@article{oai:tokyo-metro-u.repo.nii.ac.jp:00002939,
 author = {オカ, シュウイチ and タカオカ, サダオ and Oka, Shuichi and Takaoka, Sadao},
 issue = {31},
 journal = {Geographical Reports of Tokyo Metropolitan University},
 month = {},
 note = {In southwestern Hokkaido, volcanic activities were high during historical times. For examination of their effects on forest ecosystem, we conducted preliminary survey using a dendroecological technique. Tree-ring samples were collected mainly in the southern part of the Ishikari Lowland where some layers of pyroclastic fall were found. The number of tree-rings was counted and tree-ring widths were measured. As a result, we could distinguish from the 1739 tree ring measurements the effect of eruption with its subsequent Ta-a volcanic deposition. This proves that the effect on tree growth changed in proportion to distance from the origin of the pyroclastic fall.},
 pages = {149--156},
 title = {A preliminary study on the effects of pyroclastic fall deposit on the forest ecosystem in southwestern hokkaido, japan},
 year = {1996}
}