北海道十勝の累積火山灰土層における根成孔隙の発達と古気候の影響

概要

論文の詳細を見る
The voids of soils sampled from 4 strata were imaged using contrast medium and X-ray stereography. The samples were from cumulative volcanic ash soils strata at Mugan-no-saka in Tokachi region of HOKKAIDO, and belong to the last interglacial and glacial epochs. Pore systems formed by roots were found in all strata, although in one stratum the pore systems had low density. It was confirmed that the oldest pore system extends over 100 ka at least. The pores of the low density and younger pore system, however, were decayed and the stratum containing this decayed pore system developed during the cold climate at the first half of the last glacial epoch (δ ^<18>O stage 4). This stratum was characterized by a phytolith assemblage that has exceedingly superior origin of Pooideae, and was disturbed by involution. We consider that the decayed pore system was caused by freezing and thawing. Furthermore, we suggest that the correspondence of pore system change with climate change means that pore system development may be an index of environmental change.
日本ペドロジー学会の論文
1998-12-31