Abstract: In this paper, the physical and chemical properties of 0-30 soil layer under Leymus chinensis, Puccinellia tenuiflora, Chloris virgata, Suaeda corniculata, and alkali patch in the sodasaline soil regions of Songnen Plain were measured, with the interrelationships between these properties and grassland plant community distribution analyzed. The results showed that the soil physical and chemical properties were deteriorating in the order of L. chinensis, P. tenuiflora, C. virgata; S. corniculata, and alkali patch. The electrical conductivity of saturated paste (EC_e), exchangeable sodium percentage (ESP), pH, and bulk density of 0-10 cm soil layer were the decisive factors affecting the grassland plant community distribution, while the distribution of the grassland plant community could qualitatively reflect the degree of soil salinity and soil physical properties. The plant growth affected the soil chemical and physical properties. Plant growth altered the distribution patterns of soil EC_e and ESP. In the soils with vegetations, EC_e and ESP increased with soil depth; in the soils with alkali patch, both EC_e and ESP decreased with soil depth. Plant growth could improve the soil structural stability and saturated hydraulic conductivity to some extent.

Key words: time series trajectory, spatial and temporal dynamics., grassland open-cast coal mine, NDVI