MEASUREMENT RESEARCH ON ENVIRONMENTAL MITIGATION EFFECT OF PLANT CANOPIES WITH DIFFERENT PLANT SPECIES AND THE STRATIFICATION

Thermal environment was measured at six spots with different tree species and layered structures in National Government Showa Kinen Park and evaluated by MRT and CSE. The results were as follows. 1. CSE was large in double-layered forests of high trees and small in single-layered forests and MRT was low in both. 2. A variance analysis of CSE of different sunshine hours was performed for the variance factors of Forest type and the time of the day. The result revealed that both were significant at 0.1%. Forest type showed a particularly marked effect, which was large on fine days and small on cloudy days. 3. A regression equation to calculate CSE and MRT from verdure was examined, an equation to predict CSE was obtained, which expressed with Ratio of tree crown shadow to give R^2≥0.84, and an equation to predict MRT was obtained, which expressed with green leaf factor (GLF) to give R^2≥0.88.