Abstract:

In this study influence of woodland soil density on growth and distribution of fine root system of main planting tree species in the Weibei Loess Plateau was conducted by means of pot culture and field survey. Results indicated that in the woodland of Pinus tabulaeformis, soil bulk density increased with the depth on different sites; while in the woodland of Robinia pseudoacacia, soil bulk density was bigger than that in P. tabulaeformis, and there was no clear difference across the profile. Further analysis implied that there existed negative correlations between soil density and the length root of system with different diameter class in the woodland of P.tabulaeformis. Results from pot culture indicated that although effects of medium density of pot culture on fine roots growth and development of seedlings were different for different tree species, all the seedlings could grow better under the conditions of medium with mid-level density and porosity, and had the maximum biomass. Medium density of pot culture had significant effects on the growth and development of P.tabulaeformis and R. pseudoacacia seedlings' roots, especially on that of P.tabulaeformis. But it had less effect on that of Platycladus orientalis and Prunus armeniaca var. ansu, whose fine root biomass changed little in different densities of medium.

Key words: Fine root, Soil bulk density, Main planting tree species, Weibei Loess Plateau