关键词: 大型土壤动物, 功能类群, 分类, 草甸草原, 大庆市

Abstract: The study of soil fauna functional groups is important to the research of soil animal ecology.Many species have similar feeding habits and functions in a wide range of soil fauna,as well as in ecosystems.Species composition of soil fauna varies in different regions,however,there is a certain rule for them to respond to the environmental change.So soil fauna is regarded as a stable indicator to reflect changes in the environment.Researching functional groups of macrofauna is meaningful to reduce the complexity of soil fauna biodiversity,and increase the reliability of system analysis.However,very little work has been done with respect to functional categories of soil fauna in Chinese grassland ecosystems. In this paper,dynamic investigation of soil fauna was systematically done in six sites in Daqing meadow zone,which revealed compositions,characteristics and distribution law of macrofauna,response to environmental change and role of functional group. In this paper,based on the study of three function groups of soil animals in China, systematic investigation was done on soil fauna.Omnivore was divided into the original three groups,and the classification was supplemented and perfected.Thus,relatively complete function groups were formed,and soil fauna could be divided into saprophyte,herbivore, omnivore and predatory animals.The classification system of four functional groups was more scientific,accurate and operational than three previous functional group systems.In this survey,a total of 1432 soil animals were collected,which belonged to 39 categories,4 classes and 3 phyla.There was a large number and low biomass in herbivore,which indicated that the size of this group was small.The horizontal distribution of soil fauna showed that saprophyte,herbivore and predatory animals were the dominant groups in stable environment, such as in the forest and in the slightly degraded pasture.The omnivore was the dominant groups in unstable environment,which adapted to this situation.Furthermore,the regularity of vertical distribution shows that the number of individuals of all groups gradually decreased from top to bottom except the second layer with the largest number of omnivore.The regularity of temporal evolution indicated the variations of all functional groups were different in May,July and September,and there was no certain regulation.By comparing functional groups of soil fauna in Daqing meadow ecosystem with that in typical forest ecosystem,it was found that the biomass of saprophyte,herbivore,predatory and omnivore in forest ecosystem was 3.8,14,6.5 and 0.9 times of that in meadow ecosystem,respectively.

Key words: macro-soil animals, functional groups, classification, Daqing, meadow