A kashiwa oak (Quercus dentata) tree-ring width chronology from northern coastal Hokkaido, Japan

Few pareoclimatic records exist for Hokkaido, the northernmost, coldest, and least environmentally disturbed of Japan's main islands. Here, we present a chronology for kashiwa oak (Quercus dentata Thunb.) at Lake Saroma on the north central coast of Hokkaido. This record (1710-1993) was compared with meteorological data from Abashiri, the longest existing station (1899-1989) near the site. Growth correlates positively with current June-July temperatures, but negatively with prior-year August temperatures. Growth also correlates positively with prior November, December, and March temperatures and with prior February precipitation. Results suggest that these oaks grow best during warm, early summers or after warm, snowy winters. The lowest growth year is 1784, following the ''year without a summer'' elsewhere in Japan. This record contributes to a growing tree-ring network for the North Pacific rim, including sites in Japan, Kamchatka, Korea, Alaska, and Canada. It also adds a new species to those considered useful for dendroclimatology.