云勇杉木林采伐迹地阔叶树改造后的植物多样性

2002年来广东省佛山市云勇林场陆续对杉木人工林采伐迹地进行了阔叶树混交造林改造。选取3个林龄为10 a的杉木人工林采伐迹地作为样地，包括1个未改造的对照林分和2个已改造的林分，比较其植物多样性差异。无论是物种丰富度、Shannon-Wiener、Simpson物种多样性和均匀性指数，还是秩多度曲线都表明，已改造林分植物多样性远高于未改造林分；人工引入的本地树种藜蒴、阴香能自我更新。采用乡土阔叶树种及其合理混交模式，对针叶人工纯林进行改造，有利于形成稳定的近自然林。

Plant Species Diversity of Cunninghamia lanceolata Forest Cutover Lands \=after Improvement by Planting Broadleaved Trees at Yunyong of Foshan, South China

Yunyong Forest Farm of Foshan （Presently Maintenance Center for Yunyong ecological forest of Foshan）,South China,has made stand improvement on Cunninghamia lanceolata forest cutover land since 2002. The study selected 3 C.lanceolata forest cutover lands of 10 years old as sampling plots,one not-improved and two improved,and compared their plant species diversities.The species richness,indexes of Shannon-Wiener,Simp-son diversity and evenness,and rank abundance curve all indicated that （1 ）the plant species diversity of each of the two improved stands was larger than that of the not-improved stand;and （2）the planted native trees,Castan-opsis fissa and Cinnamomum burmannii,could regenerate by themselves.The stand improvement on C.lanceolata forest cutover lands by introducing and mixing native broadleaved trees was helpful to nurture stable close-to-nature forests.