At the 76th UNITAR Hiroshima Public Session held in collaboration with ANT-Hiroshima on 23rd October 2013, it was revealed that most of the trees which survived the atomic bombing of 6th August 1945 lean towards the hypocenter.
The discovery was made by Masakazu Suzuki, professor of landscape architecture at the University of Tsukuba, Nagisa Owaki, a student at the University of Tsukuba’s Graduate School of Comprehensive Human Sciences, and Chikara Horiguchi, a tree surgeon who lives in Hiroshima.
The researchers believe that the trees lean towards the hypocenter because the cells on the side of the trunk facing the hypocenter were damaged by the heat and radiation of the bomb, causing that side grow more slowly than the other.
Fifty-six of a total of about 170 survivor trees with single trunks up to two kilometers from the hypocenter were selected for the study. Of these 56 trees, twenty-seven were excluded from the study as they had either been relocated or the trunk had been too severely burned. Of the remaining twenty-nine trees, twenty-three leaned to some degree towards the hypocenter.
The findings were covered in a report by Sakiko Masuda, Staff Writer of the Chugoku Shinbun.