Host: The Japanese Forestry Society
The weeping cherry trees in Kakunodate Town,which is designated as the Natural Monument of Japan, were researched to make the plan for conservation. Height, DBH (diameter in breast height), and environmental conditions are investigated for all the 147 designated trees. Mean height was 11.4 m and mean DBH was 59.0 cm with wide variety from 5.1 to 19.0 m in height and from 28 to 117 cm in DBH. Although the mean DBH was increased in about 9cm to compare with the data observed in 27 years ago, mean height decreased in about 0.9 m. The higher trees in 27 years ago showed the larger decrease in height. When the trees are on the decline, their branches on higher position are often observed to wither. The decline in tree vigor seemed to be on progress in the weeping trees in Kakunodate. One of the main reasons for the decline seemed to be the suppression by other large trees, such as fir, ginkgo, and oak trees. Heavy suppression made the vigor of weeping cherry trees declines. The cherry trees, which grow along the street, enlarge their crown toward the direction to the street, because there is no suppress trees in the street. In addition to the suppression, consolidation were also important factors to lose the vogore of cherry trees. On the basis to the present results, maintenance and recovery of the vigor of weeping cherry trees are planning. It is also important to establish the monitoring methods which the regional people in Kakunotade are able to made, because the regional people will be watching the trees day by day. This research was a part of the Emergent Research Project and Conservation Planning Project of the Weeping Cherry Trees in Kakunodate which were conducted by the Board of Education, Kakunodate Town, Akita, Japan.
