松嫩草原黄墩蚁〔Lasisus flavus (Fabricius)〕对土壤理化性质的影响

黄墩蚁是松嫩草原土壤动物优势类群中唯一的大型土壤动物,是研究羊草草原分解者亚系统中大型土壤动物功能及作用机理的理想对象.本文研究了黄墩蚁筑巢活动对土壤物理和化学性质的影响,结果表明,黄墩蚁的筑巢活动改变了土壤颗粒的粒径分布,土壤的孔隙度增加,也明显阻止了盐分的上泛,同时增加了土壤中有机质、速效氮和速效磷的含量.受土壤理化性质改变的影响,蚁丘周围的植被组成、密度、生物量等群落特征指标也发生了较大变化.研究表明,由黄墩蚁活动引起的草原微生境的改变有利于羊草的生长和繁殖,黄墩蚁加速了羊草 虎尾草群落向羊草群落的演替,因此可以断定黄墩蚁是松嫩草原生态系统中的一个重要的干扰因子,可以利用它们这种生态作用加速退化草原的修复和重建.同时,黄墩蚁主要分布于羊草较多的生境中,对周围环境差异反应敏感,也可以作为羊草草原退化的指示物种之一.图3表2参15

Effect of Lasisus flavus (Fabricius) on Soil Physicochemical Properties of the Songnen Grassland

Lasisus flavus (Fabricius) is the only large soil animal of the dominant soil animal colony of the Songnen Grassland and is also ideal for studying the function and mechanism of the large soil animals in sub-system of decomposers. The effect of nest building activities physicochemical properties was studied. The result showed that nest building activities changed soil particle diameter, increased soil porosity, obviously prevented salinity increasing, and enhanced contents of organic matters, available N and available P in soil. The study indicated that the environment change caused by nest building activities was advantageous for A. chinense and the nest building activities accelerated the succession from A. chinense Chioris virgata community to A. chinense community, so L. flavus was considered as a major biotic disturbance factor for a grassland ecosystem. This ecological function could be used to accelerate the repair and reconstruction of the degraded grassland. L. flavus is sensitive to the changing surroundings, so it can be used to indicate degration degree of the A. chinense grassland. Fig 3, Tab 2, Ref 15