Abstract
The stick type greening devices originally developed by Okayama Prefecture Forest Experiment Station were applied on a road side slope from February to June 1997. Six devices (A, B, C, D, E and F) contained different combinations of acorns of oaks that were Quercus variabilis, Quercus serrata, Quercus glauca, Quercus mysinaefolia, Quercus phylliraeoides and Castanopsis cuspidata. The culture medium of A, B and F devices was vermiculite only and that of the C, D and E devices was a mixture of vermiculite, granite soil and bark composit. Results were as follows. (1) The germination rates of Quercus variabilis until the middle of April, Quercus glauca until the middle of June, were more than 60% when preserving seeds at below 5℃. (2) The height growth of these oaks was worse than soil improve trees such as Myrica rubra and Alunus sieboldina in all devices. (3) Mortalities of all oakswere less than 20% after three growing periods. (4) The vegetation cover ratio was more than 60% in June 1998 when the range of device interval was 30-40cm. It is suggested that though the height growth of oakswas bad, the stick type greening device waseffective for an initial greening if soilimproving trees were mixtured in the device even on the slope which slant was 40-48° and the soil hardness by yamanaka mesuring instrument was 16-20mm.
