巨桉人工林土壤化感物质的空间分布特征的研究

通过GC/MS分离鉴定四川洪雅县巨桉人工林不同层次的土壤和当地乡土植物群落-青冈次生林的土壤的化感物质,结果表明巨桉人工林土壤中存在化感物质,其化感物质占分离出的总物质的比例和种类都随土层深度的增加而递减;巨桉上层土壤的化感物质受地上部分输入、细根分布较密和活跃的土壤动物和微生物的活动等多因素的影响。巨桉人工林化感物质种类远远多于青冈林,两者化感物质的组成的类别差异较大,但两者化感物质占总物质的比例差异不大,及对降低巨桉人工林化感的不利影响等多方面进行了论述。

The Study on Spatial Distribution of Allelochemicals in the Soil of Eucalyptus grandis Plantation

In this paper allelochemicals were extracted by anhydrous ethanol from different soil layer of Eucalyptus plantation and native oak(Qucrcus acutissima) secondary forest in Hongya county,Sichuan.The extractions were identified by means of GC/MS(Agilent GC6890/MS5973).The conclusion shows that allelochemicals exist in Eucalyptus plantation positively,and the proportions of allelochemicals to the all extracted substances and compositions decrease with the increasing depth of soil.Allelochemicals from the layer of 0～5cm are affected by many factors such as the inputs of aboveground,the distribution of fine roots,the activities of soil animals and microbes.There are far more allelochemicals in the Eucalyptus plantation than that of in the oak(Qucrcus acutissima) secondary forest and big differences between them with respect of compositions.However the proportions of allelochemicals to the all extracted substances of two kinds of forest are similar.The problem about impairing the disadvantages of Eucalyptus plantation management was discussed too.