2011 Volume 15 Issue 4 Pages 147-154
The growth conditions of Hibiscus syriacus and Benthamidia florida planted on the east and west side of the street in front of Tottori Station were investigated. The soundness, flower setting and tree size were confirmed to be different between east and west in both species. The growth conditions of westward trees were worse than that of eastward trees. The survival rate of westward Hibiscus syriacus was 20% while that of eastward was 100%. It was estimated by the tree-ring analysis that the westward Hibiscus syriacus died in the same year they were planted. The insolation period was significantly shorter in the westward than eastward. The investigated trees were planted under the roofed sidewalk, which is common in snowy countries. This resulted in poor branching under the shade of the sidewalk roof. Especially, most branches of the Benthamidia florida under the sidewalk roof were dried and lost. The difference in the survival and growth of the two species is thought to be caused by the difference in shade tolerance.