11:15 AM - 11:40 AM
[MIS12-09] Expansion process of subalpine coniferous woodland since the last deglaciation based on the pollen record at the Tanohara peat bog, Shiga Highland, Japan
★Invited Papers
Keywords:subalpine coniferous woodland, pollen analysis, Tanohara peatbog, central Japan
To advance our understanding of vegetation history in the subalpine zone, we reconstructed vegetation changes at the Shiga Highland since the last deglaciation based on the well-dated pollen record from the Tanohara peat bog (1,660 m a.s.l.). The data from the site indicated 1) deciduous shrubland mainly Betula ermanii and Quercus crispula var. horikawae covered the area around the site in ca. 15.0~4.7 ka cal BP, 2) the expansion of coniferous trees such as Picea jezoensis var. hondoensis and Tsuga diversifolia started from ca. 4.7 ka cal BP, 3) Abies mariesii started to increase gradually after ca 3.0 ka cal BP. The timing of expansion onset among the coniferous trees would suggest a difference in their habitat. That is, P. jezoensis var. hondoensis can grow in harsh terrains such as talus cones or wet environments, and was likely the first species to populate the subalpine zone. In contrast, A. mariesii is deep-rooted and prefers moist soil, and likely started its expansion under the suitable conditions established by other coniferous trees.