Abstract
The plate type greening devices originally developed by Okayama Prefecture Forest Experiment Station were applied in Feburary and April 1997 on a road side slope. Two different devices (A and B) which contained different combinations of acorns of oaks with the grass seeds. In the device A vermiculite was used as a material for a germination bed while in the device B a mixture of vermiculite,mountain soils and humous were used. Results were as follows. (1) Germination rates of Quercus variabilis, Quercus serrata, Qurcus glauca, Castanopsis cuspidata were more than 50% except Quercus phylliraeoides on the device B. (2) Mortalities of these oak species on two devices, which included the grass seeds were less than 25% after two growing periods. (3) Height growth of Quercus variabilis on the device B was larger than on the device A. (4) Cover ratio by the device A from April 1997 to December 1998 was more than 80%. These results suggested that even on the slope having more than slant of 45° and soil hardness of 18-25mm, application of these oak species on the device B was effective for an greening.
