【作者】 梁丽壮；

【导师】 牛树奎；

【作者基本信息】 北京林业大学 ， 生态学， 2006， 硕士

【摘要】 松材线虫(Bursaphelenchus xylophilus)是我国毁灭性的林业外来入侵生物之一。本文以浙江省嘉兴地区平湖市17块不同林型不同受害程度的黑松林为研究对象,分析了松材线虫入侵对植物群落多样性的影响;以及不同受害程度的黑松林对松材线虫入侵的影响,并从山地森林小环境入手,分析了不同环境条件下的黑松林群落抵御能力。通过研究,主要取得以下几个结果:1.从植物多样性角度来看,不同林型、不同受害程度的黑松林内的植物多样性差异显著,针阔混交林比黑松纯林多样性指数高;黑松林群落在受到松材线虫的入侵后,由于危害程度的不同,其植物多样性指数的变化也不同。群落中乔、灌、草三层的物种多样性指数的变化,是由松材线虫危害到乔木层的黑松,进而影响到乔木层的多样性指数。而灌木层、草本层的多样性指数的变化,是受到乔木层的变化,影响到灌木层和草本层的多样性指数变化。乔木层的多样性指数,随着危害程度的增加而增加;灌木层的多样性指数随着危害程度的增加而减小;草本层的多样性指数随危害程度的增加而增加。2.群落格局角度,对不同标准地种群空间分布格局进行小尺度(5m×5m)上的理论拟和和格局强度判定,聚集强度采用扩散系数、负二项指数、Cassie指标、丛生指标以及聚块性指标。结果表明:在5m×5m取样尺度上,基本上表现出随机分布。经过统计分析,聚集程度与危害程度之间没有明显的线性关系。3.从不同的黑松林型入手,研究了不同的黑松比例与危害程度之间的关系。松树和阔叶树混交方式不同,黑松林系统抵御能力不同。总体而言,松树比例越高,黑松林系统受害越低。相反,松树比例越小,黑松林系统抵御能力越低。4.环境因子主要通过影响温度,水分对松材线虫病的危害程度产生影响。温度,水分又影响到入侵种松材线虫及其传播媒介松墨天牛及松树,对其直接或间接的产生作用。在松材线虫危害的浙江设置临时标准地,采用统计学方法研究松材线虫的危害程度与海拔、坡向、坡度、风向坡等地形因素的关系。结果表明,在松材线虫发生的小区域内,松材线虫的危害程度随着海拔的升高而降低;坡向对松材线虫危害程度有显著影响(p<0.05),南坡与其它坡向具有显著性差异;随着坡度的升高危害程度升高;风向坡对松材线虫危害程度有显著影响(p<0.05),背风坡与其他坡有明显差异。更多还原

【Abstract】 Bursaphelenchus xylophilus as one kind of invasive species is destructive to forestry in China. This thesis analyzes the the invasion of Bursaphelenchus xylophilus having effects on the diversity of flora and the P.thunbergii with various degrees of destruction having effects on the Bursaphelenchus xylophilus invasion based on the 17 blocks of heisonglin with different type and grades of destruction in Pinghu, region Jiaxing Zhejiang province. And the paper analyzes the resistance of the P.thunbergii under different circumstance. Through research, the main results are:1. In the aspect of diversity of foliage, different types of P.thunbergii with different destructive degree have a remarkable difference. The diversity of mixed P.thunbergii and broad-leaf forest is higher than pure pine forest. The index of plant diversity has a different change because of the various degree of damage as the P.thunbergii is invaded by Bursaphelenchus xylophilus. The change of the three-layer species diversity index, as the fact is that Bursaphelenchus xylophilus directly influences the P.thunbergii on arbor, further influences the diversity index of arbor. While the change of the shrub’s and the herbage’s diversity index is after the change of arbor’s, that is, the destructive degree indirectly effects the shrub’s and the herbage’s diversity index. The diversity index of arbor increases with the destructive degree, while the shrub’s diversity index is on the contrary and the herbage’is following the degree.2. From the view of community structure, put a small plot (5m×5m) test on the different standard plant space distribution, using theory and structure density determinant. The congregated intensity adopts the diffusion coefficient, negative更多还原