杉木与主要阔叶造林树种叶凋落物的混合分解

DECOMPOSITION OF LEAF LITTER OF CHINESE FIR IN MIXTURE WITH MAJOR ASSOCIATED BROAD LEAVED PLANTATION SPECIES

杉木 (Cunninghamia lanceolata)与主要阔叶造林树种叶凋落物混合分解实验是用网袋法进行的。目的是检验“杉木叶凋落物与阔叶树叶凋落物混合分解时 ,杉木叶凋落物的分解速率和养分释放都可得到加强”这样一个假设。结果发现 ,杉木与火力楠 (Michelia macclurei var. sublanea)、桤木 (Alnus cremastogyne)叶凋落物混合分解时分解速率有较强的促进作用 ,而与红栲 (Castanopsishystrix)、樟树 (Cinnamomum camphora)、刺楸 (K alopanax pictus)、木荷 (Schima superba)叶凋落物分解时不存在相互作用。至于养分的释放 ,除与木荷叶凋落物混合分解时没有发现相互作用外 ,而与其它阔叶树种叶凋落物混合分解时或强或弱表现出促进作用 ,而且促进作用的强弱与阔叶树叶凋落物初始 N含量有一定的正相关关系。如果仅从阔叶树叶凋落物与杉木叶凋落物混合分解的作用形式和强弱来考虑选择杉木的伴生树种时 ,首选树种是桤木 ,其次是刺楸 ,再其次是火力楠、红栲 ,最后才是樟树和木荷。当然只依据此单一条件来选择混交树种还不科学。

Decomposition of Chinese fir leaf litter when co occurring with broad leaved species Michelia macclurei var. sublanea, Alnus cremastogyne, Schima superba, Kalopanax pictus, Castanopsis hystrix and Cinnamomum camphora was examined using litter bag method to test the hypothesis that decomposition of Chinese fir leaf litter could be accelerated by the presence of broad leaved litter. Weight loss rate of Chinese fir was increased significantly by M. macclurei var. sublanea, A. cremastogyne, but not by S. superba, K. pictus, Castanopsis hytrix or Cinnamomum camphora. The nutrient release was enhanced to different degrees by litter of all broad leaved leaf species with the exception of S. superba which had no effect. With increasing initial nitrogen concentration of broad leaved leaf litter, the larger the enhancement. A. cremastogyne was the first choice as the companion species in the mixed plantations of Chinese fir, secondly K. pictus, thirdly M. macclurei and Castanopsis hystrix ,and lastly Cinnamomum camphora and Schima superba.