松嫩平原两种覆被盐渍化特征的时空变化研究

Study on Spatial and Temporal Changes of Saline Characters of Two Vegetation Covers in Songnen Plain

对2003年6～10月羊草草地和大豆地的盐渍化特征(含水量、pH值和含盐量)的动态变化进行分析,并对比2种土地覆被类型之间的变化差异,结果发现:羊草草地和大豆地含水量变化与采样区降雨量的变化有相同趋势,但在采样初期和末期,大豆地含水量要大于羊草草地;对于pH值和含盐量,在土壤剖面0～60 cm,两种覆被类型不同层次动态变化一致,大豆地变化的一致性可达到更深层次,但是其峰值要比羊草草地滞后20天左右出现,同时2种土地覆被类型pH值和含盐量的峰值均滞后于含水量的峰值。单因素方差分析表明采样期内2种土地覆被含水量在剖面40～80 cm差异显著,而pH值则是在整个剖面都有显著差异,含盐量在20～60 cm剖面深度差异显著。2种覆被类型各个剖面深度10月17日的pH值、含水量比6月7日有所上升,含盐量则刚好相反。

Through analyzing the dynamic changes of saline characters in Aneurolepidium chinense field and soy- bean field from June to October in 2003, comparing their differences in water content, pH and salt content , and results are as followings: (1 ) water contents in aneurolepidium chinense field and soybean field have the same ten- dency with the rainfall in these fields, however, at the beginning and the end of the sampling, the water content in the soybean field is more than that in the aneurolepidium chinense field, (2) the pH and salt content have the same dynamic change at 0～60 cm soil depth in the two vegetation covers, and in the soybean field, this consis- tency reachs to deeper level. But their peak values in the soybean field are 20 days behind that in the aneurolepidi- um chinense field. At the same time, the peak values of pH and salt content in the two vegetation covers all lag rainfall's, (3) analysis of variance (ANOVA) indicates that water content, pH value and salt content significantly change respectively at 40～80 cm, the whole depth and 20～60 cm. The pH value and water content at the end of sampling(17, Oct. ) are higher than that at the begin (7, Jun. ), however, salt content reversely changes.