择伐抚育对不同类型马尾松人工林林下生物多样性的影响

Effects of Selective Cutting on the Biodiversity of Different Pinus massoniana Plantations Types

以湖北丹江口库区不同类型马尾松人工林为研究对象,利用生物多样性指数进行择伐抚育前后林下植物多样性测度分析。结果表明,择伐抚育后,灌木层主要的优势物种变化不大,而草本优势物种则变化较剧烈。不同类型马尾松林灌木层Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数表现为松柏混交林>中密度马尾松林>低密度马尾松林>高密度马尾松林>针阔混交林,Margalef丰富度指数表现为中密度马尾松林>低密度马尾松林>高密度马尾松林>松柏混交林>针阔混交林。择伐抚育致使针阔混交林和高密度马尾松林的灌木层多样性降低,松柏混交林、中密度马尾松林、低密度马尾松林则呈现升高趋势。针阔混交林和低密度马尾松林草本层各指数均整体降低,高密度马尾松林、中密度马尾松林、松柏混交林则呈现升高趋势,可见择伐抚育导致草本层生物多样性波动较大。同时,松柏混交林的生物多样性灌木层>草本层,而高密度马尾松林、中密度马尾松林、低密度马尾松林和针阔混交林的生物多样性则是草本层>灌木层。

Based on Pinus massoniana plantation at Danjiangkou reservoir area in Hubei Province, plant diversitybefore and after cutting were analyzed by using biodiversity indices. The results showed that the dominate speciesin the shrub layer changed little while dramatic change in the herbaceous layer after selective cutting. In shrub lay-er,the Shannon-Wiener index, Simpson index and Pielou index showed the order of pine and cypress mixed forest〉medium density P. m a s soni a aa 〉low density P. m as soni a an 〉 high density P. ma s sonia an 〉coniferous and broadleaf forest. The order of Margalef richness innex was medium density P. massoniana 〉low density P. massoniana〉high density P. massoniaaa〉mixed forest of pine and cypress〉coniferous and broadleaf forest. After selective cutting, the biodiversity declined in shrub layers of conifer-broadleaf forest and high density P. massoniana, while the biodi-versity tended to increase in the forest of pine-cypress mixed forest, mediumdensity P. maaoniaa and low densityP. mas soniana. All the innices in the herb layers of conifer-broadleaf forest and low density P. massoniana de-creased ,while the indices in the herb layers of high density P. massoniiaa, medium density P. massoniana andthe pine-cypress mixed forest increased. The biodiversity of shrub layer was higher that of herbaceous layer in pine- cypress mixed forest while the biodiversity of herbaceous layer was higher than that of shrub layer for high densityP. massoniana, medium density P. massoniana, low density P. massoniana, and conifer-broadleaf mixed forest.