha usted large amount of nutrients during the period of growth and development, and si multaniously,the amount of soil microbes declined year by year,the biochemical activity and oxidative-metabolic capacity got weaker, the degradation of forest land quality and productivity was brought about. Furthermore, repeatedly planting C.lanceolata trees in curred the land capability to decline gradually, and the toxic vanillin-like substances accumulated. Hence, the environment of soil became worse, and worse, and the produc tivity was cut down by mort than 30 percent. Experiments confirmed that the mixed plantation of C.lanceolata and Michelia macclurei not only dispeled many defects of pure C.lanceolata stand, but also had better performances on ecological and economical effici ency. It is one critical way to solve the problems just related.