Distribution of the fine roots of different aged apple trees in Weibei rainfed tableland of the Loess Plateau Fine Root Biomass Vertical Distribution Character of Main Afforestation Tree Species in Horqin Sandy Land Vertical Distribution of Representative Plantation‘‘‘‘s Fine Root in Wind-water Erosion Crisscross Region,Shenmu Fine root distribution characteristics of sabina vulgaris and Artemisia ordosica communities in the Mu Us Sandland of Inner Mongolia, China