Abstract: The located observation on the soil moisture dynamics under broad-leaved Korean pine forest in Changbai Mountains in 1990～1992 and 2003 showed that the seasonal variation of soil moisture content could be divided into five periods,i.e.,gathering water stage in spring,consuming water stage in arid season,holding water stage in rainy season,losing water stage in autumn,and relatively stable stage of soil moisture in winter-spring.By using standard deviation and variation coefficient,the vertical layers of soil moisture were divided into rapid change layer,active layer,and subactive layer.Correlation analysis was applied to analyze the relationships of moisture content among different soil layers and the correlation between soil moisture and precipitation in the same period.

Key words: Suckling pigs, Iron, Growth rate, Metabolism, Environment