Abstract:

It is of great significance to study the relationship between soil meso- and micro-fauna and soil texture in oasis farmland to protect the diversity of farmland ecosystem. Taking the oasis farmland in the arid region of Ningxia as the study plot， the community composition， diversity and functional groups structure of soil fauna in silty loam and sandy loam were investigated， and the response laws of soil fauna to soil texture were clarified. The results showed that： （1） The soil texture changed the composition of soil meso- and micro-fauna community. The number of individuals and taxa of the dominant groups and the common groups of soil meso- and micro-fauna in silty loam were significantly higher than those in sandy loam （P0.05）， while there was no significant difference of the number of individuals and taxa in rare groups between the two soils （P0.05）. （2） There was no significant difference in the number of individuals and taxa of soil meso- and micro-fauna community between the two soils （P0.05）. The Shannon-Wiener diversity index of soil meso- and micro-fauna in silty loam was significantly higher than that in sandy loam （P0.05）， while the Simpson dominance index in silty loam was significantly lower than that in sandy loam （P0.05）. （3） The main trophic groups of soil meso- and micro-fauna in silty loam was omnivore， while those in sandy loam was herbivore. The number of individuals and taxa of omnivore in silty loam were significantly higher than those in sandy loam （P0.05）. The number of individuals of herbivore in silty loam was significantly lower than that in sandy loam （P0.05）， and there was no significant difference of the number of taxa between the two soils （P0.05）. The number of individuals and taxa of predator and saprophage in silty loam were significantly lower than those in sandy loam （P0.05）. （4） The soil silt and water content were the main environmental factors affecting the community composition， diversity and functional groups of soil meso- and micro-fauna. In conclusion， the community structure and functional groups structure of soil meso- and micro-fauna were profoundly affected by soil texture， and silty loam maintained a high diversity of soil meso- and micro-fauna community and had a relatively rich distribution of omnivorous groups due to its high silt content and water content. The sandy loam showed the distribution characteristics of a single dominant taxa， and the herbivorous taxa were the main ones.

Key words: oasis in arid region, soil texture, soil meso- and micro-fauna, diversity, functional groups