杉木苦竹混交林生长效应与凋落物分解研究

Tree Growth and Litter Decomposition in a Mixed Plantation of Chinese Fir and Pleioblastus amarus

分析10年生杉木林经间伐后留养苦竹形成的混交复层林的生长效应及凋落物数量及分解状况。结果表明：SJK处理（杉木林进行间伐，保留杉木密度900株· hm-2，留养苦竹，满园后，保留苦竹6000株· hm-2）能够形成层次明显的复层林分，既有利于杉木培育大径材，又可以收获苦竹竹产品，具有较高的生长效应。杉木苦竹混交复层林，不仅苦竹凋落物量大，分解快，而且形成的林分结构，凋落物混合状态，有利于杉木凋落物的分解。 SJK处理中凋落物周转期：苦竹2.27 a，杉木3.86 a，苦竹凋落物周转期比杉木短580 d；杉木纯林（杉木林不间伐，现存密度2075～2110株· hm-2）凋落物周转期为4.94 a，比SJK处理中杉木凋落物周转期长394 d。

Tree growth,litter production and decomposition of a multi-storey mixed stand of Chinese fir （ Cunninghamia lanceolata） and Pleioblastus amarus,developed from thinning a 10-year-old pure Chinese fir stand and retaining understorey species P.amarus, were studied in this article.Treatment SJK （ thinning a pure Chinese fir stand to density 900 stems· hm-2 and retaining understorey species P.amarus to density 6000 stems· hm-2 ） could develop obvious multi -storey crown,it was in favor of cultivating Chinese fir big-diameter timber , provided extra bamboo products and improved tree growth.Multi-storey mixed stand of Chinese fir and P.amarus had good stand structure ,higher litter production and decomposition rate of P.amarus,and litter mixture had a positive effect on decomposition rate of Chinese fir litter.Turnover time of P.amarus and Chinese fir leaf litter in treatment SJK were 2.27 a and 3.86 a,respectively ,and the former was 580 d shorter than the latter.Turnover time of Chinese fir leaf litter in pure plantation （unthinned,current density 2075-2110 stems· hm-2） was 4.94 a,394 d longer than that in the mixed stand with treatment SJK.