Influence of Litter Layer on Microenvironment in Northeast Leymus chinensis Grassland

In this paper,the simulation method was adopt to establish different deal of the litter layer (the litter quantity scope is 0 to 1000 g·m^-2,the gradient is 100 g·m^-2) and to discuss the influence of litter layer on the grassland microenvironment.The result indicated that the change trend of soil moisture gradually increased along with litter quantity and when litter quantity reached certain quantity,soil moisture went to steady;the change trends of the surface and underground (5 cm) temperatures were basic consistent in each month,gradually decreased along with litter quantity and went to steady when reaching certain quantity of litter quantity;there were remarkable negative correlations between the soil pH and electric conductance(EC) and the litter quantity.The content of organic material,N,P,K in the soil that contains litter layers is higher than that contains no litter layer.As the litter quantity increases,the contents also went up,when the litter increases 100 g·m^-2 averagely,organic material,the N,the P and the K increased 17.9%,7.6%,26.4% and 3.8% respectively.Also when litter amounts to 600 g·m^-2,the content of the organic material,the N,the P and the K improved 1.8 times,81.5%,1.8 times and 26.4% respectively.