Influences of Litter on Soil Organisms in Northeastern Leymus chinensis Grassland of China

Influences of different levels of litter on quantities,species and biomass of soil organisms in northeastern Leymus chinensis grassland of China were studied.The results showed that quantities,species types and biomass of soil animals increased with the increasing of litter layer at lower levels,while decreased at higher levels.The highest values of quantities,species types and biomass of soil animals presented at 500g·m-2,700g·m-2 and 600g·m-2,respectively.Quantities and biomass of microorganisms in soil had the similar trends with those of soil animals.The quantities of bacteria,actinomycete and fungi presented at 700 g·m-2 and 600 g·m-2,respectively.The highest biomass value of microorganisms presented at 600 g·m-2.Litter had positive-negative effects on soil organisms,it can improve their growth at the optimal levels of litter;but when litter levels were more than 700g·m-2,it had inhibitory effects.The optimal levels of litter was at the scope between 600 to 700g·m-2,in which the soil organisms developed well.