Relationships between vitality of Prunus yedoensis Matsum. and soil hardness in block parks

Abstract

Planting bed soils in block parks are often compacted by machine earthwork or human tread etc. Generally, soil that is too hard slows the growth of root system and is harmful to tree health. In order to specify which soil layer affects the vitality of Prunus yedoensis, soil hardness was measured to a depth of 60cm under 375 sample trees in 69 block parks in Tottori City. At the same time, vitality of each sample tree was evaluated visually. The chlorophyll amount (SPAD) of 30 leaves from each sample tree was also measured. Consequently, it become clear that the soil layer that most affected tree vitality, was in the range of 10-30cm below ground level, particularly 10-20cm. There was also a significant correlation between degree of tree vitality evaluated visually and by SPAD. Therefore, SPAD can be used as an quantitative indicator of tree vitality.