ROOT DYNAMICS OF THREE GRASSES IN HORQIN SANDY LAND OF CHINA THE ROOT LONGEVITY OF ARTEMISIA HALODENDRON INHABITING TWO SANDY LAND HABITATS ROOT GROWTH DYNAMICS OF CARAGANA KORSHINSKII USING MINIRHIZOTRONS Fine root longevity and controlling factors in a Phoebe Bournei plantation Root morphology characteristics under alternate furrow irrigation