松材线虫入侵对浙江平湖地区松林植物群落功能的影响

Influence of pine wood nematode invasion on pine community function in Pinghu region of Zhejiang Province,eastern China

使用样方法和每木调查法,对松材线虫入侵后不同比例的马尾松混交林与黑松混交林的胸径和材积生长量(变化率)、生物量等群落功能指标进行了调查分析。结果表明:就林分胸径和材积生长量而言,随着混交比例(感病树种株数占林分总株数)的减小,各功能指标受害后变化幅度就越小,表现出整个林分对松材线虫的抵抗能力就越强,在该研究中,5针5阔表现出最强抵抗力;此外,松材线虫的侵入改变了未受害时不同混交比例黑松林的胸径生长量、材积生长量的数量对应关系(纯林>7针3阔>6针4阔>5针5阔),马尾松林则无此现象;就胸径与材积生长变化率而言,松材线虫入侵后,黑松林的变化较马尾松林更明显,这说明黑松纯林抵抗松材线虫的能力比马尾松纯林弱;松材线虫的侵入加速了松林从纯林向针阔混交林,进而向顶级群落常绿阔叶林方向演替的步伐。

Based on setting plots and measuring each tree method,several functional indices,including the increment（rate） in DBH and stand volume,biomass,etc.,were investigated in the damaged stands with various proportions of Pinus massoniana and P.thunbergii and with different damage degrees.The results indicated that the forest ecosystem resistance against pine wood nematode（PWN） increased with the decrease of pines＇ proportion based on the results of increment（rate） in DBH and stand volume.In this research,the resistance kept highest when a mixture proportion of 50% appeared.Besides,PWN changed the corresponding relation（pure stands7 conifer 3 broadleaf6 conifer 4 broadleaf5 conifer 5 broadleaf） of increment in DBH and stand volume among the P.thunbergii mixed stands when without PWN in,but the P.massoniana stands had no this phenomenon.For the increment rate of DBH and stand volume,significant changes were found in P.thunbergii forest after the invasion of PWN,indicating that the resistance of pure P.thunbergii forest was higher than that of P.massoniana.The invasion of PWN accelerates the succession advancement from pure stands to mixed stands,and then to the broadleaved evergreen forests.