大阪周辺地域におけるウルム氷期以降の森林植生変遷
1979 年 18 巻 3 号 p. 121-141
詳細
1979 年 18 巻 3 号 p. 121-141
Pollen diagrams are represented from core samples taken from five boreholes in the Tenma Formation (lower terrace deposits) and the Nanba Formation (Alluvial deposits) in the Osaka plain. On the basis of pollen stratigraphy the diagrams are divided into two local pollen assemblage zones (E and F) including 11 sub-zones (E 1-5 and F 1-6). The forests characteristically inferred from the pollen assemblage are Castanopsis-Quercus (Cyclobalanopsis) Forest, Abies firma-Tsuga sieboldii Forest, Fagus Forest and Subalpine coniferous Forest. A considerable number of pollen grains preserved are thought to be derived from catchment areas of each river as the deposits accumulated.
The forest history of the area is as follows.
E1-E3 sub-zone; Subalpine coniferous Forest and Fagus Forest were extensive to cover the area from about 30, 000y.B.P. to 20, 000y.B.P..
E4 sub-zone; Subalpine coniferous Forest was the most widely spread over to the area between 20, 000y.B.P. and 18, 000y.B.P. (?).
F1-F2 sub-zone; Fagus Forest was widely expanded to the lowland area in the early Holocene (10, 000y.B.P.-7, 500y.B.P.).
F4 sub-zone; Castanopsis-Quercus (Cyclobalanopsis) Forest was widely developed in the lowland area in the middle Holocene (6, 000y.B.P.-2, 500y.B.P.)
F6 sub-zone; These forests were replaced by a secondary forest in the latest Holocene (since 1, 500y.B.P.).
