【作者】 陈小鸟；

【导师】 由文辉； 易兰；

【作者基本信息】 华东师范大学 ， 生态学， 2009， 硕士

【摘要】 森林砍伐是林业生产和森林经营活动的重要组成部分,它对森林生态系统产生较大的扰动,是一种较为常见的干扰。就不同程度的森林砍伐对其中的土壤动物群落产生的影响进行长期跟踪调查研究具有重要的生态学意义。论文以浙江天童国家森林公园内2003年经不同砍伐程度处理的5个永久样地为研究对象,在前人调查研究工作的基础上,就砍伐干扰对常绿阔叶林中土壤动物群落的影响进行了继续的跟踪调查研究。5个样地分别为:样地Ⅰ——对高度大于8m,胸径大于5cm的乔木进行择伐,保留萌枝;样地Ⅱ——清除地面所有植物,仅保留枯枝落叶层;样地Ⅲ——清除地面所有植物、枯枝落叶层和0～10cm表层土;样地Ⅳ——仅保留大树,清除下木层和草本层;样地Ⅴ——对照样地。于2007年7月至2008年10月按四季对以上样地凋落物层和土层中大型土壤动物、中小型干生土壤动物和湿生土壤动物进行了详细调查。深入研究不同砍伐程度对土壤动物群落组成、数量、垂直分布、季节变化等产生的影响,同时分析不同程度砍伐后土壤温湿度和养分含量的变化及其对土壤动物群落的影响;并在此基础上,将五个样地中土壤动物群落的现状与前人的研究工作进行比较分析,即砍伐5年后土壤动物群落的状况与砍伐前及砍伐后1个月、1年的状况进行了对比分析,探讨了土壤动物群落对森林砍伐干扰的响应。主要结果如下:1、不同砍伐程度对土壤动物类群组成和密度的影响不同砍伐程度样地中土壤动物的类群组成不同,在五个样地中线虫纲均为优势类群,其他常见类群与稀有类群组成各异。Ⅲ号样地中土壤动物的类群数最少,Ⅴ号样次之,其它3个样地类群数较接近。5个样地中,Ⅰ号样地土壤动物密度最高,主要类群蜱螨目与弹尾目在Ⅰ号样地最多,Ⅲ号样地最少。2、不同砍伐程度对土壤动物群落垂直分布的影响不同砍伐处理下土壤动物的垂直分布具有明显的表聚性,随着土层的加深,土壤动物的密度依次递减,超过85%的土壤动物生活于0～10cm层。但是在类群数上表现出逆分布的现象。3、不同砍伐程度下土壤动物群落的季节变化不同季节土壤动物群落类群组成变化规律不明显,但密度却发生明显的变化,土壤动物密度的季节变化规律为秋季>冬季>春季>夏季。不同程度的砍伐处理下土壤动物季节变化主要表现为:凋落物层Ⅰ、Ⅱ、Ⅴ号样地在秋季最高,Ⅲ号样地在冬季达到最高,而Ⅳ号样地在夏季达到最高。土层中Ⅰ、Ⅳ、Ⅴ号样地在冬季达到最高,而Ⅱ、Ⅲ号样地在秋季达到最高。4、不同砍伐处理下土壤动物群落的多样性变化运用不同多样性指数对土壤动物多样性季节变化所得结果不同,密度-类群DG指数能够综合考虑多方面的因素,最终反映出土壤动物群落多样性的四季变化,其规律为秋季>夏季>冬季>春季。各样地的多样性指数用密度-类群DG指数表示,则是Ⅰ>Ⅳ>Ⅱ>Ⅴ>Ⅲ。5、环境因子对土壤动物群落的影响各样地凋落物层与土层中的温湿度均差异显著。各样地的凋落物层与土层在总氮、总磷间没有显著性差异,而有机质、pH值差异显著。凋落物层土壤动物的总密度与pH值、总氮呈显著正相关,而与有机质、总磷相关性不显著。土层中土壤动物总密度与pH值、有机质和总氮呈显著正相关,与总磷相关性不显著。总氮含量是影响土壤动物密度的重要因素。6、砍伐前后土壤动物群落的年际变化砍伐前后土壤动物的类群组成发生变化,有些类群在砍伐后消失,有些类群在砍伐几年之后重新恢复。砍伐一年后凋落物层土壤动物密度远低于砍伐前,砍伐五年后其密度相较于第一年有所增长,但仍远低于砍伐前的密度,Ⅲ号样地仅为砍伐前的1/10。土层中的土壤动物在砍伐后一个月及一年内,其密度均减少,但经过五年的恢复,其密度反而高于砍伐前的密度。更多还原

【Abstract】 Deforestation is a common phenomenon, which is an important part of forestry production and management. It can generate disturbance in forest ecosystem, and had greater effects in nearby, which can affected farther. It is significantly to study the influence of different slash in evergreen broad-leaved forest on soil animal community.In order to understand the soil animal community in evergreen broad-leaved forest, we chosen the five slashed plots that processed in 2003 in Tiantong national forest park in Zhejiang province. On the basis of the former research, we followed it to continue research on the influence of different slash in soil animal community. We used the five following treatments in five sites: (I) big trees with height>8 m and DBH>5 cm were removed but root collar sprouts were retained; (II) ground surface vegetation was removed but litter was retained; (III) all vegetation and 0-10 cm topsoil were removed; (IV) undergrowth was removed but big trees were retained; and (V) a control plot without any disturbance. An all-round four-season investigation was conducted into the soil animal communities, including macrofauna, mesofauna and the wet type of soil animal in the litter and soil in the above plots from the July of 2007 to October of 2008. Based on a comprehensive knowledge of the feature of soil animal community in the disturbanced, the paper probed into the influence of the different slash of communities on the structure of soil animal communities as well as the seasonal change. The influences on the environment by different slash are discussed and the correlations between the change of environment and soil animal communities are analyzed, and compared to the community which had not been slashed, slashed for a month and for a year. The research results are as follows:1、Influence on composition and density of soil animal in different slashed plotsThe group composition and density of soil animal were obviously different among the plots. Group number in site III was lest and the site V was more than III. The group number in the other three plots were close to each other. The number of soil animal was most in site I, mainly group Acarina and Collembola were also mostin site I ,and lest in site III.2、Vertical distribution of soil animal in different slashed plotsThe vertical distribution of soil animal with different treatment have obvious surface segregation. More than 85% soil animal lived in 0-10 cm layer, and the number of groups and density decrease with the depth of soil. However, the group number in the different layer showed an inverse distribution.3、Seasonal change of soil animal in different slashed plotsThe group composition of soil animal did not vary widely in four seasons, but the density had changed a lot. The seasonal fluctuations of soil animal community in different slashed plots can be represented as: In the litter layer, the density in site I、II、V were highest in autumn, and site III reached the maximum in winter and the site IV reached the maximum in summer. In the soil layer, the site I, IV、V reached the highest in winter and the site II、III were in autumn reached their maximum.4、The diversity change of soil animal in different slashed plotsVarious of diversity indices were used to analyze the soil animal community structure, and displayed different results. The density-group index can comprehensive express the factor, and the sequence of the density-group index to soil animal community were atutmn> summer> winter> spring. density-group index in different slashed plots showed I >IV> II > V>III.5、The impact on soil animal by environmentThe temperature and humidity among the five plots had obviously different not only in litter but also in soil layer. Total nitrogen and total phosphorus have no obvious different among these plots both in litter and soil layer. In the litter layer, the density of soil animal have positive correlation with pH value and total nitrogen, but have no correlation with the organic matter and total phosphorus. In soil layer, the density of soil animal have positive correction with pH value, organic matter and total nitrogen, and have no correlation with total phosphorus. 6、The soil animal response to different disturbanceThe soil animal composition had changed a lot between before and after slash. Some group disappeared while other recurred after several years recover. A year after slash ,the density of soil animal in litter layer was far lower than that unslash. After five years recover, the density of soil animal was also lower than before. The density of soil animal in soil layer decreased in a month and a year after slash, but after five years recover, the density of soil animal exceed before slashed.更多还原