昆明西山半湿润常绿阔叶林及其〖HJ*3〗〖HJ*2〗次生演替群落的更新特征

对昆明西山国家森林公园处于不同演替阶段的云南油杉林、云南油杉-滇青冈混交林和滇青冈林内木本植物幼苗的种类组成、数量及更新方式等进行了调查分析。结果表明:在所调查的共144个25m2的样方中,共记录到木本植物幼苗32科45属共49种。随着演替的进行,幼苗总密度表现出先增加后降低的趋势,处于演替中期的云南油杉-滇青冈混交林内幼苗最丰富,平均密度达80株.25m-2。在不同演替阶段各植被类型中,实生和萌生两种更新方式同时存在,单一的更新方式可能使群落的更新面临较大的风险。幼苗发生了顶死或梢枯后,从其根颈处生出多个萌枝形成多干基株的更新方式结合了实生和萌生更新各自的优点,是幼苗在与环境长期作用过程中进化出的一种有效对策。

Seedling regeneration of the primary semi-humid evergreen broadleaved forest and its secondary succession communities in Xishan, Kunming

Woody plant seedlings in Keteleeria evelyniana community,Keteleeria evelyniana-Cyclobalanopsis glaucoides community,and C.glaucoides community in Xishan National Forest Park,Kunming,were surveyed and analyzed to determine their regeneration characteristics including species composition,density,regeneration mode,and etc.In all the 144 plots(5 m×5 m each),49 woody plants seedling belonging to 45 genera,32 families are recorded.The total density of seedling showed a unimodal change in response to the forest succession progress,with the highest density in the K.evelyniana-C.glaucoides community(80 stems·25 m-2).Seedling regeneration and sprouting regeneration coexisted in communities at different succession stages;single regeneration mode may increase the risk of unsuccessful regeneration of communities.However,seedling re-sprouting regeneration,which had been formed during the long-term interaction between seedlings and their environment,seems to be an effective strategy as it combined the advantages of both modes.