We reconstructed the vegetation history since the mid-Holocene in the subalpine area of the central Kitakami Mountains, northern Japan, by pollen analysis using soil samples taken from two Abies mariesii forest sites, the Aomatsuba (AMT) site located in a scattered subalpine conifer stand on Mt. Aomatsuba and the Odagoe (ODG) site located in the central part of the developed subalpine conifer zone on Mt. Hayachine. Pollen diagrams show that the vegetation of the montane zone around the study sites were continuously a deciduous broadleaved forest composed mainly of Fagus, Betula, and Quercus subgenus Lepidobalanus species after the fall of Towada-Chuseri tephra (To-Cu) erupted in 6000 yBP. Abies pollen increased abruptly after the fall of Towadaa tephra (To-a) erupted in AD 915 at both sites. A distinct difference, however, existed between the two sites. At ODG, Abies pollen contined to occur in small quantities in layers from To-Cu to To-a, but no Abies pollen occurred in these layers at AMT. These results revealed that A. mariesii was distributed around ODG until mid-Holocene, whereas A. mariesii appeared approximately 1000 years ago around AMT.
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