三种干扰方式对西双版纳热带森林群落植物多样性的影响

研究了西双版纳热带森林的 3种人为干扰破坏 (择伐、皆伐和轮歇 )后形成的次生群落在物种和群落水平上植物多样性各个方面的变化规律 ,研究结果表明 :( 1 )择伐群落和皆伐群落乔木层物种数、Simpson指数、Shannon-Wiener指数在科、属、种 3个水平上无显著差异 ,但较轮歇群落物种更为丰富 ,多样指数更高。( 2 )轮歇群落林下灌草层的物种数在科、属、种 3个水平上高于择伐群落和皆伐群落 ,但 Simpson指数和Shannon-Wiener指数则分别在各个水平上低于择伐群落和皆伐群落。 ( 3)轮歇群落先锋种类占较大比重 ,达76 % ,其它二类群落比例约为 5 0 %。( 4 )择伐和皆伐群落乔木层都由几种植物形成共同优势 ,轮歇群落则形成单优群落。 ( 5 )在生活型构成上 ,皆伐群落乔木树种种类相对较多 ,轮歇群落藤本植物较多 ,草本植物种类较为丰富 ,尤其一年生草本植物种类远多于其它群落类型

Effects of three main disturbances manners on the plant diversity of the tropical forest in Xishuangbanna

Plant diversity of three main tropical secondary forest types which suffered different disturbances manners in Xishuangbanna was studied based on the 15 plot data. The results are as follows: (1)The secondary forest from shifting terra has relatively more shrub and herbaceous plant species and lower indexes of Simpson and Shannon-Wierner when comparing to the secondary forest from the repeatedly selected logging forest and the cleared logging terra. (2)The indexes of Simpson and Shannon-Wierner in plant family, generic and specific levels from the shifting terra is higher than the secondary forest from the selected logging and the one from the cleared logging. (3)The secondary forest from the shifting terra has more pioneer species (making up to 76% of its total species) than the other two forests. (4)The forests from the selected and the cleared logging usually develop into an association with several dominant species, while the secondary forest from shifting terra usually develops into a consociation with a single dominant species, for example Macaranga denticulata forest. (5)In life form groups, the secondary forest from the shifting terra shares more herbaceous plants and lianas but less trees.