Abstract: In this paper,we use sand pots to study manchurican ash seedling root growth,root mass distribution,root/shoot mass ratio and fine root diameters in greenhouse under rich or poor nutrients and water patches. The results show that the root growth and distribution were greatly influenced by spatial heterogenous nutrients and water. There were higher root growth, root density and root mass in nutrient-rich and water-rich patches than in poor. Under poor patches, root growth, especially fine root growth was limited due to not enough nutrients and water for root foraging. Comparing both rich and poor patches in this experiment, fine root diameters was thinner and specific fine root length was higher in nutrient-rich patches. This responses is advantageous to plants growth in soil with high spatial heterogeneity in nutrient distribution. In water-poor patches, fine root growth was decrease and diameter was thinner, which was disadvantageous to plant growth.

Key words: Spatial heterogeneity, Nutrient, Water, Manchurican ash, Roots