Root Distribution Characters of Ostryopsis davidiana on Different Sites in the Loess Plateau of Western Shanxi

By means of dig methods from up to down,the root distribution characters of Ostryopsis davidiana were studied in the loess plateau of western Shanxi.The results indicated that there were significant differences in the root distribution characters on different sites.The depth of the vertical distribution of both leading roots and absorbing roots on half shady slope was larger than on half sunny slope.The root biomass on half sunny slope was obviously smaller than that of half shady slope.The distribution of soil moisture content was the same with the root distribution.This result approves that the growth of plants show diversity in different soil moisture contents on different sites.However,this diversity is benefit to roots absorption of soil moisture.Root distribution in different profiles on different slopes showed the same with the distribution of root biomass and root length.As the increase of distance to soil surface,the root quantity decreased.The vertical distribution of root in the upgrade of stake was deeper than that in the downgrade.Distribution in every layer was more even and root quantity was more in the upgrade of stake.These distributions demonstrate that most roots grow to the upgrade of stake in the form of lateral roots and diagonal roots.These characters show that root ecological plasticity in special site.