Defoliation in the landscape trees

Abstract

This report is a study on defoliaton in the different landscape trees.
The times when the leaves begin to fall and they are all gone off the trees, and these defoliaton periads were respectively measured in the trees of 250 species.
The progresses of becaming leafless in the trees of 200 Species were analysed by the diagram
The leaves began to fall at the end of September to the beginnig of octorber, and its natio was 85.4 percent of all trees.
The times when leaves were all of the tree were different by species, extenting from September to January of next year.
The average value of the defoliation periods was 55±5days, corresponding to 24.4 per cent. And theperiods extended from 25 to over 90 days.
The progresses of defoliation were divided in 7different types; three linear (A. B. C, ), Convex, Concave and sigmoid type to ordinate.
The most fraction among them was the convex type (72 species, 36 per cent.)